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Sample records for beta alanine uptake

  1. Adaptive regulation of taurine and beta-alanine uptake in a human kidney cell line from the proximal tubule

    DEFF Research Database (Denmark)

    Jessen, H; Jacobsen, Christian

    1997-01-01

    homeostasis occurs predominantly via changes in the activity of the high-affinity taurine transport system by alterations in the uptake capacity and with an unaffected half-saturation constant. An adaptive response was not observed for the structurally related beta-alanine. 3. Only colchicine, which......), mimicking the effects of diacylglycerol, induced inhibition of both beta-alanine and taurine uptake. By contrast, the Ca2(+)-ionophore A23187, mimicking the effects of IP3, only stimulated the uptake of taurine but not the influx of beta-alanine. However, the effect of PMA down-regulation and A23187 up......1. The underlying mechanisms involved in the adaptive regulation of beta-amino acid uptake in the human proximal tubule were examined by use of an immortalized human embryonic kidney epithelial cell line (IHKE). 2. The results indicated that the adaptive response to maintain whole-body taurine...

  2. Adaptive regulation of taurine and beta-alanine uptake in a human kidney cell line from the proximal tubule

    DEFF Research Database (Denmark)

    Jessen, H; Jacobsen, Christian

    1997-01-01

    1. The underlying mechanisms involved in the adaptive regulation of beta-amino acid uptake in the human proximal tubule were examined by use of an immortalized human embryonic kidney epithelial cell line (IHKE). 2. The results indicated that the adaptive response to maintain whole-body taurine...

  3. Relationship of fetal alanine uptake and placental alanine metabolism to maternal plasma alanine concentration

    NARCIS (Netherlands)

    M. Timmerman (Michelle); M. Chung; R.B. Wilkening; P.V. Fennessey (Paul); F.C. Battaglia (Frederick); G. Meschia

    1998-01-01

    textabstractUterine and umbilical uptakes of alanine (Ala) were measured in 10 ewes before (control) and during intravenous infusion of Ala, which increased maternal arterial Ala concentration from 115 +/- 14 to 629 +/- 78 microM (P < 0.001). In 8 of these ewes, placent

  4. Eukaryotic beta-alanine synthases are functionally related but have a high degree of structural diversity

    DEFF Research Database (Denmark)

    Gojkovic, Zoran; Sandrini, Michael; Piskur, Jure

    2001-01-01

    beta -Alanine synthase (EC 3.5.1.6), which catalyzes the final step of pyrimidine catabolism, has only been characterized in mammals. A Saccharomyces kluyveri pyd3 mutant that is unable to grow on N-carbamy-beta -alanine as the sole nitrogen source and exhibits diminished beta -alanine synthase...... no pyrimidine catabolic pathway, it enabled growth on N-carbamyl- beta -alanine as the sole nitrogen source. The D. discoideum and D. melanogaster PYD3 gene products are similar to mammalian beta -alanine synthases. In contrast, the S. kluyveri protein is quite different from these and more similar to bacterial...... N- carbamyl amidohydrolases. All three beta -alanine synthases are to some degree related to various aspartate transcarbamylases, which catalyze the second step of the de novo pyrimidine biosynthetic pathway. PYD3 expression in yeast seems to be inducible by dihydrouracil and N-carbamyl-beta...

  5. Beta-alanine and dopamine in the reddish brown scales of Papilio butterflies

    Energy Technology Data Exchange (ETDEWEB)

    Umebachi, Yoshishige; Ishizaki, Yumi (Kanazawa Univ. (Japan). Faculty of Science)

    1983-12-01

    (1) Reddish brown scales of the anal eye spot in the hind-wings of P. demoleus and P. machaon have been examined for ..beta..-alanine and dopamine. (2) The scales were fractionated into 70% ethanol-soluble fraction, 4% HCl-methanol-soluble fraction, and the residual scales, and the ..beta..-alanine content of each fraction was determined. Most of the ..beta..-alanine present in the scales has been found in the residual scales. On acid hydrolysis of the residual scales, the ..beta..-alanine has been rather rapidly released, and the hydrolysate has contained a large amount of ..beta..-alanine. (3) The protein-bound brown pigment (HCl-ppt fraction), which was extracted with 1 N NaOH and precipitated by being acidified with HCl, has contained a large amount of ..beta..-alanine. In most or at least some of the ..beta..-alanine, the NH/sub 2/-group has been proved to be free. (4) /sup 14/C-Labelled ..beta..-alanine and /sup 14/C-dopamine, which were injected at prepupal or pupal stage, have been incorporated in the highest degree into the residual scales. And the /sup 14/C has been confirmed to be present in the HCl-ppt fraction. (5) All these results indicate that the pigment of the reddish brown scales contains ..beta..-alanine and dopamine.

  6. Uptake of neutral alpha- and beta-amino acids by human proximal tubular cells

    DEFF Research Database (Denmark)

    Jessen, H; Røigaard, H; Jacobsen, Christian

    1996-01-01

    The transport characteristics of amino acids in primary cell cultures from the proximal tubule of human adults (AHKE cells) were examined, using alpha-aminoisobutyric acid (AIB) and beta-alanine as representatives of alpha- and beta-amino acids, respectively. The Na(+)-gradient dependent influx...... experiments revealed that all the neutral amino acids tested reduced the uptake of AIB, whereas there was no effect of taurine, L-aspartic acid, and L-arginine. By contrast, the influx of beta-alanine was only drastically reduced by beta-amino acids, whereas the inhibition by neutral alpha-amino acids...... was relatively low. Nor did L-arginine and L-aspartic acid affect the uptake of beta-alanine into AHKE cells. Comparison with the results obtained for normal (NHKE) and immortalized (IHKE) embryonic cells suggested an unaltered expression of the types of transport carriers for neutral alpha- and beta-amino acids...

  7. Degradation of pyrimidines in Saccharomyces kluyveri: transamination of beta-alanine

    DEFF Research Database (Denmark)

    Schnackerz, K D; Andersen, G; Dobritzsch, D

    2008-01-01

    Beta-alanine is an intermediate in the reductive degradation of uracil. Recently we have identified and characterized the Saccharomyces kluyveri PYD4 gene and the corresponding enzyme beta -alanine aminotransferase ((Sk)Pyd4p), highly homologous to eukaryotic gamma-aminobutyrate aminotransferase...... (GABA-AT). S. kluyveri has two aminotransferases, GABA aminotransferase ((Sk)Uga1p) with 80% and (Sk)Pyd4p with 55% identity to S. cerevisiae GABA-AT. (Sk)Pyd4p is a typical pyridoxal phosphate-dependent aminotransferase, specific for alpha-ketoglutarate (alpha KG), beta-alanine (BAL) and gamma...

  8. Exercise training and beta-alanine-induced muscle carnosine loading.

    Directory of Open Access Journals (Sweden)

    Tine eBex

    2015-05-01

    Full Text Available Purpose. Beta-alanine (BA supplementation has been shown to augment muscle carnosine concentration, thereby promoting high-intensity exercise performance. Trained muscles of athletes have a higher increase in carnosine concentration after BA supplementation compared to untrained muscles, but it remains to be determined whether this is due to an accumulation of acute exercise effects or to chronic adaptations from prior training. The aim of the present study was to investigate whether high-volume (HV and/or high-intensity (HI exercise can improve BA-induced carnosine loading in untrained subjects.Methods. All participants (n=28 were supplemented with 6.4 g/day of BA for 23 days. The subjects were allocated to a control group, HV or HI training group. During the BA supplementation period, the training groups performed 9 exercise sessions consisting of either 75–90 min continuous cycling at 35–45% Wmax (HV or 3 to 5 repeats of 30s cycling at 165% Wmax with 4 min recovery (HI. Carnosine content was measured in soleus and gastrocnemius medialis by proton magnetic resonance spectroscopy.Results. There was no difference in absolute increase in carnosine content between the groups in soleus and gastrocnemius muscle. For the average muscle carnosine content, a higher absolute increase was found in HV (+ 2.95 mM; P = 0.046 and HI (+ 3.26 mM; P = 0.028 group compared to the control group (+ 1.91 mM. However, there was no additional difference between the HV and HI training group.Conclusions. HV and HI exercise training showed no significant difference on BA-induced muscle carnosine loading in soleus and gastrocnemius muscle. It can be suggested that there can be a small cumulative effect of exercise on BA supplementation efficiency, although differences did not reach significance on individual muscle level.

  9. Enzyme-Catalyzed Polymerization of Beta-alanine Esters, A Sustainable Route Towards the Formation of Poly-Beta-alanine

    NARCIS (Netherlands)

    Steunenberg, P.; Uiterweerd, M.; Sijm, M.; Scott, E.L.; Zuilhof, H.; Sanders, J.P.M.; Franssen, M.C.R.

    2013-01-01

    The synthesis of poly-ß-alanine by a lipase catalyzed polycondensation reaction between ß-alanine esters is reported. The effect of different solvents, reaction temperatures and substrate/enzyme concentrations on polymer yield and degree of polymerization (DP) was determined. Also the effect of meth

  10. Transport of the alpha-amino-mono-carboxylic acid L-alanine by the beta-alanine carrier of the rabbit ileum

    DEFF Research Database (Denmark)

    Andersen, Vibeke; Munck, B G

    1987-01-01

    The proposal that the beta-alanine carrier of the rabbit ileum is a high affinity carrier of the neutral amino acids was examined by means of measurements of influx across the brush border membrane of the intact epithelium using L-alanine as a representative of the neutral amino acids. Confirming...... the proposal, evidence was provided for mutual competitive inhibition between beta-alanine and L-alanine; and it was also demonstrated that a process contributes to the influx of L-alanine, which is characterized by a maximum rate of transport equal to that of beta-alanine and a Kt, which is equal to the Ki...... of L-alanine against the influx of beta-alanine. In the concentration range 0.01 to 0.125 mM the influx of L-alanine was found to be linearly related to the concentration indicating a significant unstirred layer influence on present and previous estimates of the Kt values for influx of amino acids...

  11. Effect of 10 Week Beta-Alanine Supplementation on Competition and Training Performance in Elite Swimmers

    Directory of Open Access Journals (Sweden)

    Louise M. Burke

    2012-10-01

    Full Text Available Although some laboratory-based studies show an ergogenic effect with beta-alanine supplementation, there is a lack of field-based research in training and competition settings. Elite/Sub-elite swimmers (n = 23 males and 18 females, age = 21.7 ± 2.8 years; mean ± SD were supplemented with either beta-alanine (4 weeks loading phase of 4.8 g/day and 3.2 g/day thereafter or placebo for 10 weeks. Competition performance times were log-transformed, then evaluated before (National Championships and after (international or national selection meet supplementation. Swimmers also completed three standardized training sets at baseline, 4 and 10 weeks of supplementation. Capillary blood was analyzed for pH, bicarbonate and lactate concentration in both competition and training. There was an unclear effect (0.4%; ±0.8%, mean, ±90% confidence limits of beta-alanine on competition performance compared to placebo with no meaningful changes in blood chemistry. While there was a transient improvement on training performance after 4 weeks with beta-alanine (−1.3%; ±1.0%, there was an unclear effect at ten weeks (−0.2%; ±1.5% and no meaningful changes in blood chemistry. Beta-alanine supplementation appears to have minimal effect on swimming performance in non-laboratory controlled real-world training and competition settings.

  12. Effect of 10 week beta-alanine supplementation on competition and training performance in elite swimmers.

    Science.gov (United States)

    Chung, Weiliang; Shaw, Greg; Anderson, Megan E; Pyne, David B; Saunders, Philo U; Bishop, David J; Burke, Louise M

    2012-10-09

    Although some laboratory-based studies show an ergogenic effect with beta-alanine supplementation, there is a lack of field-based research in training and competition settings. Elite/Sub-elite swimmers (n = 23 males and 18 females, age = 21.7 ± 2.8 years; mean ± SD) were supplemented with either beta-alanine (4 weeks loading phase of 4.8 g/day and 3.2 g/day thereafter) or placebo for 10 weeks. Competition performance times were log-transformed, then evaluated before (National Championships) and after (international or national selection meet) supplementation. Swimmers also completed three standardized training sets at baseline, 4 and 10 weeks of supplementation. Capillary blood was analyzed for pH, bicarbonate and lactate concentration in both competition and training. There was an unclear effect (0.4%; ± 0.8%, mean, ± 90% confidence limits) of beta-alanine on competition performance compared to placebo with no meaningful changes in blood chemistry. While there was a transient improvement on training performance after 4 weeks with beta-alanine (-1.3%; ± 1.0%), there was an unclear effect at ten weeks (-0.2%; ± 1.5%) and no meaningful changes in blood chemistry. Beta-alanine supplementation appears to have minimal effect on swimming performance in non-laboratory controlled real-world training and competition settings.

  13. Uracil and beta-alanine degradation in Saccharomyces Kluyveri - discovery of a novel catabolic pathway

    DEFF Research Database (Denmark)

    Andersen, Gorm

    2006-01-01

    ’en i gær og de genetiske forudsætninger for uracil og beta-alanine (BAL) katabolisme i S. kluyveri undersøgt. Evnen til at bruge uracil, dihydrouracil (DHU), beta-ureidopropionate (BUP) og BAL som nitrogenkilde blev studeret i 38 gær arter. Disse var udvalgt, så de dækkede “Saccharomyces komplekset...

  14. Isomeric effects in ion-induced fragmentation of alpha- and beta-alanine

    NARCIS (Netherlands)

    Sobocinski, P.; Bari, S.; Postma, J.; Alvarado, F.; Hoekstra, R.; Manil, B.; Rangama, J.; Bernigaud, V.; Huber, B. A.; Schlatholter, T.; McGuigan, KG; Tokesi, K; Sulik, B

    2008-01-01

    We have investigated the dissociation of alpha- and beta- alanine following impact of slow multicharged ions, namely He(+), He(2+), O(5+) and Xe(20+) at 10 keV per charge unit. The collision products were analyzed using a reflectron-type time-of-flight mass spectrometer. In general, for a given proj

  15. Beta-alanine/alpha-ketoglutarate aminotransferase for 3-hydroxypropionic acid production

    Energy Technology Data Exchange (ETDEWEB)

    Jessen, Holly Jean; Liao, Hans H; Gort, Steven John; Selifonova, Olga V

    2014-11-18

    The present disclosure provides novel beta-alanine/alpha ketoglutarate aminotransferase nucleic acid and protein sequences having increased biological activity. Also provided are cells containing such enzymes, as well as methods of their use, for example to produce malonyl semialdehyde and downstream products thereof, such as 3-hydroxypropionic acid and derivatives thereof.

  16. Fragmentation of alpha- and beta-alanine molecules by ions at Bragg-peak energies

    NARCIS (Netherlands)

    Bari, S.; Sobocinski, P.; Postma, J.; Alvarado, F.; Hoekstra, R.; Bernigaud, V.; Manil, B.; Rangama, J.; Huber, B.; Schlathoelter, T.

    2008-01-01

    The interaction of keV He(+), He(2+), and O(5+) ions with isolated alpha and beta isomers of the amino acid alanine was studied by means of high resolution coincidence time-of-flight mass spectrometry. We observed a strong isomer dependence of characteristic fragmentation channels which manifests in

  17. Beta-alanine/alpha-ketoglutarate aminotransferase for 3-hydroxypropionic acid production

    Energy Technology Data Exchange (ETDEWEB)

    Jessen, Holly Jean [Chanhassen, MN; Liao, Hans H [Eden Prairie, MN; Gort, Steven John [Apple Valley, MN; Selifonova, Olga V [Plymouth, MN

    2011-10-04

    The present disclosure provides novel beta-alanine/alpha ketoglutarate aminotransferase nucleic acid and protein sequences having increased biological activity. Also provided are cells containing such enzymes, as well as methods of their use, for example to produce malonyl semialdehyde and downstream products thereof, such as 3-hydroxypropionic acid and derivatives thereof.

  18. Effects of glycine, beta-alanine and diazepam upon morphine-tolerant-dependent mice.

    Science.gov (United States)

    Contreras, E; Tamayo, L

    1980-05-01

    The effects in mice of glycine, beta-alanine and diazepam on the analgesic response to morphine, on the intensity of tolerance and on the physical dependence on the analgesic have been examined. The two amino acids increased the analgesic response to morphine in a dose-related manner. However, both compounds were ineffective in the analgesic test (hot plate) when administered without morphine. Diazepam was ineffective in the analgesic test and it did not alter morphine analgesia, except when administered in a high dose which decreased and analgesic response. Glycine, either in single or repeated doses, did not modify tolerance to morphine, whereas beta-alanine induced a dose-related partial antagonism, which promptly reached a plateau. Diazepam induced a small decrease in the intensity of tolerance to the analgesic. The abstinence syndrome to morphine, induced by naloxone administration to primed mice, was reduced by single doses of glycine or beta-alanine. Diazepam behaved as a weak inhibitor of the abstinence syndrome when administered at a high dose. The potentiation of morphine analgesia and the antagonism of the abstinence syndrome induced by the amino acids may be related to their hyperpolarizing action in the c.n. system. The effects of beta-alanine on morphine tolerance cannot be explained by the same mechanism.

  19. Yeast beta-alanine synthase shares a structural scaffold and origin with dizinc-dependent exopeptidases

    DEFF Research Database (Denmark)

    Lundgren, S.; Gojkovic, Zoran; Piskur, Jure

    2003-01-01

    beta-Alanine synthase (betaAS) is the final enzyme of the reductive pyrimidine catabolic pathway, which is responsible for the breakdown of pyrimidine bases, including several anticancer drugs. In eukaryotes, betaASs belong to two subfamilies, which exhibit a low degree of sequence similarity. We...... determined the structure of betaAS from Saccharomyces kluyveri to a resolution of 2.7 Angstrom. The subunit of the homodimeric enzyme consists of two domains: a larger catalytic domain with a dizinc metal center, which represents the active site of betaAS, and a smaller domain mediating the majority...... of the intersubunit contacts. Both domains exhibit a mixed alpha/beta-topology. Surprisingly, the observed high structural homology to a family of dizinc-dependent exopeptidases suggests that these two enzyme groups have a common origin. Alterations in the ligand composition of the metal-binding site can be explained...

  20. Dependence of enthalpies of dissolution of {beta}-alanyl-{beta}-alanine on the composition of (water + alcohol) mixtures at 298.15 K

    Energy Technology Data Exchange (ETDEWEB)

    Smirnov, Valeriy I., E-mail: vis@isc-ras.ru [Laboratory of Thermodynamics of Non-electrolytes Solutions and Biologically Active Substances, Institute of Solution Chemistry, Russian Academy of Sciences, 1 Akademicheskaya Street, 153045 Ivanovo (Russian Federation); Badelin, Valentin G. [Laboratory of Thermodynamics of Non-electrolytes Solutions and Biologically Active Substances, Institute of Solution Chemistry, Russian Academy of Sciences, 1 Akademicheskaya Street, 153045 Ivanovo (Russian Federation)

    2011-09-20

    Highlights: {center_dot} Enthalpies of dissolution of {beta}-alanyl-{beta}-alanine are measured in aqueous methanol, ethanol, 1-propanol and 2-propanol by calorimetry. {center_dot} Standard values of dissolution and transfer enthalpies of {beta}-alanyl-{beta}-alanine and enthalpy coefficients of pair-wise interactions are calculated. {center_dot} Dependences of the thermodynamic characteristics of dissolution of {beta}-alanyl-{beta}-alanine on the composition of (water + alcohol) mixtures are determined. - Abstract: The dissolution enthalpies of {beta}-alanyl-{beta}-alanine in aqueous methanol, ethanol, 1-propanol and 2-propanol solutions with an alcohol content up to 0.4 mole fractions have been measured calorimetrically at T = 298.15 K. The standard enthalpies of dissolution, {Delta}{sub sol}H{sup o} and transfer, {Delta}{sub tr}H{sup o}, of {beta}-alanyl-{beta}-alanine from water into mixed solvents and the enthalpy coefficients of pair-wise interactions, h{sub xy}, of {beta}-alanyl-{beta}-alanine with alcohol solvent molecules have been calculated. The results are discussed in terms of solute-solute and solute-solvent interactions.

  1. beta-Alanine elevates dopamine levels in the rat nucleus accumbens: antagonism by strychnine.

    Science.gov (United States)

    Ericson, Mia; Clarke, Rhona B C; Chau, PeiPei; Adermark, Louise; Söderpalm, Bo

    2010-04-01

    Glycine receptors (GlyRs) in the nucleus accumbens (nAc) have recently been suggested to be involved in the reinforcing and dopamine-elevating properties of ethanol via a neuronal circuitry involving the VTA. Apart from ethanol, both glycine and taurine have the ability to modulate dopamine output via GlyRs in the same brain region. In the present study, we wanted to explore whether yet another endogenous ligand for the GlyR, beta-alanine, had similar effects. To this end, we monitored dopamine in the nAc by means of in vivo microdialysis and found that local perfusion of beta-alanine increased dopamine output. In line with previous observations investigating ethanol, glycine and taurine, the competitive GlyR antagonist strychnine completely blocked the dopamine elevation. The present results suggest that beta-alanine has the ability to modulate dopamine levels in the nAc via strychnine-sensitive GlyRs, and are consistent with previous studies suggesting the importance of this receptor for modulating dopamine output.

  2. Beta-alanine-hydrochloride (2:1) crystal: structure, 13C NMR and vibrational properties, protonation character.

    Science.gov (United States)

    Godzisz, D; Ilczyszyn, M; Ciunik, Z

    2003-01-15

    The crystal structure of beta-alanine-hydrochloride (2:1) complex (2A-HCl) has been determined by X-ray diffraction method at 298 and 100 K as monoclinic, space group C2/c, Z=4. The crystal comprises chloride anions and protonated beta-alanine dimers: two beta-alanine zwitterions are joined by strong, symmetric (Ci) hydrogen bond with the O...O distance of 2.473 A at room temperature. Powder FT-IR and FT-Raman as well as solid state 13C NMR spectra provide insights into the solid structure of this complex, character of its hydrogen bonds and the beta-alanine protonation.

  3. The effect of beta-alanine supplementation on isokinetic force and cycling performance in highly trained cyclists.

    Science.gov (United States)

    Howe, Samuel T; Bellinger, Phillip M; Driller, Matthew W; Shing, Cecilia M; Fell, James W

    2013-12-01

    Beta-alanine may benefit short-duration, high-intensity exercise performance. The aim of this randomized double-blind placebo-controlled study was to examine the effects of beta-alanine supplementation on aspects of muscular performance in highly trained cyclists. Sixteen highly trained cyclists (mean ± SD; age = 24 ± 7 yr; mass = 70 ± 7 kg; VO2max = 67 ± 4 ml · kg(-1) · min(-1)) supplemented with either beta-alanine (n = 8, 65 mg · kg - 1BM) or a placebo (n = 8; dextrose monohydrate) over 4 weeks. Pre- and postsupplementation cyclists performed a 4-minute maximal cycling test to measure average power and 30 reciprocal maximal isokinetic knee contractions at a fixed angular velocity of 180° · sec(-1) to measure average power/repetition, total work done (TWD), and fatigue index (%). Blood pH, lactate (La-) and bicarbonate (HCO3-) concentrations were measured pre- and postisokinetic testing at baseline and following the supplementation period. Beta-alanine supplementation was 44% likely to increase average power output during the 4-minute cycling time trial when compared with the placebo, although this was not statistically significant (p = .25). Isokinetic average power/repetition was significantly increased post beta-alanine supplementation compared with placebo (beta-alanine: 6.8 ± 9.9 W, placebo: -4.3 ± 9.5 W, p = .04, 85% likely benefit), while fatigue index was significantly reduced (p = .03, 95% likely benefit). TWD was 89% likely to be improved following beta-alanine supplementation; however, this was not statistically significant (p = .09). There were no significant differences in blood pH, lactate, and HCO3- between groups (p > .05). Four weeks of beta-alanine supplementation resulted in worthwhile changes in time-trial performance and short-duration muscular force production in highly trained cyclists.

  4. Beta-alanine-oxalic acid (1:1) hemihydrate crystal: structure, 13C NMR and vibrational properties, protonation character.

    Science.gov (United States)

    Godzisz, D; Ilczyszyn, M; Ilczyszyn, M M

    2003-03-01

    The crystal structure of beta-alanine-oxalic acid (1:1) hemihydrate complex has been reinvestigated by X-ray diffraction method at 293 K. Formation of monoclinic crystal system belonging to C2/c space group and consisting of semi-oxalate chains, diprotonated beta-alanine dimers and water molecules bonded to both these units is confirmed. New results are obtained for distances in the carboxylic groups and hydrogen bonds. These structural observations are used for protonation degree monitoring on the carboxylic oxygen atoms. They are in accordance with our vibrational study. The 13C NMR spectra provide insights into the solid structure of this complex, character of its hydrogen bonds and the beta-alanine protonation.

  5. The influence of secretion elicitors and external pH on the kinetics of D-alanine uptake by the trap lobes of Dionaea muscipula Ellis (Venus's Flytrap).

    Science.gov (United States)

    Rea, P A; Whatley, F R

    1983-08-01

    Simple kinetic techniques were used to examine the mechanism of D-alanine uptake by the adaxial surfaces of the trap lobes of Dionaea muscipula Ellis (Venus's Flytrap.) On the basis of these analyses, the uptake of D-alanine was found to depend on the time during which the trap lobes were inoculated with elicitors of secretion before excision and measurement of uptake. Disks taken from traps that had not been subjected to a preceding period of inoculation with secretion elicitors showed a low basal rate of uptake which was neither pH-dependent nor exhibited saturation with respect to external D-alanine concentration. Disks from preinoculated traps, on the other hand, displayed an enhanced rate of uptake which showed both pH-dependence and saturation with respect to external D-alanine concentration. The capacity for enhanced uptake was lost upon prolonged inoculation or when inoculation was stopped. Of the compounds tested, only elicitors of secretion caused an enhancement of uptake. The enhanced rate of D-alanine uptake is temperature-sensitive with a Q10 characteristic of a mediated process. Uncouplers cause an instantaneous abolition of uptake whereas the effects of terminal-oxidase inhibitors are time-dependent. The pH-dependence of uptake is inferred to result from an increased affinity of the carrier system for D-alanine at low pH values. Although the ionic state of D-alanine is relatively unaffected over the pH range examined, a decrease in the external pH from 6.0 to 3.8 decreases the apparent K m for uptake by four-fold but increases V max by only 30%. It is concluded that the acid secreted by the digestive glands of Dionaea plays a direct role in facilitating the uptake of amino acids from the trap cavity.

  6. Effects of beta-alanine supplementation on brain homocarnosine/carnosine signal and cognitive function: an exploratory study.

    Directory of Open Access Journals (Sweden)

    Marina Yazigi Solis

    Full Text Available Two independent studies were conducted to examine the effects of 28 d of beta-alanine supplementation at 6.4 g d(-1 on brain homocarnosine/carnosine signal in omnivores and vegetarians (Study 1 and on cognitive function before and after exercise in trained cyclists (Study 2.In Study 1, seven healthy vegetarians (3 women and 4 men and seven age- and sex-matched omnivores undertook a brain 1H-MRS exam at baseline and after beta-alanine supplementation. In study 2, nineteen trained male cyclists completed four 20-Km cycling time trials (two pre supplementation and two post supplementation, with a battery of cognitive function tests (Stroop test, Sternberg paradigm, Rapid Visual Information Processing task being performed before and after exercise on each occasion.In Study 1, there were no within-group effects of beta-alanine supplementation on brain homocarnosine/carnosine signal in either vegetarians (p = 0.99 or omnivores (p = 0.27; nor was there any effect when data from both groups were pooled (p = 0.19. Similarly, there was no group by time interaction for brain homocarnosine/carnosine signal (p = 0.27. In study 2, exercise improved cognitive function across all tests (P 0.05 of beta-alanine supplementation on response times or accuracy for the Stroop test, Sternberg paradigm or RVIP task at rest or after exercise.28 d of beta-alanine supplementation at 6.4 g d(-1 appeared not to influence brain homocarnosine/carnosine signal in either omnivores or vegetarians; nor did it influence cognitive function before or after exercise in trained cyclists.

  7. The Cyanobacteria Derived Toxin Beta-N-Methylamino-L-Alanine and Amyotrophic Lateral Sclerosis

    Directory of Open Access Journals (Sweden)

    Elijah W. Stommel

    2010-12-01

    Full Text Available There is mounting evidence to suggest that environmental factors play a major role in the development of neurodegenerative diseases like ALS (Amyotrophic Lateral Sclerosis. The non-protein amino acid beta-N-methylamino-L-alanine (BMAA was first associated with the high incidence of Amyotrophic Lateral Sclerosis/Parkinsonism Dementia Complex (ALS/PDC in Guam, and has been implicated as a potential environmental factor in ALS, Alzheimer’s disease, and other neurodegenerative diseases. BMAA has a number of toxic effects on motor neurons including direct agonist action on NMDA and AMPA receptors, induction of oxidative stress, and depletion of glutathione. As a non-protein amino acid, there is also the strong possibility that BMAA could cause intraneuronal protein misfolding, the hallmark of neurodegeneration. While an animal model for BMAA-induced ALS is lacking, there is substantial evidence to support a link between this toxin and ALS. The ramifications of discovering an environmental trigger for ALS are enormous. In this article, we discuss the history, ecology, pharmacology and clinical ramifications of this ubiquitous, cyanobacteria-derived toxin.

  8. Cycas micronesica (Cycadales) plants devoid of endophytic cyanobacteria increase in beta-methylamino-L-alanine.

    Science.gov (United States)

    Marler, Thomas E; Snyder, Laura R; Shaw, Christopher A

    2010-09-15

    Cycads are among the most ancient of extant Spermatophytes, and are known for their pharmacologically active compounds. beta-methylamino-l-alanine (BMAA) is one metabolite that been implicated as causal of human neurodegenerative diseases in Guam. We grew Cycas micronesica seedlings without endophytic cyanobacteria symbiosis, and quantified initial and ending BMAA in various plant tissues. BMAA increased 79% during nine months of seedling growth, and root tissue contained 75% of the ultimate BMAA pool. Endophytic cyanobacteria symbionts were not the source of BMAA increase in these seedlings, which contradicts previously reported claims that biosynthesis of this toxin by cyanobacteria initiates its accumulation in the Guam environment. The preferential loading of root tissue with BMAA does not support earlier reports that this toxin serves a defensive role against herbivory of leaf or seed tissues. The long history of conflicting results in Guam's cycad toxin research continues, and recent developments underscore the sense of urgency in continued research as this endangered cycad population approaches extirpation from the island.

  9. The cyanobacteria derived toxin Beta-N-methylamino-L-alanine and amyotrophic lateral sclerosis.

    Science.gov (United States)

    Banack, Sandra Anne; Caller, Tracie A; Stommel, Elijah W

    2010-12-01

    There is mounting evidence to suggest that environmental factors play a major role in the development of neurodegenerative diseases like ALS (Amyotrophic Lateral Sclerosis). The non-protein amino acid beta-N-methylamino-L-alanine (BMAA) was first associated with the high incidence of Amyotrophic Lateral Sclerosis/Parkinsonism Dementia Complex (ALS/PDC) in Guam, and has been implicated as a potential environmental factor in ALS, Alzheimer's disease, and other neurodegenerative diseases. BMAA has a number of toxic effects on motor neurons including direct agonist action on NMDA and AMPA receptors, induction of oxidative stress, and depletion of glutathione. As a non-protein amino acid, there is also the strong possibility that BMAA could cause intraneuronal protein misfolding, the hallmark of neurodegeneration. While an animal model for BMAA-induced ALS is lacking, there is substantial evidence to support a link between this toxin and ALS. The ramifications of discovering an environmental trigger for ALS are enormous. In this article, we discuss the history, ecology, pharmacology and clinical ramifications of this ubiquitous, cyanobacteria-derived toxin.

  10. Muscle carnosine loading by beta-alanine supplementation is more pronounced in trained vs. untrained muscles.

    Science.gov (United States)

    Bex, T; Chung, W; Baguet, A; Stegen, S; Stautemas, J; Achten, E; Derave, W

    2014-01-15

    Carnosine occurs in high concentrations in human skeletal muscle and assists working capacity during high-intensity exercise. Chronic beta-alanine (BA) supplementation has consistently been shown to augment muscle carnosine concentration, but the effect of training on the carnosine loading efficiency is poorly understood. The aim of the present study was to compare muscle carnosine loading between trained and untrained arm and leg muscles. In a first study (n = 17), reliability of carnosine quantification by proton magnetic resonance spectroscopy ((1)H-MRS) was evaluated in deltoid and triceps brachii muscles. In a second study, participants (n = 35; 10 nonathletes, 10 cyclists, 10 swimmers, and 5 kayakers) were supplemented with 6.4 g/day of slow-release BA for 23 days. Carnosine content was evaluated in soleus, gastrocnemius medialis, and deltoid muscles by (1)H-MRS. All the results are reported as arbitrary units. In the nonathletes, BA supplementation increased carnosine content by 47% in the arm and 33% in the leg muscles (not significant). In kayakers, the increase was more pronounced in arm (deltoid) vs. leg (soleus + gastrocnemius) muscles (0.089 vs. 0.049), whereas the reverse pattern was observed in cyclists (0.065 vs. 0.084). Swimmers had significantly higher increase in carnosine in both deltoid (0.107 vs. 0.065) and gastrocnemius muscle (0.082 vs. 0.051) compared with nonathletes. We showed that 1) carnosine content can be reliably measured by (1)H-MRS in deltoid muscle, 2) carnosine loading is equally effective in arm vs. leg muscles of nonathletes, and 3) carnosine loading is more pronounced in trained vs. untrained muscles.

  11. Effect of Beta alanine and sodium bicarbonate supplementation on repeated-sprint performance.

    Science.gov (United States)

    Ducker, Kagan J; Dawson, Brian; Wallman, Karen E

    2013-12-01

    This study aimed to investigate if combining beta alanine (BA) and sodium bicarbonate (NaHCO3) supplementation could lead to enhanced repeated-sprint performance in team-sport athletes, beyond what is possible with either supplement alone. Participants (n = 24) completed duplicate trials of a repeated-sprint test (3 sets; 6 × 20 m departing every 25 seconds, 4 minutes active recovery between sets) and were then allocated into 4 groups as follows: BA only (n = 6; 28 days BA, acute sodium chloride placebo); NaHCO3 only (n = 6; 28 days glucose placebo, acute NaHCO3); BA/NaHCO3 (n = 6; 28 days BA, acute NaHCO3); placebo only (n = 6; 28 days glucose placebo, acute sodium chloride placebo), then completed duplicate trials postsupplementation. Sodium bicarbonate alone resulted in moderate effect size (d = 0.40-0.71) and "likely" and "very likely" benefit for overall total sprint times (TST) and for each individual set and for first sprint (sets 2 and 3) and best sprint time (sets 2 and 3). Combining BA and NaHCO3 resulted in "possible" to "likely" benefits for overall TST and for sets 2 and 3. First sprint (set 3) and best sprint time (sets 2 and 3) also showed "likely" benefit after this trial. The BA and placebo groups showed no differences in performance after supplementation. In conclusion, these results indicate that supplementation with acute NaHCO3 improved repeated-sprint performance more than either a combination of NaHCO3 and BA or BA alone.

  12. Beta-Alanine Supplementation Improves Throwing Velocities in Repeated Sprint Ability and 200-m Swimming Performance in Young Water Polo Players.

    Science.gov (United States)

    Claus, Gabriel Machado; Redkva, Paulo Eduardo; Brisola, Gabriel Mota Pinheiro; Malta, Elvis Sousa; de Araujo Bonetti de Poli, Rodrigo; Miyagi, Willian Eiji; Zagatto, Alessandro Moura

    2017-05-01

    The purpose of this study was to investigate the effects of beta-alanine supplementation on specific tests for water polo. Fifteen young water polo players (16 ± 2 years) underwent a 200-m swimming performance, repeated-sprint ability test (RSA) with free throw (shooting), and 30-s maximal tethered eggbeater kicks. Participants were randomly allocated into two groups (placebo × beta-alanine) and supplemented with 6.4g∙day(-1)of beta-alanine or a placebo for six weeks. The mean and total RSA times, the magnitude based inference analysis showed a likely beneficial effect for beta-alanine supplementation (both). The ball velocity measured in the throwing performance after each sprint in the RSA presented a very like beneficial inference in the beta-alanine group for mean (96.4%) and percentage decrement of ball velocity (92.5%, likely beneficial). Furthermore, the percentage change for mean ball velocity was different between groups (beta-alanine=+2.5% and placebo=-3.5%; p = .034). In the 30-s maximal tethered eggbeater kicks the placebo group presented decreased peak force, mean force, and fatigue index, while the beta-alanine group maintained performance in mean force (44.1%, possibly beneficial), only presenting decreases in peak force. The 200-m swimming performance showed a possibly beneficial effect (68.7%). Six weeks of beta-alanine supplementation was effective for improving ball velocity shooting in the RSA, maintaining performance in the 30-s test, and providing possibly beneficial effects in the 200-m swimming performance.

  13. Crystallization and preliminary X-ray analysis of beta-alanine synthase from the yeast Saccharomyces kluyveri

    DEFF Research Database (Denmark)

    Dobritzsch, D.; Gojkovic, Zoran; Andersen, Birgit

    2003-01-01

    In eukaryotes and some bacteria, the third step of reductive pyrimidine catabolism is catalyzed by beta-alanine synthase (EC 3.5.1.6). Crystals of the recombinant enzyme from the yeast Saccharomyces kluyveri were obtained using sodium citrate as a precipitant. The crystals belong to space group P2......(1) (unit-cell parameters a=117.2, b=77.1, c=225.5 Angstrom, beta=95.0degrees) and contain four homodimers per asymmetric unit. Data were collected to 2.7 Angstrom resolution. Introduction of heavy atoms into the crystal lattice induced a different set of unit-cell parameters (a=61.0, b=77.9, c=110.......1 Angstrom, beta=97.2degrees) in the same space group P2(1), with only one homodimer per asymmetric unit....

  14. Synthesis and biological activities of some cholecystokinin analogues substituted in position 29 by a beta-alanine.

    Science.gov (United States)

    Rodriguez, M; Rolland, M; Lignon, M F; Galas, M C; Laur, J; Aumelas, A; Martinez, J

    1989-11-01

    Syntheses of analogues of the C-terminal heptapeptide of cholecystokinin are described. These analogues were obtained by replacing glycine 29 by a beta-alanine. The C-terminal phenylalanine amide was in some cases substituted by 2-phenylethyl alcohol and/or residues of the C-terminal tetrapeptide by their D-enantiomers. These compounds were tested for their action on stimulation of amylase release from rat pancreatic acini and for their ability to inhibit binding of labeled CCK to rat pancreatic acini and guinea pig brain membranes. Some of these derivatives behaved as CCK receptor antagonists.

  15. Polymerisation of Beta-alanine through catalytic ester-amide exchange

    NARCIS (Netherlands)

    Steunenberg, P.; Könst, P.M.; Scott, E.L.; Franssen, M.C.R.; Zuilhof, H.; Sanders, J.P.M.

    2013-01-01

    Herein we present the use of group (IV) metal alkoxides as catalysts for the polymerisation of esters of p-alanine and its derivatives. The influence of different group (IV) metal alkoxides, different esters, temperature and solvents on the polymerisation are investigated. The order in which the gro

  16. X-ray structural analysis of the photolysis products of glycinate and. beta. -alaninate cobalt(III) complexes

    Energy Technology Data Exchange (ETDEWEB)

    Polynova, T.N.; Chuklanova, E.B.; Kramarenko, F.G.; Porai-Koshits, M.A.; Poznyak, A.L.; Pavlovskii, V.I.; Stel-mashok, V.E.

    1987-04-01

    The authors were recently able to isolate in crystalline form the intermediate products in the photolysis of various mixed glycinate Co(III) complexes, and have also lately isolated the intermediate products of the photolysis of analogous complexes containing longer chain anions, such as of amino-3-propionate and amino-4-butyrate. In order to determine the structures of these products it is necessary to analyze them by x-ray crystallography. In this paper they describe the structures of two compounds which contain cationic complexes isolated from UV irradiation (lambda = 254 nm) of aqueous solutions of (Coen/sub 2/(..beta..-ala))/sup 2 +/ and Codipy/sub 2/(gly))/sup 2 +/, respectively (en = ethylenediamine, dipy = 2,2'-dipyridine, gly = glycinate, and ..beta..-ala = alaninate). In both cases, the coordinates of all of the atoms, including hydrogen atoms, were determined.

  17. β-N-methylamino-L-alanine (BMAA) uptake by the animal model, Daphnia magna and subsequent oxidative stress.

    Science.gov (United States)

    Esterhuizen-Londt, Maranda; Wiegand, Claudia; Downing, Tim G

    2015-06-15

    β-N-methylamino-l-alanine (BMAA), produced by cyanobacteria, is a neurotoxin implicated in Amyotrophic lateral sclerosis/Parkinsonism dementia complex (ALS/PDC). BMAA concentrations in cyanobacteria are lower than those thought to be necessary to result in neurological damage thus bioaccumulation or biomagnification is required to achieve concentrations able to cause neurodegeneration. Many cyanobacteria produce BMAA and uptake routes into the food web require examination. In this study we investigate the uptake of BMAA by adult phytoplanktivorus Daphnia magna via exposure to dissolved pure BMAA and BMAA containing cyanobacteria, as well as the subsequent oxidative stress response in the daphnia. Free BMAA and protein-associated BMAA were quantified by LC-MS/MS. Dissolved BMAA was taken up and was found as free BMAA in D. magna. No protein-associated BMAA was detected in D. magna after a 24-h exposure period. No BMAA was detectable in D. magna after exposure to BMAA containing cyanobacteria. BMAA inhibited the oxidative stress defence and biotransformation enzymes within 24-h exposure in the tested Daphnia and could therefore impair the oxidant status and the capability of detoxifying other substances in D. magna. Copyright © 2015 Elsevier Ltd. All rights reserved.

  18. Crystal structures of yeast beta-alanine synthase complexes reveal the mode of substrate binding and large scale domain closure movements.

    Science.gov (United States)

    Lundgren, Stina; Andersen, Birgit; Piskur, Jure; Dobritzsch, Doreen

    2007-12-07

    Beta-alanine synthase is the final enzyme of the reductive pyrimidine catabolic pathway, which is responsible for the breakdown of uracil and thymine in higher organisms. The fold of the homodimeric enzyme from the yeast Saccharomyces kluyveri identifies it as a member of the AcyI/M20 family of metallopeptidases. Its subunit consists of a catalytic domain harboring a di-zinc center and a smaller dimerization domain. The present site-directed mutagenesis studies identify Glu(159) and Arg(322) as crucial for catalysis and His(262) and His(397) as functionally important but not essential. We determined the crystal structures of wild-type beta-alanine synthase in complex with the reaction product beta-alanine, and of the mutant E159A with the substrate N-carbamyl-beta-alanine, revealing the closed state of a dimeric AcyI/M20 metallopeptidase-like enzyme. Subunit closure is achieved by a approximately 30 degrees rigid body domain rotation, which completes the active site by integration of substrate binding residues that belong to the dimerization domain of the same or the partner subunit. Substrate binding is achieved via a salt bridge, a number of hydrogen bonds, and coordination to one of the zinc ions of the di-metal center.

  19. Effects of Beta-Alanine on Muscle Carnosine and Exercise Performance: A Review of the Current Literature

    Directory of Open Access Journals (Sweden)

    Matthew Cooke

    2010-01-01

    Full Text Available Muscle carnosine has been reported to serve as a physiological buffer, possess antioxidant properties, influence enzyme regulation, and affect sarcoplasmic reticulum calcium regulation.Beta-alanine (β-ALA is a non-essential amino acid. β-ALA supplementation (e.g., 2–6 grams/day has been shown to increase carnosine concentrations in skeletal muscle by 20–80%.Several studies have reported that β-ALA supplementation can increase high-intensity intermittent exercise performance and/or training adaptations. Although the specific mechanism remains to be determined, the ergogenicity of β-ALA has been most commonly attributed to an increased muscle buffering capacity.More recently, researchers have investigated the effects of co-ingesting β-ALA with creatine monohydrate to determine whether there may be synergistic and/or additive benefits. This paper overviews the theoretical rationale and potential ergogenic value of β-ALA supplementation with or without creatine as well as provides future research recommendations.

  20. Failure to Detect the Neurotoxin Beta-n-methylamino-l-alanine in Samples Collected during an Avian Vacuolar Myelinopathy (AVM) Epornitic in J. Strom Thurmond Lake

    Science.gov (United States)

    2015-08-01

    and T. G. Downing. 2011. β-N-Methylamino-l-alanine (BMAA) uptake by the aquatic macrophyte Ceratophyllum demersum. Ecotoxicology and Environmental...a reservoir with frequent outbreaks of avian vacuolar myelinopathy (AVM). The purpose of this work was to evaluate samples of aquatic vegetation...putative toxin will be important in determining the etiology of AVM and evaluating risks to fish, wildlife, and humans using these aquatic systems

  1. The effect of beta-alanine supplementation on neuromuscular fatigue in elderly (55–92 Years: a double-blind randomized study

    Directory of Open Access Journals (Sweden)

    Cramer Joel T

    2008-11-01

    Full Text Available Abstract Background Ageing is associated with a significant reduction in skeletal muscle carnosine which has been linked with a reduction in the buffering capacity of muscle and in theory, may increase the rate of fatigue during exercise. Supplementing beta-alanine has been shown to significantly increase skeletal muscle carnosine. The purpose of this study, therefore, was to examine the effects of ninety days of beta-alanine supplementation on the physical working capacity at the fatigue threshold (PWCFT in elderly men and women. Methods Using a double-blind placebo controlled design, twenty-six men (n = 9 and women (n = 17 (age ± SD = 72.8 ± 11.1 yrs were randomly assigned to either beta-alanine (BA: 800 mg × 3 per day; n = 12; CarnoSyn™ or Placebo (PL; n = 14 group. Before (pre and after (post the supplementation period, participants performed a discontinuous cycle ergometry test to determine the PWCFT. Results Significant increases in PWCFT (28.6% from pre- to post-supplementation were found for the BA treatment group (p Conclusion We suggest that BA supplementation, by improving intracellular pH control, improves muscle endurance in the elderly. This, we believe, could have importance in the prevention of falls, and the maintenance of health and independent living in elderly men and women.

  2. The cyanobacterial neurotoxin beta-N-methylamino-L-alanine (BMAA) induces neuronal and behavioral changes in honeybees

    Energy Technology Data Exchange (ETDEWEB)

    Okle, Oliver, E-mail: oliver.okle@uni-konstanz.de [Human and Environmental Toxicology, University of Konstanz, Jacob-Burckhardt-Strasse 25, 78457 Konstanz (Germany); Rath, Lisa; Galizia, C. Giovanni [Zoology and Neurobiology, University of Konstanz, Universitätsstraße 10, 78457 Konstanz (Germany); Dietrich, Daniel R., E-mail: daniel.dietrich@uni-konstanz.de [Human and Environmental Toxicology, University of Konstanz, Jacob-Burckhardt-Strasse 25, 78457 Konstanz (Germany)

    2013-07-01

    The cyanobacterially produced neurotoxin beta-N-methylamino-L-alanine (BMAA) is thought to induce amyotrophic lateral sclerosis/Parkinsonism dementia complex (ALS/PDC)-like symptoms. However, its mechanism of action and its pathway of intoxication are yet unknown. In vivo animal models suitable for investigating the neurotoxic effect of BMAA with applicability to the human are scarce. Hence, we used the honeybee (Apis mellifera) since its nervous system is relatively simple, yet having cognitive capabilities. Bees fed with BMAA-spiked sugar water had an increased mortality rate and a reduced ability to learn odors in a classical conditioning paradigm. Using {sup 14}C-BMAA we demonstrated that BMAA is biologically available to the bee, and is found in the head, thorax and abdomen with little to no excretion. BMAA is also transferred from one bee to the next via trophallaxis resulting in an exposure of the whole beehive. BMAA bath application directly onto the brain leads to an altered Ca{sup 2+} homeostasis and to generation of reactive oxygen species. These behavioral and physiological observations suggest that BMAA may have effects on bee brains similar to those assumed to occur in humans. Therefore the bee could serve as a surrogate model system for investigating the neurological effects of BMAA. - Highlights: • Investigating of neurotoxic effects of BMAA in honeybees • BMAA impairs ALS markers (ROS, Ca{sup 2+}, learning, memory, odor) in bees. • A method for the observation of ROS development in living bees brain was established. • Honeybees are a suitable model to explore neurodegenerative processes. • Neurotoxic BMAA can be spread in bee populations by trophallaxis.

  3. The ergogenic effect of beta-alanine combined with sodium bicarbonate on high-intensity swimming performance.

    Science.gov (United States)

    Painelli, Vitor de Salles; Roschel, Hamilton; Jesus, Flávia de; Sale, Craig; Harris, Roger Charles; Solis, Marina Yázigi; Benatti, Fabiana Braga; Gualano, Bruno; Lancha, Antonio Herbert; Artioli, Guilherme Giannini

    2013-05-01

    We investigated the effect of beta-alanine (BA) alone (study A) and in combination with sodium bicarbonate (SB) (study B) on 100- and 200-m swimming performance. In study A, 16 swimmers were assigned to receive either BA (3.2 g·day(-1) for 1 week and 6.4 g·day(-1) for 4 weeks) or placebo (PL; dextrose). At baseline and after 5 weeks of supplementation, 100- and 200-m races were completed. In study B, 14 were assigned to receive either BA (3.2 g·day(-1) for 1 week and 6.4 g·day(-1) for 3 weeks) or PL. Time trials were performed once before and twice after supplementation (with PL and SB), in a crossover fashion, providing 4 conditions: PL-PL, PL-SB, BA-PL, and BA-SB. In study A, BA supplementation improved 100- and 200-m time-trial performance by 2.1% (p = 0.029) and 2.0% (p = 0.0008), respectively. In study B, 200-m time-trial performance improved in all conditions, compared with presupplementation, except the PL-PL condition (PL-SB, +2.3%; BA-PL, +1.5%; BA-SB, +2.13% (p supplementation. The probability of BA having a positive effect was 65.2%; when SB was added to BA, the probability was 71.8%. BA and SB supplementation improved 100- and 200-m swimming performance. The coingestion of BA and SB induced a further nonsignificant improvement in performance.

  4. Methionine uptake in Corynebacterium glutamicum by MetQNI and by MetPS, a novel methionine and alanine importer of the NSS neurotransmitter transporter family.

    Science.gov (United States)

    Trötschel, Christian; Follmann, Martin; Nettekoven, Jeannine A; Mohrbach, Tobias; Forrest, Lucy R; Burkovski, Andreas; Marin, Kay; Krämer, Reinhard

    2008-12-02

    The soil bacterium Corynebacterium glutamicum is a model organism in amino acid biotechnology. Here we present the identification of two different L-methionine uptake systems including the first characterization of a bacterial secondary methionine carrier. The primary carrier MetQNI is a high affinity ABC-type transporter specific for l-methionine. Its expression is under the control of the transcription factor McbR, the global regulator of sulfur metabolism in C. glutamicum. Besides MetQNI, a novel secondary methionine uptake system of the NSS (neurotransmitter:sodium symporter) family was identified and named MetP. The MetP system is characterized by a lower affinity for methionine and uses Na(+) ions for energetic coupling. It is also the main alanine transporter in C. glutamicum and is expressed constitutively. These observations are consistent with models of methionine, alanine, and leucine bound to MetP, derived from the X-ray crystal structure of the LeuT transporter from Aquifex aeolicus. Complementation studies show that MetP consists of two components, a large subunit with 12 predicted transmembrane segments and, surprisingly, an additional subunit with one predicted transmembrane segment only. Thus, this new member of the NSS transporter family adds a novel feature to this class of carriers, namely, the functional dependence on an additional small subunit.

  5. Oral nutritional supplement fortified with beta-alanine improves physical working capacity in older adults: a randomized, placebo-controlled study.

    Science.gov (United States)

    McCormack, William P; Stout, Jeffrey R; Emerson, Nadia S; Scanlon, Tyler C; Warren, Ashlee M; Wells, Adam J; Gonzalez, Adam M; Mangine, Gerald T; Robinson, Edward H; Fragala, Maren S; Hoffman, Jay R

    2013-09-01

    This study examined the effects of an oral nutritional supplement fortified with two different doses of beta-alanine on body composition, muscle function and physical capacity in older adults. Using a double-blind placebo controlled design, 60 men and women (age ± SD = 70.7 ± 6.2 yrs) were randomly assigned to one of three treatment groups: 1) oral nutritional supplement (ONS; n = 20) (8 oz; 230 kcal; 12 g PRO; 31 g CHO; 6 g FAT), 2) ONS plus 800 mg beta-alanine (ONS800; n = 19), and 3) ONS plus 1200 mg beta-alanine (ONS1200; n = 21). Treatments were consumed twice per day for 12 weeks. At pre- and post-supplementation period, participants performed a discontinuous, submaximal cycle ergometry test to determine physical working capacity at fatigue threshold (PWCFT). Fat mass, total body and arm lean soft tissue mass (ALSTM) were measured with DEXA while muscle strength was assessed with handgrip dynamometry (GRIP) and 30-s sit-to-stand (STS) was used to measure lower body functionality. Muscle quality (MQ) was calculated with GRIPmax and DEXA derived ALSTM [GRIP (kg)·ALSTM (kg)(-1)]. Two-way analysis of variance was used to compare pre- to post-supplementation measures and group differences. There were 16 dropouts over the duration of the study. Final group sizes were ONS = 16 (m = 11, w = 5), ONS800 = 15 (m = 5, w = 10), and ONS1200 = 13 (m = 6, w = 7). No significant changes were observed for body composition or GRIP values pre to post. Significant increases in PW(CFT) were seen in ONS1200 (13.6%) and ONS800 (17.8%) pre- to post-supplementation (p 0.05) in change scores were found between ONS and ONS800. ONS fortified with beta-alanine may improve physical working capacity, muscle quality and function in older men and women. These findings could have importance in the perception of frailty, and the maintenance of health and independent living in older adults.

  6. Analysis of 15N incorporation into D-alanine: a new method for tracing nitrogen uptake by bacteria

    NARCIS (Netherlands)

    Veuger, B.; Middelburg, J.J.; Boschker, H.T.S.; Houtekamer, M.J.

    2005-01-01

    The quantitative contribution of bacteria to total microbial uptake of nitrogenous substrates is an aspect of the aquatic nitrogen cycle that is still largely unclear, mainly because existing methods are generally inadequate. We investigated the feasibility of measuring 15N incorporation into bacter

  7. Tetrahydro-beta-carbolines and corresponding tryptamines: In vitro inhibition of serotonin, dopamine and noradrenaline uptake in rat brain synaptosomes.

    Science.gov (United States)

    Komulainen, H; Tuomisto, J; Airaksinen, M M; Kari, I; Peura, P; Pollari, L

    1980-04-01

    The structure activity relationships of tryptolines and some other beta-carbolines and tryptamines as inhibitors of serotonin (5-HT), dopamine (DA) and noradrenaline (NA) uptake were studied in rat brain synaptosomes. All beta-carbolines inhibited to higher degree the uptake of 5-HT than that of DA or NA(IC50's 5-100 times lower). The most potent tryptoline derivative was 6-hydroxy-tetrahydro-beta-carboline (5-hydroxytryptoline, 6-OH-THBC) with an IC50 of 5.0 x 10(-7) M at a 5-HT concentration of 10(-7) M. 6-Methoxy-tetrahydro-beta-carboline (5-methoxytryptoline) was slightly weaker; the inhibition of 5-HT uptake and DA uptake being competitive. Also tetrahydro-beta-carboline (tryptoline) was more potent than its 1-methylderivative, tetrahydroharmane (methtryptoline) or norharmane (beta-carboline). All of them were, however, weaker inhibitors of 5-HT uptake than the freely rotating indoleamines N-methyl-tryptamine (N-Me-T) or 5-HT itself. N-Me-T and 5-HT were also more potent inhibitors of DA and NA uptake than most of the beta-carbolines, DA uptake, however, was inhibited better by 6-OH-THBC than by 5-HT or N-ME-T. Tetrahydro-beta-carbolines may inhibit 5-HT uptake also in vivo but is unlikely that catecholamine uptake is affected.

  8. Interleukin-1 beta stimulates glucose uptake of human peritoneal mesothelial cells in vitro.

    Science.gov (United States)

    Kruse, M; Mahiout, A; Kliem, V; Kurz, P; Koch, K M; Brunkhorst, R

    1996-01-01

    To investigate whether the glucose uptake (GU) of human peritoneal mesothelial cells (HPMC) is mediated by glucose transporters and whether this uptake is influenced by interleukin 1-beta (IL-1 beta), we measured 2-deoxy-(3H)-GU of HPMC in vitro, after exposing the cells for different times (two and 12 hours) to increasing concentrations (0.1, 1.0, and 2.0 ng/mL) of IL-1 beta. To exclude a noncarrier-mediated transport, GU was also tested in the presence of cytochalasin B. All experiments were performed in triplicate in the cells of two donors. Cytochalasin B inhibits GU of HPMC almost completely. GU of HPMC is not stimulated by insulin. GU is stimulated by IL-1 beta in a dose-dependent manner. These data indicate a GU of HPMC, which is mediated by a glucose transporter and stimulated by IL-1 beta. The increased uptake of glucose from the dialysate in patients with peritonitis may be mediated by a (cytokine-induced) increased activity of HPMC glucose transporters.

  9. Effects of interleukin-1 beta on thyrotropin secretion and thyroid hormone uptake in cultured rat anterior pituitary cells

    NARCIS (Netherlands)

    F.W.J.S. Wassen (Frank); E.P.C.M. Moerings (Ellis); H. van Toor (Hans); E.A. de Vrey (Evelyn); G. Hennemann; M.E. Everts (Maria)

    1996-01-01

    textabstractThe effects of interleukin-1 beta (IL-1 beta) and tumor necrosis factor-alpha (TNF alpha) on basal and TRH-induced TSH release, and the effects of IL-1 beta on the uptake of [125I]T3 and [125I]T4 and on nuclear binding of [125I]T3 were examined. Furthermore,

  10. Role of beta-adrenoceptors in memory consolidation: beta3-adrenoceptors act on glucose uptake and beta2-adrenoceptors on glycogenolysis.

    Science.gov (United States)

    Gibbs, Marie E; Hutchinson, Dana S; Summers, Roger J

    2008-09-01

    Noradrenaline, acting via beta(2)- and beta(3)-adrenoceptors (AR), enhances memory formation in single trial-discriminated avoidance learning in day-old chicks by mechanisms involving changes in metabolism of glucose and/or glycogen. Earlier studies of memory consolidation in chicks implicated beta(3)- rather than beta(2)-ARs in enhancement of memory consolidation by glucose, but did not elucidate whether stimulation of glucose uptake or of glycolysis was responsible. This study examines the role of glucose transport in memory formation using central injection of the nonselective facilitative glucose transporter (GLUT) inhibitor cytochalasin B, the endothelial/astrocytic GLUT-1 inhibitor phloretin and the Na(+)/energy-dependent endothelial glucose transporter (SGLT) inhibitor phlorizin. Cytochalasin B inhibited memory when injected into the mesopallium (avian cortex) either close to or between 25 and 45 min after training, whereas phloretin and phlorizin only inhibited memory at 30 min. This suggested that astrocytic/endothelial (GLUT-1) transport is critical at the time of consolidation, whereas a different transporter, probably the neuronal glucose transporter (GLUT-3), is important at the time of training. Inhibition of glucose transport by cytochalasin B, phloretin, or phlorizin also interfered with beta(3)-AR-mediated memory enhancement 20 min posttraining, whereas inhibition of glycogenolysis interfered with beta(2)-AR agonist enhancement of memory. We conclude that in astrocytes (1) activities of both GLUT-1 and SGLT are essential for memory consolidation 30 min posttraining; (2) neuronal GLUT-3 is essential at the time of training; and (3) beta(2)- and beta(3)-ARs consolidate memory by different mechanisms; beta(3)-ARs stimulate central glucose transport, whereas beta(2)-ARs stimulate central glycogenolysis.

  11. Scientific Opinion on the substantiation of a health claim related to beta-alanine and increase in physical performance during short-duration, high-intensity exercise pursuant to Article 13(5 of Regulation (EC No 1924/2006

    Directory of Open Access Journals (Sweden)

    EFSA Panel on Dietetic Products, Nutrition and Allergies (NDA

    2014-07-01

    Full Text Available Following an application from Natural Alternative International, Inc. (NAI, submitted pursuant to Article 13(5 of Regulation (EC No 1924/2006 via the Competent Authority of the United Kingdom, the Panel on Dietetic Products, Nutrition and Allergies (NDA was asked to deliver an opinion on the scientific substantiation of a health claim related to beta-alanine and increase in physical performance during short-duration, high-intensity exercise. The food constituent that is the subject of the claim is beta-alanine, which is sufficiently characterised. The Panel considers that an increase in physical performance during short-duration, high-intensity exercise is a beneficial physiological effect. In weighing the evidence the Panel took into account that only one out of 11 pertinent human intervention studies (including 14 pertinent outcomes from which conclusions could be drawn showed an effect of beta-alanine on physical performance during short-duration, high intensity exercise. The Panel concludes that a cause and effect relationship has not been established between the consumption of beta-alanine and an increase in physical performance during short-duration, high intensity exercise.

  12. The cycad neurotoxic amino acid, beta-N-methylamino-L-alanine (BMAA), elevates intracellular calcium levels in dissociated rat brain cells.

    Science.gov (United States)

    Brownson, Delia M; Mabry, Tom J; Leslie, Steven W

    2002-10-01

    Seeds of the Guam cycad Cycas micronesica K.D. Hill (Cycadaceae), which contain ss-methylamino-L-alanine (BMAA), have been implicated in the etiology of the devastating neurodisease ALS-PDC that is found among the native Chamorros on Guam. The disease also occurs in the native populations on Irian Jaya and the Kii Peninsula of Japan, and in all three areas the cycad seeds are used either dietarily or medically. ALS-PDC is a complex of amyotrophic lateral sclerosis and parkinsonism dementia complex with additional symptoms of Alzheimer's. It is well known that Ca(2+) elevations in brain cells can lead to cell death and neurodiseases. Therefore, we evaluated the ability of the cycad toxin BMAA to elevate the intracellular calcium concentration ([Ca(2+)](i)) in dissociated newborn rat brain cells loaded with fura-2 dye. BMAA produced an increase in intracellular calcium levels in a concentration-dependent manner. The increases were dependent not only on extracellular calcium concentrations, but also significantly on the presence of bicarbonate ion. Increasing concentrations of sodium bicarbonate resulted in a potentiation of the BMAA-induced [Ca(2+)](i) elevation. The bicarbonate dependence did not result from the increased sodium concentration or alkalinization of the buffer. Our results support the hypothesis that the neurotoxicity of BMAA is due to an excitotoxic mechanism, involving elevated intracellular calcium levels and bicarbonate. Furthermore, since BMAA alone produced no increase in Ca(2+) levels, these results suggest the involvement of a product of BMAA and CO(2), namely a beta-carbamate, which has a structure similar to other excitatory amino acids (EAA) such as glutamate; thus, the causative agent for ALS-PDC on Guam and elsewhere may be the beta-carbamate of BMAA. These findings support the theory that some forms of other neurodiseases may also involve environmental toxins.

  13. Glycerophosphoglycerol, Beta-Alanine, and Pantothenic Acid as Metabolic Companions of Glycolytic Activity and Cell Migration in Breast Cancer Cell Lines

    Directory of Open Access Journals (Sweden)

    Antje Hutschenreuther

    2013-11-01

    Full Text Available In cancer research, cell lines are used to explore the molecular basis of the disease as a substitute to tissue biopsies. Breast cancer in particular is a very heterogeneous type of cancer, and different subgroups of cell lines have been established according to their genomic profiles and tumor characteristics. We applied GCMS metabolite profiling to five selected breast cancer cell lines and found this heterogeneity reflected on the metabolite level as well. Metabolite profiles of MCF-7 cells belonging to the luminal gene cluster proved to be more different from those of the basal A cell line JIMT-1 and the basal B cell lines MDA-MB-231, MDA-MB-435, and MDA-MB-436 with only slight differences in the intracellular metabolite pattern. Lactate release into the cultivation medium as an indicator of glycolytic activity was correlated to the metabolite profiles and physiological characteristics of each cell line. In conclusion, pantothenic acid, beta-alanine and glycerophosphoglycerol appeared to be related to the glycolytic activity designated through high lactate release. Other physiological parameters coinciding with glycolytic activity were high glyoxalase 1 (Glo1 and lactate dehydrogenase (LDH enzyme activity as well as cell migration as an additional important characteristic contributing to the aggressiveness of tumor cells. Metabolite profiles of the cell lines are comparatively discussed with respect to known biomarkers of cancer progression.

  14. Determination of the neurotoxin BMAA (beta-N-methylamino-L-alanine) in cycad seed and cyanobacteria by LC-MS/MS (liquid chromatography tandem mass spectrometry).

    Science.gov (United States)

    Rosén, Johan; Hellenäs, Karl-Erik

    2008-12-01

    A highly specific method for the analysis of beta-N-methylamino-L-alanine (BMAA) by LC-MS/MS (liquid chromatography tandem mass spectrometry) has been developed and applied for cycad seeds and cyanobacteria. BMAA was analysed as a free fraction or as total BMAA after acidic hydrolysis to release any protein-bound BMAA. Deuterium labelled BMAA was synthesised and used as internal standard. The method comprises HILIC (hydrophilic interaction chromatography) and positive electrospray ionisation of the native compound, i.e. no derivatisation was used. For safe identification five specific product ions (m/z 102, 88, 76, 73 and 44), all derived from a precursor ion of m/z 119 and originating from different parts of the molecule, were detected (typical relative abundance 100%, 16%, 14%, 12% and 22% respectively). Cyanobacteria or muscle tissue was spiked with BMAA (10 to 1000 microg g(-1)) to validate the method (accuracy 95% to 109%, relative standard deviation 1% to 6%). The detection limit for free and total BMAA in tissue was cycad seeds, whereas previously reported findings of BMAA in samples of cyanobacteria could not be confirmed. Instead, the presence of alpha-,gamma-diamino butyric acid (DAB), an isomer of BMAA, was confirmed in one sample. The possible implications of this finding are discussed.

  15. Biotin uptake by mouse and human pancreatic beta cells/islets: a regulated, lipopolysaccharide-sensitive carrier-mediated process.

    Science.gov (United States)

    Ghosal, Abhisek; Sekar, Thillai V; Said, Hamid M

    2014-08-01

    Biotin is essential for the normal function of pancreatic beta cells. These cells obtain biotin from their surroundings via transport across their cell membrane. Little is known about the uptake mechanism involved, how it is regulated, and how it is affected by internal and external factors. We addressed these issues using the mouse-derived pancreatic beta-TC-6 cells and freshly isolated mouse and human primary pancreatic beta cells as models. The results showed biotin uptake by pancreatic beta-TC-6 cells occurs via a Na(+)-dependent, carrier-mediated process, that is sensitive to desthiobiotin, as well as to pantothenic acid and lipoate; the process is also saturable as a function of concentration (apparent Km = 22.24 ± 5.5 μM). These cells express the sodium-dependent multivitamin transporter (SMVT), whose knockdown (with doxycycline-inducible shRNA) led to a sever inhibition in biotin uptake. Similarly, uptake of biotin by mouse and human primary pancreatic islets is Na(+)-dependent and carrier-mediated, and both cell types express SMVT. Biotin uptake by pancreatic beta-TC-6 cells is also adaptively regulated (via transcriptional mechanism) by extracellular substrate level. Chronic treatment of pancreatic beta-TC-6 cells with bacterial lipopolysaccharides (LPS) leads to inhibition in biotin uptake. This inhibition is mediated via a Toll-Like receptor 4-mediated process and involves a decrease in membrane expression of SMVT. These findings show, for the first time, that pancreatic beta cells/islets take up biotin via a specific and regulated carrier-mediated process, and that the process is sensitive to the effect of LPS.

  16. Alanine Mutagenesis in the Complementarity Determining Region 3 of the MTB and HIV-1 Peptide-Bispecific T Cell Receptor Beta Chain Affects Ligand Recognition

    Directory of Open Access Journals (Sweden)

    Chao-Ying Zhou

    2017-08-01

    Full Text Available Mycobacterium tuberculosis/human immunodeficiency virus (MTB/HIV coinfection presents a special challenge to the prevention and treatment of tuberculosis and HIV/AIDS. Adoptive transfer of high-affinity T cell receptor (TCR gene-modified T cells against MTB and HIV antigens is a promising approach to treating MTB/HIV coinfected patients whose cellular immunity is obviously disordered. We have previously successfully identified that a bispecific TCR screened out from peripheral blood mononuclear cells of a HLA-A*0201+ healthy individual using the complementarity determining region 3 (CDR3 spectratype analysis recognizes both MTB Ag85B199–207 and HIV-1 Env120–128 peptide. However, it has not been known how residues on CDR3 loops, which have been shown to play a leading role in antigen binding and specificity contribute to the bispecific TCR contact with the peptide–major histocompatibility complex (MHC complexes. In this study, we provided an extensive investigation of residues in the predicted CDR3 of the bispecific TCR beta (β chain using alanine scanning mutagenesis. Our data showed that three of the five substituted residues (G115A, T116A, A117G in CDR3β of the bispecific TCR caused a significantly diminished T cell response to antigen, whereas the remaining two substituted residues (D114A, S118A resulted in completely eliminated response, thus identifying the two residues that were particularly critical for the recognition of peptide–MHC in the bispecific TCR. These findings will provide an imperative foundation for generating an improved high-affinity bispecific TCR for use in T cell adoptive immunotherapy for MTB/HIV coinfected individuals.

  17. Incremental effects of 28 days of beta-alanine supplementation on high-intensity cycling performance and blood lactate in masters female cyclists.

    Science.gov (United States)

    Glenn, J M; Gray, M; Stewart, R; Moyen, N E; Kavouras, S A; DiBrezzo, R; Turner, R; Baum, J

    2015-12-01

    Within the aging population, there exists a subset of individuals termed masters athletes (MA). As masters-level competition increases in popularity, MA must find methods to enhance individual athletic performance. Longitudinal beta-alanine (BA) supplementation is suggested to enhance physical capability during exercise; however, these effects have not been evaluated in MA. To examine the longitudinal effects of BA on time to exhaustion (TTE), total work completed (TWC), and lactate clearance in female MA cyclists. Twenty-two female MA (age = 53.3 ± 1.0) participated in this double-blind design. Subjects were randomly assigned to BA (n = 11; 800 mg BA + 8 g dextrose) or placebo (PLA; n = 11; 8 g dextrose) groups and supplemented 4 doses/day over 28 days. Every 7 days, subjects completed a cycling TTE at 120% VO2max, and TWC was calculated. Blood lactate was measured at baseline, immediate post, and 20-min post each TTE. No significant differences existed between groups for any variable at baseline (p > 0.05). After 28 days supplementation, BA had greater TTE (23 vs 1% change) and TWC (21 vs 2% change) than PLA (p < 0.05). Following the 20-min TTE recovery, lactate was 24% lower in BA compared to PLA (4.35 vs. 5.76 mmol/L, respectively). No differences existed for variables during intermittent weeks. 28 days of BA supplementation increased cycling performance via an enhanced time to exhaustion and total work completed with associated lactate clearance during passive rest in female MA.

  18. Metabotropic glutamate receptor 1 mediates the electrophysiological and toxic actions of the cycad derivative beta-N-Methylamino-L-alanine on substantia nigra pars compacta DAergic neurons.

    Science.gov (United States)

    Cucchiaroni, Maria Letizia; Viscomi, Maria Teresa; Bernardi, Giorgio; Molinari, Marco; Guatteo, Ezia; Mercuri, Nicola B

    2010-04-14

    Amyotrophic lateral sclerosis-Parkinson dementia complex (ALS-PDC) is a neurodegenerative disease with ALS, parkinsonism, and Alzheimer's symptoms that is prevalent in the Guam population. beta-N-Methylamino alanine (BMAA) has been proposed as the toxic agent damaging several neuronal types in ALS-PDC, including substantia nigra pars compacta dopaminergic (SNpc DAergic) neurons. BMAA is a mixed glutamate receptor agonist, but the specific pathways activated in DAergic neurons are not yet known. We combined electrophysiology, microfluorometry, and confocal microscopy analysis to monitor membrane potential/current, cytosolic calcium concentration ([Ca(2+)](i)) changes, cytochrome-c (cyt-c) immunoreactivity, and reactive oxygen species (ROS) production induced by BMAA. Rapid toxin applications caused reversible membrane depolarization/inward current and increase of firing rate and [Ca(2+)](i) in DAergic neurons. The inward current (I(BMAA)) was mainly mediated by activation of metabotropic glutamate receptor 1 (mGluR1), coupled to transient receptor potential (TRP) channels, and to a lesser extent, AMPA receptors. Indeed, mGluR1 (CPCCOEt) and TRP channels (SKF 96365; Ruthenium Red) antagonists reduced I(BMAA), and a small component of I(BMAA) was reduced by the AMPA receptor antagonist CNQX. Calcium accumulation was mediated by mGluR1 but not by AMPA receptors. Application of a low concentration of NMDA potentiated the BMAA-mediated calcium increase. Prolonged exposure to BMAA caused significant modifications of membrane properties, calcium overload, cell shrinkage, massive cyt-c release into the cytosol and ROS production. In SNpc GABAergic neurons, BMAA activated only AMPA receptors. Our study identifies the mGluR1-activated mechanism induced by BMAA that may cause the neuronal degeneration and parkinsonian symptoms seen in ALS-PDC. Moreover, environmental exposure to BMAA might possibly also contribute to idiopathic PD.

  19. EFSA NDA Panel (EFSA Panel on Dietetic Products, Nutrition and Allergies), 2014. Scientific Opinion on the substantiation of a health claim related to beta-alanine and increase in physical performance during short-duration, high-intensity exercise pursuant to Article 13(5) of Regulation (EC

    DEFF Research Database (Denmark)

    Tetens, Inge

    on the scientific substantiation of a health claim related to beta-alanine and increase in physical performance during short-duration, high-intensity exercise. The food constituent that is the subject of the claim is beta-alanine, which is sufficiently characterised. The Panel considers that an increase in physical...... performance during short-duration, high-intensity exercise is a beneficial physiological effect. In weighing the evidence the Panel took into account that only one out of 11 pertinent human intervention studies (including 14 pertinent outcomes) from which conclusions could be drawn showed an effect of beta-alanine...... on physical performance during short-duration, high intensity exercise. The Panel concludes that a cause and effect relationship has not been established between the consumption of beta-alanine and an increase in physical performance during short-duration, high intensity exercise....

  20. Role of the beta1-integrin cytoplasmic tail in mediating invasin-promoted internalization of Yersinia

    DEFF Research Database (Denmark)

    Gustavsson, Anna; Armulik, Annika; Brakebusch, Cord

    2002-01-01

    Invasin of Yersinia pseudotuberculosis binds to beta1-integrins on host cells and triggers internalization of the bacterium. To elucidate the mechanism behind the beta1-integrin-mediated internalization of Yersinia, a beta1-integrin-deficient cell line, GD25, transfected with wild-type beta1A, beta......1B or different mutants of the beta1A subunit was used. Both beta1A and beta1B bound to invasin-expressing bacteria, but only beta1A was able to mediate internalization of the bacteria. The cytoplasmic region of beta1A, differing from beta1B, contains two NPXY motifs surrounding a double threonine...... site. Exchanging the tyrosines of the two NPXYs to phenylalanines did not inhibit the uptake, whereas a marked reduction was seen when the first tyrosine (Y783) was exchanged to alanine. A similar reduction was seen when the two nearby threonines (TT788-9) were exchanged with alanines. It was also...

  1. **-Postprandial pancreatic [(11)C]methionine uptake after pancreaticoduodenectomy mirrors basal beta cell function and insulin release.

    Science.gov (United States)

    Steiner, Emanuel; Kazianka, Lukas; Breuer, Robert; Hacker, Marcus; Wadsak, Wolfgang; Mitterhauser, Markus; Stimpfl, Thomas; Reiter, Birgit; Karanikas, Georgios; Miholic, Johannes

    2017-03-01

    [S-methyl-(11)C]-L-methionine ([(11)C]MET) uptake in the pancreas might be a central indicator of beta cell function. Since gastric emptying was recently shown to influence glycemic control in subjects after pancreaticoduodenectomy (PD, the surgical treatment of neoplasms of the pancreas head), we looked for imaginable relationships between gastric emptying, pre- and postprandial insulin concentrations, and [(11)C]MET uptake. Nineteen tumor-free survivors after PD (age mean ± SD: 61 ± 8.7 yrs.; 10 male, 9 female) and 10 healthy controls (age: 27 ± 8.7 yrs.; 7 male, 3 female) were given a mixed test meal. One gram of paracetamol was ingested with the meal to evaluate the speed of gastric emptying. Insulin, glucose, and paracetamol plasma concentrations were measured before and over 180 minutes after ingestion. Beta cell function was calculated from fasting glucose and insulin plasma concentrations. Simultaneously, 800 MBq of [(11)C]MET were administered and the activity (maximum tissue standardized uptake values [SUVmax]) over the pancreas was measured at 15, 30, and 60 minutes after injection. Total integrated SUVmax (area under the curve [AUC]) and incremental SUVmax were calculated. The uptake of [(11)C]MET in the pancreas was significantly higher (p insulin AUC60 (R(2) = 0.66,p insulin AUC60 and beta cell function, calculated from the fasting insulin to glucose ratio, as independent predictors of (11)C-methionine uptake, i.e. total integrated SUVmax, in patients after PD (R(2) = 0.78, p < 0.0001). Postprandial [(11)C]MET uptake may represent basal and postprandial beta cell function. The findings suggest a possible usefulness of this imaging procedure for further studying beta cell function.

  2. The effect of four-week high-intensity interval training with beta-alanine supplementation on aerobic and anaerobic performance and some blood parameters in girls basketball players

    Directory of Open Access Journals (Sweden)

    bahareh ketabdar

    2017-06-01

    Full Text Available Background & Objective: The aim of the present study was to determine the effect of four-week high-intensity interval training with beta-alanine supplementation on aerobic and anaerobic performance and some blood parameters in girls basketball players. Materials & Methods: This was a quasi-experimental study. Twenty female basketball players, with the mean age of 24.65 ± 4.81 years, height of 166.97 ± 4.12 cm, weight of 59.15 ± 5.23 kg and body mass index of 21.5 ± 1.23 kg/m2, were divided into two groups, including intervention (exercise + supplement and control groups. Two days before and after the intervention, the subjects performed Wingate test (to estimate the average aerobic power and Bruce test (to estimate VO2max.The subjects attended basketball training two sessions per week; Intervention group performed high-intensity interval training in addition to the basketball training in every session. The dose of beta-alanine supplementation was 2.4, 3.6, 4.8 g per day. After four weeks, creatine kinase and lactate levels and performance tests were reevaluated. Data were analyzed by SPSS software version 21, with a significance level of P0.05. Conclusion: This study showed that high-intensity interval training with beta-alanine supplementation resulted in delay in the fatigue threshold, stabilization of PH and hydrogen ions balance, increased aerobic-anaerobic capacity and exercise performance in female basketball players.

  3. Mechanism of neuronal versus endothelial cell uptake of Alzheimer's disease amyloid beta protein.

    Directory of Open Access Journals (Sweden)

    Karunya K Kandimalla

    Full Text Available Alzheimer's disease (AD is characterized by significant neurodegeneration in the cortex and hippocampus; intraneuronal tangles of hyperphosphorylated tau protein; and accumulation of beta-amyloid (Abeta proteins 40 and 42 in the brain parenchyma as well as in the cerebral vasculature. The current understanding that AD is initiated by the neuronal accumulation of Abeta proteins due to their inefficient clearance at the blood-brain-barrier (BBB, places the neurovascular unit at the epicenter of AD pathophysiology. The objective of this study is to investigate cellular mechanisms mediating the internalization of Abeta proteins in the principle constituents of the neurovascular unit, neurons and BBB endothelial cells. Laser confocal micrographs of wild type (WT mouse brain slices treated with fluorescein labeled Abeta40 (F-Abeta40 demonstrated selective accumulation of the protein in a subpopulation of cortical and hippocampal neurons via nonsaturable, energy independent, and nonendocytotic pathways. This groundbreaking finding, which challenges the conventional belief that Abeta proteins are internalized by neurons via receptor mediated endocytosis, was verified in differentiated PC12 cells and rat primary hippocampal (RPH neurons through laser confocal microscopy and flow cytometry studies. Microscopy studies have demonstrated that a significant proportion of F-Abeta40 or F-Abeta42 internalized by differentiated PC12 cells or RPH neurons is located outside of the endosomal or lysosomal compartments, which may accumulate without degradation. In contrast, BBME cells exhibit energy dependent uptake of F-Abeta40, and accumulate the protein in acidic cell organelle, indicative of endocytotic uptake. Such a phenomenal difference in the internalization of Abeta40 between neurons and BBB endothelial cells may provide essential clues to understanding how various cells can differentially regulate Abeta proteins and help explain the vulnerability of cortical

  4. **-Postprandial pancreatic [{sup 11}C]methionine uptake after pancreaticoduodenectomy mirrors basal beta cell function and insulin release

    Energy Technology Data Exchange (ETDEWEB)

    Steiner, Emanuel; Kazianka, Lukas; Breuer, Robert; Miholic, Johannes [Medical University of Vienna, Department of Surgery, Vienna (Austria); Hacker, Marcus; Wadsak, Wolfgang; Mitterhauser, Markus [Medical University of Vienna, Department of Biomedical Imaging and Image-Guided Therapy, Division of Nuclear Medicine, Vienna (Austria); Stimpfl, Thomas; Reiter, Birgit [Medical University of Vienna, Clinical Institute of Laboratory Medicine, Forensic Toxicology, Vienna (Austria); Karanikas, Georgios [Medical University of Vienna, Department of Biomedical Imaging and Image-Guided Therapy, Division of Nuclear Medicine, Divisional Head PET-PET/CT (Nuclear Medicine), Vienna (Austria)

    2017-03-15

    [S-methyl-{sup 11}C]-L-methionine ([{sup 11}C]MET) uptake in the pancreas might be a central indicator of beta cell function. Since gastric emptying was recently shown to influence glycemic control in subjects after pancreaticoduodenectomy (PD, the surgical treatment of neoplasms of the pancreas head), we looked for imaginable relationships between gastric emptying, pre- and postprandial insulin concentrations, and [{sup 11}C]MET uptake. Nineteen tumor-free survivors after PD (age mean ± SD: 61 ± 8.7 yrs.; 10 male, 9 female) and 10 healthy controls (age: 27 ± 8.7 yrs.; 7 male, 3 female) were given a mixed test meal. One gram of paracetamol was ingested with the meal to evaluate the speed of gastric emptying. Insulin, glucose, and paracetamol plasma concentrations were measured before and over 180 minutes after ingestion. Beta cell function was calculated from fasting glucose and insulin plasma concentrations. Simultaneously, 800 MBq of [{sup 11}C]MET were administered and the activity (maximum tissue standardized uptake values [SUVmax]) over the pancreas was measured at 15, 30, and 60 minutes after injection. Total integrated SUVmax (area under the curve [AUC]) and incremental SUVmax were calculated. The uptake of [{sup 11}C]MET in the pancreas was significantly higher (p < 0.0001) in controls compared to the PD group. Gastric emptying was significantly slower in controls compared to pancreatectomy subjects (p < 0.0001). Paracetamol AUC{sub 30} correlated with the SUVmax increment between 15 and 30 minutes (R{sup 2} = 0.27, p = 0.0263), suggesting a relationship between gastric emptying and the uptake of [{sup 11}C]MET. Total integrated SUVmax correlated with insulin AUC{sub 60} (R{sup 2} = 0.66,p < 0.0001) in patients after PD. Multivariate regression analysis revealed insulin AUC{sub 60} and beta cell function, calculated from the fasting insulin to glucose ratio, as independent predictors of {sup 11}C-methionine uptake, i.e. total integrated SUVmax, in

  5. Estradiol-17 beta inhibition of androgen uptake, metabolism and binding in epididymis of adult male rats in vivo: a comparison with cyproterone acetate.

    Science.gov (United States)

    Tindall, D J; French, F S; Nayfeh, S N

    1981-03-01

    The effects of estradiol-17 beta on androgen uptake, metabolism and binding were studied in rat epididymis in vivo in comparison with cyproterone acetate. Steroids (250 ug/100 g body weight) were injected 5 min prior to 3H-testosterone in castrate rats. Estradiol-17 beta inhibited 3H-testosterone uptake into epididymal cytosol by 58% as compared to 38% by cyproterone acetate. 3H-Testosterone uptake into epididymal nuclei was inhibited 95% by estradiol-17 beta and 83% by cyproterone acetate. Total bound radioactivity in cytosol fractions was reduced to a greater extent by estradiol-17 beta than cyproterone acetate when either 3H-testosterone or 3H-dihydrotestosterone was injected. Binding of 3H-dihydrotestosterone to nuclear receptors was completely abolished by estradiol-17 beta; whereas approximately 20% binding remained in the nuclear extract after cyproterone acetate treatment. Metabolism of 3H-testosterone in vivo was also altered by estradiol-17 beta, resulting in diminished conversion to 3H-dihydrotestosterone. Cyproterone acetate, on the other hand, did not affect 3H-testosterone metabolism. Estradiol-17 beta and cyproterone acetate inhibited in vitro binding of 3H-dihydrotestosterone to the intracellular cytoplasmic receptor, but not the intraluminal androgen binding protein (ABP). These data suggest that estradiol-17 beta may have a more potent antiandrogenic effect on the epididymis than cyproterone acetate due to inhibition of 5 alpha reduction of testosterone as well as binding to the androgen receptor.

  6. Micellarization and intestinal cell uptake of beta-carotene and lutein from drumstick (Moringa oleifera) leaves.

    Science.gov (United States)

    Pullakhandam, Raghu; Failla, Mark L

    2007-06-01

    The leaves and pods of the drumstick tree are used as food and medicine in some Asian and African countries. Although relatively high concentrations of beta-carotene and lutein have been reported in the leaves, the bioavailability of these carotenoids from this source is unknown. We have analyzed the digestive stability and bioaccessibility of carotenoids in fresh and lyophilized drumstick leaves using the coupled in vitro digestion/Caco-2 cell model. Beta-carotene and lutein were stable during simulated gastric and small intestinal digestion. The efficiency of micellarization of lutein during the small intestinal phase of digestion exceeded that of beta-carotene. Addition of peanut oil (5% vol/wt) to the test food increased micellarization of both carotenoids, and particularly beta-carotene. Caco-2 cells accumulated beta-carotene and lutein from micelles generated during digestion of drumstick leaves in a time- and concentration-dependent manner. The relatively high bioaccessibility of beta-carotene and lutein from drumstick leaves ingested with oil supports the potential use of this plant food for improving vitamin A nutrition and perhaps delaying the onset of some degenerative diseases such as cataracts.

  7. Beta-N-Methylamino-l-Alanine: LC-MS/MS Optimization, Screening of Cyanobacterial Strains and Occurrence in Shellfish from Thau, a French Mediterranean Lagoon

    Directory of Open Access Journals (Sweden)

    Damien Réveillon

    2014-11-01

    Full Text Available β-N-methylamino-l-alanine (BMAA is a neurotoxic non-protein amino acid suggested to be involved in neurodegenerative diseases. It was reported to be produced by cyanobacteria, but also found in edible aquatic organisms, thus raising concern of a widespread human exposure. However, the chemical analysis of BMAA and its isomers are controversial, mainly due to the lack of selectivity of the analytical methods. Using factorial design, we have optimized the chromatographic separation of underivatized analogues by a hydrophilic interaction chromatography coupled to tandem mass spectrometry (HILIC-MS/MS method. A combination of an effective solid phase extraction (SPE clean-up, appropriate chromatographic resolution and the use of specific mass spectral transitions allowed for the development of a highly selective and sensitive analytical procedure to identify and quantify BMAA and its isomers (in both free and total form in cyanobacteria and mollusk matrices (LOQ of 0.225 and 0.15 µg/g dry weight, respectively. Ten species of cyanobacteria (six are reported to be BMAA producers were screened with this method, and neither free nor bound BMAA could be found, while both free and bound DAB were present in almost all samples. Mussels and oysters collected in 2009 in the Thau Lagoon, France, were also screened, and bound BMAA and its two isomers, DAB and AEG, were observed in all samples (from 0.6 to 14.4 µg/g DW, while only several samples contained quantifiable free BMAA.

  8. Insertion of beta-alanine in model peptides for copper binding to His96 and His111 of the human prion protein.

    Science.gov (United States)

    Rivillas-Acevedo, Lina; Maciel-Barón, Luis; García, Javier E; Juaristi, Eusebio; Quintanar, Liliana

    2013-09-01

    The prion protein coordinates copper with high affinity in the regions encompassing residues 92-99 (GGGTHSQW) and 106-115 (KTNMKHMAGA). Cu(II) binding to these sites involves the coordination of the His96/His111 imidazole ring and backbone deprotonated amides that precede the His residue. Such a coordination arrangement involves the formation of hexa- and penta-membered cycles that provide further stabilization of the metal-peptide complex. The purpose of the present study is to introduce a methylene group in the peptide backbone, to evaluate the impact of increasing the size of these cycles in Cu(II) binding. Thus, a β-alanine residue was inserted at different positions preceding the His residue in these prion fragments, and their Cu(II) coordination properties were assessed by UV-Visible absorption, circular dichroism, and electron paramagnetic resonance. Spectroscopic data show that the insertion of a methylene group leads to a completely different Cu(II) coordination that involves the His96/His111 imidazole ring and nitrogen or oxygen atoms provided by the peptide backbone towards the C-terminal. This study clearly shows that two main factors determine the nature of Cu(II)-peptide complexes involving an anchoring His residue and deprotonated amides from the backbone chain: i) the stabilization of Cu(II)-peptide complexes due to the formation of cyclic structures (i.e. chelate effect) and ii) the nature of the residues associated to the deprotonated amide groups that participate in metal ion coordination.

  9. Effect of beta-alanine supplementation on the onset of blood lactate accumulation (OBLA during treadmill running: Pre/post 2 treatment experimental design

    Directory of Open Access Journals (Sweden)

    Misic Mark

    2010-05-01

    Full Text Available Abstract Background β-Alanine (βA has been shown to improve performance during cycling. This study was the first to examine the effects of βA supplementation on the onset of blood lactate accumulation (OBLA during incremental treadmill running. Methods Seventeen recreationally-active men (mean ± SE 24.9 ± 4.7 yrs, 180.6 ± 8.9 cm, 79.25 ± 9.0 kg participated in this randomized, double-blind, placebo-controlled pre/post test 2-treatment experimental design. Subjects participated in two incremental treadmill tests before and after 28 days of supplementation with either βA (6.0 g·d-1(βA, n = 8 or an equivalent dose of Maltodextrin as the Placebo (PL, n = 9. Heart rate, percent heart rate maximum (%HRmax, %VO2max@OBLA (4.0 mmol.L-1 blood lactate concentration and VO2max (L.min-1 were determined for each treadmill test. Friedman test was used to determine within group differences; and Mann-Whitney was used to determine between group differences for pre and post values (p Results The βA group experienced a significant rightward shift in HR@OBLA beats.min-1 (p 2max@OBLA increased (p 2max (L.min-1 decreased (p Conclusions βA supplementation for 28 days enhanced sub-maximal endurance performance by delaying OBLA. However, βA supplemented individuals had a reduced aerobic capacity as evidenced by the decrease in VO2max values post supplementation.

  10. Towards a Radio-guided Surgery with $\\beta^{-}$ Decays: Uptake of a somatostatin analogue (DOTATOC) in Meningioma and High Grade Glioma

    CERN Document Server

    Collamati, Francesco; Bellini, Fabio; Bocci, Valerio; Cremonesi, Marta; De Lucia, Erika; Ferrari, Mahila; Frallicciardi, Paola M; Grana, Chiara M; Marafini, Michela; Mattei, Ilaria; Morganti, Silvio; Patera, Vincenzo; Piersanti, Luca; Recchia, Luigi; Russomando, Andrea; Sarti, Alessio; Sciubba, Adalberto; Senzacqua, Martina; Camillocci, Elena Solfaroli; Voena, Cecilia; Faccini, Riccardo

    2014-01-01

    A novel radio guided surgery (RGS) technique for cerebral tumors using $\\beta^{-}$ radiation is being developed. Checking the availability of a radio-tracer that can deliver a $\\beta^{-}$ emitter to the tumor is a fundamental step in the deployment of such technique. This paper reports a study of the uptake of 90Y labeled (DOTATOC) in the meningioma and the high grade glioma (HGG) and a feasibility study of the RGS technique in these cases.

  11. Assay of urinary alpha-fluoro-beta-alanine by gas chromatography-mass spectrometry for the biological monitoring of occupational exposure to 5-fluorouracil in oncology nurses and pharmacy technicians.

    Science.gov (United States)

    Rubino, Federico Maria; Verduci, Cinzia; Buratti, Marina; Fustinoni, Silvia; Campo, Laura; Omodeo-Salè, Emanuela; Giglio, Margherita; Iavicoli, Sergio; Brambilla, Gabri; Colombi, Antonio

    2006-03-01

    The validation of an analytical method for the measurement of the unnatural amino acid alpha-fluoro-beta-alanine (AFBA), the main metabolite of the antineoplastic drug 5-fluorouracil (5FU), in urine for the biological monitoring of the exposure of hospital workers to the drug when preparing the therapeutical doses and administering to cancer patients is described. The method employed a two-step extractive derivatization of the analyte from urine to the N-trifluoroacety-n-butyl ester derivative and detection by selected-ion monitoring gas chromatography-mass spectrometry of structurally specific fragments. The limit of detection was 20 ng/mL with quantification accuracy better than +/-20% and precision (CV%) better than +/-20% in the range 0.020-10 microg/mL. Norleucine was used as the internal standard and the sample-to-sample analysis time was less than 15 min. The validated method has been applied to the biological monitoring of some hospital workers potentially exposed to 5FU and to matched control subjects. On a total number of 65 analyzed urine samples from control and exposed subjects, only three, obtained from exposed subjects, were found to be positive, with values of 20, 30 and 1150 ng/mL, respectively.

  12. LC-MS/MS determination of the isomeric neurotoxins BMAA (beta-N-methylamino-L-alanine) and DAB (2,4-diaminobutyric acid) in cyanobacteria and seeds of Cycas revoluta and Lathyrus latifolius.

    Science.gov (United States)

    Krüger, Thomas; Mönch, Bettina; Oppenhäuser, Steven; Luckas, Bernd

    2010-01-01

    Since diverse taxa of cyanobacteria has been linked to biosynthesis of BMAA, a controversy has arisen about the detection of neurotoxic amino acids in cyanobacteria. In this context, a novel LC-MS/MS method was developed for the unambiguous determination of beta-N-methylamino-L-alanine (BMAA) and 2,4-diaminobutyric acid (DAB) in cyanobacteria and selected plant seeds. Both neurotoxic and non-proteinogenic amino acids were analyzed without derivatization considering the total concentration of the free and protein-bound form. The investigation of overall 62 cyanobacterial samples of worldwide origin by application of this method revealed the absence of BMAA, whereas seeds of Cycas revoluta contained 6.96 microg g(-1) of free BMAA. In contrast, the isomer DAB was confirmed in 16 cyanobacterial samples in concentrations of 0.07-0.83 microg g(-1),whereof one sample is distributed as nutritional supplement. In addition, seeds of Lathyrus latifolius contained 4.21 microg g(-1) of free DAB. Limits of detection were for BMAAdisadvantages of derivatization-based methods to be discussed.

  13. A beta-barrel outer membrane protein facilitates cellular uptake of polychlorophenols in Cupriavidus necator.

    Science.gov (United States)

    Belchik, Sara Mae; Schaeffer, Scott M; Hasenoehrl, Shelley; Xun, Luying

    2010-06-01

    The tcpRXABCYD operon of Cupriavidus necator JMP134 is involved in the degradation of 2,4,6-trichlorophenol (TCP). All of the gene products except TcpY have assigned functions in TCP metabolism. Sequence comparison identified TcpY as a member of COG4313, a group of hypothetical proteins. TcpY has a signal peptide, indicating it is a membrane or secreted protein. Secondary structure and topology analysis indicated TcpY as a beta-barrel outer membrane protein, similar to the Escherichia coli outer membrane protein FadL that transports hydrophobic long-chain fatty acids. Constitutive expression of tcpY in two C. necator strains rendered the cells more sensitive to TCP and other polychlorophenols. Further, C. necator JMP134 expressing cloned tcpY transported more TCP into the cell than a control with the cloning vector. Thus, TcpY is an outer membrane protein that facilitates the passing of polychlorophenols across the outer membrane of C. necator. Similarly, other COG4313 proteins are possibly outer membrane transporters of hydrophobic aromatic compounds.

  14. Significance of retardation of abnormal uptake of iodine-123-beta-methyl-p-iodophenyl-pentadecanoic acid myocardial scintigraphy in patients with vasospastic angina

    Energy Technology Data Exchange (ETDEWEB)

    Inoue, Fumitaka; Hashimoto, Toshio; Uemura, Shiro; Kawamoto, Atsuhiko; Dohi, Kazuhiro [Nara Medical Univ., Kashihara (Japan); Matsushima, Akihiko

    2001-07-01

    This study investigated retardation of abnormal uptake of iodine-123-beta-methyl-p-iodophenyl-pentadecanoic acid (BMIPP) scintigraphy in patients with vasospastic angina. Twenty-three patients with vasospastic angina showed abnormal uptake of BMIPP before medical treatment and had coronary vasospasm induced by acetylcholine. The patients were divided into two groups according to uptake of BMIPP after medical treatment: retardation of abnormal uptake of BMIPP (Group R, n=4) and normal uptake of BMIPP (Group N, n=19). Frequency of chest pain, medical treatment and autonomic nervous activity were compared between the two groups. Furthermore, the frequency of chest pain and uptake of BMIPP in group R were obtained after intensive medical treatment. Autonomic nervous activity was evaluated by heart rate variability on Holter electrocardiography. Heart rate variability contained high-frequency elements (HF; 0.15-0.4 Hz) and low-frequency elements (LF; 0.04-0.15 Hz). LF/HF was estimated for sympathetic nervous activity and HF was estimated for parasympathetic nervous activity. Daytime and nighttime autonomic nervous activity were compared between the two groups. The frequency of chest pain was higher in Group R than in Group N (p<0.05). Medical treatment was not different between the two groups. Circadian variation of sympathetic and parasympathetic nervous activity were absent in Group R. During the nighttime, Group R showed higher sympathetic nervous activity (p<0.05) and lower parasympathetic nervous activity (p<0.01) than Group N. The frequency of chest pain was significantly lower after intensive medical treatment (p<0.05), and uptake of BMIPP returned to normal in Group R. We suspected that the disorder in autonomic nervous activity was more severe in Group R, and thus induced coronary vasospasm. Retardation of abnormal uptake of BMIPP in patients with vasospastic angina indicates poor control of coronary vasospasm. Uptake of BMIPP is useful in the evaluation of

  15. Activation of Toll-like receptor 2 on microglia promotes cell uptake of Alzheimer disease-associated amyloid beta peptide.

    Science.gov (United States)

    Chen, Keqiang; Iribarren, Pablo; Hu, Jinyue; Chen, Jianhong; Gong, Wanghua; Cho, Edward H; Lockett, Stephen; Dunlop, Nancy M; Wang, Ji Ming

    2006-02-10

    The human G-protein-coupled formyl peptide receptor-like 1 (FPRL1) and its mouse homologue mFPR2 mediate the chemotactic activity of a variety of polypeptides associated with inflammation and bacterial infection, including the 42-amino acid form of amyloid beta peptide (Abeta42), a pathogenic factor in Alzheimer disease. Because mFPR2 was inducible in mouse microglial cells by proinflammatory stimulants, such as bacterial lipopolysaccharide, a ligand for the Toll-like receptor 4 (TLR4), we investigated the role of TLR2 in the regulation of mFPR2. We found that a TLR2 agonist, peptidoglycan (PGN) derived from Gram-positive bacterium Staphylococcus aureus, induced considerable mFpr2 mRNA expression in a mouse microglial cell line and primary microglial cells. This was associated with a markedly increased chemotaxis of the cells in response to mFPR2 agonist peptides. In addition, activation of TLR2 markedly enhanced mFPR2-mediated uptake of Abeta42 by microglia. Studies of the mechanistic basis showed that PGN activates MAPK and IkappaBalpha, and the effect of PGN on induction of mFPR2 was dependent on signaling pathways via ERK1/2 and p38 MAPKs. The use of TLR2 on microglial cells by PGN was supported by the fact that N9 cells transfected with short interfering RNA targeting mouse TLR2 failed to show increased expression of functional mFPR2 after stimulation with PGN. Our results demonstrated a potentially important role for TLR2 in microglial cells of promoting cell responses to chemoattractants produced in lesions of inflammatory and neurodegenerative diseases in the brain.

  16. Estradiol-17beta-BSA stimulates Ca(2+) uptake through nongenomic pathways in primary rabbit kidney proximal tubule cells: involvement of cAMP and PKC.

    Science.gov (United States)

    Han, H J; Lee, Y H; Park, S H

    2000-04-01

    The effect of estradiol-17beta-BSA (E(2)-BSA) on Ca(2+) uptake and its related signal pathways were examined in the primary cultured rabbit kidney proximal tubule cells. E(2)-BSA (10(-9) M) significantly stimulated Ca(2+) uptake from 2 h by 13% and at 8 h by 35% as compared to control, respectively. This stimulatory effect of E(2)-BSA was not inhibited by tamoxifen (10(-8) M, an intracellular estrogen receptor antagonist), actinomycin D (10(-7) M, a transcription inhibitor), and cycloheximide (4 x 10(-5) M, a protein synthesis inhibitor). However, E(2)-BSA-induced stimulation of Ca(2+) uptake was blocked by methoxyverapamil (10(-6) M, an L-type calcium channel blocker) and 5-(N-ethyl-N-isopropyl)-amiloride (10(-5) M, a Na(+)/H(+) antiporter blocker). These results suggest that E(2)-BSA stimulates Ca(2+) uptake through nongenomic pathways. Thus, we investigated which signal pathways were related to E(2)-BSA-induced stimulation of Ca(2+) uptake. 8-Br-cAMP (10(-6) M) alone increased Ca(2+) uptake by 22% compared to control. When E(2)-BSA combined with 8-Br-cAMP, Ca(2+) uptake was not significantly stimulated compared to E(2)-BSA. SQ 22536 (10(-6) M, an adenylate cyclase inhibitor) and myristoylated protein kinase A inhibitor amide 14-22 (10(-6) M, a protein kinase A inhibitor) blocked E(2)-BSA-induced stimulation of Ca(2+) uptake and E(2)-BSA also increased cAMP generation by 26% of that of control. In addition, TPA (0.02 ng/ml, an artificial PKC promoter) stimulated the Ca(2+) uptake by 14%, and the cotreatment of TPA and E(2)-BSA did not significantly stimulate Ca(2+) uptake compared to E(2)-BSA. E(2)-BSA-induced stimulation of Ca(2+) uptake was blocked by U 73122 (10(-6) M, a phospholipase C inhibitor) or bisindolylmaleimide I (10(-6) M, a protein kinase C inhibitor). Indeed, E(2)-BSA stimulated PKC activity by 26%. In conclusion, E(2)-BSA (10(-9) M) stimulated Ca(2+) uptake by nongenomic action, which is mediated by cAMP and PKC pathways.

  17. Direct evaluation of adrenocortical function by measurement of adrenal percent uptake of sup 131 I-6. beta. -iodomethyl-19-norcholesterol using single photon emission computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Ishimura, Junji (Hyogo Coll. of Medicine, Nishinomiya (Japan))

    1990-12-01

    In 55 patients (110 adrenal glands) with suspected adrenocortical abnormalities, I assessed the clinical usefulness of adrenal percent uptake of {sup 131}I-6{beta}-iodomethyl-19-norcholesterol (NCL-6-{sup 131}I) by single photon emission computed tomography (SPECT). The percent uptake of NCL-6-{sup 131}I in 6 hyperfunctioning glands of patients with the final diagnosis of Cushing's syndrome (2.62{+-}1.13(SD)%) was significantly (p<0.01) higher than that in 10 glands of patients with the final diagnosis of adenoma of primary aldosteronism (1.16{+-}0.09(SD)%). Moreover, the percent uptake of NCL-6-{sup 131}I in adrenal glands with hyperfunctioning lesions was significantly (p<0.01) higher than those in 10 contralateral normal glands of primary aldosteronism (0.55{+-}0.23(SD)%), 30 right glands (0.57{+-}0.24(SD)%) and 30 left glands (0.53{+-}0.22(SD)%) of essential hypertension with normally functioning adrenal cortices. The adrenal percent uptake of NCL-6-{sup 131}I in 24 glands with hypofunctioning adrenal cortices, including 4 glands suppressed by adenomas of Cushing's syndrome, was below the detectable limit. The data presented above show that the adrenocortical function can be evaluated directly based on measurement of adrenal percent uptake of NCL-6-{sup 131}I using SPECT. (author).

  18. Radiosynthesis of [{sup 18}F] N-(3-Fluoropropyl)-2-{beta}-Carbomethoxy-3-{beta}-(4-Bromophenyl) Nortropane and the regional brain uptake in non human primate using PET

    Energy Technology Data Exchange (ETDEWEB)

    Chaly, Thomas E-mail: tchaly@nshs.edu; Baldwin, R.M.; Neumeyer, John L.; Hellman, Matthew J.; Dhawan, Vijay; Garg, Pradeep K.; Tamagnan, Gilles; Staley, Julie K.; Al-Tikriti, Mohammed S.; Hou, Yankun; Zoghbi, Sami S.; Gu Xiaohui; Zong, R.; Eidelberg, David

    2004-01-01

    A synthetic procedure for the preparation of [{sup 18}F]FPCBT, an imaging agent for the dopamine transporter (DAT), has been developed. The radiosynthesis was carried out in a two step procedure. Even though the yield was low, we were able to prepare 20 to 30mCi of the product, which was enough for two or three studies. The radiochemical purity was greater than 96%. The in vivo properties of this radiotracer were evaluated using baboon and it showed highest uptake in the striatum. The studies also revealed that the maximum uptake was reached within 7 to 10 minutes post injection. Plasma metabolite analysis indicated that there is only one metabolite and it is less lipophilic than the parent compound. [{sup 18}F]FPCBT displayed good brain uptake and its high target to non target ratio indicate that it is a potential candidate for DAT imaging.

  19. Angiopoietin-like 4 mediates PPAR delta effect on lipoprotein lipase-dependent fatty acid uptake but not on beta-oxidation in myotubes.

    Directory of Open Access Journals (Sweden)

    Marius R Robciuc

    Full Text Available Peroxisome proliferator-activated receptor (PPAR delta is an important regulator of fatty acid (FA metabolism. Angiopoietin-like 4 (Angptl4, a multifunctional protein, is one of the major targets of PPAR delta in skeletal muscle cells. Here we investigated the regulation of Angptl4 and its role in mediating PPAR delta functions using human, rat and mouse myotubes. Expression of Angptl4 was upregulated during myotubes differentiation and by oleic acid, insulin and PPAR delta agonist GW501516. Treatment with GW501516 or Angptl4 overexpression inhibited both lipoprotein lipase (LPL activity and LPL-dependent uptake of FAs whereas uptake of BSA-bound FAs was not affected by either treatment. Activation of retinoic X receptor (RXR, PPAR delta functional partner, using bexarotene upregulated Angptl4 expression and inhibited LPL activity in a PPAR delta dependent fashion. Silencing of Angptl4 blocked the effect of GW501516 and bexarotene on LPL activity. Treatment with GW501516 but not Angptl4 overexpression significantly increased palmitate oxidation. Furthermore, Angptl4 overexpression did not affect the capacity of GW501516 to increase palmitate oxidation. Basal and insulin stimulated glucose uptake, glycogen synthesis and glucose oxidation were not significantly modulated by Angptl4 overexpression. Our findings suggest that FAs-PPARdelta/RXR-Angptl4 axis controls the LPL-dependent uptake of FAs in myotubes, whereas the effect of PPAR delta activation on beta-oxidation is independent of Angptl4.

  20. Effects of beta interferon on human fibroblasts at different population doubling levels. Proliferation, cell volume, thymidine uptake, and DNA synthesis

    OpenAIRE

    1984-01-01

    Cellular aging had no effect on the ability of beta interferon to increase cell volume and population doubling time in 76-109 cells, a line of human skin fibroblasts. However, DNA synthesis in cells at high population doubling levels (PDL 55-70) was inhibited after 72 h of beta interferon treatment (1,000 U/ml) while no inhibition of DNA synthesis was observed in cells at middle population doubling levels (PDL 30-40).

  1. Cellular uptake of beta-carotene from protein stabilized solid lipid nano-particles prepared by homogenization-evaporation method

    Science.gov (United States)

    Using a homogenization-evaporation method, beta-carotene (BC) loaded nano-particles were prepared with different ratios of food-grade sodium caseinate (SC), whey protein isolate (WPI), or soy protein isolate (SPI) to BC and evaluated for their physiochemical stability, in vitro cytotoxicity, and cel...

  2. Nucleic acid related compounds. 65. New syntheses of 1-(beta-D-arabinofuranosyl)-5(E)-(2-iodovinyl)uracil (IVAraU) from vinylsilane precursors. Radioiodine uptake as a marker for thymidine kinase positive herpes viral infections

    Energy Technology Data Exchange (ETDEWEB)

    Robins, M.J.; Manfredini, S.; Wood, S.G.; Wanklin, R.J.; Rennie, B.A.; Sacks, S.L. (Department of Chemistry, Brigham Young University, Provo, UT (USA))

    1991-07-01

    (Trimethylsilyl)acetylene was coupled with 1-(2,3,5-tri-O-acetyl-beta-D- arabinofuranosyl)-5-iodouracil to give 1- (2,3,5-tri-O-acetyl-beta-D-arabinofuranosyl)-5-(2-(trimethylsilyl)eth yny l) uracil. Lindlar hydrogenation of 4 gave 1-(2,3,4-tri-O-acetyl-beta-D-arabinofuranosyl)-5(Z)-(2- (trimethylsilyl)vinyl)uracil. Treatment of 5 with iodine monochloride (or sodium iodide/phenyliodine(III) dichloride) in benzene gave 1-(2,3,5-tri-O-acetyl-beta-D-arabinofuranosyl)-5(E)-(2-iodovinyl)uracil (7), whereas polar solvents favored the (Z)-iodovinyl isomer 8. Deacetylation of 7 gave 1-(beta-D-arabinofuranosyl)-5(E)-(2-iodovinyl)uracil (IVAraU, 9). A microscale in situ synthesis with Na{asterisk}I gave ({asterisk}I)IVAraU. Treatment of HSV-infected cells with (125I)IVAraU resulted in virus-dependent uptake associated with nucleoside phosphorylation by wild type or acyclovir-resistant DNA polymerase mutants (but not with TK-HSV-1 mutants). Uptake was virus-inoculum dependent and was detectable within 4 h postinfection. The process was not completely reversible. Virus-specified uptake of (125I)IVAraU may allow automated in vitro detection of HSV isolates.

  3. The polyproline II conformation in short alanine peptides is noncooperative.

    Science.gov (United States)

    Chen, Kang; Liu, Zhigang; Kallenbach, Neville R

    2004-10-26

    The finding that short alanine peptides possess a high fraction of polyproline II (PII) structure (Phi=-75 degrees, Psi=+145 degrees ) at low temperature has broad implications for unfolded states of proteins. An important question concerns whether or not this structure is locally determined or cooperative. We have monitored the conformation of alanine in a series of model peptides AcGGAnGGNH2 (n=1-3) over a temperature range from -10 degrees C to +80 degrees C. Use of 15N-labeled alanine substitutions makes it possible to measure 3JalphaN coupling constants accurately over the full temperature range. Based on a 1D next-neighbor model, the cooperative parameter sigma of PII nucleation is evaluated from the coupling constant data. The finding that sigma is close to unity (1 +/- 0.2) indicates a noncooperative role for alanine in PII structure formation, consistent with statistical surveys of the Protein Data Bank that suggest that most PII structure occurs in isolated residues. Lack of cooperativity in these models implies that hydration effects that influence PII conformation in water are highly localized. Using a nuclear Overhauser effect ratio strategy to define the alanine Psi angle, we estimate that, at 40 degrees C, the time-averaged alanine conformation (Phi=-80 degrees, Psi=+170 degrees ) deviates from canonical PII structure, indicating that PII melts at high temperature. Thus, the high-temperature state of short alanine peptides seems to be an unfolded ensemble with higher distribution in the extended beta structure basin, but not a coil.

  4. Glucagon and plasma catecholamines during beta-receptor blockade in exercising man

    DEFF Research Database (Denmark)

    Galbo, H; Holst, Janett; Christensen, N J

    1976-01-01

    Seven men ran at 60% of individual maximal oxygen uptake to exhaustion during beta-adrenergic blockade with propranolol (P), during lipolytic blockade with nicotinic acid (N), or without drugs (C). The total work times (83 +/- 9 (P), 122 +/- 8 (N), 166 +/- 10 (C) min, mean and SE) differed...... decrease glucagon concentrations increased progressively in parallel with declining plasma glucose and were at exhaustion always three times preexercise values. Thus beta-adrenergic blockade did not diminish the glucagon response. Nor was this response increased when alpha-receptor stimulation in P...... experiments was intensified. Carbohydrate combustion was smaller and NEFA and glycerol concentrations in serum larger during C experiments. Alanine concentrations were never raised at exhaustion. Accordingly, neither stimulation of adrenergic receptors nor NEFA and alanine concentrations are major...

  5. Estimation of glucose-alanine-lactate-glutamine cycles in postabsorptive humans: role of skeletal muscle.

    Science.gov (United States)

    Perriello, G; Jorde, R; Nurjhan, N; Stumvoll, M; Dailey, G; Jenssen, T; Bier, D M; Gerich, J E

    1995-09-01

    To evaluate transfer of carbon between plasma glucose and plasma alanine (glucose-alanine cycle) and lactate (Cori cycle), to assess the contribution of skeletal muscle to these cycles, and to determine whether a glucose-glutamine cycle exists in postabsorptive humans, we infused 11 normal overnight-fasted volunteers with [2-3H]glucose, [6-14C]glucose, and [3-13C]alanine to isotopic steady state and in 7 of these simultaneously measured forearm net balance, uptake, and release of labeled and unlabeled glucose, lactate, and alanine. We found that 40.9 +/- 3.3, 66.8 +/- 3.2, and 13.4 +/- 1.1%, respectively, of plasma alanine, lactate, and glutamine carbon came from plasma glucose. More plasma glucose was converted to plasma alanine than could be derived from plasma alanine (1.89 +/- 0.20 vs. 1.48 +/- 0.15 mumol.kg-1.min-1, P < 0.001). A similar direction of net carbon flux was found for lactate (8.5 vs. 4.2 mumol.kg-1.min-1), with only glutamine adding more carbon to plasma glucose than was received from it (1.0 vs. 0.75 mumol.kg-1.min-1). Skeletal muscle accounted for 50.2 +/- 3.9 and 45.5 +/- 5.7% of the overall appearance of alanine and lactate in plasma and 54.2 +/- 5.4 and 36.4 +/- 4.2% of their respective origins from plasma glucose. Skeletal muscle release of alanine and lactate that had been formed from plasma glucose accounted for 19.1 +/- 2.1 and 48.4 +/- 4.8%, respectively, of muscle glucose uptake and 42.4 +/- 5.5 and 49.9 +/- 5.8% of the overall release of alanine and lactate from muscle.(ABSTRACT TRUNCATED AT 250 WORDS)

  6. Extraosseous radiotracer uptake on bone scan in beta-thalassemia: report of one case; Fixation extraosseuse du radiotraceur lors de la realisation d'une scintigraphie du squelette chez un patient atteint de beta-thalassemie: a propos d'un cas

    Energy Technology Data Exchange (ETDEWEB)

    Guezguez, M.; Nouira, M.; Sfar, R.; Chatti, K.; Ben Fradj, M.; Ben Ali, K.; Ajmi, S.; Essabbah, H. [CHU Sahloul, Service de Medecine Nucleaire, Sousse (Tunisia); Zrour, S. [EPS F. Bourguiba, Service de Rhumatologie, Monastir (Tunisia)

    2009-10-15

    Red blood cell transfusion, main therapeutic modality of beta-thalassemia, leads to iron overload which may perturb several metabolic ways. The aim of this paper is to illustrate the uptake abnormalities observed on bone scan of thalassaemic patients and to discuss mechanisms of extraosseous accumulation of the radiopharmaceutical in this pathology. We report a 16-year-old child suffering from beta-thalassemia major undergoing transfusion therapy. A bone scan was indicated to look for osseous infection. This study revealed a little skeletal uptake and abnormal liver, splenic and renal accumulation. A repeat bone scan, performed three weeks later showed a better skeletal uptake which enabled the discovery of focal abnormalities and made the diagnostic easier. The effect of iron overload on radiopharmaceuticals uptake in bone scan is known since 1975. Dissociation of {sup 99m}Tc from the carrier ligand due to the presence of iron excess seems the most plausible hypothesis. Free {sup 99m}Tc can be bound to other tissular substrates which can explain extraosseous uptake. The normally available pool for bone is reduced and then the skeletal uptake decreased. This report limits considerably the sensitivity of the bone scan. A well-led iron chelation and eventually the use of diuretic drug may guarantee a better quality of bone scan images. (authors)

  7. Characterisation of L-alanine and glycine absorption across the gut of an ancient vertebrate.

    Science.gov (United States)

    Glover, Chris N; Bucking, Carol; Wood, Chris M

    2011-08-01

    This study utilised an in vitro technique to characterise absorption of two amino acids across the intestinal epithelium of Pacific hagfish, Eptatretus stoutii. Uptake of L-alanine and glycine conformed to Michaelis-Menten kinetics. An uptake affinity (K(m); substrate concentration required to attain a 50% uptake saturation) of 7.0 mM and an uptake capacity (J (max)) of 83 nmol cm(-2) h(-1) were described for L-alanine. The K(m) and J(max) for glycine were 2.2 mM and 11.9 nmol cm(-2) h(-1), respectively. Evidence suggested that the pathways of L-alanine and glycine absorption were shared, and sodium dependent. Further analysis indicated that glycine uptake was independent of luminal pH and proline, but a component of uptake was significantly impaired by 100-fold excesses of threonine or asparagine. The presence of a short-term (24 h) exposure to waterborne glycine, similar in nature to that which may be expected to occur when feeding inside an animal carcass, had no significant impact on gastrointestinal glycine uptake. This may indicate a lack of cross talk between absorptive epithelia. These results are the first published data to describe gastrointestinal uptake of an organic nutrient in the oldest extant vertebrate and may provide potential insight into the evolution of nutrient transport systems.

  8. Application of nuclear magnetic resonance spectroscopy, Fourier transform infrared spectroscopy, UV-Visible spectroscopy and kinetic modeling for elucidation of adsorption chemistry in uptake of tetracycline by zeolite beta.

    Science.gov (United States)

    Kang, Jin; Liu, Huijuan; Zheng, Yu-Ming; Qu, Jiuhui; Chen, J Paul

    2011-02-01

    Extensive usage of tetracycline has resulted in its contamination in surface water and groundwater. The adsorption of tetracycline on zeolite beta was systematically investigated for the decontamination of the antibiotic polluted water in this study. Ninety percent of uptake by the zeolite beta occured in 0.25h, and the adsorption equilibrium was obtained within 3h, which was well described by an intraparticle diffusion model. The adsorption generally increased when pH was increased from 4.0 to 5.0, and then decreased significantly as the pH was further increased, which was caused by the pH-dependent speciation of tetracycline and surface charge of zeolite beta. Both Freundlich and Langmuir equations well described the adsorption isotherm. A thermodynamic analysis showed that the sorption process was spontaneous and endothermic. Aluminum atoms in the zeolite played a crucial role in the uptake; the adsorption increased with the increasing aluminum content in zeolite. The UV-Visible spectroscopy study showed that the spectra of tetracycline changed upon the interaction with zeolite beta, which could be ascribed to the formation of complexes of tetracycline and aluminum atoms in the zeolite surface. Nuclear magnetic resonance spectroscopy study further confirmed the participation of Al in the tetracycline adsorption. Fourier transform infrared spectroscopy studies showed that the amino functional groups in tetracycline were involved in the complexation with the zeolite surface.

  9. Allosteric inhibition of Staphylococcus aureus d-alanine:d-alanine ligase revealed by crystallographic studies

    OpenAIRE

    Liu, Shenping; Chang, Jeanne S.; Herberg, John T.; Horng, Miao-Miao; Tomich, Paul K.; Lin, Alice H.; Marotti, Keith R

    2006-01-01

    d-alanine:d-alanine ligase (DDl) is an essential enzyme in bacterial cell wall biosynthesis and an important target for developing new antibiotics. It catalyzes the formation of d-alanine:d-alanine dipeptide, sequentially by using one d-alanine and one ATP as substrates for the first-half reaction, and a second d-alanine substrate to complete the reaction. Some gain of function DDl mutants can use an alternate second substrate, causing resistance to vancomycin, one of the last lines of defens...

  10. Vibrational dynamics of crystalline L-alanine

    Energy Technology Data Exchange (ETDEWEB)

    Bordallo, H.N.; Eckert, J. [Los Alamos National Lab., NM (United States); Barthes, M. [Univ. Montpellier II (France)

    1997-11-01

    The authors report a new, complete vibrational analysis of L-alanine and L-alanine-d{sub 4} which utilizes IINS intensities in addition to frequency information. The use of both isotopomers resulted in a self-consistent force field for and assignment of the molecular vibrations in L-alanine. Some details of the calculation as well as a comparison of calculated and observed IINS spectra are presented. The study clarifies a number of important issues on the vibrational dynamics of this molecule and presents a self-consistent force field for the molecular vibrations in crystalline L-alanine.

  11. Genetic analysis of the first 4 patients with beta-ureidopropionase deficiency.

    NARCIS (Netherlands)

    Kuilenburg, A.B.P. van; Meinsma, R.; Assman, B.; Hoffman, G.F.; Voit, T.; Ribes, A.; Lorente, I.; Busch, R.; Mayatepek, E.; Abeling, N.G.G.M.; Wevers, R.A.; Rutsch, F.; Gennip, A.H. van

    2006-01-01

    beta-Ureidopropionase is the third enzyme of the pyrimidine degradation pathway and it catalyses the irreversible hydrolysis of N-carbamyl-ss-aminoisobutyric acid or N-carbamyl-ss-alanine to beta-aminoisobutyric acid or ss-alanine, ammonia, and CO2. Analysis of the beta-ureidopropionase gene (UPB1)

  12. UPTAKE OF RADIOLIGANDS BY RAT-HEART AND LUNG INVIVO - CGP-12177 DOES AND CGP-26505 DOES NOT REFLECT BINDING TO BETA-ADRENOCEPTORS

    NARCIS (Netherlands)

    van Waarde, A; Meeder, JG; BLANKSMA, PK; BRODDE, OE; VISSER, GM; ELSINGA, PH; PAANS, AMJ; VAALBURG, W; LIE, KI

    1992-01-01

    The biodistribution of (-)-4-(3-t-butylamino-2-hydroxypropoxy)-[5,7-H-3-benzimidazol-2-one (CGP12177, a non-selective beta-adrenoceptor antagonist) and 1-[2-(3-carbamoyl-4-hydroxy)-(5-H-3-phenoxy)]-2-propanol methanesulfonate, (CGP26505, a beta1-adrenoceptor antagonist) was studied in rats pretreate

  13. Proliferation and function of microbodies in the nematophagous fungus Arthrobotrys oligospora during growth on oleic acid or D-alanine as the sole carbon source

    NARCIS (Netherlands)

    Dijksterhuis, Jan; Harder, Willem; Veenhuis, Marten

    1993-01-01

    The nematophagous fungus Arthrobotrys oligospora is able to grow on oleic acid or D-alanine as the sole carbon source. During growth on oleic acid, activities of enzymes of the beta-oxidation pathway, but not catalase, were induced. In the presence of D-alanine, both D-amino acid oxidase and catalas

  14. Response of Alanine Dosemeter to Heavy Ions

    Institute of Scientific and Technical Information of China (English)

    LiWenjian; SuXu; YangYingjie; YuanJianlei; DangBingrong; WangXiao; MaQiufeng; ZhouLibin; HaoJifang; MaoShuhong

    2003-01-01

    The amino acid L-α-alanine has been investigated for use as a radiation detector in low and high LET radiation fields[1]. The radiatioa detector is cheap and easy to handle. The radiation inducing free radicals are stable at normal laboratory conditions for doses below 104 Gy over a long period of time, which makes the detector useful for intercomparison and documentation purposes. The dosimetric features of alanine-based electron spin resonance (ESR) detectors in high energy electron beams used in radiotherapy were considered[2]. The 5 mm long alanine detectors were found to be the most suitable for carrying out in vivo dosimetry on patients undergoing electron beam radiotherapy. However, data concerning dosimetry of the alanine dosemeter to heavy charged particles are lacking, especially in China.

  15. Β-alanine and l-histidine transport across the inner blood-retinal barrier: potential involvement in L-carnosine supply.

    Science.gov (United States)

    Usui, Takuya; Kubo, Yoshiyuki; Akanuma, Shin-Ichi; Hosoya, Ken-Ichi

    2013-08-01

    The supply of L-carnosine, a bioactive dipeptide of β-alanine and l-histidine, to the retina across the blood-retinal barrier (BRB) was studied. The in vivo and in vitro studies revealed low uptake activities for [(3)H]Gly-Sar, a representative dipeptide, suggesting that l-carnosine transport plays only a minor role at the BRB. The in vivo study using rats showed approximately 18- and 23-fold greater retinal uptake indexes (RUI) for [(3)H]β-alanine and [(3)H]l-histidine compared with that of a paracellular marker, respectively. The RUI of [(3)H]β-alanine was taurine- and γ-aminobutyric acid-sensitive, and the in vitro uptake by TR-iBRB2 cells showed time- concentration- and temperature-dependent [(3)H]β-alanine uptake, suggesting that a carrier-mediated process was involved in β-alanine transport across the inner BRB. [(3)H]β-Alanine uptake was inhibited by taurine and β-guanidinopropionic acid, suggesting that taurine transporter (TAUT/SLC6A6) is responsible for the influx transport of β-alanine across the inner BRB. Regarding l-histidine, the l-leucine-sensitive RUI of [(3)H]l-histidine was identified, and the in vitro [(3)H]l-histidine uptake by TR-iBRB2 cells suggested that a carrier-mediated process was involved in l-histidine transport across the inner BRB. The inhibition profile suggested that L-type amino acid transporter (LAT1/SLC7A5) is responsible for the influx transport of l-histidine across the inner BRB. These results show that the influx transports of β-alanine and l-histidine across the inner BRB is carried out by TAUT and LAT1, respectively, suggesting that the retinal l-carnosine is supplied by enzymatic synthesis from two kinds of amino acids transported across the inner BRB.

  16. Enzyme-catalyzed ring-opening polymerization of unsubstituted beta-lactam

    NARCIS (Netherlands)

    Schwab, Leendert W.; Kroon, Renee; Schouten, Arend Jan; Loos, Katja

    2008-01-01

    The synthesis of poly(beta-alanine) by Candida antarctica lipase B immobilized as novozyme 435 catalyzed ring-opening of 2-azetidinone is reported. After removal of cyclic side products and low molecular weight species pure linear poly(beta-alanine) is obtained. The formation of the polymer is confi

  17. Chronic treatment with 5-aminoimidazole-4-carboxamide-1-beta-D-ribofuranoside increases insulin-stimulated glucose uptake and GLUT4 translocation in rat skeletal muscles in a fiber type-specific manner.

    Science.gov (United States)

    Buhl, E S; Jessen, N; Schmitz, O; Pedersen, S B; Pedersen, O; Holman, G D; Lund, S

    2001-01-01

    Recent studies have demonstrated that chronic administration of AICAR (5-aminoimidazole-4-carboxamide- 1-beta-D-ribofuranoside), an activator of the AMP-activated protein kinase, increases hexokinase activity and the contents of total GLUT4 and glycogen in rat skeletal muscles. To explore whether AICAR also affects insulin-stimulated glucose transport and GLUT4 cell surface content, Wistar rats were subcutaneously injected with AICAR for 5 days in succession (1 mg/g body wt). Maximally insulin-stimulated (60 nmol/l) glucose uptake was markedly increased in epitrochlearis (EPI) muscle (average 63%, P fiber type-specific increase in insulin-stimulated glucose uptake and GLUT4 cell surface content in rat skeletal muscle with the greatest effect observed on white fast-twitch glycolytic muscles (EPI). These results are comparable with the effects of chronic exercise training, and it brings the AMP-activated protein kinase into focus as a new interesting target for future pharmacological intervention in insulin-resistant conditions.

  18. Introduction of an N-glycan sequon into HEXA enhances human beta-hexosaminidase cellular uptake in a model of Sandhoff disease.

    Science.gov (United States)

    Matsuoka, Kazuhiko; Tsuji, Daisuke; Aikawa, Sei-Ichi; Matsuzawa, Fumiko; Sakuraba, Hitoshi; Itoh, Kohji

    2010-08-01

    Human lysosomal beta-hexosaminidase A is a heterodimer composed of alpha- and beta-subunits encoded by HEXA and HEXB, respectively. We genetically introduced an additional N-glycosylation sequon into HEXA, which caused amino acid substitutions (S51 to N and A53 to T) at homologous positions to N84 and T86 in the beta-subunit. The mutant HexA (NgHexA) obtained from a Chinese hamster ovary (CHO) cell line co-expressing the mutated HEXA and wild-type HEXB complementary DNAs was demonstrated to contain an additional mannose-6-phosphate (M6P)-type-N-glycan. NgHexA was more efficiently taken up than the wild-type HexA and delivered to lysosomes, where it degraded accumulated substrates including GM2 ganglioside (GM2) when administered to cultured fibroblasts derived from a Sandhoff disease (SD) patient. On intracerebroventricular (i.c.v.) administration of NgHexA to SD model mice, NgHexA more efficiently restored the HexA activity and reduced the GM2 and GA2 (asialoGM2) accumulated in neural cells of the brain parenchyma than the wild-type HexA. These findings indicate that i.c.v. administration of the modified human HexA with an additional M6P-type N-glycan is applicable for enzyme replacement therapy (ERT) involving an M6P-receptor as a molecular target for HexA deficiencies including Tay-Sachs disease and SD.

  19. Potential energy surface of alanine polypeptide chains

    DEFF Research Database (Denmark)

    Solov'yov, Ilia; Yakubovich, Alexander V.; Solov'yov, Andrey V.

    2006-01-01

    The multidimensional potential energy surfaces of the peptide chains consisting of three and six alanine (Ala) residues have been studied with respect to the degrees of freedom related to the twist of these molecules relative to the peptide backbone (these degrees of freedom are responsible...

  20. Effect of. cap alpha. -,. beta. -adrenergic receptor agonists and antagonists of the efflux of /sup 22/Na and uptake of /sup 42/K by rat brain cortical slices

    Energy Technology Data Exchange (ETDEWEB)

    Phillis, J.W.; Wu, P.H.; Thierry, D.L.

    1982-03-18

    The effects of norepinephrine on ion fluxes in rat brain cortical slices have now been ascertained. /sup 22/Na efflux and /sup 42/K influx are enhanced by norepinephrine. The increase in ion fluxes can be blocked by ouabain, phentolamine and propranolol, suggesting that the catecholamine activates a membrane sodium pump by a receptor-mediated step. The facilitation of /sup 22/Na efflux is stereospecific as demonstrated by the very weak action of D-norepinephrine at 10/sup -5/ M concentration. Various ..cap alpha..-adrenergic and ..beta..-adrenergic receptor agonists, including oxymetazoline, naphazoline, clonidine, tramazoline, methoxamine, phenylephrine, L-isoproterenol and methoxyphenamine are potent stimulants of the sodium pump as demonstrated by their enhancement of ion fluxes in rat brain cortical slices. The results are consistent with the hypothesis that norepinephrine hyperpolarizes central neurons by activating an ouabain-sensitive, receptor-mediated sodium pump.

  1. beta-Ureidopropionase deficiency: an inborn error of pyrimidine degradation associated with neurological abnormalities.

    NARCIS (Netherlands)

    Kuilenburg, A.B.P. van; Meinsma, R.; Beke, E.; Assmann, B.; Ribes, A.; Lorente, I.; Busch, R.; Mayatepek, E.; Abeling, N.G.G.M.; Cruchten, A.C. van; Stroomer, A.E.; Lenthe, H. van; Zoetekouw, L.; Kulik, W.; Hoffmann, G.F.; Voit, T.; Wevers, R.A.; Rutsch, F.; Gennip, A.H. van

    2004-01-01

    beta-Ureidopropionase deficiency is an inborn error of the pyrimidine degradation pathway, affecting the cleavage of N-carbamyl-beta-alanine and N-carbamyl-beta-aminoisobutyric acid. In this study, we report the elucidation of the genetic basis underlying a beta-ureidopropionase deficiency in four p

  2. On the existence of ‘L-alanine cadmium bromide'

    Science.gov (United States)

    Srinivasan, Bikshandarkoil R.

    2013-12-01

    It is argued that the recently reported nonlinear optical crystal L-alanine cadmium bromide, grown by slow solvent evaporation method at room temperature [P. Ilayabarathi, J. Chandrasekaran, Spectrochim. Acta 96A (2012) 684-689] is the well-known L-alanine crystal. The isolation of L-alanine crystal is explained due to fractional crystallization.

  3. On the existence of 'L-alanine cadmium bromide'.

    Science.gov (United States)

    Srinivasan, Bikshandarkoil R

    2013-12-01

    It is argued that the recently reported nonlinear optical crystal L-alanine cadmium bromide, grown by slow solvent evaporation method at room temperature [P. Ilayabarathi, J. Chandrasekaran, Spectrochim. Acta 96A (2012) 684-689] is the well-known L-alanine crystal. The isolation of L-alanine crystal is explained due to fractional crystallization.

  4. Plasmid-encoded asp operon confers a proton motive metabolic cycle catalyzed by an aspartate-alanine exchange reaction.

    Science.gov (United States)

    Abe, Keietsu; Ohnishi, Fumito; Yagi, Kyoko; Nakajima, Tasuku; Higuchi, Takeshi; Sano, Motoaki; Machida, Masayuki; Sarker, Rafiquel I; Maloney, Peter C

    2002-06-01

    Tetragenococcus halophila D10 catalyzes the decarboxylation of L-aspartate with nearly stoichiometric release of L-alanine and CO(2). This trait is encoded on a 25-kb plasmid, pD1. We found in this plasmid a putative asp operon consisting of two genes, which we designated aspD and aspT, encoding an L-aspartate-beta-decarboxylase (AspD) and an aspartate-alanine antiporter (AspT), respectively, and determined the nucleotide sequences. The sequence analysis revealed that the genes of the asp operon in pD1 were in the following order: promoter --> aspD --> aspT. The deduced amino acid sequence of AspD showed similarity to the sequences of two known L-aspartate-beta-decarboxylases from Pseudomonas dacunhae and Alcaligenes faecalis. Hydropathy analyses suggested that the aspT gene product encodes a hydrophobic protein with multiple membrane-spanning regions. The operon was subcloned into the Escherichia coli expression vector pTrc99A, and the two genes were cotranscribed in the resulting plasmid, pTrcAsp. Expression of the asp operon in E. coli coincided with appearance of the capacity to catalyze the decarboxylation of aspartate to alanine. Histidine-tagged AspD (AspDHis) was also expressed in E. coli and purified from cell extracts. The purified AspDHis clearly exhibited activity of L-aspartate-beta-decarboxylase. Recombinant AspT was solubilized from E. coli membranes and reconstituted in proteoliposomes. The reconstituted AspT catalyzed self-exchange of aspartate and electrogenic heterologous exchange of aspartate with alanine. Thus, the asp operon confers a proton motive metabolic cycle consisting of the electrogenic aspartate-alanine antiporter and the aspartate decarboxylase, which keeps intracellular levels of alanine, the countersubstrate for aspartate, high.

  5. Bad Beta, Good Beta

    OpenAIRE

    Campbell, John; Vuolteenaho, Tuomo

    2003-01-01

    This paper explains the size and value "anomalies" in stock returns using an economically motivated two-beta model. We break the beta of a stock with the market portfolio into two components, one reflecting news about the market's future cash flows and one reflecting news about the market's discount rates. Intertemporal asset pricing theory suggests that the former should have a higher price of risk; thus beta, like cholesterol, comes in "had" and "good" varieties. Empirically, we find that v...

  6. Genetic analysis of beta1 integrin "activation motifs" in mice

    DEFF Research Database (Denmark)

    Czuchra, Aleksandra; Meyer, Hannelore; Legate, Kyle R

    2006-01-01

    tails, leading to tail separation and integrin activation. We analyzed mice in which we mutated the tyrosines of the beta1 tail and the membrane-proximal aspartic acid required for the salt bridge. Tyrosine-to-alanine substitutions abolished beta1 integrin functions and led to a beta1 integrin......-null phenotype in vivo. Surprisingly, neither the substitution of the tyrosines with phenylalanine nor the aspartic acid with alanine resulted in an obvious defect. These data suggest that the NPXY motifs of the beta1 integrin tail are essential for beta1 integrin function, whereas tyrosine phosphorylation......Akey feature of integrins is their ability to regulate the affinity for ligands, a process termed integrin activation. The final step in integrin activation is talin binding to the NPXY motif of the integrin beta cytoplasmic domains. Talin binding disrupts the salt bridge between the alpha/beta...

  7. Membrane topology of the electrogenic aspartate-alanine antiporter AspT of Tetragenococcus halophilus.

    Science.gov (United States)

    Nanatani, Kei; Ohonishi, Fumito; Yoneyama, Hiroshi; Nakajima, Tasuku; Abe, Keietsu

    2005-03-04

    AspT is an electrogenic aspartate:alanine exchange protein that represents the vectorial component of a proton-motive metabolic cycle found in some strains of Tetragenococcus halophilus. AspT is the sole member of a new family, the Aspartate: Alanine Exchanger (AAE) family, in secondary transporters, according to the computational classification proposed by Saier et al. (http://www.biology.ucsd.edu/~msaier/transport/). We analyzed the topology of AspT biochemically, by using fusion methods in combination with alkaline phosphatase or beta-lactamase. These results suggested that AspT has a unique topology; 8 TMS, a large cytoplasmic loop (183 amino acids) between TMS5 and TMS6, and N- and C-termini that both face the periplasm. These results demonstrated a unique 2D-structure of AspT as the novel AAE family.

  8. Green reduction of graphene oxide using alanine.

    Science.gov (United States)

    Wang, Jiabin; Salihi, Elif Caliskan; Šiller, Lidija

    2017-03-01

    There remains a real need for the easy, eco-friendly and scalable preparation method of graphene due to various potential applications. Chemical reduction is the most versatile method for the large scale production of graphene. Here we report the operating conditions for a one-step, economical and green synthesis method for the reduction of graphene oxide using a biomolecule (alanine). Graphene oxide was produced by the oxidation and exfoliation of natural graphite flake with strong oxidants using Hummers method (Hummers and Offeman, 1958), but the method was revised in our laboratory to set up a safe and environmentally friendly route. The reduction of graphene oxide was investigated using alanine at various operating conditions in order to set up optimum conditions (treatment time, temperature and concentration of the reagent). Samples have been characterized by using UV-Visible spectroscopy, Fourier transform infrared spectroscopy, transmission electron microscopy, Raman spectroscopy and X-ray diffraction analysis. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

  9. Crystallization and preliminary crystallographic analysis of d-alanine-d-alanine ligase from Streptococcus mutans

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Yong-Zhi; Sheng, Yu [Institute for Nanobiomedical Technology and Membrane Biology, West China Hospital, Sichuan University, Chengdu 610065, Sichuan (China); Li, Lan-Fen [National Laboratory of Protein Engineering and Plant Genetic Engineering, College of Life Sciences, Peking University, Beijing 100871 (China); Tang, De-Wei [Institute for Nanobiomedical Technology and Membrane Biology, West China Hospital, Sichuan University, Chengdu 610065, Sichuan (China); Liu, Xiang-Yu [National Laboratory of Protein Engineering and Plant Genetic Engineering, College of Life Sciences, Peking University, Beijing 100871 (China); Zhao, Xiaojun, E-mail: zhaoxj@scu.edu.cn [Institute for Nanobiomedical Technology and Membrane Biology, West China Hospital, Sichuan University, Chengdu 610065, Sichuan (China); Liang, Yu-He, E-mail: zhaoxj@scu.edu.cn; Su, Xiao-Dong [National Laboratory of Protein Engineering and Plant Genetic Engineering, College of Life Sciences, Peking University, Beijing 100871 (China); Institute for Nanobiomedical Technology and Membrane Biology, West China Hospital, Sichuan University, Chengdu 610065, Sichuan (China)

    2007-09-01

    A potential target for antibiotic drug design, d-alanine-d-alanine ligase from S. mutans, was expressed in E. coli, purified and crystallized. Diffraction data were collected to 2.4 Å resolution. d-Alanine-d-alanine ligase is encoded by the gene ddl (SMU-599) in Streptococcus mutans. This ligase plays a very important role in cell-wall biosynthesis and may be a potential target for drug design. To study the structure and function of this ligase, the gene ddl was amplified from S. mutans genomic DNA and cloned into the expression vector pET28a. The protein was expressed in soluble form in Escherichia coli strain BL21 (DE3). Homogeneous protein was obtained using a two-step procedure consisting of Ni{sup 2+}-chelating and size-exclusion chromatography. Purified protein was crystallized and the cube-shaped crystal diffracted to 2.4 Å. The crystal belongs to space group P3{sub 1}21 or P3{sub 2}21, with unit-cell parameters a = b = 79.50, c = 108.97 Å. There is one molecule per asymmetric unit.

  10. Dose Response of Alanine Detectors Irradiated with Carbon Ion Beams

    DEFF Research Database (Denmark)

    Herrmann, Rochus; Jäkel, Oliver; Palmans, Hugo

    2011-01-01

    Purpose: The dose response of the alanine detector shows a dependence on particle energy and type, when irradiated with ion beams. The purpose of this study is to investigate the response behaviour of the alanine detector in clinical carbon ion beams and compare the results with model predictions....... Methods: Alanine detectors have been irradiated with carbon ions with an energy range of 89-400 MeV/u. The relative effectiveness of alanine has been measured in this regime. Pristine and spread out Bragg peak depth-dose curves have been measured with alanine dosimeters. The track-structure based alanine......-dose curves deviate from predictions in the peak region, most pronounced at the distal edge of the peak. Conclusions: The used model and its implementation show a good overall agreement for quasi mono energetic measurements. Deviations in depth-dose measurements are mainly attributed to uncertainties...

  11. Alanine aminotransferase controls seed dormancy in barley

    Science.gov (United States)

    Sato, Kazuhiro; Yamane, Miki; Yamaji, Nami; Kanamori, Hiroyuki; Tagiri, Akemi; Schwerdt, Julian G.; Fincher, Geoffrey B.; Matsumoto, Takashi; Takeda, Kazuyoshi; Komatsuda, Takao

    2016-01-01

    Dormancy allows wild barley grains to survive dry summers in the Near East. After domestication, barley was selected for shorter dormancy periods. Here we isolate the major seed dormancy gene qsd1 from wild barley, which encodes an alanine aminotransferase (AlaAT). The seed dormancy gene is expressed specifically in the embryo. The AlaAT isoenzymes encoded by the long and short dormancy alleles differ in a single amino acid residue. The reduced dormancy allele Qsd1 evolved from barleys that were first domesticated in the southern Levant and had the long dormancy qsd1 allele that can be traced back to wild barleys. The reduced dormancy mutation likely contributed to the enhanced performance of barley in industrial applications such as beer and whisky production, which involve controlled germination. In contrast, the long dormancy allele might be used to control pre-harvest sprouting in higher rainfall areas to enhance global adaptation of barley. PMID:27188711

  12. Beta Thalassemia

    Science.gov (United States)

    Beta thalassemia is found in people of Mediterranean, Middle Eastern, African, South Asian (Indian, Pakistani, etc.), Southeast Asian and Chinese descent. 1 Beta Thalassemia ßß Normal beta globin genes found on chromosomes ...

  13. Dosimetry for the external radiation therapy. Dosimetry with alanine; Dosimetrie fuer die externe Strahlentherapie. Dosimetrie mit Alanin

    Energy Technology Data Exchange (ETDEWEB)

    Anton, Mathias [Physikalisch-Technische Bundesanstalt (PTB), Braunschweig (Germany). Arbeitsgruppe ' Alanin-Dosimetrie'

    2013-06-15

    The alanine-ESR dosimetry in the PTB is described. The response power of alanine related to the water energy dose for X-rays with average energy of 10-1000 keV is presented. Furthermore the application of alanine for the quality assurance in the radiation therapy is described by means of the prostate irradiation and the therapy of a tumor in the neck region as examples. (HSI)

  14. Exogenous alanine and/or glucose plus kanamycin kills antibiotic-resistant bacteria.

    Science.gov (United States)

    Peng, Bo; Su, Yu-Bin; Li, Hui; Han, Yi; Guo, Chang; Tian, Yao-Mei; Peng, Xuan-Xian

    2015-02-03

    Multidrug-resistant bacteria are an increasingly serious threat to human and animal health. However, novel drugs that can manage infections by multidrug-resistant bacteria have proved elusive. Here we show that glucose and alanine abundances are greatly suppressed in kanamycin-resistant Edwardsiella tarda by GC-MS-based metabolomics. Exogenous alanine or glucose restores susceptibility of multidrug-resistant E. tarda to killing by kanamycin, demonstrating an approach to killing multidrug-resistant bacteria. The mechanism underlying this approach is that exogenous glucose or alanine promotes the TCA cycle by substrate activation, which in turn increases production of NADH and proton motive force and stimulates uptake of antibiotic. Similar results are obtained with other Gram-negative bacteria (Vibrio parahaemolyticus, Klebsiella pneumoniae, Pseudomonas aeruginosa) and Gram-positive bacterium (Staphylococcus aureus), and the results are also reproduced in a mouse model for urinary tract infection. This study establishes a functional metabolomics-based strategy to manage infection by antibiotic-resistant bacteria. Copyright © 2015 Elsevier Inc. All rights reserved.

  15. Crystal structure of the Apo form of D-Alanine:D-Alanine ligase (DDl) from Streptococcus mutans.

    Science.gov (United States)

    Lu, Yongzhi; Xu, Hongyan; Zhao, Xiaojun

    2010-08-01

    D-Alanine:D-Alanine ligase (DDl) catalyzes the formation of D-Alanine:D-Alanine dipeptide and is an essential enzyme in bacterial cell wall biosynthesis.. This enzyme does not have a human ortholog, making it an attractive target for developing new antibiotic drugs. We determined the crystal structure at 2.23 A resolution of DDl from Streptococcus mutans (SmDDl), the principal aetiological agent of human dental caries. This structure reveals that SmDDl is a dimer and has a disordered omega-loop region.

  16. STUDY OF LYSINE AND ALANINE DELIVERANCE THROUGH POLYPYRROLE MEMBRANE

    Directory of Open Access Journals (Sweden)

    Adhitasari Suratman

    2010-06-01

    Full Text Available Electropolymerization processes of pyrrole and the usage of polypyrrole membrane as lysine and alanine deliverance have been studied by cyclic voltammetry technique. Polypyrrole membrane was prepared by electropolymerization processes of pyrrole in water based solvent containing sodium perchlorate as supporting electrolyte. Electropolymerization processes were carried out within potential range of 0-1100 mV vs Ag/AgCl reference electrode and at the scanning rate of 100 mV/s. In this study, lysine and alanine have been used as molecules which could easily be loaded on and released from polypyrrole membrane. The presence of lysine or alanine during electropolymerization process reduced the rate of electropolymerization of polypyrrole. In lysine or alanine transfer processes into polypyrrole membrane, the interaction between polypyrrole and lysine or alanine showed by the curve of E½ oxidation in respect of - log C. It proved that the E½ oxidation shifted to more positive potential showed by the increasing of concentration of lysine or alanine. Beside that, voltammetric responses of lysine and alanine transfered into polypyrrole membrane were found to be Nernstian. The results indicated that polypyrrole could be used as a sensor of lysine and alanine.   Keywords: Electropolymerization, polypyrrole membrane, voltammetry technique

  17. The structure of alanine racemase from Acinetobacter baumannii.

    Science.gov (United States)

    Davis, Emily; Scaletti-Hutchinson, Emma; Opel-Reading, Helen; Nakatani, Yoshio; Krause, Kurt L

    2014-09-01

    Acinetobacter baumannii is an opportunistic Gram-negative bacterium which is a common cause of hospital-acquired infections. Numerous antibiotic-resistant strains exist, emphasizing the need for the development of new antimicrobials. Alanine racemase (Alr) is a pyridoxal 5'-phosphate dependent enzyme that is responsible for racemization between enantiomers of alanine. As D-alanine is an essential component of the bacterial cell wall, its inhibition is lethal to prokaryotes, making it an excellent antibiotic drug target. The crystal structure of A. baumannii alanine racemase (AlrAba) from the highly antibiotic-resistant NCTC13302 strain has been solved to 1.9 Å resolution. Comparison of AlrAba with alanine racemases from closely related bacteria demonstrates a conserved overall fold. The substrate entryway and active site of the enzymes were shown to be highly conserved. The structure of AlrAba will provide the template required for future structure-based drug-design studies.

  18. Metabolic consequences of β-alanine supplementation during exhaustive supramaximal cycling and 4000-m time-trial performance.

    Science.gov (United States)

    Bellinger, Phillip M; Minahan, Clare L

    2016-08-01

    The present study investigated the effects of β-alanine supplementation on the resultant blood acidosis, lactate accumulation, and energy provision during supramaximal-intensity cycling, as well as the aerobic and anaerobic contribution to power output during a 4000-m cycling time trial (TT). Seventeen trained cyclists (maximal oxygen uptake = 4.47 ± 0.55 L·min(-1)) were administered 6.4 g of β-alanine (n = 9) or placebo (n = 8) daily for 4 weeks. Participants performed a supramaximal cycling test to exhaustion (equivalent to 120% maximal oxygen uptake) before (PreExh) and after (PostExh) the 4-week supplementation period, as well as an additional postsupplementation supramaximal cycling test identical in duration and power output to PreExh (PostMatch). Anaerobic capacity was quantified and blood pH, lactate, and bicarbonate concentrations were measured pre-, immediately post-, and 5 min postexercise. Subjects also performed a 4000-m cycling TT before and after supplementation while the aerobic and anaerobic contributions to power output were quantified. β-Alanine supplementation increased time to exhaustion (+12.8 ± 8.2 s; P = 0.041) and anaerobic capacity (+1.1 ± 0.7 kJ; P = 0.048) in PostExh compared with PreExh. Performance time in the 4000-m TT was reduced following β-alanine supplementation (-6.3 ± 4.6 s; P = 0.034) and the mean anaerobic power output was likely to be greater (+6.2 ± 4.5 W; P = 0.035). β-Alanine supplementation increased time to exhaustion concomitant with an augmented anaerobic capacity during supramaximal intensity cycling, which was also mirrored by a meaningful increase in the anaerobic contribution to power output during a 4000-m cycling TT, resulting in an enhanced overall performance.

  19. Enzymatic Production of l-Alanine by Pseudomonas dacunhae

    Science.gov (United States)

    Chibata, Ichiro; Kakimoto, Toshio; Kato, Jyoji

    1965-01-01

    To establish an advantageous method for the production of l-alanine, a procedure was studied for converting l-aspartic acid to l-alanine by microbial l-aspartic β-decarboxylase. A number of organisms were screened to test their ability to form and accumulate alanine from aspartic acid. Pseudomonas dacunhae was selected as the most advantageous organism. With this organism, enzyme activity as high as 3,910 μliters of CO2 per hr per ml of medium could be produced by shaking the culture at 30 C in the medium containing ammonium fumarate, sodium fumarate, corn steep liquor, peptone, and inorganic salts. For the enzymatic conversion of l-aspartic acid to l-alanine, the culture broth was employed as the enzyme source. A large amount of l-aspartic acid (as much as 40% of the broth) was converted stoichiometrically to alanine in 72 hr at 37 C. Furthermore, appropriate addition of a surface-active agent to the reaction mixture was found to be highly effective in shortening the time required for the conversion. Accumulated l-alanine was readily isolated in pure form by ordinary procedures with ion-exchange resins. Yields of isolated l-alanine of over 90% from l-aspartic acid were easily attainable. PMID:5867644

  20. β-Alanine supplementation for athletic performance: an update.

    Science.gov (United States)

    Bellinger, Phillip M

    2014-06-01

    β-alanine supplementation has become a common practice among competitive athletes participating in a range of different sports. Although the mechanism by which chronic β-alanine supplementation could have an ergogenic effect is widely debated, the popular view is that β-alanine supplementation augments intramuscular carnosine content, leading to an increase in muscle buffer capacity, a delay in the onset of muscular fatigue, and a facilitated recovery during repeated bouts of high-intensity exercise. β-alanine supplementation appears to be most effective for exercise tasks that rely heavily on ATP synthesis from anaerobic glycolysis. However, research investigating its efficacy as an ergogenic aid remains equivocal, making it difficult to draw conclusions as to its effectiveness for training and competition. The aim of this review was to update, summarize, and critically evaluate the findings associated with β-alanine supplementation and exercise performance with the most recent research available to allow the development of practical recommendations for coaches and athletes. A critical review of the literature reveals that when significant ergogenic effects have been found, they have been generally shown in untrained individuals performing exercise bouts under laboratory conditions. The body of scientific data available concerning highly trained athletes performing single competition-like exercise tasks indicates that this type of population receives modest but potentially worthwhile performance benefits from β-alanine supplementation. Recent data indicate that athletes may not only be using β-alanine supplementation to enhance sports performance but also as a training aid to augment bouts of high-intensity training. β-alanine supplementation has also been shown to increase resistance training performance and training volume in team-sport athletes, which may allow for greater overload and superior adaptations compared with training alone. The ergogenic

  1. The antiproton depth–dose curve measured with alanine detectors

    CERN Document Server

    Bassler, Niels; Palmans, Hugo; Holzscheiter, Michael H; Kovacevic, Sandra

    2008-01-01

    n this paper we report on the measurement of the antiproton depth–dose curve, with alanine detectors. The results are compared with simulations using the particle energy spectrum calculated by FLUKA, and using the track structure model of Hansen and Olsen for conversion of calculated dose into response. A good agreement is observed between the measured and calculated relative effectiveness although an underestimation of the measured values beyond the Bragg-peak remains unexplained. The model prediction of response of alanine towards heavy charged particles encourages future use of the alanine detectors for dosimetry of mixed radiation fields.

  2. Experimental beta-alaninuria induced by (aminooxyacetate.

    Directory of Open Access Journals (Sweden)

    Kurozumi Y

    1999-02-01

    Full Text Available Experimental beta-alaninuria was induced in rats by injection of (aminooxyacetate (AOA, a potent inhibitor of aminotransferases, in order to elucidate the pathogenesis of hyper-beta-alaninemia. A 27-fold increase of beta-alanine (BALA excretion was induced by subcutaneous injection of 1 5 mg of AOA per kg of body weight. A 13-fold and a 9-fold increase of beta-aminoisobutyric acid (BAIBA and gamma-aminobutyric acid (GABA, respectively, were also induced simultaneously by the AOA injection. Identification of BALA and BAIBA isolated from the rat urine was performed by chromatographic and mass spectrometric analyses. The effects of AOA injection on the tissue levels of these amino acids were also studied. Contents of BALA in the liver and kidney and GABA in the brain increased significantly in response to AOA injection. The present study indicates that BALA transaminase is involved in hyper-beta-alaninemia.

  3. Thyroid Scan and Uptake

    Science.gov (United States)

    ... News Physician Resources Professions Site Index A-Z Thyroid Scan and Uptake Thyroid scan and uptake uses ... the Thyroid Scan and Uptake? What is a Thyroid Scan and Uptake? A thyroid scan is a ...

  4. Thyroid Scan and Uptake

    Medline Plus

    Full Text Available ... News Physician Resources Professions Site Index A-Z Thyroid Scan and Uptake Thyroid scan and uptake uses ... the Thyroid Scan and Uptake? What is a Thyroid Scan and Uptake? A thyroid scan is a ...

  5. Thyroid Scan and Uptake

    Science.gov (United States)

    ... Physician Resources Professions Site Index A-Z Thyroid Scan and Uptake Thyroid scan and uptake uses small ... Thyroid Scan and Uptake? What is a Thyroid Scan and Uptake? A thyroid scan is a type ...

  6. Colorimetry method for estimation of glycine, alanine and isoleucine

    Directory of Open Access Journals (Sweden)

    Shah S

    2007-01-01

    Full Text Available A simple and sensitive colorimetry method has been developed for estimation of amino acids glycine, alanine and isoleucine. Amino acids were derivatized with dichlone in presence of sodium bicarbonate. Amino acids showed maximum absorbance at 470 nm. The method was validated in terms of linearity (5-25 µg/ml for glycine, alanine and isoleucine, precision (intra-day variation 0.13-0.78, 0.22-1.29, 0.58-2.52% and inter-day variation 0.52-2.49, 0.43-3.12, 0.58- 4.48% for glycine, alanine and isoleucine respectively, accuracy (91.43-98.86, 96.26-105.99 and 95.73-104.82 for glycine, alanine and isoleucine respectively, limit of detection (0.6, 1 and 1 µg/ml for glycine, alanine and isoleucine respectively and limit of quantification (5 µg/ml for glycine, alanine and isoleucine. The method was found to be simple and sensitive.

  7. Structure of D-alanine-D-alanine ligase from Yersinia pestis: nucleotide phosphate recognition by the serine loop.

    Science.gov (United States)

    Tran, Huyen Thi; Hong, Myoung Ki; Ngo, Ho Phuong Thuy; Huynh, Kim Hung; Ahn, Yeh Jin; Wang, Zhong; Kang, Lin Woo

    2016-01-01

    D-Alanyl-D-alanine is an essential precursor of bacterial peptidoglycan and is synthesized by D-alanine-D-alanine ligase (DDL) with hydrolysis of ATP; this reaction makes DDL an important drug target for the development of antibacterial agents. Five crystal structures of DDL from Yersinia pestis (YpDDL) were determined at 1.7-2.5 Å resolution: apo, AMP-bound, ADP-bound, adenosine 5'-(β,γ-imido)triphosphate-bound, and D-alanyl-D-alanine- and ADP-bound structures. YpDDL consists of three domains, in which four loops, loop 1, loop 2 (the serine loop), loop 3 (the ω-loop) and loop 4, constitute the binding sites for two D-alanine molecules and one ATP molecule. Some of them, especially the serine loop and the ω-loop, show flexible conformations, and the serine loop is mainly responsible for the conformational change in substrate nucleotide phosphates. Enzyme-kinetics assays were carried out for both the D-alanine and ATP substrates and a substrate-binding mechanism was proposed for YpDDL involving conformational changes of the loops.

  8. Synthesis of L-[{beta}-{sup 11}C]amino acids using immobilized enzymes

    Energy Technology Data Exchange (ETDEWEB)

    Ikemoto, M.; Yada, T. [Ikeda Food Research Corporation, Minooki-cho, Fukuyama-shi, Hiroshima (Japan); Sasaki, M. [Sumitomo Heavy Industries, Kitashinagawa, Shinagawa-ku, Tokyo (Japan); Haradahira, T. [Division of Advanced Technology for Medical Imaging, National Institute of Radiological Sciences, Chiba (Japan); Omura, H.; Furuya, Y.; Watanabe, Y.; Suzuki, K. [Subfemtomole Biorecognition Project, Japan Science and Technology Corporation, Osaka (Japan)

    1999-04-01

    L-[{beta}-{sup 11}C]-3,4-dihydroxyphenylalanine(L-[{beta}-{sup 11}C]DOPA) and L-[{beta}-{sup 11}C]-5-hydroxytryptophan(L-[{beta}-{sup 11}C]-5-HTP) were synthesized in one step with immobilized thermostable enzymes (alanine racemase, D-amino acid oxidase, and {beta}-tyrosinase or tryptophanase) on an aminopropyl-CPG carrier in a single column and by passing D,L-[3-{sup 11}C]alanine through the column with coenzymes and other substrates. L-[{beta}-{sup 11}C]DOPA and L-[{beta}-{sup 11}C]-5-HTP could be obtained at yields of 53% and 60%, respectively, by optimizing the amounts and the ratios of the enzymes used, the reaction temperature, the pH, and the flow rate. Moreover, the same immobilized enzyme column could be used repeatedly.

  9. EPR/alanine dosimetry for two therapeutic proton beams

    Energy Technology Data Exchange (ETDEWEB)

    Marrale, Maurizio, E-mail: maurizio.marrale@unipa.it [Dipartimento di Fisica e Chimica, Università di Palermo, Viale delle Scienze, Edificio 18, 90128 Palermo (Italy); Gruppo V Sezione INFN di Catania, Via Santa Sofia, 64, 95123 Catania (Italy); Carlino, Antonio [Dipartimento di Fisica e Chimica, Università di Palermo, Viale delle Scienze, Edificio 18, 90128 Palermo (Italy); EBG MedAustron GmbH, Marie Curie-Straße 5, A-2700 Wiener Neustadt (Austria); Gallo, Salvatore [Dipartimento di Fisica e Chimica, Università di Palermo, Viale delle Scienze, Edificio 18, 90128 Palermo (Italy); Gruppo V Sezione INFN di Catania, Via Santa Sofia, 64, 95123 Catania (Italy); Laboratorio PH3DRA, Dipartimento di Fisica e Astronomia, Università di Catania, Via Santa Sofia 64, 95123 Catania (Italy); Longo, Anna; Panzeca, Salvatore [Dipartimento di Fisica e Chimica, Università di Palermo, Viale delle Scienze, Edificio 18, 90128 Palermo (Italy); Gruppo V Sezione INFN di Catania, Via Santa Sofia, 64, 95123 Catania (Italy); Bolsi, Alessandra; Hrbacek, Jan; Lomax, Tony [Center for Proton Therapy, Paul Scherrer Institute, 5232 Villigen PSI (Switzerland)

    2016-02-01

    In this work the analysis of the electron paramagnetic resonance (EPR) response of alanine pellets exposed to two different clinical proton beams employed for radiotherapy is performed. One beam is characterized by a passive delivery technique and is dedicated to the eyes treatment (OPTIS2 beam line). Alanine pellets were irradiated with a 70 MeV proton beam corresponding to 35 mm range in eye tissue. We investigated how collimators with different sizes and shape used to conform the dose to the planned target volume influence the delivered dose. For this purpose we performed measurements with varying the collimator size (Output Factor) and the results were compared with those obtained with other dosimetric techniques (such as Markus chamber and diode detector). This analysis showed that the dosimeter response is independent of collimator diameter if this is larger than or equal to 10 mm. The other beam is characterized by an active spot-scanning technique, the Gantry1 beam line (maximum energy 230 MeV), and is used to treat deep-seated tumors. The dose linearity of alanine response in the clinical dose range was tested and the alanine dose response at selected locations in depth was measured and compared with the TPS planned dose in a quasi-clinical scenario. The alanine response was found to be linear in the dose in the clinical explored range (from 10 to 70 Gy). Furthermore, a depth dose profile in a quasi-clinical scenario was measured and compared to the dose computed by the Treatment Planning System PSIPLAN. The comparison of calibrated proton alanine measurements and TPS dose shows a difference under 1% in the SOBP and a “quenching” effect up to 4% in the distal part of SOBP. The positive dosimetric characteristics of the alanine pellets confirm the feasibility to use these detectors for “in vivo” dosimetry in clinical proton beams.

  10. Constitutive uptake and degradation of fatty acids by Yersinia pestis.

    OpenAIRE

    Moncla, B. J.; Hillier, S L; Charnetzky, W T

    1983-01-01

    Yersinia pestis was found to utilize palmitic acid as a primary carbon and energy source. No inhibition of growth by palmitic acid was observed. Comparison of palmitic acid uptake by cells pregrown either with or without palmitic acid demonstrated that fatty acid uptake was constitutive. High basal levels of two enzymes of beta-oxidation, beta-hydroxyacyl-coenzyme A dehydrogenase and thiolase, and the two enzymes of the glyoxylate shunt, isocitrate lyase and malate synthase, were found in cel...

  11. Mechanistic Insight in the Enzymatic Ring-Opening Polymerization of beta-Propiolactam

    NARCIS (Netherlands)

    Schwab, Leendert W.; Baum, Iris; Fels, Gregor; Loos, Katja; Cheng, HN; Gross, RA

    2010-01-01

    Here we report the polymerization of beta-propiolactam to poly(beta-alanine) catalyzed by the immobilized Candida antarctica lipase B (N435). The polymer is characterized by (1)H-NMR spectroscopy and MALDI-ToF mass spectrometry. The best results were obtained with N435 (dried for 24 hours in vacua a

  12. β-alanine supplementation to improve exercise capacity and performance: a systematic review and meta-analysis.

    Science.gov (United States)

    Saunders, Bryan; Elliott-Sale, Kirsty; Artioli, Guilherme G; Swinton, Paul A; Dolan, Eimear; Roschel, Hamilton; Sale, Craig; Gualano, Bruno

    2017-04-01

    To conduct a systematic review and meta-analysis of the evidence on the effects of β-alanine supplementation on exercise capacity and performance. This study was designed in accordance with PRISMA guidelines. A 3-level mixed effects model was employed to model effect sizes and account for dependencies within data. 3 databases (PubMed, Google Scholar, Web of Science) were searched using a number of terms ('β-alanine' and 'Beta-alanine' combined with 'supplementation', 'exercise', 'training', 'athlete', 'performance' and 'carnosine'). Inclusion/exclusion criteria limited articles to double-blinded, placebo-controlled studies investigating the effects of β-alanine supplementation on an exercise measure. All healthy participant populations were considered, while supplementation protocols were restricted to chronic ingestion. Cross-over designs were excluded due to the long washout period for skeletal muscle carnosine following supplementation. A single outcome measure was extracted for each exercise protocol and converted to effect sizes for meta-analyses. 40 individual studies employing 65 different exercise protocols and totalling 70 exercise measures in 1461 participants were included in the analyses. A significant overall effect size of 0.18 (95% CI 0.08 to 0.28) was shown. Meta-regression demonstrated that exercise duration significantly (p=0.004) moderated effect sizes. Subgroup analyses also identified the type of exercise as a significant (p=0.013) moderator of effect sizes within an exercise time frame of 0.5-10 min with greater effect sizes for exercise capacity (0.4998 (95% CI 0.246 to 0.753)) versus performance (0.1078 (95% CI -0.201 to 0.416)). There was no moderating effect of training status (p=0.559), intermittent or continuous exercise (p=0.436) or total amount of β-alanine ingested (p=0.438). Co-supplementation with sodium bicarbonate resulted in the largest effect size when compared with placebo (0.43 (95% CI 0.22 to 0.64)). β-alanine had a

  13. A simple and realistic model system for studying hydrogen bonds in beta-sheets

    DEFF Research Database (Denmark)

    Rossmeisl, Jan; Hinnemann, Berit; Jacobsen, Karsten Wedel

    2003-01-01

    We investigate the interaction between peptide chains at the level of state-of-the-art ab initio density functional theory. We propose an interacting periodic polypeptide model for studying the interactions in beta-sheets and apply this to glycine and alanine peptide chains in both parallel...... and antiparallel structures. The calculated structures of alanine are compared to x-ray structures of beta-sheets and the model is found to reproduce the geometry of the hydrogen bonds very well both concerning parallel and antiparallel beta-sheets. We investigate the structures of both the N-H...O=C and the C...

  14. [Effect of synthetic cyclopentane beta,beta'-triketones on amino acid metabolism in roots of buckwheat (Fagopyrum esculentum Moench.) seedlings].

    Science.gov (United States)

    Demina, E A; Tishchenko, L Ia; Shestak, O P; Novikov, V L; Anisimov, M M

    2009-01-01

    Germination of buckwheat seeds in solutions of synthetic mono- and tricyclic cyclopentane-containing beta,beta'-triketones of various concentrations was accompanied by inhibition of seedling root growth and changes in the contents of glutamate, gamma-aminobutyric acid, proline, glutamine, and alanine. The monocyclic triketone also affected the amount of isoleucine. It is likely that the increase in proline content is a nonspecific response significant for enhancing stress tolerance in seedlings.

  15. [Axolemmal transporters for neurotransmitter uptake].

    Science.gov (United States)

    García-López, M

    Neurotransmission is a fundamental process in interneuronal communication. It starts with the release of the neurotransmitter following a nerve impulse and ends either by uptake by specific specific transporters or by metabolization to an inactive compound. In this review we will consider the molecular, ion dependence and electrogenic properties of the axolemal transporters for neurotransmitters and also the pathological consequences of their impairment as well as the drugs that can interact with them. Most axolemmal transporters have been cloned and grouped into two large families according to their molecular characteristics and electrogenic properties: 1. Those dependent on Na+/Cl- include transporters of GABA, noradrenaline, dopamine, serotonin, choline, proline, betaine, glycine and taurine, and 2. Those dependent on Na+/K+, which include the transporters of glutamate, alanine, serine and cysteine. The clonation of transporters has permitted (and will continue to permit) the correlation of molecular alterations of transporters with different neuro-degenerative disorders (e.g. multiple sclerosis, Parkinson's disease, Alzheimer's disease), with brain lesions (e.g. cerebral ischemia, status epilepticus) and with psychiatric alterations (e.g. schizophrenia, depression). In this respect, chemical synthesis of new selective drugs which interact with the different systems for uptake of neurotransmitters will offer new approaches to the treatment of many disorders of the central nervous system which still have no satisfactory drug treatment.

  16. Cholesterol efflux via ATP-binding cassette transporter A1 (ABCA1) and cholesterol uptake via the LDL receptor influences cholesterol-induced impairment of beta cell function in mice

    NARCIS (Netherlands)

    Kruit, J. K.; Kremer, P. H. C.; Dai, L.; Tang, R.; Ruddle, P.; de Haan, W.; Brunham, L. R.; Verchere, C. B.; Hayden, M. R.

    2010-01-01

    Cellular cholesterol accumulation is an emerging mechanism for beta cell dysfunction in type 2 diabetes. Absence of the cholesterol transporter ATP-binding cassette transporter A1 (ABCA1) results in increased islet cholesterol and impaired insulin secretion, indicating that impaired cholesterol effl

  17. 尿N-乙酰-β-D氨基葡萄糖酶、丙氨酸氨肽酶和α1-微球蛋白检测在唑来膦酸致肾损伤早期诊断作用%Effects of detecting of N-acety-beta-D-glucosaminidase,Alanine aminopeptidase andα1-microglobulin in urine on early diag-nosis of kidney injury induced by zoledronic acid

    Institute of Scientific and Technical Information of China (English)

    刘星; 刘大为; 谢晓冬; 郭占文; 郑振东; 张丽辉; 张娇蕊; 刘永叶

    2016-01-01

    目的 探讨尿N-乙酰-β-D氨基葡萄糖酶(NAG)、丙氨酸氨肽酶(AAP)和α1-微球蛋白(α1-MG)检测在唑来膦酸致肾损伤早期诊断中的作用.方法 选取2012年2月至2014年7月沈阳军区总医院收治的100例应用唑来膦酸治疗的恶性肿瘤骨转移患者为研究对象.其中,男性48例,女性52例,年龄25~82岁,平均(60±11)岁.患者接受唑来膦酸注射液4 mg静脉滴注,1次/25~35 d,30 min滴完,连续应用3次.每次用药前和用药次日,留取患者清晨尿液及静脉血,检测并比较尿NAG、AAP、α1-MG和血肌酐(Scr)、尿素氮(BUN)水平.结果 每次用药前、后比较尿NAG水平,差异均有统计学意义(P0.05);而第2次和第3次用药前后,尿α1-MG水平比较,差异有统计学意义(P0.05).每次用药前后,Scr、BUN水平比较,差异均无统计学意义(P>0.05).3次用药后,尿NAG、α1-MG水平组间比较,差异均有统计学意义(P0.05).结论 唑来膦酸致肾损伤患者尿NAG、AAP和α1-MG水平变化早于血肌酐.尿NAG、AAP和α1-MG联合检测可作为肾损伤的早期诊断指标.%Objective To explore the effects of detecting of N-acety-beta-D-glucosaminidase( NAG) ,Alanine aminopeptidase( AAP) andα1-microglobulin(α1-MG) in urine on early diagnosis of kidney injury induced by zoledronic acid. Methods A total of 100 pa-tients comprised 48 males and 52 females with a mean age of (60 ± 11)years were enrolled into the study. The patients with malignant tumor bone metastasis and received zoledronic acid from February 2012 to July 2014 in the General Hospital of Shenyang Military Command. They received IV infusion of zoledronic acid 4 mg,once for 25 to 35 days,finished within 30 minutes. The therapy was ap-plied 3 times continuously. The patients′urine and venous blood samples were taken before and after each medication′s morning. The level of NAG,AAP and α1-MG in urine and serum creatinine,blood urea nitrogen were detected and compared. Results The differ

  18. The Response of Alanine Dosimeters in Thermal Neutron Fields

    DEFF Research Database (Denmark)

    Schmitz, T.; Bassler, Niels; Sharpe, P.

    Purpose: Boron Neutron Capture Therapy (BNCT) is a special kind of particle therapy, based on the neutron induced fission of the boron isotope 10B [1]. We have performed dosimetry experiments on the mixed neutron and gamma fields at the TRIGA Mark II research reactor in Mainz. Commonly, dosimetry...... in such fields is realized by foil activation and ion chambers [2]. Here we investigate alanine as an easier and more robust alternative dosimeter. Methods: We have performed four phantom experiments at the TRIGA Mark II research reactor in Mainz [3], in a predominantly thermal neutron field with a strong gamma...... neutron capture of hydrogen. The primary gamma dose deposited originate from the reactor core itself. Conclusion: Alanine dosimeters are suitable of measurements in mixed neutron fields and the alanine response in thermal neutron fields can be fully understood by the used interpretation model. In further...

  19. First-principles studies of pure and fluorine substituted alanines

    Science.gov (United States)

    Ahmad, Sardar; Vaizie, Hamide; Rahnamaye Aliabad, H. A.; Ahmad, Rashid; Khan, Imad; Ali, Zahid; Jalali-Asadabadi, S.; Ahmad, Iftikhar; Khan, Amir Abdullah

    2016-05-01

    This paper communicates the structural, electronic and optical properties of L-alanine, monofluoro and difluoro substituted alanines using density functional calculations. These compounds exist in orthorhombic crystal structure and the calculated structural parameters such as lattice constants, bond angles and bond lengths are in agreement with the experimental results. L-alanine is an indirect band gap insulator, while its fluorine substituted compounds (monofluoroalanine and difluoroalanine) are direct band gap insulators. The substitution causes reduction in the band gap and hence these optically tailored direct wide band gap materials have enhanced optical properties in the ultraviolet (UV) region of electromagnetic spectrum. Therefore, optical properties like dielectric function, refractive index, reflectivity and energy loss function are also investigated. These compounds have almost isotropic nature in the lower frequency range while at higher energies, they have a significant anisotropic nature.

  20. Medical reference dosimetry using EPR measurements of alanine

    DEFF Research Database (Denmark)

    Helt-Hansen, Jakob; Rosendal, F.; Kofoed, I.M.

    2009-01-01

    Background. Electron spin resonance (EPR) is used to determine the absorbed dose of alanine dosimeters exposed to clinical photon beams in a solid-water phantom. Alanine is potentially suitable for medical reference dosimetry, because of its near water equivalence over a wide energy spectrum, low...... on scaling of known spectra was developed to extract the alanine signal. Results. The dose accuracy, including calibration uncertainty, is less than 2% (k=1) above 4 Gy (n=4). The measurement uncertainty is fairly constant in absolute terms (30 mGy) and the relative uncertainty therefore rises for dose...... measurements below 4 Gy. Typical reproducibility is 1% (k=1) above 10 Gy and 2% between 4 and 10 Gy. Below 4 Gy the uncertainty is higher. A depth dose curve measurement was performed in a solid-water phantom irradiated to a dose of 20 Gy at the maximum dose point (dmax) in 6 and 18 MV photon beams...

  1. Magnitude of a conformational change in the glycine receptor beta1-beta2 loop is correlated with agonist efficacy

    DEFF Research Database (Denmark)

    Pless, Stephan Alexander; Lynch, Joseph W

    2009-01-01

    associated with the closed-flip transition in the alpha1-glycine receptor. We employed voltage-clamp fluorometry to compare ligand-binding domain conformational changes induced by the following agonists, listed from highest to lowest affinity and efficacy: glycine > beta-alanine > taurine. Voltage...

  2. On the existence of ``l-threonine formate'', ``l-alanine lithium chloride'' and ``bis l-alanine lithium chloride'' crystals

    Science.gov (United States)

    Petrosyan, A. M.; Ghazaryan, V. V.; Fleck, M.

    2013-03-01

    We argue that the recently reported crystals "L-threonine formate" as well as "L-alanine lithium chloride" and "bis L-alanine lithium chloride" actually are the well-known crystals L-threonine and L-alanine, respectively.

  3. Alanine Radiation Detectors in Therapeutic Carbon Ion Beams

    DEFF Research Database (Denmark)

    Herrmann, Rochus; Jäkel, Oliver; Palmans, Hugo;

    of the depth dose curves. Solid state detectors, such as diamond detectors, radiochromic films, TLDs and the amino acid alanine are used due to there good spatial resolution. If used in particle beams their response often exhibits a dependence on particle energy and type, so the acquired signal is not always...... at energies below 20 MeV/u. We implemented this model in the Monte Carlo code FLUKA. At the GSI heavy ion facility in Darmstadt, Germany, alanine has been irradiated with carbon ions at energies between 88 an 400 MeV/u, which is the energy range used for therapy. The irradiation and the detector response have...

  4. The Antiproton Depth Dose Curve Measured with Alanine Detectors

    DEFF Research Database (Denmark)

    Bassler, Niels; Hansen, Johnny Witterseh; Palmans, Hugo;

    2008-01-01

    In this paper we report on the measurement of the antiproton depth dose curve, with alanine detectors. The results are compared with simulations using the particle energy spectrum calculated by FLUKA, and using the track structure model of Hansen et Olsen for conversion of calculated dose...

  5. Computational alanine scanning with linear scaling semiempirical quantum mechanical methods.

    Science.gov (United States)

    Diller, David J; Humblet, Christine; Zhang, Xiaohua; Westerhoff, Lance M

    2010-08-01

    Alanine scanning is a powerful experimental tool for understanding the key interactions in protein-protein interfaces. Linear scaling semiempirical quantum mechanical calculations are now sufficiently fast and robust to allow meaningful calculations on large systems such as proteins, RNA and DNA. In particular, they have proven useful in understanding protein-ligand interactions. Here we ask the question: can these linear scaling quantum mechanical methods developed for protein-ligand scoring be useful for computational alanine scanning? To answer this question, we assembled 15 protein-protein complexes with available crystal structures and sufficient alanine scanning data. In all, the data set contains Delta Delta Gs for 400 single point alanine mutations of these 15 complexes. We show that with only one adjusted parameter the quantum mechanics-based methods outperform both buried accessible surface area and a potential of mean force and compare favorably to a variety of published empirical methods. Finally, we closely examined the outliers in the data set and discuss some of the challenges that arise from this examination.

  6. Eating a healthy lunch improves serum alanine aminotransferase activity.

    Science.gov (United States)

    Iwamoto, Masako; Yagi, Kaori; Yazumi, Kayoko; Komine, Airi; Shirouchi, Bungo; Sato, Masao

    2013-09-14

    Nutritional guidance and diet control play important roles in the treatment of obesity and non-alcoholic fatty liver. However, in Japan, nutritional guidance is difficult to provide in practice. Therefore, we evaluated the effects of providing the 'once-a-day' intervention of a healthy lunch on various metabolic parameters. For a 1-month preparatory period, 10 subjects generally consumed the lunches that were provided by the worksite cafeteria. This was followed by a 1-week washout period, after which, the subjects consumed healthy, low-calorie, well-balanced lunches for a 1-month test period. After the preparatory and test periods, blood samples were obtained from all subjects. The serum levels of indices relevant to metabolic syndrome and fatty liver were measured. Serum alanine aminotransferase activity significantly decreased by 20.3% after the healthy intervention. However, the indices of metabolic syndrome did not significantly change. Analysis of the relationship between serum alanine aminotransferase activity and nutrient content indicated that the improvement of serum alanine aminotransferase status was due to the higher vegetable content and lower animal-source protein of the meals provided. In summary, the 'once-a-day' intervention of providing a healthy lunch improved serum alanine aminotransferase status. A diet high in vegetables and low in animal-based protein is important in maintaining a healthy condition.

  7. Threonine 788 in integrin subunit beta1 regulates integrin activation

    DEFF Research Database (Denmark)

    Nilsson, Stina; Kaniowska, Dorota; Brakebusch, Cord

    2006-01-01

    was identified as a site with major influence on integrin function. The mutation to A788 strongly reduced beta1-dependent cell attachment and exposure of the extracellular 9EG7 epitope, whereas replacement of T789 with alanine did not interfere with the ligand-binding ability. Talin has been shown to mediate......In the present study, the functional role of suggested phosphorylation of the conserved threonines in the cytoplasmic domain of integrin subunit beta1 was investigated. Mutants mimicking phosphorylated and unphosphorylated forms of beta1 were expressed in beta1 deficient GD25 cells. T788 in beta1...... integrin activation, but the talin head domain bound equally well to the wild-type beta1 and the mutants indicating that the T788A mutation caused defect integrin activation by another mechanism. The phosphorylation-mimicking mutation T788D was fully active in promoting cell adhesion. GD25 cells expressing...

  8. Crystal structures of d-alanine-d-alanine ligase from Xanthomonas oryzae pv. oryzae alone and in complex with nucleotides.

    Science.gov (United States)

    Doan, Thanh Thi Ngoc; Kim, Jin-Kwang; Ngo, Ho-Phuong-Thuy; Tran, Huyen-Thi; Cha, Sun-Shin; Min Chung, Kyung; Huynh, Kim-Hung; Ahn, Yeh-Jin; Kang, Lin-Woo

    2014-03-01

    D-Alanine-D-alanine ligase (DDL) catalyzes the biosynthesis of d-alanyl-d-alanine, an essential bacterial peptidoglycan precursor, and is an important drug target for the development of antibacterials. We determined four different crystal structures of DDL from Xanthomonas oryzae pv. oryzae (Xoo) causing Bacteria Blight (BB), which include apo, ADP-bound, ATP-bound, and AMPPNP-bound structures at the resolution between 2.3 and 2.0 Å. Similarly with other DDLs, the active site of XoDDL is formed by three loops from three domains at the center of enzyme. Compared with d-alanyl-d-alanine and ATP-bound TtDDL structure, the γ-phosphate of ATP in XoDDL structure was shifted outside toward solution. We swapped the ω-loop (loop3) of XoDDL with those of Escherichia coli and Helicobacter pylori DDLs, and measured the enzymatic kinetics of wild-type XoDDL and two mutant XoDDLs with the swapped ω-loops. Results showed that the direct interactions between ω-loop and other two loops are essential for the active ATP conformation for D-ala-phosphate formation.

  9. A gene duplication led to specialized gamma-aminobutyrate and beta-alanine aminotransferase in yeast

    DEFF Research Database (Denmark)

    Andersen, Gorm; Andersen, Birgit; Dobritzsch, D.

    2007-01-01

    and related yeasts have two different genes/enzymes to apparently 'distinguish' between the two reactions in a single cell. It is likely that upon duplication similar to 200 million years ago, a specialized Uga1p evolved into a 'novel' transaminase enzyme with broader substrate specificity....

  10. Formation of simple biomolecules from alanine in ocean by impacts

    Science.gov (United States)

    Umeda, Y.; Sekine, T.; Furukawa, Y.; Kakegawa, T.; Kobayashi, T.

    2013-12-01

    The biomolecules on the Earth are thought either to have originated from the extraterrestrial parts carried with flying meteorites or to have been formed from the inorganic materials on the Earth through given energy. From the standpoint to address the importance of impact energy, it is required to simulate experimentally the chemical reactions during impacts, because violent impacts may have occurred 3.8-4.0 Gyr ago to create biomolecules initially. It has been demonstrated that shock reactions among ocean (H2O), atmospheric nitrogen, and meteoritic constitution (Fe) can induce locally reduction environment to form simple bioorganic molecules such as ammonia and amino acid (Nakazawa et al., 2005; Furukawa et al., 2009). We need to know possible processes for alanine how chemical reactions proceed during repeated impacts and how complicated biomolecules are formed. Alanine can be formed from glycine (Umeda et al., in preparation). In this study, we carried out shock recovery experiments at pressures of 4.4-5.7 GPa to investigate the chemical reactions of alanine. Experiments were carried out with a propellant gun. Stainless steel containers (30 mm in diameter, 30 mm long) with 13C-labeled alanine aqueous solution immersed in olivine or hematite powders were used as targets. Air gap was present in the sample room (18 mm in diameter, 2 mm thick) behind the sample. The powder, solution, and air represent meteorite, ocean, and atmosphere on early Earth, respectively. Two powders of olivine and hematite help to keep the oxygen fugacity low and high during experiments, respectively in order to investigate the effect of oxygen fugacity on chemical processes of alanine. The recovered containers, after cleaned completely, were immersed into liquid nitrogen to freeze sample solution and then we drilled on the impact surface to extract water-soluble run products using pure water. Thus obtained products were analyzed by LC/MS for four amino acids (glycine, alanine, valine, and

  11. Amino acid uptake and energy coupling dependent on photosynthesis in Anacystis nidulans.

    OpenAIRE

    Lee-Kaden, J; Simonis, W

    1982-01-01

    The photoautotrophic cyanobacterium Anacystis nidulans was used to investigate the membrane transport of branched-chain, neutral amino acids and its dependence on photosynthetic reactions. The uptake of alpha-amino [1-14C]isobutyric acid and L-[1-14C]leucine followed Michaelis, Menten kinetics and resulted in an energy-dependent accumulation. As in bacteria, different uptake systems for neutral amino acids were present: two DAG (D-alanine, aminoisobutyric acid, and glycine) systems responsibl...

  12. Insulin secretion in lipodystrophic HIV-infected patients is associated with high levels of nonglucose secretagogues and insulin resistance of beta-cells

    DEFF Research Database (Denmark)

    Haugaard, Steen B; Andersen, Ove; Storgaard, Heidi

    2004-01-01

    We examined whether plasma concentrations of nonglucose insulin secretagogues are associated with prehepatic insulin secretion rates (ISR) in nondiabetic, insulin-resistant, human immunodeficiency virus (HIV)-infected, lipodystrophic patients (LIPO). Additionally, the negative feedback of insulin...... of insulin on beta-cells and an increased stimulation of ISR by FFA, alanine, triglyceride, and glucagon.......%), and clamp insulin (32%), all P alanine, and glucagon (all r > 0.65, P ..., and glucose (all r > 0.41, P alanine. In LIPO, ISRclamp correlated significantly with clamp free fatty acids (FFA), alanine, triglyceride, and glucagon (all r > 0.51, P

  13. Degradation of glycine and alanine on irradiated quartz.

    Science.gov (United States)

    Pawlikowski, Maciej; Benko, Aleksandra; Wróbel, Tomasz P

    2013-04-01

    Recent researches suggest participation of minerals in the formation of life under primordial conditions. Among all of the minerals, quartz seems to be one of the most probable to take part in such processes. However, an external source of energy is needed, e.g. electric discharge. A device simulating the proposed conditions was designed and was used to simulate prebiotic conditions. Investigation of processes occurring during the stimulation of quartz with electric discharge was studied by means of Ultraviolet-visible (UV-VIS) spectroscopy, in order to monitor the generation kinetics of free radicals. Additionally, infrared spectroscopy was applied to identify chemical reaction products created in a solution of alanine or glycine, in the presence of quartz treated with electric discharge. Formation of increased amounts of free radicals, compared to experiments performed without quartz and/or amino acid, is reported, along with identification of possible degradation products of alanine. No synthetic reactions were observed.

  14. Proton response of alanine based pellets and films

    Energy Technology Data Exchange (ETDEWEB)

    Onori, S.; De Angelis, C.; Fattibene, P. [Istituto Superiore di Sanita, Rome (Italy). Lab. di Fisica]|[Istituto Nazionale di Fisica Nucleare, Rome (Italy). Sezione Sanita; D`Errico, F. [DCMN, Universita degli Studi di Pisa (Italy); Egger, E. [Paul Scherrer Inst. (PSI), Villigen (Switzerland); Janovsky, I. [Nuclear Research Institute, Rez (Czech Republic)

    1997-01-01

    The performance of two different alanine-ESR systems (1 mm ISS pellets and NRI films) in therapy proton beams was checked against reference dosimetry provided by a Markus parallel plate ionization chamber. Irradiations were performed at the OPTIS facility of the PSI with a 62 MeV proton beam. The energy dependence of the response was derived from the analysis of film stacks irradiated with pristine beams. In fact, 250 {mu}m films allowed for a high resolution sampling of the proton slowing down mechanisms. Moreover pellets were irradiated in unmodulated and modulated beams. Alanine dose distributions were always in good agreement with the PSI Markus chamber results. Simple density scaling allowed for the conversion of the results to the dose distributions in water, consistently with the good tissue equivalence properties of these detectors. (Author).

  15. Crystal Structures of Aedes Aegypt Alanine Glyoxylate Aminotransferase

    Energy Technology Data Exchange (ETDEWEB)

    Han,Q.; Robinson, H.; Gao, Y.; Vogelaar, N.; Wilson, S.; Rizzi, M.; Li, J.

    2006-01-01

    Mosquitoes are unique in having evolved two alanine glyoxylate aminotransferases (AGTs). One is 3-hydroxykynurenine transaminase (HKT), which is primarily responsible for catalyzing the transamination of 3-hydroxykynurenine (3-HK) to xanthurenic acid (XA). Interestingly, XA is used by malaria parasites as a chemical trigger for their development within the mosquito. This 3-HK to XA conversion is considered the major mechanism mosquitoes use to detoxify the chemically reactive and potentially toxic 3-HK. The other AGT is a typical dipteran insect AGT and is specific for converting glyoxylic acid to glycine. Here we report the 1.75{angstrom} high-resolution three-dimensional crystal structure of AGT from the mosquito Aedes aegypti (AeAGT) and structures of its complexes with reactants glyoxylic acid and alanine at 1.75 and 2.1{angstrom} resolution, respectively. This is the first time that the three-dimensional crystal structures of an AGT with its amino acceptor, glyoxylic acid, and amino donor, alanine, have been determined. The protein is dimeric and adopts the type I-fold of pyridoxal 5-phosphate (PLP)-dependent aminotransferases. The PLP co-factor is covalently bound to the active site in the crystal structure, and its binding site is similar to those of other AGTs. The comparison of the AeAGT-glyoxylic acid structure with other AGT structures revealed that these glyoxylic acid binding residues are conserved in most AGTs. Comparison of the AeAGT-alanine structure with that of the Anopheles HKT-inhibitor complex suggests that a Ser-Asn-Phe motif in the latter may be responsible for the substrate specificity of HKT enzymes for 3-HK.

  16. Crystal structures of Aedes aegypti alanine glyoxylate aminotransferase.

    Science.gov (United States)

    Han, Qian; Robinson, Howard; Gao, Yi Gui; Vogelaar, Nancy; Wilson, Scott R; Rizzi, Menico; Li, Jianyong

    2006-12-01

    Mosquitoes are unique in having evolved two alanine glyoxylate aminotransferases (AGTs). One is 3-hydroxykynurenine transaminase (HKT), which is primarily responsible for catalyzing the transamination of 3-hydroxykynurenine (3-HK) to xanthurenic acid (XA). Interestingly, XA is used by malaria parasites as a chemical trigger for their development within the mosquito. This 3-HK to XA conversion is considered the major mechanism mosquitoes use to detoxify the chemically reactive and potentially toxic 3-HK. The other AGT is a typical dipteran insect AGT and is specific for converting glyoxylic acid to glycine. Here we report the 1.75A high-resolution three-dimensional crystal structure of AGT from the mosquito Aedes aegypti (AeAGT) and structures of its complexes with reactants glyoxylic acid and alanine at 1.75 and 2.1A resolution, respectively. This is the first time that the three-dimensional crystal structures of an AGT with its amino acceptor, glyoxylic acid, and amino donor, alanine, have been determined. The protein is dimeric and adopts the type I-fold of pyridoxal 5-phosphate (PLP)-dependent aminotransferases. The PLP co-factor is covalently bound to the active site in the crystal structure, and its binding site is similar to those of other AGTs. The comparison of the AeAGT-glyoxylic acid structure with other AGT structures revealed that these glyoxylic acid binding residues are conserved in most AGTs. Comparison of the AeAGT-alanine structure with that of the Anopheles HKT-inhibitor complex suggests that a Ser-Asn-Phe motif in the latter may be responsible for the substrate specificity of HKT enzymes for 3-HK.

  17. Pressure-induced phase transitions in L-alanine, revisited.

    Science.gov (United States)

    Tumanov, N A; Boldyreva, E V; Kolesov, B A; Kurnosov, A V; Quesada Cabrera, R

    2010-08-01

    The effect of pressure on L-alanine has been studied by X-ray powder diffraction (up to 12.3 GPa), single-crystal X-ray diffraction, Raman spectroscopy and optical microscopy (up to approximately 6 GPa). No structural phase transitions have been observed. At approximately 2 GPa the cell parameters a and b become accidentally equal to each other, but without a change in space-group symmetry. Neither of two transitions reported by others (to a tetragonal phase at approximately 2 GPa and to a monoclinic phase at approximately 9 GPa) was observed. The changes in cell parameters were continuous up to the highest measured pressures and the cells remained orthorhombic. Some important changes in the intermolecular interactions occur, which also manifest themselves in the Raman spectra. Two new orthorhombic phases could be crystallized from a MeOH/EtOH/H(2)O pressure-transmitting mixture in the pressure range 0.8-4.7 GPa, but only if the sample was kept at these pressures for at least 1-2 d. The new phases converted back to L-alanine on decompression. Judging from the Raman spectra and cell parameters, the new phases are most probably not L-alanine but its solvates.

  18. Cellular and Physiological Effects of Dietary Supplementation with β-Hydroxy-β-Methylbutyrate (HMB and β-Alanine in Late Middle-Aged Mice.

    Directory of Open Access Journals (Sweden)

    Julian Vallejo

    Full Text Available There is growing evidence that severe decline of skeletal muscle mass and function with age may be mitigated by exercise and dietary supplementation with protein and amino acid ingredient technologies. The purposes of this study were to examine the effects of the leucine catabolite, beta-hydroxy-beta-methylbutyrate (HMB, in C2C12 myoblasts and myotubes, and to investigate the effects of dietary supplementation with HMB, the amino acid β-alanine and the combination thereof, on muscle contractility in a preclinical model of pre-sarcopenia. In C2C12 myotubes, HMB enhanced sarcoplasmic reticulum (SR calcium release beyond vehicle control in the presence of all SR agonists tested (KCl, P<0.01; caffeine, P = 0.03; ionomycin, P = 0.03. HMB also improved C2C12 myoblast viability (25 μM HMB, P = 0.03 and increased proliferation (25 μM HMB, P = 0.04; 125 μM HMB, P<0.01. Furthermore, an ex vivo muscle contractility study was performed on EDL and soleus muscle from 19 month old, male C57BL/6nTac mice. For 8 weeks, mice were fed control AIN-93M diet, diet with HMB, diet with β-alanine, or diet with HMB and β-alanine. In β-alanine fed mice, EDL muscle showed a 7% increase in maximum absolute force compared to the control diet (202 ± 3vs. 188± 5 mN, P = 0.02. At submaximal frequency of stimulation (20 Hz, EDL from mice fed HMB plus β-alanine showed an 11% increase in absolute force (88.6 ± 2.2 vs. 79.8 ± 2.4 mN, P = 0.025 and a 13% increase in specific force (12.2 ± 0.4 vs. 10.8 ± 0.4 N/cm2, P = 0.021. Also in EDL muscle, β-alanine increased the rate of force development at all frequencies tested (P<0.025, while HMB reduced the time to reach peak contractile force (TTP, with a significant effect at 80 Hz (P = 0.0156. In soleus muscle, all experimental diets were associated with a decrease in TTP, compared to control diet. Our findings highlight beneficial effects of HMB and β-alanine supplementation on skeletal muscle function in aging mice.

  19. Role of H{sub 2}O{sub 2} on the kinetics of low-affinity high-capacity Na{sup +}-dependent alanine transport in SHR proximal tubular epithelial cells

    Energy Technology Data Exchange (ETDEWEB)

    Pinto, Vanda; Pinho, Maria Joao [Institute of Pharmacology and Therapeutics, Faculty of Medicine, University of Porto, 4200-319 Porto (Portugal); Jose, Pedro A. [Center for Molecular Physiology Research, Children' s National Medical Center, Department of Pediatrics, George Washington School of Medicine and Health Sciences, Washington, DC (United States); Soares-da-Silva, Patricio, E-mail: pss@med.up.pt [Institute of Pharmacology and Therapeutics, Faculty of Medicine, University of Porto, 4200-319 Porto (Portugal)

    2010-07-30

    Research highlights: {yields} H{sub 2}O{sub 2} in excess is required for the presence of a low-affinity high-capacity component for the Na{sup +}-dependent [{sup 14}C]-L-alanine uptake in SHR PTE cells only. {yields} It is suggested that Na{sup +} binding in renal ASCT2 may be regulated by ROS in SHR PTE cells. -- Abstract: The presence of high and low sodium affinity states for the Na{sup +}-dependent [{sup 14}C]-L-alanine uptake in immortalized renal proximal tubular epithelial (PTE) cells was previously reported (Am. J. Physiol. 293 (2007) R538-R547). This study evaluated the role of H{sub 2}O{sub 2} on the Na{sup +}-dependent [{sup 14}C]-L-alanine uptake of ASCT2 in immortalized renal PTE cells from Wistar Kyoto rat (WKY) and spontaneously hypertensive rat (SHR). Na{sup +} dependence of [{sup 14}C]-L-alanine uptake was investigated replacing NaCl with an equimolar concentration of choline chloride in vehicle- and apocynin-treated cells. Na{sup +} removal from the uptake solution abolished transport activity in both WKY and SHR PTE cells. Decreases in H{sub 2}O{sub 2} levels in the extracellular medium significantly reduced Na{sup +}-K{sub m} and V{sub max} values of the low-affinity high-capacity component in SHR PTE cells, with no effect on the high-affinity low-capacity state of the Na{sup +}-dependent [{sup 14}C]-L-alanine uptake. After removal of apocynin from the culture medium, H{sub 2}O{sub 2} levels returned to basal values within 1 to 3 h in both WKY and SHR PTE cells and these were found stable for the next 24 h. Under these experimental conditions, the Na{sup +}-K{sub m} and V{sub max} of the high-affinity low-capacity state were unaffected and the low-affinity high-capacity component remained significantly decreased 1 day but not 4 days after apocynin removal. In conclusion, H{sub 2}O{sub 2} in excess is required for the presence of a low-affinity high-capacity component for the Na{sup +}-dependent [{sup 14}C]-L-alanine uptake in SHR PTE cells only

  20. Isotopic effects in mechanistic studies of biotransformations of fluorine derivatives of L-alanine catalysed by L-alanine dehydrogenase.

    Science.gov (United States)

    Szymańska-Majchrzak, Jolanta; Pałka, Katarzyna; Kańska, Marianna

    2017-05-01

    Synthesis of 3-fluoro-[2-(2)H]-L-alanine (3-F-[(2)H]-L-Ala) in reductive amination of 3-fluoropyruvic acid catalysed by L-alanine dehydrogenase (AlaDH) was described. Fluorine derivative was used to study oxidative deamination catalysed by AlaDH applied kinetic (for 3-F-L-Ala in H2O - KIE's on Vmax: 1.1; on Vmax/KM: 1.2; for 3-F-L-Ala in (2)H2O - on Vmax: 1.4; on Vmax/KM: 2.1) and solvent isotope effect methods (for 3-F-L-Ala - SIE's on Vmax: 1.0; on Vmax/KM: 0.87; for 3-F-[2-(2)H]-L-Ala - on Vmax: 1.4; on Vmax/KM: 1.5). Studies explain some details of reaction mechanism. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. Thyroid Scan and Uptake

    Medline Plus

    Full Text Available ... Uptake? A thyroid scan is a type of nuclear medicine imaging. The radioactive iodine uptake test (RAIU) ... of thyroid function, but does not involve imaging. Nuclear medicine is a branch of medical imaging that ...

  2. Thyroid Scan and Uptake

    Medline Plus

    Full Text Available ... limitations of the Thyroid Scan and Uptake? What is a Thyroid Scan and Uptake? A thyroid scan ... tissues in your body. top of page How is the procedure performed? Nuclear medicine imaging is usually ...

  3. Thyroid Scan and Uptake

    Medline Plus

    Full Text Available ... Uptake? A thyroid scan is a type of nuclear medicine imaging. The radioactive iodine uptake test (RAIU) ... of thyroid function, but does not involve imaging. Nuclear medicine is a branch of medical imaging that ...

  4. Thyroid Scan and Uptake

    Medline Plus

    Full Text Available ... of the Thyroid Scan and Uptake? What is a Thyroid Scan and Uptake? A thyroid scan is ... code: Phone no: Thank you! Do you have a personal story about radiology? Share your patient story ...

  5. Thyroid Scan and Uptake

    Medline Plus

    Full Text Available ... known as a thyroid uptake. It is a measurement of thyroid function, but does not involve imaging. ... eating can affect the accuracy of the uptake measurement. Jewelry and other metallic accessories should be left ...

  6. Analysis of an Alanine/Arginine Mixture by Using TLC/FTIR Technique

    Directory of Open Access Journals (Sweden)

    Jun Liu

    2014-01-01

    Full Text Available We applied TLC/FTIR coupled with mapping technique to analyze an alanine/arginine mixture. Narrow band TLC plates prepared by using AgI as a stationary phase were used to separate alanine and arginine. The distribution of alanine and arginine spots was manifested by a 3D chromatogram. Alanine and arginine can be successfully separated by the narrow band TLC plate. In addition, the FTIR spectra of the separated alanine and arginine spots on the narrow band TLC plate are roughly the same as the corresponding reference IR spectra.

  7. Metabolic consequences of beta-adrenergic receptor blockade for the acutely ischemic dog myocardium

    Energy Technology Data Exchange (ETDEWEB)

    Westera, G.; Hollander, W. den; Wall, E.E. van der; Eenige, M.J. van; Scholtalbers, S.; Visser, F.C.; Roos, J.P.

    1984-02-01

    In an experimental study in 50 dogs the myocardial uptake of free fatty acids (FFAs) after beta-blockade was determined using radioiodinated heptadecanoic acid as a metabolic tracer. All 4 beta-blockers used (metoprolol, timolol, propranolol and pindolol) lowered the uptake of FFAs in the normal canine heart. Uptake of FFAs was also diminished after coronary artery occlusion per se, but administration of beta-blockers exerted little additional influence on the uptake of FFAs. This observation was qualitatively parallelled by the uptake of /sup 201/Tl in concomitant experiments. Plasma FFA levels were increased by pindolol (non-selective with intrinsic sympathomimetic activity), not changed by metoprolol (a cardioselective betablocking agent) and lowered by timolol and propranolol (both non-selective compounds). The extent of ischemic tissue, as reflected by uptake of iodoheptadecanoic acid and /sup 201/Tl, was diminished by metoprolol but not by other beta-blockers. Regional distribution of both tracers, as shown in the endo-epicardial uptake ratios, was hardly influenced by beta-blockade, except for a small increase of /sup 201/Tl uptake in non-occluded endocardium. Uptake of /sup 201/Tl as well as of iodoheptadecanoic acid in the ischemic area was increased by metoprolol, timolol and propranolol and decreased by pindolol. We conclude that beta-blocking agents confer different effects on myocardial uptake and metabolism of FFAs which might possibly be related to their different inherent properties.

  8. Pressure-induced phase transformations in L-alanine crystals

    DEFF Research Database (Denmark)

    Olsen, J. Staun; Gerward, Leif; Freire, P.T.C.

    2008-01-01

    Raman scattering and synchrotron X-ray diffraction have been used to investigate the high-pressure behavior of L-alanine. This study has confirmed a structural phase transition observed by Raman scattering at 2.3 GPa and identified it as a change from orthorhombic to tetragonal structure. Another...... phase transformation from tetragonal to monoclinic structure has been observed at about 9 GPa. From the equation of state, the zero-pressure bulk modulus and its pressure derivative have been determined as (31.5 +/- 1.4) GPa and 4.4 +/- 0.4, respectively....

  9. Topology of AspT, the aspartate:alanine antiporter of Tetragenococcus halophilus, determined by site-directed fluorescence labeling.

    Science.gov (United States)

    Nanatani, Kei; Fujiki, Takashi; Kanou, Kazuhiko; Takeda-Shitaka, Mayuko; Umeyama, Hideaki; Ye, Liwen; Wang, Xicheng; Nakajima, Tasuku; Uchida, Takafumi; Maloney, Peter C; Abe, Keietsu

    2007-10-01

    The gram-positive lactic acid bacterium Tetragenococcus halophilus catalyzes the decarboxylation of L-aspartate (Asp) with release of L-alanine (Ala) and CO(2). The decarboxylation reaction consists of two steps: electrogenic exchange of Asp for Ala catalyzed by an aspartate:alanine antiporter (AspT) and intracellular decarboxylation of the transported Asp catalyzed by an L-aspartate-beta-decarboxylase (AspD). AspT belongs to the newly classified aspartate:alanine exchanger family (transporter classification no. 2.A.81) of transporters. In this study, we were interested in the relationship between the structure and function of AspT and thus analyzed the topology by means of the substituted-cysteine accessibility method using the impermeant, fluorescent, thiol-specific probe Oregon Green 488 maleimide (OGM) and the impermeant, nonfluorescent, thiol-specific probe [2-(trimethylammonium)ethyl]methanethiosulfonate bromide. We generated 23 single-cysteine variants from a six-histidine-tagged cysteineless AspT template. A cysteine position was assigned an external location if the corresponding single-cysteine variant reacted with OGM added to intact cells, and a position was assigned an internal location if OGM labeling required cell lysis. The topology analyses revealed that AspT has a unique topology; the protein has 10 transmembrane helices (TMs), a large hydrophilic cytoplasmic loop (about 180 amino acids) between TM5 and TM6, N and C termini that face the periplasm, and a positively charged residue (arginine 76) within TM3. Moreover, the three-dimensional structure constructed by means of the full automatic modeling system indicates that the large hydrophilic cytoplasmic loop of AspT possesses a TrkA_C domain and a TrkA_C-like domain and that the three-dimensional structures of these domains are similar to each other even though their amino acid sequences show low similarity.

  10. Membrane topology of aspartate:alanine antiporter AspT from Comamonas testosteroni.

    Science.gov (United States)

    Fujiki, Takashi; Nanatani, Kei; Nishitani, Kei; Yagi, Kyoko; Ohnishi, Fumito; Yoneyama, Hiroshi; Uchida, Takafumi; Nakajima, Tasuku; Abea, Keietsu

    2007-01-01

    We cloned the aspT gene encoding the L-aspartate:L-alanine antiporter AspTCt in Comamonas testosteroni genomic DNA. Analysis of the nucleotide sequence revealed that C. testosteroni has an asp operon containing aspT upstream of the l-aspartate 4-decarboxylase gene, and that the gene order of the asp operon of C. testosteroni is the inverse of that of Tetragenococcus halophilus. We used proteoliposomes to confirm the transport processes of AspTCt. To elucidate the two-dimensional structure of AspTCt, we analysed its membrane topology by means of alkaline phosphatase (PhoA) and beta-lactamase (BlaM) fusion methods. The fusion analyses revealed that AspTCt has seven transmembrane segments (TMs), a large cytoplasmic loop containing approximately 200 amino acid residues between TM4 and TM5, a cytoplasmic N-terminus, and a periplasmic C-terminus. These results suggest that the orientation of the N-terminus of AspTCt differs from that of tetragenococcal AspT, even though these two AspT orthologues catalyse the same transport reactions.

  11. Ergogenic effects of β-alanine and carnosine: proposed future research to quantify their efficacy.

    Science.gov (United States)

    Caruso, John; Charles, Jessica; Unruh, Kayla; Giebel, Rachel; Learmonth, Lexis; Potter, William

    2012-07-01

    β-alanine is an amino acid that, when combined with histidine, forms the dipeptide carnosine within skeletal muscle. Carnosine and β-alanine each have multiple purposes within the human body; this review focuses on their roles as ergogenic aids to exercise performance and suggests how to best quantify the former's merits as a buffer. Carnosine normally makes a small contribution to a cell's total buffer capacity; yet β-alanine supplementation raises intracellular carnosine concentrations that in turn improve a muscle's ability to buffer protons. Numerous studies assessed the impact of oral β-alanine intake on muscle carnosine levels and exercise performance. β-alanine may best act as an ergogenic aid when metabolic acidosis is the primary factor for compromised exercise performance. Blood lactate kinetics, whereby the concentration of the metabolite is measured as it enters and leaves the vasculature over time, affords the best opportunity to assess the merits of β-alanine supplementation's ergogenic effect. Optimal β-alanine dosages have not been determined for persons of different ages, genders and nutritional/health conditions. Doses as high as 6.4 g day(-1), for ten weeks have been administered to healthy subjects. Paraesthesia is to date the only side effect from oral β-alanine ingestion. The severity and duration of paraesthesia episodes are dose-dependent. It may be unwise for persons with a history of paraesthesia to ingest β-alanine. As for any supplement, caution should be exercised with β-alanine supplementation.

  12. Non-enzymic beta-decarboxylation of aspartic acid.

    Science.gov (United States)

    Doctor, V. M.; Oro, J.

    1972-01-01

    Study of the mechanism of nonenzymic beta-decarboxylation of aspartic acid in the presence of metal ions and pyridoxal. The results suggest that aspartic acid is first converted to oxalacetic acid by transamination with pyridoxal which in turn is converted to pyridoxamine. This is followed by decarboxylation of oxalacetic acid to form pyruvic acid which transaminates with pyridoxamine to form alanine. The possible significance of these results to prebiotic molecular evolution is briefly discussed.

  13. Caffeine–N-phthaloyl-β-alanine (1/1

    Directory of Open Access Journals (Sweden)

    Moazzam H. Bhatti

    2012-06-01

    Full Text Available The title co-crystal [systematic name: 3-(1,3-dioxoisoindolin-2-ylpropanoic acid–1,3,7-trimethyl-1H-purine-2,6(3H,7H-dione (1/1], C8H10N4O2·C11H9NO4, is the combination of 1:1 adduct of N-phthaloyl-β-alanine with caffeine. The phthalimide and purine rings in the N-phthaloyl-β-alanine and caffeine molecules are essentially planar, with r.m.s. deviations of the fitted atoms of 0.0078 and 0.0118 Å, respectively. In the crystal, the two molecules are linked via an O—H...N hydrogen bond involving the intact carboxylic acid (COOH group. The crystal structure is consolidated by C—H...O interactions. The H atoms of a methyl group of the caffeine molecule are disordered over two sets of sites of equal occupancy.

  14. The effect of immunonutrition (glutamine, alanine on fracture healing

    Directory of Open Access Journals (Sweden)

    Abdullah Küçükalp

    2014-11-01

    Full Text Available Background: There have been various studies related to fracture healing. Glutamine is an amino acid with an important role in many cell and organ functions. This study aimed to make a clinical, radiological, and histopathological evaluation of the effects of glutamine on fracture healing. Methods: Twenty rabbits were randomly allocated into two groups of control and immunonutrition. A fracture of the fibula was made to the right hind leg. All rabbits received standard food and water. From post-operative first day for 30 days, the study group received an additional 2 ml/kg/day 20% L-alanine L-glutamine solution via a gastric catheter, and the control group received 2 ml/kg/day isotonic via gastric catheter. At the end of 30 days, the rabbits were sacrificed and the fractures were examined clinically, radiologically, and histopathologically in respect to the degree of union. Results: Radiological evaluation of the control group determined a mean score of 2.5 according to the orthopaedists and 2.65 according to the radiologists. In the clinical evaluation, the mean score was 1.875 for the control group and 2.0 for the study group. Histopathological evaluation determined a mean score of 8.5 for the control group and 9.0 for the study group. Conclusion: One month after orally administered glutamine–alanine, positive effects were observed on fracture healing radiologically, clinically, and histopathologically, although no statistically significant difference was determined.

  15. Preparation of new series of poly(amide-imide) reinforced layer silicate nano composite containing N-trimellitimide-L-alanine

    Energy Technology Data Exchange (ETDEWEB)

    Faghihi, K.; Soleimani, M. [Polymer Research Laboratory, Department of Chemistry, Faculty of Science, Islamic Azad University, Arak Branch, Arak (Iran, Islamic Republic of); Shabanian, M., E-mail: k-faghihi@araku.ac.ir [Young Researches Club, Islamic Azad University, Arak Branch, Arak (Iran, Islamic Republic of)

    2011-07-01

    A new poly(amide-imide)-montmorillonite series were generated through solution intercalation technique. Cloisite 20A was used as a modified montmorillonite for ample compatibility with the poly(amide-imide) (PAI) matrix. The PAI 5 chains were synthesized by the direct polycondensation reaction of N-trimellitylimido-L-alanine (3) with 4,4'-diamino diphenyl ether (4) in the presence of tryphenyl phosphites (TPP), CaCl{sub 2}, pyridine and N-methyl-2-pyrrolidone (NMP). Morphology and structure of the resulting PAI-nano composite films 5a-5d with (5-20 Wt%) silicate particles were characterized by Ftir spectroscopy, X-ray diffraction and scanning electron microscopy. The effect of clay dispersion and the interaction between clay and polymeric chains on the properties of nano composites films were investigated by using UV-Vis spectroscopy, thermogravimetric analysis and water uptake measurements. (Author)

  16. Environmental modulation of microcystin and β-N-methylamino-L-alanine as a function of nitrogen availability.

    Science.gov (United States)

    Scott, L L; Downing, S; Phelan, R R; Downing, T G

    2014-09-01

    The most significant modulators of the cyanotoxins microcystin and β-N-methylamino-L-alanine in laboratory cyanobacterial cultures are the concentration of growth-medium combined nitrogen and nitrogen uptake rate. The lack of field studies that support these observations led us to investigate the cellular content of these cyanotoxins in cyanobacterial bloom material isolated from a freshwater impoundment and to compare these to the combined nitrogen availability. We established that these toxins typically occur in an inverse relationship in nature and that their presence is mainly dependent on the environmental combined nitrogen concentration, with cellular microcystin present at exogenous combined nitrogen concentrations of 29 μM and higher and cellular BMAA correlating negatively with exogenous nitrogen at concentrations below 40 μM. Furthermore, opposing nutrient and light gradients that form in dense cyanobacterial blooms may result in both microcystin and BMAA being present at a single sampling site.

  17. Metabolic response to various beta-adrenoceptor agonists in beta3-adrenoceptor knockout mice: evidence for a new beta-adrenergic receptor in brown adipose tissue.

    Science.gov (United States)

    Preitner, F; Muzzin, P; Revelli, J P; Seydoux, J; Galitzky, J; Berlan, M; Lafontan, M; Giacobino, J P

    1998-08-01

    The beta3-adrenoceptor plays an important role in the adrenergic response of brown and white adipose tissues (BAT and WAT). In this study, in vitro metabolic responses to beta-adrenoceptor stimulation were compared in adipose tissues of beta3-adrenoceptor knockout and wild type mice. The measured parameters were BAT fragment oxygen uptake (MO2) and isolated white adipocyte lipolysis. In BAT of wild type mice (-)-norepinephrine maximally stimulated MO2 4.1+/-0.8 fold. Similar maximal stimulations were obtained with beta1-, beta2- or beta3-adrenoceptor selective agonists (dobutamine 5.1+/-0.3, terbutaline 5.3+/-0.3 and CL 316,243 4.8+/-0.9 fold, respectively); in BAT of beta3-adrenoceptor knockout mice, the beta1- and beta2-responses were fully conserved. In BAT of wild type mice, the beta1/beta2-antagonist and beta3-partial agonist CGP 12177 elicited a maximal MO2 response (4.7+/-0.4 fold). In beta3-adrenoceptor knockout BAT, this response was fully conserved despite an absence of response to CL 316,243. This unexpected result suggests that an atypical beta-adrenoceptor, distinct from the beta1-, beta2- and beta3-subtypes and referred to as a putative beta4-adrenoceptor is present in BAT and that it can mediate in vitro a maximal MO2 stimulation. In isolated white adipocytes of wild type mice, (-)-epinephrine maximally stimulated lipolysis 12.1+/-2.6 fold. Similar maximal stimulations were obtained with beta1-, beta2- or beta3-adrenoceptor selective agonists (TO509 12+/-2, procaterol 11+/-3, CL 316,243 11+/-3 fold, respectively) or with CGP 12177 (7.1+/-1.5 fold). In isolated white adipocytes of beta3-adrenoceptor knockout mice, the lipolytic responses to (-)epinephrine, to the beta1-, beta2-, beta3-adrenoceptor selective agonists and to CGP 12177 were almost or totally depressed, whereas those to ACTH, forskolin and dibutyryl cyclic AMP were conserved.

  18. The effect of ammonium ions on the activity of glutamate dehydrogenase, alanine aminotransferase and aspartate aminotransferase in Cucumis sativus L. seedlings

    Directory of Open Access Journals (Sweden)

    Genowefa Kubiak-Dobosz

    2014-02-01

    Full Text Available Changes in the activity of glutamate dehydrogenase (GDH, alanine aminotransferase (GPT and aspartate aminotransferase (GOT were studied in various organs of Cucumis sativus L. seedlings in relation to the uptake of mineral nitrogen (in form of N03- or NH4+ from the medium. Activity of GDH, GPT, and GOT was higher in young leaves and roots of cucumber seedlings if the plants developed- in an ammonium medium. No similar changes of aminotransferases activity were noted in the cotyledons. Factors affecting varying effect of ammonium ions upon GPT and GOT activity are discussed for particular organs of cucumber seedlings.

  19. Activity of the lactate-alanine shuttle is independent of glutamate-glutamine cycle activity in cerebellar neuronal-astrocytic cultures

    DEFF Research Database (Denmark)

    Bak, Lasse K; Sickmann, Helle M; Schousboe, Arne

    2004-01-01

    The glutamate-glutamine cycle describes the neuronal release of glutamate into the synaptic cleft, astrocytic uptake, and conversion into glutamine, followed by release for use as a neuronal glutamate precursor. This only explains the fate of the carbon atoms, however, and not that of the ammonia...... metabolites. Altogether, the results of this study support the existence of the lactate-alanine shuttle and the associated glutamate-glutamine cycle. No direct coupling of the two shuttles was observed, however, and only the glutamate-glutamine cycle seemed activity dependent....

  20. Role of L-alanine for redox self-sufficient amination of alcohols

    OpenAIRE

    Klatte, Stephanie; Wendisch, Volker F

    2015-01-01

    Background In white biotechnology biocatalysis represents a key technology for chemical functionalization of non-natural compounds. The plasmid-born overproduction of an alcohol dehydrogenase, an L-alanine-dependent transaminase and an alanine dehydrogenase allows for redox self-sufficient amination of alcohols in whole cell biotransformation. Here, conditions to optimize the whole cell biocatalyst presented in (Bioorg Med Chem 22:5578–5585, 2014), and the role of L-alanine for efficient amin...

  1. Ergogenic Effects of β-Alanine and Carnosine: Proposed Future Research to Quantify Their Efficacy

    OpenAIRE

    John Caruso; Jessica Charles; Kayla Unruh; Rachel Giebel; Lexis Learmonth; William Potter

    2012-01-01

    β-alanine is an amino acid that, when combined with histidine, forms the dipeptide carnosine within skeletal muscle. Carnosine and β-alanine each have multiple purposes within the human body; this review focuses on their roles as ergogenic aids to exercise performance and suggests how to best quantify the former’s merits as a buffer. Carnosine normally makes a small contribution to a cell’s total buffer capacity; yet β-alanine supplementation raises intracellular carnosine concentrations that...

  2. Hydrophobic interactions and hydrogen bonds in \\beta-sheet formation

    CERN Document Server

    Narayanan, Chitra

    2013-01-01

    In this study, we investigate interactions of extended conformations of homodimeric peptides made of small (glycine or alanine) and large hydrophobic (valine or leucine) sidechains using all-atom molecular dynamics simulations to decipher driving forces for \\beta-sheet formation. We make use of a periodic boundary condition setup in which individual peptides are infinitely long and stretched. Dimers adopt \\beta-sheet conformations at short interpeptide distances (\\xi ~ 0.5 nm) and at intermediate distances (~ 0.8 nm), valine and leucine homodimers assume cross-\\beta-like conformations with side chains interpenetrating each other. These two states are identified as minima in the Potential of Mean Force (PMF). While the number of interpeptide hydrogen bonds increases with decreasing interpeptide distance, the total hydrogen bond number in the system does not change significantly, suggesting that formation of \\beta-sheet structures from extended conformations is not driven by hydrogen bonds. This is supported by...

  3. Evolutionary Diversification of Alanine Transaminases in Yeast: Catabolic Specialization and Biosynthetic Redundancy

    Directory of Open Access Journals (Sweden)

    Ximena Escalera-Fanjul

    2017-06-01

    Full Text Available Gene duplication is one of the major evolutionary mechanisms providing raw material for the generation of genes with new or modified functions. The yeast Saccharomyces cerevisiae originated after an allopolyploidization event, which involved mating between two different ancestral yeast species. ScALT1 and ScALT2 codify proteins with 65% identity, which were proposed to be paralogous alanine transaminases. Further analysis of their physiological role showed that while ScALT1 encodes an alanine transaminase which constitutes the main pathway for alanine biosynthesis and the sole pathway for alanine catabolism, ScAlt2 does not display alanine transaminase activity and is not involved in alanine metabolism. Moreover, phylogenetic studies have suggested that ScALT1 and ScALT2 come from each one of the two parental strains which gave rise to the ancestral hybrid. The present work has been aimed to the understanding of the properties of the ancestral type Lacchancea kluyveri LkALT1 and Kluyveromyces lactis KlALT1, alanine transaminases in order to better understand the ScALT1 and ScALT2 evolutionary history. These ancestral -type species were chosen since they harbor ALT1 genes, which are related to ScALT2. Presented results show that, although LkALT1 and KlALT1 constitute ScALT1 orthologous genes, encoding alanine transaminases, both yeasts display LkAlt1 and KlAlt1 independent alanine transaminase activity and additional unidentified alanine biosynthetic and catabolic pathway(s. Furthermore, phenotypic analysis of null mutants uncovered the fact that KlAlt1 and LkAlt1 have an additional role, not related to alanine metabolism but is necessary to achieve wild type growth rate. Our study shows that the ancestral alanine transaminase function has been retained by the ScALT1 encoded enzyme, which has specialized its catabolic character, while losing the alanine independent role observed in the ancestral type enzymes. The fact that ScAlt2 conserves 64

  4. Ab initio study of alanine polypeptide chains twisting

    CERN Document Server

    Solovyov, I A; Solovyov, A V; Yakubovitch, A V; Greiner, Walter; Solov'yov, Andrey V.; Solov'yov, Ilia A.; Yakubovitch, Alexander V.

    2005-01-01

    We have investigated the potential energy surfaces for alanine chains consisting of three and six amino acids. For these molecules we have calculated potential energy surfaces as a function of the Ramachandran angles Phi and Psi, which are widely used for the characterization of the polypeptide chains. These particular degrees of freedom are essential for the characterization of proteins folding process. Calculations have been carried out within ab initio theoretical framework based on the density functional theory and accounting for all the electrons in the system. We have determined stable conformations and calculated the energy barriers for transitions between them. Using a thermodynamic approach, we have estimated the times of characteristic transitions between these conformations. The results of our calculations have been compared with those obtained by other theoretical methods and with the available experimental data extracted from the Protein Data Base. This comparison demonstrates a reasonable corres...

  5. Integrating diffusion maps with umbrella sampling: application to alanine dipeptide.

    Science.gov (United States)

    Ferguson, Andrew L; Panagiotopoulos, Athanassios Z; Debenedetti, Pablo G; Kevrekidis, Ioannis G

    2011-04-07

    Nonlinear dimensionality reduction techniques can be applied to molecular simulation trajectories to systematically extract a small number of variables with which to parametrize the important dynamical motions of the system. For molecular systems exhibiting free energy barriers exceeding a few k(B)T, inadequate sampling of the barrier regions between stable or metastable basins can lead to a poor global characterization of the free energy landscape. We present an adaptation of a nonlinear dimensionality reduction technique known as the diffusion map that extends its applicability to biased umbrella sampling simulation trajectories in which restraining potentials are employed to drive the system into high free energy regions and improve sampling of phase space. We then propose a bootstrapped approach to iteratively discover good low-dimensional parametrizations by interleaving successive rounds of umbrella sampling and diffusion mapping, and we illustrate the technique through a study of alanine dipeptide in explicit solvent.

  6. Microhardness studies on nonlinear optical -alanine single crystals

    Indian Academy of Sciences (India)

    R Hanumantharao; S Kalainathan

    2013-06-01

    Vickers and Knoop microhardness tests were carried out on grown -alanine single crystals by slow evaporation technique over a load range of 10–50 g on selected broad (2 0 3) plane. Vickers (v) and Knoop (k) microhardness for the above loads were found to be in the range of 60–71 kg/mm2 and 35–47 kg/mm2, respectively. Vickers microhardness number (v) and Knoop microhardness number (k) were found to increase with increasing load. Meyer’s index number () calculated from v shows that the material belongs to the soft material category. Using Wooster’s empirical relation, the elastic stiffness constant (11) was calculated from Vickers hardness values. Young’s modulus was calculated using Knoop hardness values. Hardness anisotropy has been observed in accordance with the orientation of the crystal.

  7. Alanine aminotransferase variants conferring diverse NUE phenotypes in Arabidopsis thaliana.

    Directory of Open Access Journals (Sweden)

    Chandra H McAllister

    Full Text Available Alanine aminotransferase (AlaAT, E.C. 2.6.1.2, is a pyridoxal-5'-phosphate-dependent (PLP enzyme that catalyzes the reversible transfer of an amino group from alanine to 2-oxoglutarate to produce glutamate and pyruvate, or vice versa. It has been well documented in both greenhouse and field studies that tissue-specific over-expression of AlaAT from barley (Hordeum vulgare, HvAlaAT results in a significant increase in plant NUE in both canola and rice. While the physical phenotypes associated with over-expression of HvAlaAT have been well characterized, the role this enzyme plays in vivo to create a more N efficient plant remains unknown. Furthermore, the importance of HvAlaAT, in contrast to other AlaAT enzyme homologues in creating this phenotype has not yet been explored. To address the role of AlaAT in NUE, AlaAT variants from diverse sources and different subcellular locations, were expressed in the wild-type Arabidopsis thaliana Col-0 background and alaat1;2 (alaat1-1;alaat2-1 knockout background in various N environments. The analysis and comparison of both the physical and physiological properties of AlaAT over-expressing transgenic plants demonstrated significant differences between plants expressing the different AlaAT enzymes under different external conditions. This analysis indicates that the over-expression of AlaAT variants other than HvAlaAT in crop plants could further increase the NUE phenotype(s previously observed.

  8. Assessing microbial utilization of free versus sorbed Alanine by using position-specific 13C labeling and 13C-PLFA analysis

    Science.gov (United States)

    Herschbach, Jennifer; Apostel, Carolin; Spielvogel, Sandra; Kuzyakov, Yakov; Dippold, Michaela

    2016-04-01

    Microbial utilization is a key transformation process of soil organic matter (SOM). Sorption of low molecular weight organic substances (LMWOS) to soil mineral surfaces blocks or delays microbial uptake and therefore mineralization of LMWOS to CO2, as well as all other biochemical transformations. We used position-specific labeling, a tool of isotope applications novel to soil science, combined with 13C-phospholipid fatty acid (PLFA) analysis, to assess microbial utilization of sorbed and non-sorbed Alanine in soil. Alanine has various functional groups enabling different sorption mechanisms via its positive charge (e.g. to clay minerals by cation exchange), as well as via its negative charge (e.g. to iron oxides by ligand exchange). To assess changes in the transformation pathways caused by sorption, we added uniformly and position-specifically 13C and 14C labeled Alanine to the Ap of a loamy Luvisol in a short-term (10 days) incubation experiment. To allow for sorption of the tracer solution to an aliquot of this soil, microbial activity was minimized in this subsample by sterilizing the soil by γ-radiation. After shaking, the remaining solutions were filtered and the non-sorbed Alanine was removed with Millipore water and then added to non-sterilized soil. For the free Alanine treatment, solutions with Alanine of similar amount and isotopic composition were prepared, added to the soil and incubated as well. The respired CO2 was trapped in NaOH and its 14C-activity was determined at increasing times intervals. Microbial utilization of Alanine's individual C positions was evaluated in distinct microbial groups classified by 13C-PLFA analysis. Sorption to soil minerals delayed respiration to CO2 and reduced initial respiration rate by 80%. Irrespective of sorption, the highest amount was respired from the carboxylic position (C-1), whereas the amino-bound (C-2) and the methylic position (C-3) were preferentially incorporated into PLFA of microorganisms due to the

  9. Thyroid Scan and Uptake

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    Full Text Available ... of the Thyroid Scan and Uptake? What is a Thyroid Scan and Uptake? A thyroid scan is ... encourage linking to this site. × Recommend RadiologyInfo to a friend Send to (friend's e-mail address): From ( ...

  10. Thyroid Scan and Uptake

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    Full Text Available Toggle navigation Test/Treatment Patient Type Screening/Wellness Disease/Condition Safety En Español More Info Images/Videos About Us News Physician ... of nuclear medicine imaging. The radioactive iodine uptake test (RAIU) is also known as a thyroid uptake. ...

  11. Thyroid Scan and Uptake

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    Full Text Available ... of the Thyroid Scan and Uptake? What is a Thyroid Scan and Uptake? A thyroid scan is ... encourage linking to this site. × Recommend RadiologyInfo to a friend Send to (friend's e-mail address): From ( ...

  12. Thyroid Scan and Uptake

    Medline Plus

    Full Text Available Toggle navigation Test/Treatment Patient Type Screening/Wellness Disease/Condition Safety En Español More Info Images/Videos About Us News Physician ... of nuclear medicine imaging. The radioactive iodine uptake test (RAIU) is also known as a thyroid uptake. ...

  13. Growth of transplastomic cells expressing D-amino acid oxidase in chloroplasts is tolerant to D-alanine and inhibited by D-valine.

    Science.gov (United States)

    Gisby, Martin F; Mudd, Elisabeth A; Day, Anil

    2012-12-01

    Dual-conditional positive/negative selection markers are versatile genetic tools for manipulating genomes. Plastid genomes are relatively small and conserved DNA molecules that can be manipulated precisely by homologous recombination. High-yield expression of recombinant products and maternal inheritance of plastid-encoded traits make plastids attractive sites for modification. Here, we describe the cloning and expression of a dao gene encoding D-amino acid oxidase from Schizosaccharomyces pombe in tobacco (Nicotiana tabacum) plastids. The results provide genetic evidence for the uptake of D-amino acids into plastids, which contain a target that is inhibited by D-alanine. Importantly, this nonantibiotic-based selection system allows the use of cheap and widely available D-amino acids, which are relatively nontoxic to animals and microbes, to either select against (D-valine) or for (D-alanine) cells containing transgenic plastids. Positive/negative selection with d-amino acids was effective in vitro and against transplastomic seedlings grown in soil. The dual functionality of dao is highly suited to the polyploid plastid compartment, where it can be used to provide tolerance against potential D-alanine-based herbicides, control the timing of recombination events such as marker excision, influence the segregation of transgenic plastid genomes, identify loci affecting dao function in mutant screens, and develop D-valine-based methods to manage the spread of transgenic plastids tagged with dao.

  14. Efficient L-Alanine Production by a Thermo-Regulated Switch in Escherichia coli.

    Science.gov (United States)

    Zhou, Li; Deng, Can; Cui, Wen-Jing; Liu, Zhong-Mei; Zhou, Zhe-Min

    2016-01-01

    L-Alanine has important applications in food, pharmaceutical and veterinary and is used as a substrate for production of engineered thermoplastics. Microbial fermentation could reduce the production cost and promote the application of L-alanine. However, the presence of L-alanine significantly inhibit cell growth rate and cause a decrease in the ultimate L-alanine productivity. For efficient L-alanine production, a thermo-regulated genetic switch was designed to dynamically control the expression of L-alanine dehydrogenase (alaD) from Geobacillus stearothermophilus on the Escherichia coli B0016-060BC chromosome. The optimal cultivation conditions for the genetically switched alanine production using B0016-060BC were the following: an aerobic growth phase at 33 °C with a 1-h thermo-induction at 42 °C followed by an oxygen-limited phase at 42 °C. In a bioreactor experiment using the scaled-up conditions optimized in a shake flask, B0016-060BC accumulated 50.3 g biomass/100 g glucose during the aerobic growth phase and 96 g alanine/100 g glucose during the oxygen-limited phase, respectively. The L-alanine titer reached 120.8 g/l with higher overall and oxygen-limited volumetric productivities of 3.09 and 4.18 g/l h, respectively, using glucose as the sole carbon source. Efficient cell growth and L-alanine production were reached separately, by switching cultivation temperature. The results revealed the application of a thermo-regulated strategy for heterologous metabolic production and pointed to strategies for improving L-alanine production.

  15. Beta Thalassemia (For Parents)

    Science.gov (United States)

    ... Kids to Be Smart About Social Media Beta Thalassemia KidsHealth > For Parents > Beta Thalassemia Print A A ... Complications Symptoms Diagnosis Treatment en español Beta talasemia Thalassemias Thalassemias are a group of blood disorders that ...

  16. 40 CFR 721.520 - Alanine, N-(2-carboxyethyl)-N-alkyl-, salt.

    Science.gov (United States)

    2010-07-01

    ...-, salt. 721.520 Section 721.520 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED... Specific Chemical Substances § 721.520 Alanine, N-(2-carboxyethyl)-N-alkyl-, salt. (a) Chemical substance... alanine, N-(2-carboxyethyl)-N- alkyl-, salt (P-89-336) is subject to reporting under this section for the...

  17. Using Position-Specific 13C and 14C Labeling and 13C-PLFA Analysis to Assess Microbial Transformations of Free Versus Sorbed Alanine

    Science.gov (United States)

    Apostel, C.; Herschbach, J.; Bore, E. K.; Kuzyakov, Y.; Dippold, M. A.

    2015-12-01

    Sorption of charged or partially charged low molecular weight organic substances (LMWOS) to soil mineral surfaces delays microbial uptake and therefore mineralization of LMWOS to CO2, as well as all other biochemical transformations. We used position-specific labeling, a tool of isotope applications novel to soil sciences, to compare the transformation mechanisms of sorbed and non-sorbed alanine in soil. Alanine as an amino acid links C- and N-cycles in soil and therefore is a model substance for the pool of LMWOS. To assess transformations of sorbed alanine, we added position-specific and uniformly 13C and 14C labeled alanine tracer to soil that had previously been sterilized by γ-radiation. The labeled soil was added to non-sterilized soil from the same site and incubated. Soil labeled with the same tracers without previous sorption was prepared and incubated as well. We captured the respired CO2 and determined its 14C-activity at increasing time intervals. The incorporation of 14C into microbial biomass was determined by chloroform fumigation extraction (CFE), and utilization of individual C positions by distinct microbial groups was evaluated by 13C-phospholipid fatty acid analysis (PLFA). A dual peak in the respired CO2 revealed two sorption mechanisms. To compare the fate of individual C atoms independent of their concentration and pool size in soil, we applied the divergence index (DI). The DI reveals the convergent or divergent behavior of C from individual molecule positions during microbial utilization. Alanine C-1 position was mainly oxidized to CO2, while its C-2 and C-3 were preferentially incorporated in microbial biomass and PLFA. This indicates that sorption by the COOH group does not protect this group from preferential oxidation. Microbial metabolism was determinative for the preferential oxidation of individual molecule positions. The use of position-specific labeling revealed mechanisms and kinetics of microbial utilization of sorbed and non

  18. Dependence of alanine gel dosimeter response as a function of photon clinical beams dose rate

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Cleber Feijo, E-mail: cleber.feijo@famesp.com.br [Faculdade Metodo de Sao Paulo (FAMESP), SP (Brazil); Campos, Leticia Lucente, E-mail: Icrodri@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2013-11-01

    Gel dosimetry is a new area developed by Gore, it is ery useful for application in radiotherapy because using NMR imaging as evaluation technique is possible to evaluate three dimensional absorbed dose distribution. The measure technique is based on difference of ferrous (Fe{sup 2+}) and ferric (Fe{sup 3+}) ) ions concentration that can be measured also by spectrophotometry technique. The Alanine gel dosimeter was developed at IPEN. The alanine is an amino acid and tissue equivalent material that presents significant improvement on previous alanine dosimetry systems. The addition of Alanine increases the production of ferric ions in the solution. This work aims to study the dose rate dependence of photon clinical beams radiation on the alanine gel dosimeter optical response, as well as the response repeatability and gel production reproducibility, since this property is very important for characterization and standardization of any dosimeter. (author)

  19. Preliminary assessment of LiF and alanine detectors for the dosimetry of proton therapy beams

    Energy Technology Data Exchange (ETDEWEB)

    Fattibene, P.; Calicchia, A.; De Angelis, C.; Onori, S. [Istituto Superiore di Sanita, Rome (Italy)]|[Istituto Nazionale di Fisica Nucleare, Rome (Italy). Sezione Sanita; d`Errico, F. [Pisa Univ. (Italy). Dipt. di Costruzioni Meccaniche e Nucleari]|[Istituto Nazionale di Fisica Nucleare, Pisa (Italy); Egger, E. [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1996-12-31

    An experimental intercomparison between the proton response of LiF TLD-100 and alanine detectors is reported. The investigations were performed with LiF chips and alanine pellets in a 62 MeV proton beam at the Paul Scherrer Institut in Villigen (CH). Results were compared with reference dosimetry provided by Markus type parallel plate ionization chamber. The response of the detectors was studied, in a phantom, at different beam penetration depths in pristine and modulated beams. For both alanine and TL detectors, within the experimental uncertainty of the measurements, no significant energy dependence in the response was observed down to the Bragg peak region. The sensitivity of alanine and LiF detectors to protons was measured in the centre of modulated Bragg peak and no significant difference was found with respect to {sup 60}Co. Contrary to LiF, alanine also offers a remarkable tissue equivalence which favours its choice for in-phantom dosimetry. (author).

  20. Impact of charged amino acid substitution in the transmembrane domain of L-alanine exporter, AlaE, of Escherichia coli on the L-alanine export.

    Science.gov (United States)

    Kim, Seryoung; Ihara, Kohei; Katsube, Satoshi; Ando, Tasuke; Isogai, Emiko; Yoneyama, Hiroshi

    2017-01-01

    The Escherichia coli alaE gene encodes the L-alanine exporter, AlaE, that catalyzes active export of L-alanine using proton electrochemical potential. The transporter comprises only 149 amino acid residues and four predicted transmembrane domains (TMs), which contain three charged amino acid residues. The AlaE-deficient L-alanine non-metabolizing cells (ΔalaE cells) appeared hypersusceptible to L-alanyl-L-alanine showing a minimum inhibitory concentration (MIC) of 2.5 µg/ml for the dipeptide due to a toxic accumulation of L-alanine. To elucidate the mechanism by which AlaE exports L-alanine, we replaced charged amino acid residues in the TMs, glutamic acid-30 (TM-I), arginine-45 (TM-II), and aspartic acid-84 (TM-III) with their respective charge-conserved amino acid or a net neutral cysteine. The ΔalaE cells producing R45K or R45C appeared hypersusceptible to the dipeptide, indicating that arginine-45 is essential for AlaE activity. MIC of the dipeptide in the ΔalaE cells expressing E30D and E30C was 156 µg/ml and >10,000 µg/ml, respectively, thereby suggesting that a negative charge at this position is not essential. The ΔalaE cells expressing D84E or D84C showed an MIC >10,000 and 78 µg/ml, respectively, implying that a negative charge is required at this position. These results were generally consistent with that of the L-alanine accumulation experiments in intact cells. We therefore concluded that charged amino acid residues (R45 and D84) in the AlaE transmembrane domain play a pivotal role in L-alanine export. Replacement of three cysteine residues at C22, C28 (both in TM-I), and C135 (C-terminal region) with alanine showed only a marginal effect on L-alanine export.

  1. Estimating kinetic rates from accelerated molecular dynamics simulations: Alanine dipeptide in explicit solvent as a case study

    Science.gov (United States)

    de Oliveira, César Augusto F.; Hamelberg, Donald; McCammon, J. Andrew

    2007-11-01

    Molecular dynamics (MD) simulation is the standard computational technique used to obtain information on the time evolution of the conformations of proteins and many other molecular systems. However, for most biological systems of interest, the time scale for slow conformational transitions is still inaccessible to standard MD simulations. Several sampling methods have been proposed to address this issue, including the accelerated molecular dynamics method. In this work, we study the extent of sampling of the phi/psi space of alanine dipeptide in explicit water using accelerated molecular dynamics and present a framework to recover the correct kinetic rate constant for the helix to beta-strand transition. We show that the accelerated MD can drastically enhance the sampling of the phi/psi conformational phase space when compared to normal MD. In addition, the free energy density plots of the phi/psi space show that all minima regions are accurately sampled and the canonical distribution is recovered. Moreover, the kinetic rate constant for the helix to beta-strand transition is accurately estimated from these simulations by relating the diffusion coefficient to the local energetic roughness of the energy landscape. Surprisingly, even for such a low barrier transition, it is difficult to obtain enough transitions to accurately estimate the rate constant when one uses normal MD.

  2. Ergogenic Effects of β-Alanine and Carnosine: Proposed Future Research to Quantify Their Efficacy

    Directory of Open Access Journals (Sweden)

    John Caruso

    2012-06-01

    Full Text Available β-alanine is an amino acid that, when combined with histidine, forms the dipeptide carnosine within skeletal muscle. Carnosine and β-alanine each have multiple purposes within the human body; this review focuses on their roles as ergogenic aids to exercise performance and suggests how to best quantify the former’s merits as a buffer. Carnosine normally makes a small contribution to a cell’s total buffer capacity; yet β-alanine supplementation raises intracellular carnosine concentrations that in turn improve a muscle’s ability to buffer protons. Numerous studies assessed the impact of oral β-alanine intake on muscle carnosine levels and exercise performance. β-alanine may best act as an ergogenic aid when metabolic acidosis is the primary factor for compromised exercise performance. Blood lactate kinetics, whereby the concentration of the metabolite is measured as it enters and leaves the vasculature over time, affords the best opportunity to assess the merits of β-alanine supplementation’s ergogenic effect. Optimal β-alanine dosages have not been determined for persons of different ages, genders and nutritional/health conditions. Doses as high as 6.4 g day−1, for ten weeks have been administered to healthy subjects. Paraesthesia is to date the only side effect from oral β-alanine ingestion. The severity and duration of paraesthesia episodes are dose-dependent. It may be unwise for persons with a history of paraesthesia to ingest β-alanine. As for any supplement, caution should be exercised with β-alanine supplementation.

  3. Thyroid Scan and Uptake

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    Full Text Available ... uptake are not performed on patients who are pregnant because of the risk of exposing the fetus to radiation. These tests are also not recommended for breastfeeding women. Nuclear medicine procedures can be time consuming. It ...

  4. Thyroid Scan and Uptake

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    Full Text Available ... is taken by mouth, in either liquid or capsule form, it is typically swallowed up to 24 ... I-123 or I-131) in liquid or capsule form to swallow. The thyroid uptake will begin ...

  5. Thyroid Scan and Uptake

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    Full Text Available ... which are encased in metal and plastic and most often shaped like a box, attached to a ... will I experience during and after the procedure? Most thyroid scan and thyroid uptake procedures are painless. ...

  6. Thyroid Scan and Uptake

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    Full Text Available ... scan and uptake uses small amounts of radioactive materials called radiotracers, a special camera and a computer ... last two months that used iodine-based contrast material. Your doctor will instruct you on how to ...

  7. Thyroid Scan and Uptake

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    Full Text Available ... eat for several hours before your exam because eating can affect the accuracy of the uptake measurement. ... often unattainable using other imaging procedures. For many diseases, nuclear medicine scans yield the most useful information ...

  8. Thyroid Scan and Uptake

    Medline Plus

    Full Text Available ... RAIU) is also known as a thyroid uptake. It is a measurement of thyroid function, but does ... they offer the potential to identify disease in its earliest stages as well as a patient’s immediate ...

  9. Thyroid Scan and Uptake

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    Full Text Available ... time for the imaging to begin, you will sit in a chair facing a stationary probe positioned ... counter used for thyroid uptake exams. The patient sits with the camera directed at the neck for ...

  10. Thyroid Scan and Uptake

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    Full Text Available ... for several hours before your exam because eating can affect the accuracy of the uptake measurement. Jewelry ... small hand-held device resembling a microphone that can detect and measure the amount of the radiotracer ...

  11. Thyroid Scan and Uptake

    Medline Plus

    Full Text Available ... information about your thyroid’s size, shape, position and function that is often unattainable using other imaging procedures. ... thyroid uptake. It is a measurement of thyroid function, but does not involve imaging. Nuclear medicine is ...

  12. Thyroid Scan and Uptake

    Medline Plus

    Full Text Available ... A thyroid scan is a type of nuclear medicine imaging. The radioactive iodine uptake test (RAIU) is ... thyroid function, but does not involve imaging. Nuclear medicine is a branch of medical imaging that uses ...

  13. Thyroid Scan and Uptake

    Medline Plus

    Full Text Available ... RAIU) is also known as a thyroid uptake. It is a measurement of thyroid function, but does ... they offer the potential to identify disease in its earliest stages as well as a patient’s immediate ...

  14. Thermochemical Study of Lanthanum Complex Crystal with β-Alanine

    Institute of Scientific and Technical Information of China (English)

    陈平初; 屈松生; 詹正坤; 吴新明

    2002-01-01

    Lanthanum complex crystal with β-alanine (1∶3) was synthesized. Through the DTA,TG,chemistry analysis and comparison with literature, it shows that its form is {[La2(β-ala)6* (H2O)4](ClO4)6*H2O}n, and its purity is 98.86%. The dissolution enthalpy of the reactants and products in 2 mol*L-1 HCl solution (298.15K) was measured by using the isoperibol reaction calorimetry. ΔrHm was calculated by a designed thermochemical cycle of the coordination reaction. From the results and other auxiliary quantities, the standard molar enthalpy of formation of [La2(β-ala)6*(H2O)4](ClO4)6*H2O is obtained to be ΔfHm°{[La2(β-ala)6*(H2O)4](ClO4)6*H2O} = - 7062.911 kJ*mol-1.

  15. Enzymatic characterization and crystal structure analysis of the D-alanine-D-alanine ligase from Helicobacter pylori.

    Science.gov (United States)

    Wu, Dalei; Zhang, Liang; Kong, Yunhua; Du, Jiamu; Chen, Shuai; Chen, Jing; Ding, Jianping; Jiang, Hualiang; Shen, Xu

    2008-09-01

    D-Alanine-D-alanine ligase is the second enzyme in the D-Ala branch of bacterial cell wall peptidoglycan assembly, and recognized as an attractive antimicrobial target. In this work, the D-Ala-D-Ala ligase of Helicobacter pylori strain SS1 (HpDdl) was kinetically and structurally characterized. The determined apparent K(m) of ATP (0.87 microM), the K(m1) (1.89 mM) and K(m2) of D-Ala (627 mM), and the k(cat) (115 min(-1)) at pH 8.0 indicated its relatively weak binding affinity and poor catalytic activity against the substrate D-Ala in vitro. However, by complementary assay of expressing HpDdl in Escherichia coli Delta ddl mutant, HpDdl was confirmed to be capable of D-Ala-D-Ala ligating in vivo. Through sequence alignment with other members of the D-Ala-D-X ligase superfamily, HpDdl keeps two conservatively substituted residues (Ile16 and Leu241) and two nonconserved residues (Leu308 and Tyr311) broadly located in the active region of the enzyme. Kinetic analyses against the corresponding HpDdl mutants (I16V, L241Y, L241F, L308T, and Y311S) suggested that these residues, especially Leu308 and Tyr311, might partly contribute to the unique catalytic properties of the enzyme. This was fairly proved by the crystal structure of HpDdl, which revealed that there is a 3(10)-helix (including residues from Gly306 to Leu312) near the D-Ala binding region in the C-terminal domain, where HpDdl has two sequence deletions compared with other homologs. Such 3(10)-helix may participate in D-Ala binding and conformational change of the enzyme. Our present work hopefully provides useful information for understanding the D-Ala-D-Ala ligase of Helicobacter pylori.

  16. Revised mechanism of D-alanine incorporation into cell wall polymers in Gram-positive bacteria.

    Science.gov (United States)

    Reichmann, Nathalie T; Cassona, Carolina Picarra; Gründling, Angelika

    2013-09-01

    Teichoic acids (TAs) are important for growth, biofilm formation, adhesion and virulence of Gram-positive bacterial pathogens. The chemical structures of the TAs vary between bacteria, though they typically consist of zwitterionic polymers that are anchored to either the peptidoglycan layer as in the case of wall teichoic acid (WTA) or the cell membrane and named lipoteichoic acid (LTA). The polymers are modified with D-alanines and a lack of this decoration leads to increased susceptibility to cationic antimicrobial peptides. Four proteins, DltA-D, are essential for the incorporation of d-alanines into cell wall polymers and it has been established that DltA transfers D-alanines in the cytoplasm of the cell onto the carrier protein DltC. However, two conflicting models have been proposed for the remainder of the mechanism. Using a cellular protein localization and membrane topology analysis, we show here that DltC does not traverse the membrane and that DltD is anchored to the outside of the cell. These data are in agreement with the originally proposed model for D-alanine incorporation through a process that has been proposed to proceed via a D-alanine undecaprenyl phosphate membrane intermediate. Furthermore, we found that WTA isolated from a Staphylococcus aureus strain lacking LTA contains only a small amount of D-alanine, indicating that LTA has a role, either direct or indirect, in the efficient D-alanine incorporation into WTA in living cells.

  17. β - Alanine protects mice from memory deficits induced by ageing, scopolamine, diazepam and ethanol

    Directory of Open Access Journals (Sweden)

    Dhingra D

    2006-01-01

    Full Text Available The present study was undertaken to investigate the effects of β-alanine (a glycine agonist, on learning and memory in mice. β-alanine (5, 10, 20 and 40 mg/kg i.p. was administered for 6 successive days, to young (3 months old and aged-mice (16 months old. The learning and memory parameters were assessed, using elevated plus-maze and passive-avoidance apparatus. The effect of β-alanine (20 mg/kg for 6 days on locomotor function of young and aged mice, was studied using photoactometer, to rule out the increase in locomotor performance of mice. β-alanine at both the doses (10 and 20 mg/kg, significantly improved learning and memory of young- and aged- mice. β-alanine also reversed scopolamine (0.4 mg/kg i.p., ethanol (1.0 g/kg i.p. and diazepam (1.0 mg/kg i.p. -induced amnesia in young mice. There was no significant effect of β-alanine on the locomotor activity of both young and aged mice. The probable underlying mechanism of the memory-enhancing effect of β-alanine appears to be related to its antioxidant, anti-amyloid and procholinergic activities.

  18. Growth and characterization of L-Alanine-doped Zinc Thiourea Chloride single crystal (ZTC)

    Science.gov (United States)

    Dhumane, N. R.; Hussaini, S. S.; Dongre, V. G.; Ghugare, P.; Shirsat, M. D.

    2009-06-01

    Single crystal of L-Alanine-doped Zinc Thiourea Chloride (ZTC) was grown by slow evaporation technique. L-Alanine was added in saturated ZTC solution by molar percent. The second-harmonic generation efficiency was studied by Kurtz and Perry powder SHG test for 1, 2, and 3 mole% L-Alanine-doped ZTC and compared with pure ZTC. We observed enhancement in the SHG efficiency of L-Alanine-doped ZTC. Higher enhancement was observed for 3 mole% L-Alanine-doped ZTC. Incorporation of L-Alanine in the crystal was confirmed by energy dispersive X-ray analysis (EDAX). The Fourier transform infrared spectroscopy (FTIR) qualitatively confirms the presence of all the functional groups. The unit cell parameters and crystal structure were determined by single crystal X-ray diffraction. The UV-visible absorption spectra of L-Alanine-doped ZTC show excellent transmittance from 300 nm to 1100 nm. The thermal stability of the grown crystal was also studied by thermo-gravimetric analysis (TGA).

  19. In vivo dosimetry with L-alpha-alanine

    Energy Technology Data Exchange (ETDEWEB)

    Boey, R.; Van Der Velden, K. [Industriele Hogeschool van het Gemeenschapsonderwijs Limburg, Hasselt (Belgium); Schaeken, B. [Algemeen Ziekenhuis Middelheim, Antwerp (Belgium). Dept. of Radiotherapy

    1995-12-01

    When organic substances are irradiated, stable electrons can be formed. The concentration of these electrons is detected via electron paramagnetic resonance (EPR), a non-destructive form of dosimetry. L-alpha-alanine is extremely suited as a detector because of its high stability and high yield of unpaired electrons. With an EMS 104 spectrometer, we measure the peak-to-peak value of the first derivate of the resonance-spectrum. This value is proportional to the concentration of unpaired electrons and therefore with the absorbed dose. Prior to the in vivo measurements in teletherapy, a calibration curve had to be established. This clearly showed a linear relationship between the EPR-signal and the absorbed dose, except for very low dose where precision was low (20% 1 sd). This indicates that the background signal of the dosimeter is strongly orientation dependent. For this reason it was decided to use pre-irradiated detectors. A number of in vivo measurements has been performed. It was found that the error propagation plays a major role in the calculation of the measured absorbed dose, in the range 1 Gy-6 Gy. Contrary to in vivo measurements in brachytherapy, where higher doses are measured, large uncertainties (30% 1 sd) on the entry dose calculations were observed. For this reason, it is recommended to use a statistical method of reducing this standard deviation to an acceptable level. The proposed method, consisting of 2 detectors and the usage of weight coefficients on our standard deviations, gave promising results. However, theoretical calculations and in vivo measurements show that this method is still not satisfactory to reduce the uncertainty to an acceptable standard in clinical situations.

  20. Normal serum alanine aminotransferase activity in uncomplicated obesity

    Institute of Scientific and Technical Information of China (English)

    Gianluca Iacobellis; Antonio Moschetta; Maria Cristina Ribaudo; Alessandra Zappaterreno; Concetta Valeria Iannucci; Frida Leonetti

    2005-01-01

    AIM: To evaluate serum alanine aminotransferase (ALT)activity in a well-characterized group of uncomplicated obese subjects and its correlation with insulin resistance,plasma adiponectin, and leptin concentrations.METHODS: One hundred and five uncomplicatedobese subjects (87 women, 18 men, age 34.3±9.6 years,BMI 39.9±8.3 kg/m2)were studied. Serum ALT activity was evaluated. Insulin sensitivity was assessed by euglycemic hyperinsulinemic clamp (M index) and fasting insulin. Plasma leptin and adiponectin levels were also measured.RESULTS: Serum ALT concentration in the whole group of uncomplicated obese subjects was 17.73±6.33 U/L with none of the subjects presenting ALT levels greater than 43 U/L and only 9 (11%) women and 3 (19%) men showed ALT levels >19 and >30 U/L for women and men,respectively. No significant difference was detected in serum ALT levels between severe obese subjects (BMI >40 kg/m2) and those with BMI <40 kg/m2 (18.63±6.25 vs 17.26±6.02 U/L). ALT was significantly correlated with fasting insulin (r = 0.485, P = 0.02) and triglycerides (r= 0.358, P= 0.03).CONCLUSION: Serum ALT activity is practically normal in uncomplicated obese subjects, independently of their obesity degree. These findings suggest the role of obesityrelated comorbidities and not of BMI as main risk factors for elevated ALT levels in obese subjects.

  1. Temperature dependences of piezoelectric, elastic and dielectric constants of L-alanine crystal

    Science.gov (United States)

    Tylczyński, Z.; Sterczyńska, A.; Wiesner, M.

    2011-09-01

    Temperature changes in the components of piezoelectric, elastic and dielectric tensors were studied in L-alanine crystals in the range 100-300 K. A jumpwise increase in the c55 component of the elastic stiffness accompanied by maxima in damping of all face-shear modes observed at 199 K in L-alanine crystal were interpreted as a result of changes in the NH3+ vibrations occurring through electron-phonon coupling. All components of the piezoelectric tensor show small anomalies in this temperature range. The components of the electromechanical coupling coefficient determined indicate that L-alanine is a weak piezoelectric.

  2. Interactions of L-alanine with alumina as studied by vibrational spectroscopy.

    Science.gov (United States)

    Garcia, Ana R; de Barros, Ricardo Brito; Fidalgo, Alexandra; Ilharco, Laura M

    2007-09-25

    The interactions of L-alanine with gamma- and alpha-alumina have been investigated by diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS). L-alanine/alumina samples were dried from aqueous suspensions, at 36.5 degrees C, with two amino acid concentrations (0.4 and 0.8 mmol g-1) and at different pH values (1, 6, and 13). The vibrational spectra proved that the nature of L-alanine interactions with both aluminas is the same (hydrogen bonding), although the groups involved depend on the L-alanine form and on alumina surface groups, both controlled by the pH. For samples prepared at pH 1, cationic L-alanine [CH3CH(NH3+)COOH] displaces physisorbed water from alumina, and strong hydrogen bonds are established between the carbonyl groups of alanine, as electron donors, and the surface Al-OH2+ groups of alumina. This occurs at the expense of alanine dimer dissociation and breaking of intramolecular bonds. When samples are prepared at pH 6, the interacting groups are Al-OH2+ and the carboxylate groups of zwitterionic L-alanine [CH3CH(NH3+)COO-]. The affinity of L-alanine toward alumina decreases, as the strong NH3+...-OOC intermolecular hydrogen bonds prevail over the interactions with alumina. Thus, for a load of 0.8 mmol g-1, phase segregation is observed. On alpha-alumina, crystal deposition is even observed for a load of 0.4 mmol g-1. At pH 13, the carboxylate groups of anionic L-alanine [CH3CH(NH2)COO-] are not affected by alumina. Instead, hydrogen bond interactions occur between NH2 and the Al-OH surface groups of the substrate. Complementary N2 adsorption-desorption isotherms showed that adsorption of L-alanine occurs onto the alumina pore network for samples prepared at pH 1 and 13, whereas at pH 6 the amino acid/alumina interactions are not strong enough to promote adsorption. The mesoporous structure and the high specific surface area of gamma-alumina make it a more efficient substrate for adsorption of L-alanine. For each alumina, however, it is

  3. Optical and Spectral Studies on β Alanine Metal Halide Hybrid Crystals

    Science.gov (United States)

    Sweetlin, M. Daniel; Selvarajan, P.; Perumal, S.; Ramalingom, S.

    2011-10-01

    We have synthesized and grown β alanine metal halide hybrid crystals viz. β alanine cadmium chloride (BACC), an amino acid transition metal halide complex crystal and β alanine potassium chloride (BAPC), an amino acid alkali metal halide complex crystal by slow evaporation method. The grown crystals were found to be transparent and have well defined morphology. The optical characteristics of the grown crystals were carried out with the help of UV-Vis Spectroscopy. The optical transmittances of the spectrums show that BAPC is more transparent than BACC. The Photoluminescence of the materials were determined by the Photoluminescent Spectroscopy

  4. Spectroscopic Evidence for an Oxazolone Structure of the b(2) Fragment Ion from Protonated Tri-Alanine

    NARCIS (Netherlands)

    Oomens, J.; Young, S.; Molesworth, S.; Van Stipdonk, M.

    2009-01-01

    Infrared multiple photon dissociation (IRMPD) spectroscopy is used to identify the structure of the b(2)(+) ion generated from protonated tri-alanine by collision induced dissociation (CID). The IRMPD spectrum of b(2)(+) differs markedly from that of protonated cyclo-alanine-alanine, demonstrating t

  5. Characterization of the l-alanine exporter AlaE of Escherichia coli and its potential role in protecting cells from a toxic-level accumulation of l-alanine and its derivatives.

    Science.gov (United States)

    Kim, Seryoung; Ihara, Kohei; Katsube, Satoshi; Hori, Hatsuhiro; Ando, Tasuke; Isogai, Emiko; Yoneyama, Hiroshi

    2015-08-01

    We previously reported that the alaE gene of Escherichia coli encodes the l-alanine exporter AlaE. The objective of this study was to elucidate the mechanism of the AlaE exporter. The minimum inhibitory concentration of l-alanine and l-alanyl-l-alanine in alaE-deficient l-alanine-nonmetabolizing cells MLA301ΔalaE was 4- and >4000-fold lower, respectively, than in the alaE-positive parent cells MLA301, suggesting that AlaE functions as an efflux pump to avoid a toxic-level accumulation of intracellular l-alanine and its derivatives. Furthermore, the growth of the alaE-deficient mutant derived from the l-alanine-metabolizing strain was strongly inhibited in the presence of a physiological level of l-alanyl-l-alanine. Intact MLA301ΔalaE and MLA301ΔalaE/pAlaE cells producing plasmid-borne AlaE, accumulated approximately 200% and 50%, respectively, of the [(3) H]l-alanine detected in MLA301 cells, suggesting that AlaE exports l-alanine. When 200 mmol/L l-alanine-loaded inverted membrane vesicles prepared from MLA301ΔalaE/pAlaE were placed in a solution containing 200 mmol/L or 0.34 μmol/L l-alanine, energy-dependent [(3) H]l-alanine accumulation occurred under either condition. This energy-dependent uphill accumulation of [(3) H]l-alanine was strongly inhibited in the presence of carbonyl cyanide m-chlorophenylhydrazone but not by dicyclohexylcarbodiimide, suggesting that the AlaE-mediated l-alanine extrusion was driven by proton motive force. Based on these results, physiological roles of the l-alanine exporter are discussed.

  6. Shared receptor components but distinct complexes for alpha and beta interferons.

    Science.gov (United States)

    Lewerenz, M; Mogensen, K E; Uzé, G

    1998-09-25

    The type I interferon family includes 13 alpha, one omega and one beta subtypes recognized by a complex containing the receptor subunits ifnar1 and ifnar2 and their associated Janus tyrosine kinases, Tyk2 and Jak1. To investigate the reported differences in the way that alpha and beta interferons signal through the receptor, we introduced alanine-substitutions in the ifnar2 extracellular domain, and expressed the mutants in U5A cells, lacking endogenous ifnar2. A selection, designed to recover mutants that responded preferentially to alpha or beta interferon yielded three groups: I, neutral; II, sensitive to alpha interferon, partially resistant to beta interferon; III, resistant to alpha interferon, partially sensitive to beta interferon. A mutant clone, TMK, fully resistant to alpha interferon with good sensitivity to beta interferon, was characterized in detail and compared with U5A cells complemented with wild-type ifnar2 and also with Tyk2-deficient 11.1 cells, which exhibit a similar alpha-unresponsive phenotype with a partial beta interferon response. Using anti-receptor antibodies and mutant forms of beta interferon, three distinct modes of ligand interaction could be discerned: (i) alpha interferon with ifnar1 and ifnar2; (ii) beta interferon with ifnar1 and ifnar2; (iii) beta interferon with ifnar2 alone. We conclude that alpha and beta interferons signal differently through their receptors because the two ligand subtypes interact with the receptor subunits ifnar 1 and ifnar2 in entirely different ways.

  7. A comparative study on the growth and characterization of nonlinear optical amino acid crystals: L-alanine (LA) and L-alanine alaninium nitrate (LAAN).

    Science.gov (United States)

    Aravindan, A; Srinivasan, P; Vijayan, N; Gopalakrishnan, R; Ramasamy, P

    2008-11-15

    A comparative study on the properties of L-alanine and LAAN crystals has been made and discussed. It may be concluded that the protonation of the amino group in the L-alanine molecule is the key factor in increasing the relative SHG efficiency of LAAN. The protonation is justified by the crystal structure analysis, FTIR and photoluminescence studies. The factor group vibrations are compared and found that there is an increase in vibrational modes of LA when reacted with nitric acid forming LAAN.

  8. Determination of the carbon, hydrogen and nitrogen contents of alanine and their uncertainties using the certified reference material L-alanine (NMIJ CRM 6011-a).

    Science.gov (United States)

    Itoh, Nobuyasu; Sato, Ayako; Yamazaki, Taichi; Numata, Masahiko; Takatsu, Akiko

    2013-01-01

    The carbon, hydrogen, and nitrogen (CHN) contents of alanine and their uncertainties were estimated using a CHN analyzer and the certified reference material (CRM) L-alanine. The CHN contents and their uncertainties, as measured using the single-point calibration method, were 40.36 ± 0.20% for C, 7.86 ± 0.13% for H, and 15.66 ± 0.09% for N; the results obtained using the bracket calibration method were also comparable. The method described in this study is reasonable, convenient, and meets the general requirement of having uncertainties ≤ 0.4%.

  9. Mitochondrial calcium uptake.

    Science.gov (United States)

    Williams, George S B; Boyman, Liron; Chikando, Aristide C; Khairallah, Ramzi J; Lederer, W J

    2013-06-25

    Calcium (Ca(2+)) uptake into the mitochondrial matrix is critically important to cellular function. As a regulator of matrix Ca(2+) levels, this flux influences energy production and can initiate cell death. If large, this flux could potentially alter intracellular Ca(2+) ([Ca(2+)]i) signals. Despite years of study, fundamental disagreements on the extent and speed of mitochondrial Ca(2+) uptake still exist. Here, we review and quantitatively analyze mitochondrial Ca(2+) uptake fluxes from different tissues and interpret the results with respect to the recently proposed mitochondrial Ca(2+) uniporter (MCU) candidate. This quantitative analysis yields four clear results: (i) under physiological conditions, Ca(2+) influx into the mitochondria via the MCU is small relative to other cytosolic Ca(2+) extrusion pathways; (ii) single MCU conductance is ∼6-7 pS (105 mM [Ca(2+)]), and MCU flux appears to be modulated by [Ca(2+)]i, suggesting Ca(2+) regulation of MCU open probability (P(O)); (iii) in the heart, two features are clear: the number of MCU channels per mitochondrion can be calculated, and MCU probability is low under normal conditions; and (iv) in skeletal muscle and liver cells, uptake per mitochondrion varies in magnitude but total uptake per cell still appears to be modest. Based on our analysis of available quantitative data, we conclude that although Ca(2+) critically regulates mitochondrial function, the mitochondria do not act as a significant dynamic buffer of cytosolic Ca(2+) under physiological conditions. Nevertheless, with prolonged (superphysiological) elevations of [Ca(2+)]i, mitochondrial Ca(2+) uptake can increase 10- to 1,000-fold and begin to shape [Ca(2+)]i dynamics.

  10. Implementation of an alanine dosimetry service; Puesta en marcha de un servicio de dosimetria de alanima

    Energy Technology Data Exchange (ETDEWEB)

    Gago Arias, A.; Nunez Pelaez, N.; Peteiro Vilaseco, E.; Gomez Rodriguez, F.; Gonzalez Castano, D. M.

    2011-07-01

    This work facing the implementation of an alanine dosimetry service, linked to the installation of Co{sub 6}0 Radio physics Laboratory (LP) and Paramagnetic Resonance Service of the University of Santiago de Compostela (USC).

  11. SYNTHESIS OF D-AND L-β-(4-CHLOROPHENYL)-α-ALANINE

    Institute of Scientific and Technical Information of China (English)

    沈宗璇; 张雅文; 顾德本; 滕洪流; 杨冰

    1991-01-01

    N-acetyl-β-(4-chloropheayl)-DL-α-alanine ethyl ester was synthesized from p-chlorobenzyl chloride via diethyl malonate method. The ethyl ester was effectively resofued by enzymatic hydrolysis with using of subtilisin carlsberg.

  12. 21 CFR 862.1030 - Alanine amino transferase (ALT/SGPT) test system.

    Science.gov (United States)

    2010-04-01

    ... serum and plasma. Alanine amino transferase measurements are used in the diagnosis and treatment of certain liver diseases (e.g., viral hepatitis and cirrhosis) and heart diseases. (b) Classification. Class...

  13. Second harmonic generation studies in L-alanine single crystals grown from solution

    Science.gov (United States)

    Boomadevi, Shanmugam; Pandiyan, Krishnamoorthy

    2014-01-01

    Single crystals of L-alanine of dimensions 2×1.1×0.5 cm3 were grown by evaporation method using deionised water as a solvent. The morphology of the grown crystals had (1 2 0) and (0 1 1) as their prominent faces. UV-vis-near IR spectrum shows the transparency range of L-alanine crystal available for frequency doubling from 250 to 1400 nm. Phase-matched second harmonic generation was observed in L-alanine sample by using 7 ns Q-switched Nd:YAG laser with OPO set up. In the present work, phase matching was achieved by angle and wavelength tuning. The angular and spectral phase-matching bandwidths were determined experimentally for a 1.5 mm thick L-alanine crystal and the results have been compared with their theoretical results. Further the possible reasons for the broadening of SHG spectrum have been discussed.

  14. Second harmonic generation studies in L-alanine single crystals grown from solution

    Energy Technology Data Exchange (ETDEWEB)

    Boomadevi, Shanmugam, E-mail: sboomi@gmail.com [Department of Physics, Periyar Maniammai University, Thanjavur-613 403, Tamil Nadu (India); Pandiyan, Krishnamoorthy [School of Electrical and Electronics Engineering, SASTRA University, Thanjavur-613 401, Tamil Nadu (India)

    2014-01-01

    Single crystals of L-alanine of dimensions 2×1.1×0.5 cm{sup 3} were grown by evaporation method using deionised water as a solvent. The morphology of the grown crystals had (1 2 0) and (0 1 1) as their prominent faces. UV–vis-near IR spectrum shows the transparency range of L-alanine crystal available for frequency doubling from 250 to 1400 nm. Phase-matched second harmonic generation was observed in L-alanine sample by using 7 ns Q-switched Nd:YAG laser with OPO set up. In the present work, phase matching was achieved by angle and wavelength tuning. The angular and spectral phase-matching bandwidths were determined experimentally for a 1.5 mm thick L-alanine crystal and the results have been compared with their theoretical results. Further the possible reasons for the broadening of SHG spectrum have been discussed.

  15. Substrate Specificity of the Aspartate:Alanine Antiporter (AspT) of Tetragenococcus halophilus in Reconstituted Liposomes*

    OpenAIRE

    Sasahara, Ayako; Nanatani, Kei; Enomoto, Masaru; Kuwahara, Shigefumi; Abe, Keietsu

    2011-01-01

    The aspartate:alanine antiporter (AspT) of the lactic acid bacterium Tetragenococcus halophilus is a member of the aspartate:alanine exchanger (AAEx) transporter family. T. halophilus AspT catalyzes the electrogenic exchange of l-aspartate1− with l-alanine0. Although physiological functions of AspT were well studied, l-aspartate1−:l-alanine0 antiport mechanisms are still unsolved. Here we report that the binding sites of l-aspartate and l-alanine are independently present in AspT by means of ...

  16. Unexpected inhibition of peptidoglycan LD-transpeptidase from Enterococcus faecium by the beta-lactam imipenem.

    Science.gov (United States)

    Mainardi, Jean-Luc; Hugonnet, Jean-Emmanuel; Rusconi, Filippo; Fourgeaud, Martine; Dubost, Lionel; Moumi, Angèle Nguekam; Delfosse, Vanessa; Mayer, Claudine; Gutmann, Laurent; Rice, Louis B; Arthur, Michel

    2007-10-19

    The beta-lactam antibiotics mimic the D-alanyl(4)-D-alanine(5) extremity of peptidoglycan precursors and act as "suicide" substrates of the DD-transpeptidases that catalyze the last cross-linking step of peptidoglycan synthesis. We have previously shown that bypass of the dd-transpeptidases by the LD-transpeptidase of Enterococcus faecium (Ldt(fm)) leads to high level resistance to ampicillin. Ldt(fm) is specific for the L-lysyl(3)-D-alanine(4) bond of peptidoglycan precursors containing a tetrapeptide stem lacking D-alanine(5). This specificity was proposed to account for resistance, because the substrate of Ldt(fm) does not mimic beta-lactams in contrast to the D-alanyl(4)-D-alanine(5) extremity of pentapeptide stems used by the DD-transpeptidases. Here, we unexpectedly show that imipenem, a beta-lactam of the carbapenem class, totally inhibited Ldt(fm) at a low drug concentration that was sufficient to inhibit growth of the bacteria. Peptidoglycan cross-linking was also inhibited, indicating that Ldt(fm) is the in vivo target of imipenem. Stoichiometric and covalent modification of Ldt(fm) by imipenem was detected by mass spectrometry. The modification was mapped into the trypsin fragment of Ldt(fm) containing the catalytic Cys residue, and the Cys to Ala substitution prevented imipenem binding. The mass increment matched the mass of imipenem, indicating that inactivation of Ldt(fm) is likely to involve rupture of the beta-lactam ring and acylation of the catalytic Cys residue. Thus, the spectrum of activity of beta-lactams is not restricted to transpeptidases of the DD-specificity, as previously thought. Combination therapy with imipenem and ampicillin could therefore be active against E. faecium strains having the dual capacity to manufacture peptidoglycan with transpeptidases of the LD- and DD-specificities.

  17. SU-E-T-643: Pure Alanine Dosimeter for Verification Dosimetry in IMRT

    Energy Technology Data Exchange (ETDEWEB)

    Al-Karmi, Anan M.; Zraiqat, Fadi [Physics Department, King Fahd University of Petroleum & Minerals, Dhahran 31261 (Saudi Arabia)

    2015-06-15

    Purpose: The objective of this study was evaluation of accuracy of pure alanine dosimeters measuring intensity-modulated radiation therapy (IMRT) dose distributions in a thorax phantom. Methods: Alanine dosimeters were prepared in the form of 110 mg pure L-α-alanine powder filled into clear tissue-equivalent polymethylmethacrylate (PMMA) plastic tubes with the dimensions 25 mm length, 3 mm inner diameter, and 1 mm wall thickness. A dose-response calibration curve was established for the alanine by placing the dosimeters at 1.5 cm depth in a 30×30×30 cm{sup 3} solid water phantom and then irradiating on a linac with 6 MV photon beam at 10×10 cm{sup 2} field size to doses ranging from 1 to 5 Gy. Electron paramagnetic resonance (EPR) spectroscopy was used to determine the absorbed dose in alanine. An IMRT treatment plan was designed for a commercial heterogeneous CIRS thorax phantom and the dose values were calculated at three different points located in tissue, lung, and bone equivalent materials. A set of dose measurements was carried out to compare measured and calculated dose values by placing the alanine dosimeters at those selected locations inside the thorax phantom and delivering the IMRT to the phantom. Results: The alanine dose measurements and the IMRT plan dose calculations were found to be in agreement within ±2%. Specifically, the deviations were −0.5%, 1.3%, and −1.7% for tissue, lung, and bone; respectively. The slightly large deviations observed for lung and bone may be attributed to tissue inhomogeneity, steep dose gradients in these regions, and uncontrollable changes in spectrometer conditions. Conclusion: The results described herein confirmed that pure alanine dosimeter was suitable for in-phantom dosimetry of IMRT beams because of its high sensitivity and acceptable accuracy. This makes the dosimeter a promising option for quality control of the therapeutic beams, complementing the commonly used ionization chambers, TLDs, and films.

  18. L-alanine supplementation in late infantile glycogen storage disease type II.

    Science.gov (United States)

    Bodamer, Olaf A; Haas, Dorothea; Hermans, Monique M; Reuser, Arnold J; Hoffmann, Georg F

    2002-08-01

    We report a male with late infantile glycogen storage disease type II (Pompe's disease) who presented at 12 months of age with muscular hypotonia and developmental delay. Oral supplementation with L-alanine has been administered for 5 years. Progression of skeletal myopathy was slow, and cardiomyopathy resolved almost completely. L-alanine may be a valuable supplement for infants with glycogen storage disease type II.

  19. Thyroid Scan and Uptake

    Medline Plus

    Full Text Available ... type your comment or suggestion into the following text box: Comment: E-mail: Area code: Phone no: Thank you! Images × Image Gallery Photograph of a typical probe counter used for thyroid uptake exams. The patient sits with the camera directed at the neck for five minutes, and then the leg for ...

  20. Effect of abomasal glucose infusion on alanine metabolism and urea production in sheep.

    Science.gov (United States)

    Obitsu, T; Bremner, D; Milne, E; Lobley, G E

    2000-08-01

    The effect of abomasal infusion of glucose (120 kJ/d per kg body weight (BW)0.75, 758 mmol/d) on urea production, plasma alanine-N flux rate and the conversion of alanine-N to urea was studied in sheep offered a low-N diet at limited energy intake (500 kJ/d per kg BW0.75), based on hay and grass pellets. Glucose provision reduced urinary N (P = 0.040) and urea (P = 0.009) elimination but this was offset by poorer N digestibility. Urea-N production was significantly reduced (822 v. 619 mmol/d, P = 0.024) by glucose while plasma alanine-N flux rate was elevated (295 v. 342 mmol/d, P = 0.011). The quantity of urea-N derived from alanine tended to be decreased by glucose (127 v. 95 mmol/d) but the fraction of urea production from alanine was unaltered (15%). Plasma urea and alanine concentrations (plus those of the branched chain amino acids) decreased in response to exogenous glucose, an effect probably related to enhanced anabolic usage of amino acids and lowered urea production.

  1. Electrochemical analysis of the alanine phenylthiohydantoin derivative by cathodic stripping voltammetry.

    Science.gov (United States)

    Vilaseca, C; Quintana, M C; Vicente, J; Hernández, P; Hernández, L

    2008-08-01

    A square-wave cathodic stripping voltammetry method for alanine determination as its phenylthiohydantoin (PTH-alanine) derivative is developed. To this end, all the chemical and instrumental variables affecting the determination of PTH-alanine are optimized. From studies of the mechanisms governing the electrochemical response of PTH-alanine, it was concluded that it is an electrochemically irreversible system with a diffusive-adsorptive reduction phenomenon. Under optimal conditions, the variation of analytical signal (I(p)) with PTH-alanine concentration is linear in the 2.4x10(-8)-4.8x10(-7) M range, with a LOD of 1.2x10(-8) M and a LOQ of 4.2x10(-8) M, a RSD (%) less than 11%, and a E(r) (%) less than 10%. The optimized method was applied to the determination of PTH-alanine obtained from a synthetic protein after Edman reaction and the results were corroborated by high-performance liquid chromatography with UV detection.

  2. Expression, crystallization and preliminary X-ray crystallographic analysis of D-alanine-D-alanine ligase from OXA-23-producing Acinetobacter baumannii K0420859.

    Science.gov (United States)

    Huynh, Kim-Hung; Tran, Huyen-Thi; Pham, Tan-Viet; Ngo, Ho-Phuong-Thuy; Cha, Sun-Shin; Chung, Kyung Min; Lee, Sang Hee; Kang, Lin-Woo

    2014-04-01

    Acinetobacter baumannii causes bacteraemia, pneumonia, other respiratory-tract and urinary-tract infections in humans. OXA-23 carbapenemase-producing A. baumannii K0420859 (A. baumannii OXA-23) is resistant to carbapenem, a common antibacterial drug. To develop an efficient and novel antibacterial drug against A. baumannii OXA-23, D-alanine-D-alanine ligase, which is essential in bacterial cell-wall synthesis, is of interest. Here, the D-alanine-D-alanine ligase (AbDdl) gene from A. baumannii OXA-23 was cloned and expressed, and the AbDdl protein was purified and crystallized; this enzyme can be used as a novel target for an antibacterial drug against A. baumannii OXA-23. The AbDdl crystal diffracted to a resolution of 2.8 Å and belonged to the orthorhombic space group P212121, with unit-cell parameters a = 113.4, b = 116.7, c = 176.5 Å, a corresponding VM of 2.8 Å(3) Da(-1) and a solvent content of 56.3%, and six protomers in the asymmetric unit.

  3. Beta-carotene

    Science.gov (United States)

    ... patches on the tongue and mouth called oral leukoplakia. Taking beta-carotene by mouth for up to 12 months seems to decrease symptoms of oral leukoplakia. Osteoarthritis. Beta-carotene taken by mouth may prevent ...

  4. Betting Against Beta

    DEFF Research Database (Denmark)

    Frazzini, Andrea; Heje Pedersen, Lasse

    .S. equities, 20 international equity markets, Treasury bonds, corporate bonds, and futures; (2) A betting-against-beta (BAB) factor, which is long leveraged low beta assets and short high-beta assets, produces significant positive risk-adjusted returns; (3) When funding constraints tighten, the return...

  5. Beta-methylamino-L-alanine analysis by liquid chromatography tandem mass spectrometry with iTRAQ as the derivative.

    Science.gov (United States)

    Kushnir, Mark M; Bergquist, Jonas

    2009-01-01

    Amino acid BMMA is produced by cyanobacteria and has been linked to the development of neurodegenerative diseases. We developed a method for quantitative analysis of BMAA in biological samples and plant extracts. The method is utilizing iTRAQ and LC-MS/MS detection using multiple reaction monitoring mode. The method uses 50 microL of sample and has a limit of quantitation of 300 ng mL(-1), within-run run imprecision below 1%. Using this method we analyzed human serum samples, human cerebrospinal fluid samples and extract of the cycad seed. No BMAA could be detected in the human samples. Content of BMAA in the seed was 50 mg kg(-1).

  6. Forward-Looking Betas

    DEFF Research Database (Denmark)

    Christoffersen, Peter; Jacobs, Kris; Vainberg, Gregory

    Few issues are more important for finance practice than the computation of market betas. Existing approaches compute market betas using historical data. While these approaches differ in terms of statistical sophistication and the modeling of the time-variation in the betas, they are all backward......-looking. This paper introduces a radically different approach to estimating market betas. Using the tools in Bakshi and Madan (2000) and Bakshi, Kapadia and Madan (2003) we employ the information embedded in the prices of individual stock options and index options to compute our forward-looking market beta...

  7. Growth enhancing effect of exogenous glycine and characterization of its uptake in halotolerant cyanobacterium Aphanothece halophytica.

    Science.gov (United States)

    Bualuang, Aporn; Incharoensakdi, Aran

    2015-02-01

    Alkaliphilic halotolerant cyanobacterium Aphanothece halophytica showed optimal growth in the medium containing 0.5 M NaCl. The increase of exogenously added glycine to the medium up to 10 mM significantly promoted cell growth under both normal (0.5 M NaCl) and salt stress (2.0 M NaCl) conditions. Salt stress imposed by either 2.0 or 3.0 M NaCl retarded cell growth; however, exogenously added glycine at 10 mM concentration to salt-stress medium resulted in the reduction of growth inhibition particularly under 3.0 M NaCl condition. The uptake of glycine by intact A. halophytica was shown to exhibit saturation kinetics with an apparent K s of 160 μM and V max of 3.9 nmol/min/mg protein. The optimal pH for glycine uptake was at pH 8.0. The uptake activity was decreased in the presence of high concentration of NaCl. Both metabolic inhibitors and ionophores decreased glycine uptake in A. halophytica suggesting an energy-dependent glycine uptake. Several neutral amino acids showed considerable inhibition of glycine uptake with higher than 50 % inhibition observed with serine, cysteine and alanine whereas acidic, basic and aromatic amino acids showed only slight inhibition of glycine uptake.

  8. The cyanobacterial neurotoxin β-N-methylamino-l-alanine (BMAA) induces neuronal and behavioral changes in honeybees.

    Science.gov (United States)

    Okle, Oliver; Rath, Lisa; Galizia, C Giovanni; Dietrich, Daniel R

    2013-07-01

    The cyanobacterially produced neurotoxin beta-N-methylamino-l-alanine (BMAA) is thought to induce amyotrophic lateral sclerosis/Parkinsonism dementia complex (ALS/PDC)-like symptoms. However, its mechanism of action and its pathway of intoxication are yet unknown. In vivo animal models suitable for investigating the neurotoxic effect of BMAA with applicability to the human are scarce. Hence, we used the honeybee (Apis mellifera) since its nervous system is relatively simple, yet having cognitive capabilities. Bees fed with BMAA-spiked sugar water had an increased mortality rate and a reduced ability to learn odors in a classical conditioning paradigm. Using (14)C-BMAA we demonstrated that BMAA is biologically available to the bee, and is found in the head, thorax and abdomen with little to no excretion. BMAA is also transferred from one bee to the next via trophallaxis resulting in an exposure of the whole beehive. BMAA bath application directly onto the brain leads to an altered Ca(2+) homeostasis and to generation of reactive oxygen species. These behavioral and physiological observations suggest that BMAA may have effects on bee brains similar to those assumed to occur in humans. Therefore the bee could serve as a surrogate model system for investigating the neurological effects of BMAA.

  9. Alanine racemase is essential for the growth and interspecies competitiveness of Streptococcus mutans

    Institute of Scientific and Technical Information of China (English)

    Yuan Wei; Xin Xu; Ming-Yun Li; Wei Qiu; Xue-Dong Zhou; Xin Zheng; Ke-Ke Zhang; Shi-Da Wang; Yu-Qing Li; Lei Cheng; Ji-Yao Li

    2016-01-01

    D-alanine (D-Ala) is an essential amino acid that has a key role in bacterial cell wall synthesis. Alanine racemase (Alr) is a unique enzyme that interconverts L-alanine and D-alanine in most bacteria, making this enzyme a potential target for antimicrobial drug development. Streptococcus mutans is a major causative factor of dental caries. The factors involved in the survival, virulence and interspecies interactions of S. mutans could be exploited as potential targets for caries control. The current study aimed to investigate the physiological role of Alr in S. mutans. We constructed alr mutant strain of S. mutans and evaluated its phenotypic traits and interspecies competitiveness compared with the wild-type strain. We found that alr deletion was lethal to S. mutans. A minimal supplement of D-Ala (150μg·mL−1) was required for the optimal growth of the alr mutant. The depletion of D-alanine in the growth medium resulted in cell wall perforation and cell lysis in the alr mutant strain. We also determined the compromised competitiveness of the alr mutant strain relative to the wild-type S. mutans against other oral streptococci (S. sanguinis or S. gordonii), demonstrated using either conditioned medium assays or dual-species fluorescent in situ hybridization analysis. Given the importance and necessity of alr to the growth and competitiveness of S. mutans, Alr may represent a promising target to modulate the cariogenicity of oral biofilms and to benefit the management of dental caries.

  10. Alanine and TLD coupled detectors for fast neutron dose measurements in neutron capture therapy (NCT).

    Science.gov (United States)

    Cecilia, A; Baccaro, S; Cemmi, A; Colli, V; Gambarini, G; Rosi, G; Scolari, L

    2004-01-01

    A method was investigated to measure gamma and fast neutron doses in phantoms exposed to an epithermal neutron beam designed for neutron capture therapy (NCT). The gamma dose component was measured by TLD-300 [CaF2:Tm] and the fast neutron dose, mainly due to elastic scattering with hydrogen nuclei, was measured by alanine dosemeters [CH3CH(NH2)COOH]. The gamma and fast neutron doses deposited in alanine dosemeters are very near to those released in tissue, because of the alanine tissue equivalence. Couples of TLD-300 and alanine dosemeters were irradiated in phantoms positioned in the epithermal column of the Tapiro reactor (ENEA-Casaccia RC). The dosemeter response depends on the linear energy transfer (LET) of radiation, hence the precision and reliability of the fast neutron dose values obtained with the proposed method have been investigated. Results showed that the combination of alanine and TLD detectors is a promising method to separate gamma dose and fast neutron dose in NCT.

  11. Glucose-stimulated prehepatic insulin secretion is associated with circulating alanine, triglyceride, glucagon, lactate and TNF-alpha in patients with HIV-lipodystrophy

    DEFF Research Database (Denmark)

    Haugaard, S B; Andersen, O; Pedersen, S B

    2006-01-01

    technique. The disposition index (Di=ISREG0-10 min x SIRd) was calculated to estimate the beta-cell response relative to insulin sensitivity. RESULTS: FISR was increased by 69% (P... and ISREG0-10 min. Increased concentrations of the nonglucose insulin secretagogues triglyceride (+124%), alanine (+35%) and glucagon (+88%), and also lactate (+96%) and tumour necrosis factor (TNF)-alpha (+62%) were observed in the 10 LIPO patients with aberrations in FISR and ISREG0-10 min compared...... with the remaining HIV-infected patients (all Palanine, glucagon, lactate and TNF-alpha may be associated with alterations in the first-phase prehepatic insulin secretion response to intravenous glucose in normoglycaemic lipodystrophic HIV-infected patients....

  12. Glucose-stimulated prehepatic insulin secretion is associated with circulating alanine, triglyceride, glucagons, lactate and TNF-alfa in patients with HIV-lipodystrophy

    DEFF Research Database (Denmark)

    Haugaard, Steen B; Andersen, Ove; Pedersen, SB

    2006-01-01

    technique. The disposition index (Di=ISREG0-10 min x SIRd) was calculated to estimate the beta-cell response relative to insulin sensitivity. RESULTS: FISR was increased by 69% (P... and ISREG0-10 min. Increased concentrations of the nonglucose insulin secretagogues triglyceride (+124%), alanine (+35%) and glucagon (+88%), and also lactate (+96%) and tumour necrosis factor (TNF)-alpha (+62%) were observed in the 10 LIPO patients with aberrations in FISR and ISREG0-10 min compared...... with the remaining HIV-infected patients (all Palanine, glucagon, lactate and TNF-alpha may be associated with alterations in the first-phase prehepatic insulin secretion response to intravenous glucose in normoglycaemic lipodystrophic HIV-infected patients....

  13. Membrane receptor-initiated signaling in 1,25(OH)2D3-stimulated calcium uptake in intestinal epithelial cells.

    Science.gov (United States)

    Khanal, Ramesh C; Peters, Tremaine M Sterling; Smith, Nathan M; Nemere, Ilka

    2008-11-01

    Demonstrating 1,25(OH)2D3-stimulated calcium uptake in isolated chick intestinal epithelial cells has been complicated by simultaneous enhancement of both uptake and efflux. We now report that in intestinal cells of adult birds, or those of young birds cultured for 72 h, 1,25(OH)2D3-stimulates 45Ca uptake to greater than 140% of corresponding controls within 3 min of addition. Such cells have lost hormone-stimulated protein kinase C (PKC) activity, believed to mediate calcium efflux. To further test this hypothesis, freshly isolated cells were preincubated with calphostin C, and calcium uptake monitored in the presence or absence of steroid. Only cells treated with the PKC inhibitor demonstrated a significant increase in 45Ca uptake in response to 1,25(OH)2D3, relative to corresponding controls. In addition, phorbol ester was shown to stimulate efflux, while forskolin stimulated uptake. To further investigate the mechanisms involved in calcium uptake, we assessed the role of TRPV6 and its activation by beta-glucuronidase. beta-Glucuronidase secretion from isolated intestinal epithelial cells was significantly increased by treatment with 1,25(OH)2D3, PTH, or forskolin, but not by phorbol ester. Treatment of cells with beta-glucuronidase, in turn, stimulated 45Ca uptake. Finally, transfection of cells with siRNA to either beta-glucuronidase or TRPV6 abolished 1,25(OH)2D3-enhanced calcium uptake relative to controls transfected with scrambled siRNA. Confocal microscopy further indicated rapid redistribution of enzyme and calcium channel after steroid. 1,25(OH)2D3 and PTH increase calcium uptake by stimulating the PKA pathway to release beta-glucuronidase, which in turn activates TRPV6. 1,25(OH)2D3-enhanced calcium efflux is mediated by the PKC pathway.

  14. Probing the Catalytic Charge-Relay System in Alanine Racemase with Genetically Encoded Histidine Mimetics.

    Science.gov (United States)

    Sharma, Vangmayee; Wang, Yane-Shih; Liu, Wenshe R

    2016-12-16

    Histidine is a unique amino acid with an imidazole side chain in which both of the nitrogen atoms are capable of serving as a proton donor and proton acceptor in hydrogen bonding interactions. In order to probe the functional role of histidine involved in hydrogen bonding networks, fine-tuning the hydrogen bonding potential of the imidazole side chain is required but not feasible through traditional mutagenesis methods. Here, we show that two close mimetics of histidine, 3-methyl-histidine and thiazole alanine, can be genetically encoded using engineered pyrrolysine incorporation machinery. Replacement of the three histidine residues predicted to be involved in an extended charge-relay system in alanine racemase with 3-methyl-histidine or thiazole alanine shows a dramatic loss in the enzyme's catalytic efficiency, implying the role of this extended charge-relay system in activating the active site residue Y265, a general acid/base catalyst in the enzyme.

  15. Sensitivity of alanine dosimeters with gadolinium exposed to 6 MV photons at clinical doses.

    Science.gov (United States)

    Marrale, M; Longo, A; Spanò, M; Bartolotta, A; D'Oca, M C; Brai, M

    2011-12-01

    In this study we analyzed the ESR signal of alanine dosimeters with gadolinium exposed to 6 MV linear accelerator photons. We observed that the addition of gadolinium brings about an improvement in the sensitivity to photons because of its high atomic number. The experimental data indicated that the addition of gadolinium increases the sensitivity of the alanine to 6 MV photons. This enhancement was better observed at high gadolinium concentrations for which the tissue equivalence is heavily reduced. However, information about the irradiation setup and of the radiation beam features allows one to correct for this difference. Monte Carlo simulations were carried out to obtain information on the expected effect of the addition of gadolinium on the dose absorbed by the alanine molecules inside the pellets. These results are compared with the experimental values, and the agreement is discussed.

  16. Small-Field Dosimetry in A 6 MV Photon Beam Using Alanine and Liquid Ionisation Chamber

    DEFF Research Database (Denmark)

    Zimmermann, S.; Riis, H. L.; Hjelm-Hansen, M.

    2012-01-01

    Lion ionisation chamber for small-field dosimetry in liquid water. Materials and Methods: The measurements were carried out on a Siemens Primus 58 leaves MLC. The alanine dosimeters were cylindric Ø4.9 mm × 3.0 mm and density of 1.2 g/cm3. The alanine dosimeters were placed on the top of a solid water stick of Ø4......, 2 times 4 sweeps with a 90° turn in between, total measurement time was 3 minutes per dosimeter. The alanine dosimetry system was calibrated using a Co60 gamma cell ensuring traceability to a national standard. Results: The results are summarized in Table 1. At depths below 2 mm, we noted...

  17. Adsorption of L-Alanine on Cu(111) Studied by Scanning Tunnelling Microscopy

    Institute of Scientific and Technical Information of China (English)

    GE Si-Ping; L(U) Chao; ZHAO Ru-Guang

    2006-01-01

    The adsorption of L-alanine on Cu(111)surface is studied by means of scanning tunnelling microscopy under ultra-high Vacuum conditions.The results show that the adsorbates are chemisorbed on the surface,and can form a two-dimensional gas phase,chain phase and solid phase,depending on deposition rate and amount.The adsorbed molecules can be imaged as individual protrusions and parallel chains in gas and chain phases respectively.It is also found that alanine can form(2×2)superstructure on Cu(111)and copper step facet to directions in solid phase.On the basis of our scanning tunnelling microscopic images,a model js proposed for the Cu(111)(2×2)-alanine superstructure.In the model,we point out the close link between -direction hydrogen bond chains with the same direction copper step faceting.

  18. Nucleation kinetics, growth and studies of β-alanine single crystals

    Science.gov (United States)

    Shanthi, D.; Selvarajan, P.; HemaDurga, K. K.; Lincy Mary Ponmani, S.

    2013-06-01

    Solubility and metastable zone width for the re-crystallized salt of β-alanine was determined. Induction period measurement for the selected supersaturation ratios at room temperature (31 °C) was carried out for supersaturated aqueous solutions of β-alanine and it is noticed that induction period decreases with increase of supersaturation ratio. The nucleation parameters such as Gibbs free energy change, radius and number of molecules of the critical nucleus, interfacial tension and the nucleation rate have been evaluated by classical nucleation theory. Single crystals of β-alanine were grown using the optimized nucleation parameters by solution method and grown crystals have been subjected to various studies like XRD studies, FTIR, optical, thermal and SHG studies.

  19. Radiation chemistry of L-Alanine: application to EPR dosimetry (1)

    Energy Technology Data Exchange (ETDEWEB)

    Kim, M. J.; Jeo, Y. H.; Ha, Y. K.; Park, Y. S.; Choi, I. G. [KAERI, Taejon (Korea, Republic of)

    2003-10-01

    High energy ionizing radiation leaves stable radicals to certain organic materials, such as alanine and tartrate. Electron Paramagnetic Resonance (EPR) spectroscopy is a powerful tool for the identification and quantification of these radiation-induced radicals. An EPR method has been applied to study the radical characteristics of L-alanine after gamma radiation dose in the range of {approx}mGy to 60 kGy. The free radicals induced by gamma radiation were fairly stable, and EPR intensity, radical concentration, was proportional to the absorbed dose up to 60 kGy. From the results of our EPR measurements, it can be concluded that an alanine/EPR method is a useful technique for gamma radiation dosimetry from very low to high dose range.

  20. The background of the total synthesis of yeast alanine transfer RNA

    Institute of Scientific and Technical Information of China (English)

    QI GuoRong

    2010-01-01

    @@ The research findings concerning the total synthesis of yeast alanine transfer RNA (yeast alanine tRNA) were successively published in Chinese Science Bulletin (1982) and Science in China (1983) [1].The research work started in 1968 and was finished in November 1981.It was the first artificial synthesis of a nucleic acid molecule, which followed the first artificial synthesis of protein, crystalline bovine insulin, in China in 1965, both scientific milestones occurring in China.The composition, sequence and biological functions of the synthesized nucleic acid were identical to those of the natural yeast alanine tRNA.The research lasted for 13 years.From 1982 to 1984, one of the investigators in charge of the research Prof.

  1. Substrate Specificity of the Aspartate:Alanine Antiporter (AspT) of Tetragenococcus halophilus in Reconstituted Liposomes*

    Science.gov (United States)

    Sasahara, Ayako; Nanatani, Kei; Enomoto, Masaru; Kuwahara, Shigefumi; Abe, Keietsu

    2011-01-01

    The aspartate:alanine antiporter (AspT) of the lactic acid bacterium Tetragenococcus halophilus is a member of the aspartate:alanine exchanger (AAEx) transporter family. T. halophilus AspT catalyzes the electrogenic exchange of l-aspartate1− with l-alanine0. Although physiological functions of AspT were well studied, l-aspartate1−:l-alanine0 antiport mechanisms are still unsolved. Here we report that the binding sites of l-aspartate and l-alanine are independently present in AspT by means of the kinetic studies. We purified His6-tagged T. halophilus AspT and characterized its kinetic properties when reconstituted in liposomes (Km = 0.35 ± 0.03 mm for l-aspartate, Km = 0.098 ± 0 mm for d-aspartate, Km = 26 ± 2 mm for l-alanine, Km = 3.3 ± 0.2 mm for d-alanine). Competitive inhibition by various amino acids of l-aspartate or l-alanine in self-exchange reactions revealed that l-cysteine selectively inhibited l-aspartate self-exchange but only weakly inhibited l-alanine self-exchange. Additionally, l-serine selectively inhibited l-alanine self-exchange but barely inhibited l-aspartate self-exchange. The aspartate analogs l-cysteine sulfinic acid, l-cysteic acid, and d-cysteic acid competitively and strongly inhibited l-aspartate self-exchange compared with l-alanine self-exchange. Taken together, these kinetic data suggest that the putative binding sites of l-aspartate and l-alanine are independently located in the substrate translocation pathway of AspT. PMID:21719707

  2. Substrate specificity of the aspartate:alanine antiporter (AspT) of Tetragenococcus halophilus in reconstituted liposomes.

    Science.gov (United States)

    Sasahara, Ayako; Nanatani, Kei; Enomoto, Masaru; Kuwahara, Shigefumi; Abe, Keietsu

    2011-08-19

    The aspartate:alanine antiporter (AspT) of the lactic acid bacterium Tetragenococcus halophilus is a member of the aspartate:alanine exchanger (AAEx) transporter family. T. halophilus AspT catalyzes the electrogenic exchange of L-aspartate(1-) with L-alanine(0). Although physiological functions of AspT were well studied, L-aspartate(1-):L-alanine(0) antiport mechanisms are still unsolved. Here we report that the binding sites of L-aspartate and L-alanine are independently present in AspT by means of the kinetic studies. We purified His(6)-tagged T. halophilus AspT and characterized its kinetic properties when reconstituted in liposomes (K(m) = 0.35 ± 0.03 mm for L-aspartate, K(m) = 0.098 ± 0 mm for D-aspartate, K(m) = 26 ± 2 mm for L-alanine, K(m) = 3.3 ± 0.2 mm for D-alanine). Competitive inhibition by various amino acids of L-aspartate or L-alanine in self-exchange reactions revealed that L-cysteine selectively inhibited L-aspartate self-exchange but only weakly inhibited L-alanine self-exchange. Additionally, L-serine selectively inhibited L-alanine self-exchange but barely inhibited L-aspartate self-exchange. The aspartate analogs L-cysteine sulfinic acid, L-cysteic acid, and D-cysteic acid competitively and strongly inhibited L-aspartate self-exchange compared with L-alanine self-exchange. Taken together, these kinetic data suggest that the putative binding sites of L-aspartate and L-alanine are independently located in the substrate translocation pathway of AspT.

  3. Exosomes: Mechanisms of Uptake

    Directory of Open Access Journals (Sweden)

    Kelly J. McKelvey

    2015-07-01

    Full Text Available Exosomes are 30–100 nm microvesicles which contain complex cellular signals of RNA, protein and lipids. Because of this, exosomes are implicated as having limitless therapeutic potential for the treatment of cancer, pregnancy complications, infections, and autoimmune diseases. To date we know a considerable amount about exosome biogenesis and secretion, but there is a paucity of data regarding the uptake of exosomes by immune and non- immune cell types (e.g., cancer cells and the internal signalling pathways by which these exosomes elicit a cellular response. Answering these questions is of para‐ mount importance.

  4. Exosomes: Mechanisms of Uptake

    Directory of Open Access Journals (Sweden)

    Kelly J. McKelvey

    2015-07-01

    Full Text Available Exosomes are 30–100 nm microvesicles which contain complex cellular signals of RNA, protein and lipids. Because of this, exosomes are implicated as having limitless therapeutic potential for the treatment of cancer, pregnancy complications, infections, and autoimmune diseases. To date we know a considerable amount about exosome biogenesis and secretion, but there is a paucity of data regarding the uptake of exosomes by immune and non-immune cell types (e.g., cancer cells and the internal signalling pathways by which these exosomes elicit a cellular response. Answering these questions is of paramount importance.

  5. The crystal structure of the D-alanine-D-alanine ligase from Acinetobacter baumannii suggests a flexible conformational change in the central domain before nucleotide binding.

    Science.gov (United States)

    Huynh, Kim-Hung; Hong, Myoung-ki; Lee, Clarice; Tran, Huyen-Thi; Lee, Sang Hee; Ahn, Yeh-Jin; Cha, Sun-Shin; Kang, Lin-Woo

    2015-11-01

    Acinetobacter baumannii, which is emerging as a multidrug-resistant nosocomial pathogen, causes a number of diseases, including pneumonia, bacteremia, meningitis, and skin infections. With ATP hydrolysis, the D-alanine-D-alanine ligase (DDL) catalyzes the synthesis of D-alanyl-D-alanine, which is an essential component of bacterial peptidoglycan. In this study, we determined the crystal structure of DDL from A. baumannii (AbDDL) at a resolution of 2.2 Å. The asymmetric unit contained six protomers of AbDDL. Five protomers had a closed conformation in the central domain, while one protomer had an open conformation in the central domain. The central domain with an open conformation did not interact with crystallographic symmetry-related protomers and the conformational change of the central domain was not due to crystal packing. The central domain of AbDDL can have an ensemble of the open and closed conformations before the binding of substrate ATP. The conformational change of the central domain is important for the catalytic activity and the detail information will be useful for the development of inhibitors against AbDDL and putative antibacterial agents against A. baumannii. The AbDDL structure was compared with that of other DDLs that were in complex with potent inhibitors and the catalytic activity of AbDDL was confirmed using enzyme kinetics assays.

  6. The effect of β-alanine supplementation on cycling time trials of different length.

    Science.gov (United States)

    Bellinger, Phillip M; Minahan, Clare L

    2016-10-01

    The varying results reported in response to β-alanine supplementation may be related to the duration and nature of the exercise protocol employed. We investigated the effects of β-alanine supplementation on a wide range of cycling performance tests in order to produce a clear concise set of criteria for its efficacy. Fourteen trained cyclists (Age = 24.8 ± 6.7 years; VO2max = 65.4 ± 10.2 mL·kg·min(-1)) participated in this placebo-controlled, double-blind study. Prior to supplementation, subjects completed two (familiarization and baseline) supramaximal cycling bouts until exhaustion (120% pre-supplementation VO2max) and two 1-, 4- and 10-km cycling time trial (TT). Subjects then supplemented orally for 4 weeks with 6.4 g/d placebo or β-alanine and repeated the battery of performance tests. Blood lactate was measured pre-exercise, post-exercise and 5  min post-exercise. β-alanine supplementation elicited significant increases in time to exhaustion (TTE) (17.6 ± 11.5 s; p = 0.013, effect compared with placebo) and was likely to be beneficial to 4-km TT performance time (-7.8 ± 8.1 s; 94% likelihood), despite not being statistically different (p = 0.060). Performance times in the 1- and 10-km TT were not affected by treatment. For the highly trained cyclists in the current study, β-alanine supplementation significantly extended supramaximal cycling TTE and may have provided a worthwhile improvement to 4-km TT performance. However, 1- and 10-km cycling TT performance appears to be unaffected by β-alanine supplementation.

  7. Exchange of aspartate and alanine. Mechanism for development of a proton-motive force in bacteria.

    Science.gov (United States)

    Abe, K; Hayashi, H; Maloney, P C; Malone, P C

    1996-02-09

    We examined the idea that aspartate metabolism by Lactobacillus subsp. M3 is organized as a proton-motive metabolic cycle by using reconstitution to monitor the activity of the carrier, termed AspT, expected to carry out the electrogenic exchange of precursor (aspartate) and product (alanine). Membranes of Lactobacillus subsp. M3 were extracted with 1.25% octyl glucoside in the presence of 0. 4% Escherichia coli phospholipid and 20% glycerol. The extracts were then used to prepare proteoliposomes loaded with either aspartate or alanine. Aspartate-loaded proteoliposomes accumulated external [3H]aspartate by exchange with internal substrate; this homologous self-exchange (Kt = 0.4 mm) was insensitive to potassium or proton ionophores and was unaffected by the presence or absence of Na+, K+, or Mg2+. Alanine-loaded proteoliposomes also took up [3H]aspartate in a heterologous antiport reaction that was stimulated or inhibited by an inside-positive or inside-negative membrane potential, respectively. Several lines of evidence suggest that these homologous and heterologous exchange reactions were catalyzed by the same functional unit. Thus, [3H]aspartate taken up by AspT during self-exchange was released by a delayed addition of alanine. In addition, the spontaneous loss of AspT activity that occurs when a detergent extract is held at 37 degrees C prior to reconstitution was prevented by the presence of either aspartate (KD(aspartate) = 0.3 mm) or alanine (KD(alanine) > or = 10 mm), indicating that both substrates interact directly with AspT. These findings are consistent with operation of a proton-motive metabolic cycle during aspartate metabolism by Lactobacillus subsp. M3.

  8. Relative response of the alanine dosimeter to medium energy x-rays.

    Science.gov (United States)

    Anton, M; Büermann, L

    2015-08-01

    The response of the alanine dosimeter to kilovoltage x-rays with respect to the dose to water was measured, relative to the response to Co-60 radiation.Two series of x-ray qualities were investigated, one ranging from 30 kV to 100 kV tube voltage (TW series), the other one ranging from 70 kV to 280 kV (TH series). Due to the use of the water calorimeter as a primary standard, the uncertainty of the delivered dose is significantly lower than for other published data. The alanine response was measured as described in a previous publication (Anton et al 2013 Phys. Med. Biol. 58 3259-82). The uncertainty component due to the alanine measurement and analysis is ⩽0.4%, the major part of the combined uncertainty of the relative response originates from the uncertainty of the delivered dose. The relative uncertainties of the relative response vary from ⩽2% for the TW series to ⩽1.1% for the TH series.Different from the behaviour of the alanine dosimeter for megavoltage x-rays or electrons, the relative response drops significantly from unity for Co-60 radiation to less than 64% for the TW quality with a tube voltage of 30 kV. In order to reproduce this behaviour through Monte Carlo simulations, not only the ratio of the absorbed dose to alanine to the absorbed dose to water has to be known, but also the intrinsic efficiency, i.e. the dependence of the number of free radicals generated per unit of absorbed dose on the photon energy. This quantity is not yet accessible for the TW series.For a possible use of the alanine dosimeter for kilovoltage x-rays, for example in electronic brachytherapy, users should rely on the measured data for the relative response which have become available with this publication.

  9. Forward-Looking Betas

    DEFF Research Database (Denmark)

    Christoffersen, Peter; Jacobs, Kris; Vainberg, Gregory

    -looking. This paper introduces a radically different approach to estimating market betas. Using the tools in Bakshi and Madan (2000) and Bakshi, Kapadia and Madan (2003) we employ the information embedded in the prices of individual stock options and index options to compute our forward-looking market beta......Few issues are more important for finance practice than the computation of market betas. Existing approaches compute market betas using historical data. While these approaches differ in terms of statistical sophistication and the modeling of the time-variation in the betas, they are all backward...... at the daily frequency. This beta can be computed using option data for a single day, and is able to reflect sudden changes in the structure of the underlying company. Based on an empirical investigation of daily cross-sections of option contracts on thirty underlying companies, we conclude that these forward...

  10. Betting against Beta

    DEFF Research Database (Denmark)

    Frazzini, Andrea; Heje Pedersen, Lasse

    2014-01-01

    We present a model with leverage and margin constraints that vary across investors and time. We find evidence consistent with each of the model's five central predictions: (1) Because constrained investors bid up high-beta assets, high beta is associated with low alpha, as we find empirically for......, the return of the BAB factor is low. (4) Increased funding liquidity risk compresses betas toward one. (5) More constrained investors hold riskier assets....... for US equities, 20 international equity markets, Treasury bonds, corporate bonds, and futures. (2) A betting against beta (BAB) factor, which is long leveraged low-beta assets and short high-beta assets, produces significant positive risk-adjusted returns. (3) When funding constraints tighten...

  11. Betting Against Beta

    DEFF Research Database (Denmark)

    Frazzini, Andrea; Heje Pedersen, Lasse

    We present a model with leverage and margin constraints that vary across investors and time. We find evidence consistent with each of the model’s five central predictions: (1) Since constrained investors bid up high-beta assets, high beta is associated with low alpha, as we find empirically for U...... of the BAB factor is low; (4) Increased funding liquidity risk compresses betas toward one; (5) More constrained investors hold riskier assets........S. equities, 20 international equity markets, Treasury bonds, corporate bonds, and futures; (2) A betting-against-beta (BAB) factor, which is long leveraged low beta assets and short high-beta assets, produces significant positive risk-adjusted returns; (3) When funding constraints tighten, the return...

  12. Effect of β-alanine treatment on mitochondrial taurine level and 5-taurinomethyluridine content

    Science.gov (United States)

    2010-01-01

    Background The β-amino acid, taurine, is a nutritional requirement in some species. In these species, the depletion of intracellular stores of taurine leads to the development of severe organ dysfunction. The basis underlying these defects is poorly understood, although there is some suggestion that oxidative stress may contribute to the abnormalities. Recent studies indicate that taurine is required for normal mitochondrial protein synthesis and normal electron transport chain activity; it is known that defects in these events can lead to severe mitochondrial oxidative stress. The present study examines the effect of taurine deficiency on the first step of mitochondrial protein synthesis regulation by taurine, namely, the formation of taurinomethyluridine containing tRNA. Methods Isolated rat cardiomyocytes were rendered taurine deficient by incubation with medium containing the taurine transport inhibitor, β-alanine. The time course of cellular and mitochondrial taurine depletion was measured. The primer extension method was employed to evaluate the effect of β-alanine treatment on taurinomethyluridine content of tRNALeu. The protein levels of ND6 were also determined by Western blot analysis. Results β-alanine caused a time-dependent decrease in cellular taurine content, which were reduced in half after 48 hrs of incubation. The amount of taurine in the mitochondria was considerably less than that in the cytosol and was unaffected by β-alanine treatment. Approximately 70% of the tRNALeu in the untreated cell lacked taurinomethyluridine and these levels were unchanged following β-alanine treatment. Protein content of ND6, however, was significantly reduced after 48 hours incubation with β-alanine. Conclusions The taurine levels of the cytosol and the mitochondria are not directly coupled. The β-alanine-mediated reduction in taurine levels is too small to affect taurinomethyluridine levels. Nonetheless, it interferes with mitochondrial protein synthesis

  13. Active Oxygen Radical Scavenging Ability of Water-Soluble β-Alanine C60 Adducts

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Water-soluble β-alanine C60 adducts were synthesized, and the scavenging ability to superoxygen anion radical O2-and hydroxyl radicalOH were studied by autoxidation ofpyrogallol and chemiluminescence, respectively. It was found that β-alanine C60 adducts showed an excellent efficiency in eliminating superoxygen anion radical and hydroxyl radical. The 50% inhibition concentration (IC50) for superoxygen anion radical and hydroxyl radical were 0.15 mg/mL and 0.048 mg/mL, respectively. The difference should be mainly attributed to the different scavenging mechanisms.

  14. Poly[μ3-β-alanine-aqua-μ4-sulfato-dilithium

    OpenAIRE

    M. Daniel Sweetlin; Eapen, Shibu M.; Perumal, S.; S. Ramalingom

    2012-01-01

    The title compound, [Li2(SO4)(C3H7NO2)(H2O)]n, is a coordination polymer in which the β-alanine residues remain in the zwitterionic form. The crystal structure consists of corrugated sheets of [LiO4] and [SO4] tetrahedra parallel to (010) with the β-alanine molecules located between the sheets. The two independent Li+ cations are four-coordinated by O atoms in a distorted tetrahedral geometry. The crystal structure is formed by stacking of alternate organic and inorganic lay...

  15. Poly[μ3-β-alanine-aqua-μ4-sulfato-dilithium

    Directory of Open Access Journals (Sweden)

    M. Daniel Sweetlin

    2012-02-01

    Full Text Available The title compound, [Li2(SO4(C3H7NO2(H2O]n, is a coordination polymer in which the β-alanine residues remain in the zwitterionic form. The crystal structure consists of corrugated sheets of [LiO4] and [SO4] tetrahedra parallel to (010 with the β-alanine molecules located between the sheets. The two independent Li+ cations are four-coordinated by O atoms in a distorted tetrahedral geometry. The crystal structure is formed by stacking of alternate organic and inorganic layers along the a axis. The crystal structure is further stabilized by N—H...O hydrogen bonds.

  16. Poly[μ3-β-alanine-aqua-μ4-sulfato-dilithium

    OpenAIRE

    Sweetlin, M. Daniel; Eapen, Shibu M.; Perumal, S.; S. Ramalingom

    2012-01-01

    The title compound, [Li2(SO4)(C3H7NO2)(H2O)] n , is a coordination polymer in which the β-alanine residues remain in the zwitterionic form. The crystal structure consists of corrugated sheets of [LiO4] and [SO4] tetra­hedra parallel to (010) with the β-alanine mol­ecules located between the sheets. The two independent Li+ cations are four-coordinated by O atoms in a distorted tetra­hedral geometry. The crystal structure is formed by stacking of alternate organic and inorganic layers along the...

  17. Standard Enthalpies of Formation of Solid Complexes of Lanthanide Nitrates with Alanine

    Institute of Scientific and Technical Information of China (English)

    杨旭武; 陈三平; 高胜利; 刘晓华; 史启祯

    2002-01-01

    The combustion energies of fourteen solid complexes of lanthanide nitrate with alanine were determined. The standard enthalpies of combustion, Δc,coor(s)H°, and standard enthalpies of formation, Δf,coor(s)H°, were calculated for these complexes. The relationship of Δc,coor(s)H° and Δf,coor(s)H° with the atomic numbers of the elements in the lanthanide series were examined. The results show that a certain amount of covalence is present in the chemical bond between the lanthanide cations and alanine.

  18. Synthesis, Characterization and Metal Ion Detection of Novel Fluoroionophores Based on Heterocyclic Substituted Alanines

    Directory of Open Access Journals (Sweden)

    M. Manuela M Raposo

    2007-10-01

    Full Text Available The synthesis of new fluorescent probes containing the thiophene andbenzoxazole moieties combined with an alanine residue is described. The resulting highlyfluorescent heterocyclic alanine derivatives respond via a quenching effect, withparamagnetic Cu(II and Ni(II metal ions and with diamagnetic Hg(II, as shown by theabsorption and steady-state fluorescence spectroscopy studies. The formation ofmononuclear or dinuclear metal complexes was postulated based on the presence of thefree carboxylic acid as binding site and also with the interaction with the donor atoms inthe chromophore. Interaction with other important biological metal ions such as Zn(II,Ca(II and Na(I was also explored.

  19. Oxidation of phenyl alanine by pyridinium chlorochromate in acidic DMF–water medium: A kinetic study

    Directory of Open Access Journals (Sweden)

    B.L. Hiran

    2016-11-01

    Full Text Available The kinetics of oxidation of phenyl alanine by pyridinium chlorochromate in DMF–water (70:30% mixture in presence of perchloric acid leads to the formation of corresponding aldehyde. The reaction is of first order each in [PCC], [HClO4] and [AA]. Michaelis–Menten type kinetics was observed with phenyl alanine. The reaction rates were determined at different temperatures [25, 30, 35, 40, 45, 50 °C] and the activation parameters were calculated. The reaction does not induce polymerization of acrylonitrile. With an increase in the amount of DMF in its aqueous mixture, the rate increases. A suitable mechanism for the reaction was postulated.

  20. Beta-cryptoxanthin from citrus juices: assessment of bioaccessibility using an in vitro digestion/Caco-2 cell culture model.

    Science.gov (United States)

    Dhuique-Mayer, Claudie; Borel, Patrick; Reboul, Emmanuelle; Caporiccio, Bertrand; Besancon, Pierre; Amiot, Marie-Josèphe

    2007-05-01

    Beta-Cryptoxanthin (beta-CX), a provitaminic carotenoid of potential interest for health, is found principally in Citrus fruit in both free and esterified forms. Little is known about the intestinal absorption of beta-CX especially with regard to the esterified forms. The aim of this study was to evaluate the absorption of free and esterified beta-CX using simulated digestion coupled with the Caco-2 model. Bioaccessibility was investigated by measuring the transfer of carotenoids from different citrus juices into micelles using an in vitro digestion system. Then, carotenoid uptake was evaluated by adding carotenoid-rich micelles (from the in vitro digestion) or synthetic micelles (made from synthetic lipids and carotenoids purified from citrus juice) to human intestinal cells (Caco-2 TC7 clone). Our results showed that beta-cryptoxanthin esters (beta-CXE) were partially hydrolysed during the in vitro digestion. The bioaccessibility of free beta-CX measured was significantly higher (40 (SD 1.05) %) than that of beta-carotene (30 (SD 1.9) %) and beta-CXE (16 (SD 1.5) %). In the same way, the incorporation of free beta-CX (27 (SD 1.01) %) into synthetic micelles exceeded (Pdigestion, the uptake of beta-carotene, free beta-CX and beta-CXE forms by Caco-2 cells was 14.3 (SD 1.8), 3.9 (SD 1.3), and 0.7 (SD 0.08) % respectively. These results showed a preferential uptake by Caco-2 cells of beta-carotene and free beta-CX compared with the two esters of beta-CX.

  1. Imperfect World of $\\beta\\beta$-decay Nuclear Data Sets

    CERN Document Server

    Pritychenko, B

    2015-01-01

    The precision of double-beta ($\\beta\\beta$) decay experimental half lives and their uncertainties is reanalyzed. The method of Benford's distributions has been applied to nuclear reaction, structure and decay data sets. First-digit distribution trend for $\\beta\\beta$-decay T$_{1/2}^{2\

  2. Effect of diet-induced obesity on kinetic parameters of amino acid uptake by rat erythrocytes.

    Science.gov (United States)

    Picó, C; Pons, A; Palou, A

    1992-11-01

    The effects of cafeteria diet-induced obesity upon in vitro uptake of L-Alanine, Glycine, L-Lysine, L-Glutamine, L-Glutamic acid, L-Phenylalanine and L-Leucine by isolated rat erythrocytes have been studied. The total Phe and Leu uptakes followed Michaelis-Menten kinetics. The Glu uptake was fitted to diffusion kinetics. The uptakes of Ala, Gly, Lys and Gln were best explained by a two-component transport: one saturable and one diffusion. Obesity increased the Km value for Ala, Gln and Leu, and the Vmax value for Ala, but decreased the Vmax for Lys. Kinetic parameters of Phe uptake were unaffected by obesity. In addition, the pseudo-first order rate constant (Vmax/Km) for Ala, Gly, Gln, Lys and Leu uptake decreased as a result of cafeteria diet-induced obesity. The Kd value for Ala, Gly, Gln and Glu decreased and that of Lys increased as result of obesity. These adaptations could, at least in part, explain alterations in amino acid distribution between blood cells and plasma related to overfeeding or obesity.

  3. Effect of long-term transfusion therapy on the glycometabolic status and pancreatic beta cell function in patients with beta Thalassemia major

    Directory of Open Access Journals (Sweden)

    Kamalakshi G Bhat

    2014-01-01

    Full Text Available Background: Diabetes mellitus is a major complication of iron overload in patients with beta thalassemia major. Design: This is a descriptive study conducted in a Tertiary Care Teaching Hospital to analyze beta cell function and insulin resistance, and their relation to iron overload status in beta thalassemia major. Fasting glucose, two-hour post load glucose, fasting insulin, alanine amino transaminase (ALT, and ferritin were used as outcome measures. The homeostatic model assessment (HOMA model was used to calculate the beta cell function and insulin resistance index. Results: Of the 30 cases, 20% had impaired fasting glucose, 3.3% had impaired glucose tolerance, and none had diabetes. Fasting glucose was not significant between the cases and controls (P = 0.113. Fasting insulin (P = 0.001, ferritin (P = 0.001, and ALT (P = 0.001 levels were significantly high in the cases. Insulin resistance index was significantly higher in the cases (P = 0.001 as also the beta cell function (P = 0.001. With increase in age and the number of units transfused there is a decline in beta cell function, fasting insulin, and insulin resistance after attaining the maximum level. This suggests that initial insulin resistance is followed by insulin depletion due to loss of beta cell function, leading to diabetes mellitus. Conclusion: Impaired glucose tolerance (IGT and insulin resistance precede the onset of insulin-dependent diabetes and adequate chelation therapy is essential for delaying the onset or for prevention of diabetes.

  4. Effect of long-term transfusion therapy on the glycometabolic status and pancreatic Beta cell function in patients with Beta thalassemia major.

    Science.gov (United States)

    Bhat, Kamalakshi G; Periasamy, Prakash K

    2014-04-01

    Diabetes mellitus is a major complication of iron overload in patients with beta thalassemia major. This is a descriptive study conducted in a Tertiary Care Teaching Hospital to analyze beta cell function and insulin resistance, and their relation to iron overload status in beta thalassemia major. Fasting glucose, two-hour post load glucose, fasting insulin, alanine amino transaminase (ALT), and ferritin were used as outcome measures. The homeostatic model assessment (HOMA model) was used to calculate the beta cell function and insulin resistance index. Of the 30 cases, 20% had impaired fasting glucose, 3.3% had impaired glucose tolerance, and none had diabetes. Fasting glucose was not significant between the cases and controls (P = 0.113). Fasting insulin (P = 0.001), ferritin (P = 0.001), and ALT (P = 0.001) levels were significantly high in the cases. Insulin resistance index was significantly higher in the cases (P = 0.001) as also the beta cell function (P = 0.001). With increase in age and the number of units transfused there is a decline in beta cell function, fasting insulin, and insulin resistance after attaining the maximum level. This suggests that initial insulin resistance is followed by insulin depletion due to loss of beta cell function, leading to diabetes mellitus. Impaired glucose tolerance (IGT) and insulin resistance precede the onset of insulin-dependent diabetes and adequate chelation therapy is essential for delaying the onset or for prevention of diabetes.

  5. Liver alanine aminotransferase, insulin resistance and endothelial dysfunction in normotriglyceridaemic subjects with type 2 diabetes mellitus

    NARCIS (Netherlands)

    Schindhelm, RK; Diamant, M; Bakker, SJL; van Dijk, RAJM; Scheffer, PG; Teerlink, T; Kostense, PJ; Heine, RJ

    2005-01-01

    Background Plasma levels of liver transaminases, including alanine aminotransferase (ALT), are elevated in most cases of nonalcoholic fatty liver disease (NAFLD). Elevated ALT levels are associated with insulin resistance, and subjects with NAFLD have features of the metabolic syndrome that confer h

  6. On the fragmentation of biomolecules: fragmentation of alanine dipeptide along the polypeptide chain

    DEFF Research Database (Denmark)

    Solov'yov, Ilia; Yakubovich, Alexander; Solov'yov, Andrey;

    2006-01-01

    The interaction potential between amino acids in alanine dipeptide has been studied for the first time taking into account exact molecular geometry. Ab initio calculation has been performed in the framework of density functional theory taking into account all electrons in the system. The fragment...

  7. Protein Homeostasis Defects of Alanine-Glyoxylate Aminotransferase: New Therapeutic Strategies in Primary Hyperoxaluria Type I

    Directory of Open Access Journals (Sweden)

    Angel L. Pey

    2013-01-01

    Full Text Available Alanine-glyoxylate aminotransferase catalyzes the transamination between L-alanine and glyoxylate to produce pyruvate and glycine using pyridoxal 5′-phosphate (PLP as cofactor. Human alanine-glyoxylate aminotransferase is a peroxisomal enzyme expressed in the hepatocytes, the main site of glyoxylate detoxification. Its deficit causes primary hyperoxaluria type I, a rare but severe inborn error of metabolism. Single amino acid changes are the main type of mutation causing this disease, and considerable effort has been dedicated to the understanding of the molecular consequences of such missense mutations. In this review, we summarize the role of protein homeostasis in the basic mechanisms of primary hyperoxaluria. Intrinsic physicochemical properties of polypeptide chains such as thermodynamic stability, folding, unfolding, and misfolding rates as well as the interaction of different folding states with protein homeostasis networks are essential to understand this disease. The view presented has important implications for the development of new therapeutic strategies based on targeting specific elements of alanine-glyoxylate aminotransferase homeostasis.

  8. Positron and electron scattering by glycine and alanine: Shape resonances and methylation effect

    Science.gov (United States)

    Nunes, Fernanda B.; Bettega, Márcio H. F.; Sanchez, Sergio d'Almeida

    2016-12-01

    We report integral cross sections (ICSs) for both positron and electron scattering by glycine and alanine amino acids. These molecules differ only by a methyl group. We computed the scattering cross sections using the Schwinger multichannel method for both glycine and alanine in different levels of approximation for both projectiles. The alanine ICSs are greater in magnitude than the glycine ICSs for both positron and electron scattering, probably due to the larger size of the molecule. In electron scattering calculations, we found two resonances for each molecule. Glycine presents one at 1.8 eV, and another centered at around 8.5 eV, in the static-exchange plus polarization (SEP) approximation. The ICS for alanine shows one resonance at 2.5 eV and another at around 9.5 eV, also in SEP approximation. The results are in good agreement with most of the data present in the literature. The comparison of the electron scattering ICSs for both molecules indicates that the methylation of glycine destabilizes the resonances, shifting them to higher energies.

  9. Follow-up of mild alanine aminotransferase elevation identifies hidden hepatitis C in primary care

    NARCIS (Netherlands)

    Helsper, C.W.; van Essen, G.A.; Frijling, B.D.; de Wit, N.J.

    2012-01-01

    BACKGROUND: Hepatitis C (HCV) and hepatitis B (HBV) virus infection can lead to serious complications if left untreated, but often remain undetected in primary care. Mild alanine aminotransferase (ALT) elevations (30-100 IU/l) are commonly found and could be associated with viral hepatitis;

  10. Spectral characterization of a non-centrosymmetric organic compound: D-(-)-alanine

    Science.gov (United States)

    Moovendaran, K.; Martin Britto Dhas, S. A.; Natarajan, S.

    2013-08-01

    The crystal growth of D-(-)-alanine (1), a non-centrosymmetric solid is reported. It was characterized by NMR, infrared, Raman, UV-Vis-NIR and CD spectra. Experimental vibrational frequencies are compared with theoretically calculated values. Second harmonic generation (SHG) and first hyperpolarizability measurements are reported.

  11. Growth and characterization of pure and semiorganic nonlinear optical Lithium Sulphate admixtured l-alanine crystal

    Science.gov (United States)

    Vela, T.; Selvarajan, P.; Freeda, T. H.; Balasubramanian, K.

    2013-04-01

    Lithium sulphate admixtured l-alanine (LSLA) salt was synthesized and the solubility of the commercially available l-alanine and the synthesized LSLA sample was determined in de-ionized water at various temperatures. In accordance with the solubility data, the saturated aqueous solutions of l-alanine and lithium admixtured l-alanine were prepared separately and the single crystals of the samples were grown by the solution method with a slow evaporation technique. Studying single x-ray diffraction shows that pure and LSLA crystal belong to the orthorhombic system with a non-centrosymmetric space group P212121. Using the powder x-ray diffraction study, the crystallinity of the grown crystals is confirmed and the diffraction peaks are indexed. The various functional groups present in the pure and LSLA crystal are elucidated from Fourier transform infrared spectroscopy study. UV-visible transmittance is recorded to study the optical transmittance range for the grown crystals. The powder second harmonic generation test confirms the nonlinear optical property of the grown crystals. From the microhardness test, the hardness of the grown crystals is estimated. The dielectric behaviour, such as the dielectric constant and the loss of the sample, are measured as a function of temperature and frequency. The ac conductivity of the grown crystals is also studied and the activation energy is calculated.

  12. [Temperature-dependent optical activity and birefringence study of D-alanine single crystal].

    Science.gov (United States)

    Li, Zong-Sheng; Gong, Yan; Wang, Wen-Qing; Du, Wei-Min

    2006-02-01

    The measurement of the anisotropy of optical acitivity and birefringence is one of the most important clues to studying physical properties of a biaxial crystal of D-alanine. In order to investigate a second-order phase transition predicted by A. Salam between two states of D-alanine, the behavior of birefringence and optical activity is useful for the phenomenological approach to the transition mechanism. The optical activity as a peculiar quantity can respond to the modulation of the crystal lattice and to the change in the bonding nature of constituent atoms. In the present paper, the authors use the PEM-90 photoelastic modulator to study the conformation change of D-alanine at the temperature ranging from 220 to 290 K. The temperature dependence of I(2f)/I(dc) showed that the conformation of D-alanine molecule in single crystal changed around 250 K. The obtained results provide an obvious evidence of optical rotation phase transition predicted by Salam.

  13. Probing the interaction of the amino acid alanine with the surface of ZnO(1010).

    Science.gov (United States)

    Gao, Y K; Traeger, F; Shekhah, O; Idriss, H; Wöll, C

    2009-10-01

    The adsorption modes and stability of the amino acid alanine (NH(2)-CH(CH(3))-COOH) have been studied on the nonpolar single crystal surface of zinc oxide, ZnO(1010), experimentally by X-ray photoelectron spectroscopy (XPS) and computationally using density functional theory (DFT). Deposition at 200 K was found to lead to the formation of multilayers identified by an XPS N1s peak at 401.7 eV assigned to the NH(3)(+) group, a fingerprint of the zwitterionic structure of alanine in the solid state. Heating to 300 K resulted in the removal of most of the multilayers with the remaining surface coverage estimated to 0.4 with respect to Zn cations. At this temperature most of the alanine molecules are found to be deprotonated (dissociated), yielding a carboxylate species (NH(2)-CH(CH(3))-COO(-) (a) + OH (s); where O is surface oxygen, (a) for adsorbed and (s) for surface species). Further heating of the surface resulted in a gradual decrease of the surface coverage and by 500 K a large fraction of adsorbed alanine molecules have desorbed from the surface. Total energy DFT computations of different adsorbate species identified two stable dissociative adsorption modes: bidentate and monodentate. The bidentate species with adsorption energy of 1.75 eV was found to be more stable than the monodentate species by about 0.7 eV.

  14. Investigation on physical properties of L-alanine: An effect of Methylene blue dye

    Science.gov (United States)

    Shkir, Mohd.; Yahia, I. S.; Al-Qahtani, A. M. A.; Ganesh, V.; AlFaify, S.

    2017-03-01

    In the present investigation, a bulk size (35 mm × 25 mm × 15 mm) single crystal of 0.1 wt% Methylene blue dye (MLB) added L-alanine is grown at room temperature using solution technique for the first time. The L-alanine crystals with higher concentrations of dye (0.5 and 1 wt%) were also grown. Solubility study was performed at different temperatures. Structural, vibrational and good quality was inveterate by powder XRD, FT-Raman and SEM analyses. High transmittance in dyed crystals was confirmed. The presence of MLB dye was confirmed by an absorption band centered at 650 nm. Optical band gap was calculated for pure and dyed L-alanine crystals and found to be 5.45 and 4.49 eV respectively. Photoluminescence intensity of UV-A emission band centered at 332 nm was found to be enhanced due to the presence of dye. The dielectric measurement was done in the wide frequency range. Furthermore, the third order nonlinear optical parameters are enhanced in dyed L-alanine crystals determined by Z-scan technique.

  15. High-pressure X-ray diffraction of L-ALANINE crystal

    DEFF Research Database (Denmark)

    Olsen, J.S.; Gerward, Leif; Souza, A.G.

    2006-01-01

    L-ALANINE has been studied by X-ray diffraction at ambient temperature and pressure up to 10.3 GPa. The material is found to transform to a tetragonal structure between 2 and 3 GPa. and to a monoclinic structure between 8 and 10 GPa. The experimental bulk modulus is 25(5) GPa for the orthorhombic...

  16. High-pressure X-ray diffraction of L-ALANINE crystal

    DEFF Research Database (Denmark)

    Olsen, J.S.; Gerward, Leif; Souza, A.G.

    2006-01-01

    L-ALANINE has been studied by X-ray diffraction at ambient temperature and pressure up to 10.3 GPa. The material is found to transform to a tetragonal structure between 2 and 3 GPa. and to a monoclinic structure between 8 and 10 GPa. The experimental bulk modulus is 25(5) GPa for the orthorhombic...

  17. [Effects of ß-alanine supplementation on wingate tests in university female footballers].

    Science.gov (United States)

    Rodríguez Rodríguez, Fernando; Delgado Ormeño, Alex; Rivera Lobos, Patricio; Tapia Aranda, Víctor; Cristi-Montero, Carlos

    2014-11-01

    Football is a sport that develops actions intermittent high-intensity exercise using the anaerobic pathway, for that reason, the muscle fatigue would produce primarily by increasing acidosis. Carnosine, which is formed from L-histidine, ß-alanine, has proven to produce an effect "buffer" of acidosis. To determine the effect of ß-alanine supplementation, on three successive Wingate tests and compare the average power, maximum power and lactate blood in selected female college soccer. We evaluated 10 football players who were three Wingate, 5 min rest between each sprint, determining the average power, maximum and lactate at the end of each test, then consumed 2,4 gr/day of ß-alanine for 30 days and repeated the tests. The control group (n=8) performed the same tests, but without consuming the supplement. Monark cycle ergometer was used (Ergomedic 874E) and to measure lactate the Lactate Pro 2. The group with supplementation significantly improved mean power difference from the control group. The maximum power improved only in the first sprint unlike the control group and Lactate did not differ. The evidence shows that the ß-alanine improves performance on tests of more than 30 second long, but in our study improves average power and peak power even when performing consecutive sprint, being able to emulate the reality of the football game. Copyright AULA MEDICA EDICIONES 2014. Published by AULA MEDICA. All rights reserved.

  18. Negative Beta Encoder

    CERN Document Server

    Kohda, Tohru; Aihara, Kazuyuki

    2008-01-01

    A new class of analog-digital (A/D), digital-analog (D/A) converters as an alternative to conventional ones, called $\\beta$-encoder, has been shown to have exponential accuracy in the bit rates while possessing self-correction property for fluctuations of amplifier factor $\\beta$ and quantizer threshold $\

  19. Double beta decay experiments

    CERN Document Server

    Barabash, A S

    2011-01-01

    The present status of double beta decay experiments is reviewed. The results of the most sensitive experiments are discussed. Proposals for future double beta decay experiments with a sensitivity to the $$ at the level of (0.01--0.1) eV are considered.

  20. Sorting out Downside Beta

    NARCIS (Netherlands)

    G.T. Post (Thierry); P. van Vliet (Pim); S.D. Lansdorp (Simon)

    2009-01-01

    textabstractDownside risk, when properly defined and estimated, helps to explain the cross-section of US stock returns. Sorting stocks by a proper estimate of downside market beta leads to a substantially larger cross-sectional spread in average returns than sorting on regular market beta. This

  1. Effects of endogenous D-alanine synthesis and autoinhibition of Bacillus anthracis germination on in vitro and in vivo infections.

    Science.gov (United States)

    McKevitt, Matthew T; Bryant, Katie M; Shakir, Salika M; Larabee, Jason L; Blanke, Steven R; Lovchik, Julie; Lyons, C Rick; Ballard, Jimmy D

    2007-12-01

    Bacillus anthracis transitions from a dormant spore to a vegetative bacillus through a series of structural and biochemical changes collectively referred to as germination. The timing of germination is important during early steps in infection and may determine if B. anthracis survives or succumbs to responsive macrophages. In the current study experiments determined the contribution of endogenous D-alanine production to the efficiency and timing of B. anthracis spore germination under in vitro and in vivo conditions. Racemase-mediated production of endogenous D-alanine by B. anthracis altered the kinetics for initiation of germination over a range of spore densities and exhibited a threshold effect wherein small changes in spore number resulted in major changes in germination efficiency. This threshold effect correlated with D-alanine production, was prevented by an alanine racemase inhibitor, and required L-alanine. Interestingly, endogenous production of inhibitory levels of D-alanine was detected under experimental conditions that did not support germination and in a germination-deficient mutant of B. anthracis. Racemase-dependent production of D-alanine enhanced survival of B. anthracis during interaction with murine macrophages, suggesting a role for inhibition of germination during interaction with these cells. Finally, in vivo experiments revealed an approximately twofold decrease in the 50% lethal dose of B. anthracis spores administered in the presence of D-alanine, indicating that rates of germination may be directly influenced by the levels of this amino acid during early stages of disease.

  2. Genetics Home Reference: beta thalassemia

    Science.gov (United States)

    ... Facebook Twitter Home Health Conditions beta thalassemia beta thalassemia Printable PDF Open All Close All Enable Javascript to view the expand/collapse boxes. Description Beta thalassemia is a blood disorder that reduces the production ...

  3. Glutamate Racemase Is the Primary Target of β-Chloro-d-Alanine in Mycobacterium tuberculosis

    Science.gov (United States)

    Rodenburg, Anne; Khoury, Hania; de Chiara, Cesira; Howell, Steve; Snijders, Ambrosius P.

    2016-01-01

    The increasing global prevalence of drug resistance among many leading human pathogens necessitates both the development of antibiotics with novel mechanisms of action and a better understanding of the physiological activities of preexisting clinically effective drugs. Inhibition of peptidoglycan (PG) biosynthesis and cross-linking has traditionally enjoyed immense success as an antibiotic target in multiple bacterial pathogens, except in Mycobacterium tuberculosis, where it has so far been underexploited. d-Cycloserine, a clinically approved antituberculosis therapeutic, inhibits enzymes within the d-alanine subbranch of the PG-biosynthetic pathway and has been a focus in our laboratory for understanding peptidoglycan biosynthesis inhibition and for drug development in studies of M. tuberculosis. During our studies on alternative inhibitors of the d-alanine pathway, we discovered that the canonical alanine racemase (Alr) inhibitor β-chloro–d-alanine (BCDA) is a very poor inhibitor of recombinant M. tuberculosis Alr, despite having potent antituberculosis activity. Through a combination of enzymology, microbiology, metabolomics, and proteomics, we show here that BCDA does not inhibit the d-alanine pathway in intact cells, consistent with its poor in vitro activity, and that it is instead a mechanism-based inactivator of glutamate racemase (MurI), an upstream enzyme in the same early stage of PG biosynthesis. This is the first report to our knowledge of inhibition of MurI in M. tuberculosis and thus provides a valuable tool for studying this essential and enigmatic enzyme and a starting point for future MurI-targeted antibacterial development. PMID:27480853

  4. Role of Alanine Dehydrogenase of Mycobacterium tuberculosis during Recovery from Hypoxic Nonreplicating Persistence.

    Directory of Open Access Journals (Sweden)

    Michelle M Giffin

    Full Text Available Mycobacterium tuberculosis can maintain a nonreplicating persistent state in the host for decades, but must maintain the ability to efficiently reactivate and produce active disease to survive and spread in a population. Among the enzymes expressed during this dormancy is alanine dehydrogenase, which converts pyruvate to alanine, and glyoxylate to glycine concurrent with the oxidation of NADH to NAD. It is involved in the metabolic remodeling of M. tuberculosis through its possible interactions with both the glyoxylate and methylcitrate cycle. Both mRNA levels and enzymatic activities of isocitrate lyase, the first enzyme of the glyoxylate cycle, and alanine dehydrogenase increased during entry into nonreplicating persistence, while the gene and activity for the second enzyme of the glyoxylate cycle, malate synthase were not. This could suggest a shift in carbon flow away from the glyoxylate cycle and instead through alanine dehydrogenase. Expression of ald was also induced in vitro by other persistence-inducing stresses such as nitric oxide, and was expressed at high levels in vivo during the initial lung infection in mice. Enzyme activity was maintained during extended hypoxia even after transcription levels decreased. An ald knockout mutant of M. tuberculosis showed no reduction in anaerobic survival in vitro, but resulted in a significant lag in the resumption of growth after reoxygenation. During reactivation the ald mutant had an altered NADH/NAD ratio, and alanine dehydrogenase is proposed to maintain the optimal NADH/NAD ratio during anaerobiosis in preparation of eventual regrowth, and during the initial response during reoxygenation.

  5. Alanine racemase is essential for the growth and interspecies competitiveness of Streptococcus mutans.

    Science.gov (United States)

    Wei, Yuan; Qiu, Wei; Zhou, Xue-Dong; Zheng, Xin; Zhang, Ke-Ke; Wang, Shi-Da; Li, Yu-Qing; Cheng, Lei; Li, Ji-Yao; Xu, Xin; Li, Ming-Yun

    2016-12-16

    D-alanine (D-Ala) is an essential amino acid that has a key role in bacterial cell wall synthesis. Alanine racemase (Alr) is a unique enzyme that interconverts L-alanine and D-alanine in most bacteria, making this enzyme a potential target for antimicrobial drug development. Streptococcus mutans is a major causative factor of dental caries. The factors involved in the survival, virulence and interspecies interactions of S. mutans could be exploited as potential targets for caries control. The current study aimed to investigate the physiological role of Alr in S. mutans. We constructed alr mutant strain of S. mutans and evaluated its phenotypic traits and interspecies competitiveness compared with the wild-type strain. We found that alr deletion was lethal to S. mutans. A minimal supplement of D-Ala (150 μg·mL(-1)) was required for the optimal growth of the alr mutant. The depletion of D-alanine in the growth medium resulted in cell wall perforation and cell lysis in the alr mutant strain. We also determined the compromised competitiveness of the alr mutant strain relative to the wild-type S. mutans against other oral streptococci (S. sanguinis or S. gordonii), demonstrated using either conditioned medium assays or dual-species fluorescent in situ hybridization analysis. Given the importance and necessity of alr to the growth and competitiveness of S. mutans, Alr may represent a promising target to modulate the cariogenicity of oral biofilms and to benefit the management of dental caries.

  6. Thermal Condensation of Glycine and Alanine on Metal Ferrite Surface: Primitive Peptide Bond Formation Scenario

    Science.gov (United States)

    Iqubal, Md. Asif; Sharma, Rachana; Jheeta, Sohan; Kamaluddin

    2017-01-01

    The amino acid condensation reaction on a heterogeneous mineral surface has been regarded as one of the important pathways for peptide bond formation. Keeping this in view, we have studied the oligomerization of the simple amino acids, glycine and alanine, on nickel ferrite (NiFe2O4), cobalt ferrite (CoFe2O4), copper ferrite (CuFe2O4), zinc ferrite (ZnFe2O4), and manganese ferrite (MnFe2O4) nanoparticles surfaces, in the temperature range from 50–120 °C for 1–35 days, without applying any wetting/drying cycles. Among the metal ferrites tested for their catalytic activity, NiFe2O4 produced the highest yield of products by oligomerizing glycine to the trimer level and alanine to the dimer level, whereas MnFe2O4 was the least efficient catalyst, producing the lowest yield of products, as well as shorter oligomers of amino acids under the same set of experimental conditions. It produced primarily diketopiperazine (Ala) with a trace amount of alanine dimer from alanine condensation, while glycine was oligomerized to the dimer level. The trend in product formation is in accordance with the surface area of the minerals used. A temperature as low as 50 °C can even favor peptide bond formation in the present study, which is important in the sense that the condensation process is highly feasible without any sort of localized heat that may originate from volcanoes or hydrothermal vents. However, at a high temperature of 120 °C, anhydrides of glycine and alanine formation are favored, while the optimum temperature for the highest yield of product formation was found to be 90 °C. PMID:28346388

  7. Biochemical and structural characterization of alanine racemase from Bacillus anthracis (Ames

    Directory of Open Access Journals (Sweden)

    Hill Ryan E

    2009-08-01

    Full Text Available Abstract Background Bacillus anthracis is the causative agent of anthrax and a potential bioterrorism threat. Here we report the biochemical and structural characterization of B. anthracis (Ames alanine racemase (AlrBax, an essential enzyme in prokaryotes and a target for antimicrobial drug development. We also compare the native AlrBax structure to a recently reported structure of the same enzyme obtained through reductive lysine methylation. Results B. anthracis has two open reading frames encoding for putative alanine racemases. We show that only one, dal1, is able to complement a D-alanine auxotrophic strain of E. coli. Purified Dal1, which we term AlrBax, is shown to be a dimer in solution by dynamic light scattering and has a Vmax for racemization (L- to D-alanine of 101 U/mg. The crystal structure of unmodified AlrBax is reported here to 1.95 Å resolution. Despite the overall similarity of the fold to other alanine racemases, AlrBax makes use of a chloride ion to position key active site residues for catalysis, a feature not yet observed for this enzyme in other species. Crystal contacts are more extensive in the methylated structure compared to the unmethylated structure. Conclusion The chloride ion in AlrBax is functioning effectively as a carbamylated lysine making it an integral and unique part of this structure. Despite differences in space group and crystal form, the two AlrBax structures are very similar, supporting the case that reductive methylation is a valid rescue strategy for proteins recalcitrant to crystallization, and does not, in this case, result in artifacts in the tertiary structure.

  8. Structural and functional characterization of the alanine racemase from Streptomyces coelicolor A3(2).

    Science.gov (United States)

    Tassoni, Raffaella; van der Aart, Lizah T; Ubbink, Marcellus; van Wezel, Gilles P; Pannu, Navraj S

    2017-01-29

    The conversion of l-alanine (L-Ala) into d-alanine (D-Ala) in bacteria is performed by pyridoxal phosphate-dependent enzymes called alanine racemases. D-Ala is an essential component of the bacterial peptidoglycan and hence required for survival. The Gram-positive bacterium Streptomyces coelicolor has at least one alanine racemase encoded by alr. Here, we describe an alr deletion mutant of S. coelicolor which depends on D-Ala for growth and shows increased sensitivity to the antibiotic d-cycloserine (DCS). The crystal structure of the alanine racemase (Alr) was solved with and without the inhibitors DCS or propionate, at 1.64 Å and 1.51 Å resolution, respectively. The crystal structures revealed that Alr is a homodimer with residues from both monomers contributing to the active site. The dimeric state of the enzyme in solution was confirmed by gel filtration chromatography, with and without L-Ala or d-cycloserine. The activity of the enzyme was 66 ± 3 U mg(-1) for the racemization of L- to D-Ala, and 104 ± 7 U mg(-1) for the opposite direction. Comparison of Alr from S. coelicolor with orthologous enzymes from other bacteria, including the closely related d-cycloserine-resistant Alr from S. lavendulae, strongly suggests that structural features such as the hinge angle or the surface area between the monomers do not contribute to d-cycloserine resistance, and the molecular basis for resistance therefore remains elusive.

  9. Structural features and kinetic characterization of alanine racemase from Staphylococcus aureus (Mu50).

    Science.gov (United States)

    Scaletti, Emma R; Luckner, Sylvia R; Krause, Kurt L

    2012-01-01

    Staphylococcus aureus is an opportunistic Gram-positive bacterium which causes a wide variety of diseases ranging from minor skin infections to potentially fatal conditions such as pneumonia, meningitis and septicaemia. The pathogen is a leading cause of nosocomial acquired infections, a problem that is exacerbated by the existence of methicillin- and glycopeptide antibiotic-resistant strains which can be challenging to treat. Alanine racemase (Alr) is a pyridoxal-5'-phosphate-dependent enzyme which catalyzes reversible racemization between enantiomers of alanine. As D-alanine is an essential component of the bacterial cell-wall peptidoglycan, inhibition of Alr is lethal to prokaryotes. Additionally, while ubiquitous amongst bacteria, this enzyme is absent in humans and most eukaryotes, making it an excellent antibiotic drug target. The crystal structure of S. aureus alanine racemase (Alr(Sas)), the sequence of which corresponds to that from the highly antibiotic-resistant Mu50 strain, has been solved to 2.15 Å resolution. Comparison of the Alr(Sas) structure with those of various alanine racemases demonstrates a conserved overall fold, with the enzyme sharing most similarity to those from other Gram-positive bacteria. Structural examination indicates that the active-site binding pocket, dimer interface and active-site entryway of the enzyme are potential targets for structure-aided inhibitor design. Kinetic constants were calculated in this study and are reported here. The potential for a disulfide bond in this structure is noted. This structural and biochemical information provides a template for future structure-based drug-development efforts targeting Alr(Sas).

  10. K-band EPR dosimetry: small-field beam profile determination with miniature alanine dosimeter

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Felipe [Departmento de Fisica e Matematica, FFCLRP-Universidade de Sao Paulo, Av. Bandeirantes, 3900, 14040-901, Ribeirao Preto-SP (Brazil); Department of Radiological Health, Caja de Seguro Social, Panama City (Panama); Department of Physics, Faculty of Natural and Exact Sciences and Technology, University of Panama, Panama City (Panama); Graeff, Carlos F.O. [Departmento de Fisica e Matematica, FFCLRP-Universidade de Sao Paulo, Av. Bandeirantes, 3900, 14040-901, Ribeirao Preto-SP (Brazil); Baffa, Oswaldo [Departmento de Fisica e Matematica, FFCLRP-Universidade de Sao Paulo, Av. Bandeirantes, 3900, 14040-901, Ribeirao Preto-SP (Brazil)

    2005-02-01

    The use of small-size alanine dosimeters presents a challenge because the signal intensity is less than the spectrometer sensitivity. K-band (24 GHz) EPR spectrometer seems to be a good compromise between size and sensitivity of the sample. Miniature alanine pellets were evaluated for small-field radiation dosimetry. Dosimeters of DL-alanine/PVC with dimensions of 1.5 mm diameter and 2.5 mm length with 5 mg mass were developed. These dosimeters were irradiated with 10 MV X-rays in the dose range 0.05-60 Gy and the first harmonic (1 h) spectra were recorded. Microwave power, frequency and amplitude of modulation were optimized to obtain the best signal-to-noise ratio (S/N). For beam profile determination, a group of 25 dosimeters were placed in an acrylic device with dimensions of (7.5x2.5x1) cm{sup 3} and irradiated with a (3x3) cm{sup 2} 10 MV X-rays beam field size. The dose at the central region of the beam was 20 Gy at a depth of 2.2 cm (build up for acrylic). The acrylic device was oriented perpendicular to the beam axis and to the gantry rotation axis. For the purposes of comparison of the spatial resolution, the beam profile was also determined with a radiographic film and 2 mm aperture optical densitometer; in this case the dose was 1 cGy. The results showed a similar spatial resolution for both types of dosimeters. The dispersion in dose reading was larger for alanine in comparison with the film, but alanine dosimeters can be read faster and more directly than film over a wide dose range.

  11. Directional and balancing selection in human beta-defensins

    Directory of Open Access Journals (Sweden)

    Armour John AL

    2008-04-01

    Full Text Available Abstract Background In primates, infection is an important force driving gene evolution, and this is reflected in the importance of infectious disease in human morbidity today. The beta-defensins are key components of the innate immune system, with antimicrobial and cell signalling roles, but also reproductive functions. Here we examine evolution of beta-defensins in catarrhine primates and variation within different human populations. Results We show that five beta-defensin genes that do not show copy number variation in humans show evidence of positive selection in catarrhine primates, and identify specific codons that have been under selective pressure. Direct haplotyping of DEFB127 in humans suggests long-term balancing selection: there are two highly diverged haplotype clades carrying different variants of a codon that, in primates, is positively selected. For DEFB132, we show that extensive diversity, including a four-state amino acid polymorphism (valine, isoleucine, alanine and threonine at position 93, is present in hunter-gatherer populations, both African and non-African, but not found in samples from agricultural populations. Conclusion Some, but not all, beta-defensin genes show positive selection in catarrhine primates. There is suggestive evidence of different selective pressures on these genes in humans, but the nature of the selective pressure remains unclear and is likely to differ between populations.

  12. Directional and balancing selection in human beta-defensins.

    Science.gov (United States)

    Hollox, Edward J; Armour, John A L

    2008-04-16

    In primates, infection is an important force driving gene evolution, and this is reflected in the importance of infectious disease in human morbidity today. The beta-defensins are key components of the innate immune system, with antimicrobial and cell signalling roles, but also reproductive functions. Here we examine evolution of beta-defensins in catarrhine primates and variation within different human populations. We show that five beta-defensin genes that do not show copy number variation in humans show evidence of positive selection in catarrhine primates, and identify specific codons that have been under selective pressure. Direct haplotyping of DEFB127 in humans suggests long-term balancing selection: there are two highly diverged haplotype clades carrying different variants of a codon that, in primates, is positively selected. For DEFB132, we show that extensive diversity, including a four-state amino acid polymorphism (valine, isoleucine, alanine and threonine at position 93), is present in hunter-gatherer populations, both African and non-African, but not found in samples from agricultural populations. Some, but not all, beta-defensin genes show positive selection in catarrhine primates. There is suggestive evidence of different selective pressures on these genes in humans, but the nature of the selective pressure remains unclear and is likely to differ between populations.

  13. Rapid synthesis of beta zeolites

    Science.gov (United States)

    Fan, Wei; Chang, Chun -Chih; Dornath, Paul; Wang, Zhuopeng

    2015-08-18

    The invention provides methods for rapidly synthesizing heteroatom containing zeolites including Sn-Beta, Si-Beta, Ti-Beta, Zr-Beta and Fe-Beta. The methods for synthesizing heteroatom zeolites include using well-crystalline zeolite crystals as seeds and using a fluoride-free, caustic medium in a seeded dry-gel conversion method. The Beta zeolite catalysts made by the methods of the invention catalyze both isomerization and dehydration reactions.

  14. Reduction of FDG uptake in brown adipose tissue in clinical patients by a single dose of propranolol

    Energy Technology Data Exchange (ETDEWEB)

    Soederlund, Veli [Karolinska University Hospital, Department of Radiology, Stockholm (Sweden); Larsson, Stig A. [Karolinska University Hospital, Department of Nuclear Medicine, Stockholm (Sweden); Jacobsson, Hans [Karolinska University Hospital, Department of Radiology, Stockholm (Sweden); Karolinska University Hospital, Department of Nuclear Medicine, Stockholm (Sweden)

    2007-07-15

    Uptake in brown adipose tissue (hibernating fat) is sometimes seen at FDG-PET examinations. Despite a characteristic appearance, this may hide clinically relevant uptake. Stimulation of the sympathetic nervous system increases glucose uptake of brown fat. We now re-examine patients with brown fat activity that could disguise tumour uptake after pre-treatment with propranolol (a non-selective {beta}-blocker) in order to reduce the uptake. Our first examinations of this kind are reported. Eleven patients with strong brown fat uptake were studied. There was a mean of 5 days (range 2-8) between the examinations. At the second examination, 80 mg of propranolol was given orally 2 h before FDG administration. In addition to visual evaluation of the brown fat uptake, SUV assessments of the uptake in brown fat, lung, heart, liver, spleen and bone marrow were made. All patients showed complete or almost complete disappearance of the brown fat activity at the second examination (p < 0.001) both upon visual evaluation and when comparing SUVs. In seven patients there was also uptake in a known or strongly suspected malignancy, which remained unchanged between the examinations. Beyond an insignificant decrease in the myocardial uptake, there was no redistribution to the various examined organs at the second examination. Pre-treatment with a single dose of propranolol blocks the FDG uptake in brown adipose tissue, thereby increasing the specificity of the examination. The tumour uptake seems not to be impaired. (orig.)

  15. Uptake of nuclides by plants

    Energy Technology Data Exchange (ETDEWEB)

    Greger, Maria [Stockholm Univ. (Sweden). Dept. of Botany

    2004-04-01

    This review on plant uptake of elements has been prepared to demonstrate how plants take up different elements. The work discusses the nutrient elements, as well as the general uptake and translocation in plants, both via roots and by foliar absorption. Knowledge of the uptake by the various elements within the periodic system is then reviewed. The work also discusses transfer factors (TF) as well as difficulties using TF to understand the uptake by plants. The review also focuses on species differences. Knowledge necessary to understand and calculate plant influence on radionuclide recirculation in the environment is discussed, in which the plant uptake of a specific nuclide and the fate of that nuclide in the plant must be understood. Plants themselves determine the uptake, the soil/sediment determines the availability of the nuclides and the nuclides themselves can interact with each other, which also influences the uptake. Consequently, it is not possible to predict the nuclide uptake in plants by only analysing the nuclide concentration of the soil/substrate.

  16. Fractal analysis of striatal dopamine re-uptake sites

    Energy Technology Data Exchange (ETDEWEB)

    Kuikka, J.T.; Bergstroem, K.A. [Department of Clinical Physiology, Kuopio University Hospital, Kuopio (Finland); Tiihonen, J.; Raesaenen, P. [Department of Forensic Psychiatry, University of Kuopio and Niuvanniemi Hospital, Kuopio (Finland); Karhu, J. [Department of Clinical Neurophysiology, Kuopio University Hospital, Kuopio (Finland)

    1997-09-01

    Spatial variation in regional blood flow, metabolism and receptor density within the brain and in other organs is measurable even with a low spatial resolution technique such as emission tomography. It has been previously shown that the observed variance increases with increasing number of subregions in the organ/tissue studied. This resolution-dependent variance can be described by fractal analysis. We studied striatal dopamine re-uptake sites in 39 healthy volunteers with high-resolution single-photon emission tomography using iodine-123 labelled 2{beta}-carbomethoxy-3{beta}-(4-iodophenyl)tropane ([{sup 123}I]{beta}-CIT). The mean fractal dimension was 1.15{+-}0.07. The results indicate that regional striatal dopamine re-uptake sites involve considerable spatial heterogeneity which is higher than the uniform density (dimension=1.00) but much lower than complete randomness (dimension=1.50). There was a gender difference, with females having a higher heterogeneity in both the left and the right striatum. In addition, we found striatal asymmetry (left-to-right heterogeneity ratio of 1.19{+-}0.15; P<0.001), suggesting functional hemispheric lateralization consistent with the control of motor behaviour and integrative functions. (orig.). With 5 figs., 1 tab.

  17. Clinical impact of diagnostic SPET investigations with a dopamine re-uptake ligand

    DEFF Research Database (Denmark)

    Løkkegaard, Annemette; Werdelin, Lene M; Friberg, Lars

    2002-01-01

    referred to [(123)I]-beta-CIT SPET from the neurological department, Bispebjerg Hospital. In 58 subjects the scans revealed altered tracer uptake consistent with Parkinson's disease, progressive supranuclear palsy and multiple system atrophy. A significant change in the management or treatment because...

  18. Concurrent Low Brain and High Liver Uptake on FDG PET Are Associated with Cardiovascular Risk Factors

    Science.gov (United States)

    Nam, Hyun-Yeol; Jun, Sungmin; Pak, Kyoungjune

    2017-01-01

    Objective Concurrent low brain and high liver uptake are sometimes observed on fluorine-18-labeled fluoro-2-deoxy-D-glucose (FDG) positron emission tomography (PET). We investigated the potential clinical significance of this uptake pattern related to metabolic syndrome (MS). Materials and Methods We retrospectively reviewed data from 264 consecutive males who had undergone general health check-ups, including FDG PET/CT scans. After an overnight fast, the men had their peripheral blood drawn and the levels of various laboratory parameters measured; an FDG PET/CT scan was performed on the same day. We measured the maximum standardized uptake values of the brain and liver from regions of interest manually placed over the frontal cortex at the level of the centrum semiovale and the right lobe of the liver parenchyma, respectively. Results Fasting blood glucose (FBG; odds ratio [OR] = 1.063, p < 0.001) and glycated hemoglobin (HbA1c; OR = 3.634, p = 0.010) were the strongest predictive factors for low brain FDG uptake, whereas waist circumference (OR = 1.200, p < 0.001) and γ-glutamyl transpeptidase (OR = 1.012, p = 0.001) were the strongest predictive factors for high liver uptake. Eleven subjects (4.2%) showed concurrent low brain and high liver FDG uptake, and all but one of these subjects (90.9%) had MS. Systolic blood pressure, waist circumference, FBG, triglyceride, alanine aminotransferase, insulin resistance (measured by homeostasis model assessment), insulin, HbA1c, and body mass index were higher in subjects with this FDG uptake pattern than in those without (all, p < 0.001). Conclusion Concurrent low brain and high liver FDG uptake were closely associated with MS. Moreover, subjects with this pattern had higher values for various cardiovascular risk factors than did those without. PMID:28246520

  19. Concurrent low brain and high liver uptake on FDG PET are associated with cardiovascular risk factors

    Energy Technology Data Exchange (ETDEWEB)

    Nam, Hyun Yeol [Dept. of Nuclear Medicine, Samsung Changwon Hospital, Sungkyunkwan University School of Medicine, Changwon (Korea, Republic of); Jun, Sung Min [Dept. of Nuclear Medicine, Kosin University Gospel Hospital, Kosin University College of Medicine, Busan (Korea, Republic of); Pak, Kyoung June; Kim, In Joo [Dept. of Nuclear Medicine and Biomedical Research Institute, Pusan National University Hospital, Busan (Korea, Republic of)

    2017-04-15

    Concurrent low brain and high liver uptake are sometimes observed on fluorine-18-labeled fluoro-2-deoxy-D-glucose (FDG) positron emission tomography (PET). We investigated the potential clinical significance of this uptake pattern related to metabolic syndrome (MS). We retrospectively reviewed data from 264 consecutive males who had undergone general health check-ups, including FDG PET/CT scans. After an overnight fast, the men had their peripheral blood drawn and the levels of various laboratory parameters measured; an FDG PET/CT scan was performed on the same day. We measured the maximum standardized uptake values of the brain and liver from regions of interest manually placed over the frontal cortex at the level of the centrum semiovale and the right lobe of the liver parenchyma, respectively. Fasting blood glucose (FBG; odds ratio [OR] = 1.063, p < 0.001) and glycated hemoglobin (HbA1c; OR = 3.634, p = 0.010) were the strongest predictive factors for low brain FDG uptake, whereas waist circumference (OR = 1.200, p < 0.001) and γ-glutamyl transpeptidase (OR = 1.012, p = 0.001) were the strongest predictive factors for high liver uptake. Eleven subjects (4.2%) showed concurrent low brain and high liver FDG uptake, and all but one of these subjects (90.9%) had MS. Systolic blood pressure, waist circumference, FBG, triglyceride, alanine aminotransferase, insulin resistance (measured by homeostasis model assessment), insulin, HbA1c, and body mass index were higher in subjects with this FDG uptake pattern than in those without (all, p < 0.001). Concurrent low brain and high liver FDG uptake were closely associated with MS. Moreover, subjects with this pattern had higher values for various cardiovascular risk factors than did those without.

  20. Amino acid uptake and energy coupling dependent on photosynthesis in Anacystis nidulans.

    Science.gov (United States)

    Lee-Kaden, J; Simonis, W

    1982-07-01

    The photoautotrophic cyanobacterium Anacystis nidulans was used to investigate the membrane transport of branched-chain, neutral amino acids and its dependence on photosynthetic reactions. The uptake of alpha-amino [1-14C]isobutyric acid and L-[1-14C]leucine followed Michaelis, Menten kinetics and resulted in an energy-dependent accumulation. As in bacteria, different uptake systems for neutral amino acids were present: two DAG (D-alanine, aminoisobutyric acid, and glycine) systems responsible for uptake of alpha-amino [1-14C]isobutyric acid, and one LIV (leucine, isoleucine, and valine) system, responsible for uptake of leucine. The low-affinity DAG system seemed to be dependent on the presence of Na+ ions. Uptake was enhanced by white light and by monochromatic light of 630 nm. In far red light (717 nm) with and without nitrogen flushing, considerable uptake dependent on light intensity and inhibition by dibromothymoquinone and by high concentrations of KCN were observed. Therefore, the energy generated by photosystem I reactions only could perform this membrane transport. The proton translocator carbonylcyanide m-chlorophenylhydrazone and N,N-dicyclohexylcarbodiimide as an ATPase inhibitor reduced amino acid uptake to a high degree. A pH dependence of aminoisobutyric acid and leucine uptake was obvious, with a maximum at pH 6 to 7 and some at a pH as high as 9.5. At higher pH, increasing concentrations of Na+ K+ and also of triphenylmethylphosphonium ions inhibited the transport of aminoisobutyric acid. These findings are consistent with the assumption that ATP from photosynthetic reactions drives a membrane-bound proton-translocating ATPase producing a proton motive force, consisting at higher pH chiefly in a delta psi amount, which promotes a secondary active H+ or Na+/amino acid symport carrier.

  1. The alanine detector in BNCT dosimetry: Dose response in thermal and epithermal neutron fields

    Energy Technology Data Exchange (ETDEWEB)

    Schmitz, T., E-mail: schmito@uni-mainz.de [Institute for nuclear chemistry, Johannes Gutenberg-University, Mainz D-55128 (Germany); Bassler, N. [Department of Physics and Astronomy, Aarhus University, Ny Munkegade 120, Aarhus C, Aarhus 8000 (Denmark); Blaickner, M. [AIT Austrian Institute of Technology GmbH, Vienna A-1220 (Austria); Ziegner, M. [AIT Austrian Institute of Technology GmbH, Vienna A-1220, Austria and TU Wien, Vienna University of Technology, Vienna A-1020 (Austria); Hsiao, M. C. [Insitute of Nuclear Engineering and Science, National Tsing Hua University, Hsinchu 30013, Taiwan (China); Liu, Y. H. [Nuclear Science and Technology Development Center, National Tsing Hua University, Hsinchu 30013, Taiwan (China); Koivunoro, H. [Department of Physics, University of Helsinki, POB 64, FI-00014, Finland and HUS Medical Imaging Center, Helsinki University Central Hospital, FI-00029 HUS (Finland); Auterinen, I.; Serén, T.; Kotiluoto, P. [VTT Technical Research Centre of Finland, Espoo (Finland); Palmans, H. [National Physical Laboratory, Acoustics and Ionising Radiation Division, Teddington TW11 0LW, United Kingdom and Medical Physics Group, EBG MedAustron GmbH, Wiener Neustadt A-2700 (Austria); Sharpe, P. [National Physical Laboratory, Acoustics and Ionising Radiation Division, Teddington TW11 0LW (United Kingdom); Langguth, P. [Department of Pharmacy and Toxicology, University of Mainz, Mainz D-55128 (Germany); Hampel, G. [Institut für Kernchemie, Johannes Gutenberg-Universität, Mainz D-55128 (Germany)

    2015-01-15

    Purpose: The response of alanine solid state dosimeters to ionizing radiation strongly depends on particle type and energy. Due to nuclear interactions, neutron fields usually also consist of secondary particles such as photons and protons of diverse energies. Various experiments have been carried out in three different neutron beams to explore the alanine dose response behavior and to validate model predictions. Additionally, application in medical neutron fields for boron neutron capture therapy is discussed. Methods: Alanine detectors have been irradiated in the thermal neutron field of the research reactor TRIGA Mainz, Germany, in five experimental conditions, generating different secondary particle spectra. Further irradiations have been made in the epithermal neutron beams at the research reactors FiR 1 in Helsinki, Finland, and Tsing Hua open pool reactor in HsinChu, Taiwan ROC. Readout has been performed with electron spin resonance spectrometry with reference to an absorbed dose standard in a {sup 60}Co gamma ray beam. Absorbed doses and dose components have been calculated using the Monte Carlo codes FLUKA and MCNP. The relative effectiveness (RE), linking absorbed dose and detector response, has been calculated using the Hansen and Olsen alanine response model. Results: The measured dose response of the alanine detector in the different experiments has been evaluated and compared to model predictions. Therefore, a relative effectiveness has been calculated for each dose component, accounting for its dependence on particle type and energy. Agreement within 5% between model and measurement has been achieved for most irradiated detectors. Significant differences have been observed in response behavior between thermal and epithermal neutron fields, especially regarding dose composition and depth dose curves. The calculated dose components could be verified with the experimental results in the different primary and secondary particle fields. Conclusions: The

  2. 3D culture of tonsil-derived mesenchymal stem cells in poly(ethylene glycol)-poly(L-alanine-co-L-phenyl alanine) thermogel.

    Science.gov (United States)

    Park, Min Hee; Yu, Yeonsil; Moon, Hyo Jung; Ko, Du Young; Kim, Han Su; Lee, Hyukjin; Ryu, Kyung Ha; Jeong, Byeongmoon

    2014-11-01

    Poly(ethylene glycol)-poly(L-alanine-co-L-phenyl alanine) (PEG-PAF) aqueous solutions undergo sol-to-gel transition as the temperature increases. The transition is driven by the micelle aggregation involving the partial dehydration of the PEG block and the partial increase in β-sheet content of the PAF block. Tonsil-tissue-derived mesenchymal stem cells (TMSCs), a new stem cell resource, are encapsulated through the sol-to-gel transition of the TMSC-suspended PEG-PAF aqueous solutions. The encapsulated TMSCs are in vitro 3D cultured by using induction media supplemented with adipogenic, osteogenic, or chondrogenic factors, where the TMSCs preferentially undergo chondrogenesis with high expressions of type II collagen and sulfated glycosaminoglycan. As a feasibility study of the PEG-PAF thermogel for injectable tissue engineering, the TMSCs encapsulated in hydrogels are implanted in the subcutaneous layer of mice by injecting the TMSC suspended PEG-PAF aqueous solution. The in vivo studies also prove that TMSCs undergo chondrogenesis with high expression of the chondrogenic biomarkers. This study suggests that the TMSCs can be an excellent resource of MSCs, and the thermogelling PEG-PAF is a promising injectable tissue engineering scaffold, particularly for chondrogenic differentiation of the stem cells. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Mutation in a D-alanine-D-alanine ligase of Azospirillum brasilense Cd results in an overproduction of exopolysaccharides and a decreased tolerance to saline stress.

    Science.gov (United States)

    Jofré, Edgardo; Fischer, Sonia; Príncipe, Analía; Castro, Marina; Ferrari, Walter; Lagares, Antonio; Mori, Gladys

    2009-01-01

    Bacteria of the genus Azospirillum are free-living nitrogen-fixing, rhizobacteria that are found in close association with plant roots, where they exert beneficial effects on plant growth and yield in many crops of agronomic importance. Unlike other bacteria, little is known about the genetics and biochemistry of exopolysaccharides in Azospirillum brasilense. In an attempt to characterize genes associated with exopolysaccharides production, we generated an A. brasilense Cd Tn5 mutant that showed exopolysaccharides overproduction, decreased tolerance to saline conditions, altered cell morphology, and increased sensitivity to detergents. Genetic characterization showed that the Tn5 was inserted within a ddlB gene encoding for a d-alanine-d-alanine ligase, and located upstream of the ftsQAZ gene cluster responsible for cell division in different bacteria. Heterologous complementation of the ddlB Tn5 mutant restored the exopolysaccharides production to wild-type levels and the ability to grow in the presence of detergents, but not the morphology and growth characteristics of the wild-type bacteria, suggesting a polar effect of Tn5 on the fts genes. This result and the construction of a nonpolar ddlB mutant provide solid evidence of the presence of transcriptional coupling between a gene associated with peptidoglycan biosynthesis and the fts genes required to control cell division.

  4. Effect of adrenergic receptor ligands on metaiodobenzylguanidine uptake and storage in neuroblastoma cells

    Energy Technology Data Exchange (ETDEWEB)

    Babich, J.W. [Division of Nuclear Medicine, Department of Radiology, Massachusetts General Hospital, Boston, Massachusetts (United States)]|[Department of Radiology, Harvard Medical School, Boston, Massachusetts (United States); Graham, W. [Division of Nuclear Medicine, Department of Radiology, Massachusetts General Hospital, Boston, Massachusetts (United States); Fischman, A.J. [Division of Nuclear Medicine, Department of Radiology, Massachusetts General Hospital, Boston, Massachusetts (United States)]|[Department of Radiology, Harvard Medical School, Boston, Massachusetts (United States)

    1997-05-01

    The effects of adrenergic receptor ligands on uptake and storage of the radiopharmaceutical [{sup 125}I]metaiodobenzylguanidine (MIBG) were studied in the human neuroblastoma cell line SK-N-SH. For uptake studies, cells were with varying concentrations of {alpha}-agonist (clonidine, methoxamine, and xylazine), {alpha}-antagonist (phentolamine, tolazoline, phenoxybenzamine, yohimbine, and prazosin), {beta}-antagonist (propranolol, atenolol), {beta}-agonist (isoprenaline and salbutamol), mixed {alpha}/{beta} antagonist (labetalol), or the neuronal blocking agent guanethidine, prior to the addition of [{sup 125}I]MIBG (0.1 {mu}M). The incubation was continued for 2 h and specific cell-associated radioactivity was measured. For the storage studies, cells were incubated with [{sup 125}I]MIBG for 2 h, followed by replacement with fresh medium with or without drug (MIBG, clonidine, or yohimbine). Cell-associated radioactivity was measured at various times over the next 20 h. Propanolol reduced [{sup 125}I]MIBG uptake by approximately 30% (P<0.01) at all concentrations tested, most likely due to nonspecific membrane changes. In conclusion, the results of this study establish that selected adrenergic ligands can significantly influence the pattern of uptake and storage of MIBG in cultured neuroblastoma cells, most likely through inhibition of uptake or through noncompetitive inhibition. The potential inplications of these findings justify further study. (orig./VHE). With 4 figs., 1 tab.

  5. Potential transfer of neurotoxic amino acid β-N-methylamino-alanine (BMAA) from mother to infant during breast-feeding: Predictions from human cell lines.

    Science.gov (United States)

    Andersson, Marie; Ersson, Lisa; Brandt, Ingvar; Bergström, Ulrika

    2017-04-01

    β-N-methylamino-alanine (BMAA) is a non-protein amino acid produced by cyanobacteria, diatoms and dinoflagellates. BMAA has potential to biomagnify in a terrestrial food chain, and to bioaccumulate in fish and shellfish. We have reported that administration of [(14)C]l-BMAA to lactating mice and rats results in a mother to off-spring transfer via the milk. A preferential enantiomer-specific uptake of [(14)C]l-BMAA has also been demonstrated in differentiated murine mammary epithelium HC11 cells. These findings, together with neurotoxic effects of BMAA demonstrated both in vitro and in vivo, highlight the need to determine whether such transfer could also occur in humans. Here, we used four cell lines of human origin to examine and compare the transport of the two BMAA enantiomers in vitro. The uptake patterns of [(14)C]l- and [(14)C]d-BMAA in the human mammary MCF7 cell line were in agreement with the results in murine HC11 cells, suggesting a potential secretion of BMAA into human breast milk. The permeability coefficients for both [(14)C]l- and [(14)C]d-BMAA over monolayers of human intestinal Caco2 cells supported an efficient absorption from the human intestine. As a final step, transport experiments confirmed that [(14)C]l-and [(14)C]d-BMAA can be taken up by human SHSY5Y neuroblastoma cells and even more efficiently by human U343 glioblastoma cells. In competition experiments with various amino acids, the ASCT2 specific inhibitor benzylserine was the most effective inhibitor of [(14)C]l-BMAA uptake tested here. Altogether, our results suggest that BMAA can be transferred from an exposed mother, via the milk, to the brain of the nursed infant. Copyright © 2017. Published by Elsevier Inc.

  6. Neutrinoless double beta decay

    Indian Academy of Sciences (India)

    Kai Zuber

    2012-10-01

    The physics potential of neutrinoless double beta decay is discussed. Furthermore, experimental considerations as well as the current status of experiments are presented. Finally, an outlook towards the future, work on nuclear matrix elements and alternative processes is given.

  7. Association between FDG uptake, CSF biomarkers and cognitive performance in patients with probable Alzheimer's disease

    Energy Technology Data Exchange (ETDEWEB)

    Arlt, Soenke; Jahn, Holger; Eichenlaub, Martin [University Medical Center Hamburg-Eppendorf, Department of Psychiatry and Psychotherapy, Hamburg (Germany); Brassen, Stefanie [University Medical Center Hamburg-Eppendorf, Institute for Systems Neuroscience, Hamburg (Germany); Wilke, Florian; Apostolova, Ivayla; Buchert, Ralph [University Medical Center Hamburg-Eppendorf, Department of Nuclear Medicine, Hamburg (Germany); Wenzel, Fabian; Young, Stewart [Philips Research, Digital Imaging Department, Hamburg (Germany); Thiele, Frank [Philips Research, Molecular Imaging Department, Aachen (Germany)

    2009-07-15

    Brain imaging of FDG uptake and cerebrospinal fluid (CSF) concentration of amyloid-beta 1-42 (A{beta}{sub 1-42}) or tau proteins are promising biomarkers in the diagnosis of Alzheimer's disease (AD). There is still uncertainty regarding any association between decreased FDG uptake and alterations in CSF markers. The relationship between FDG uptake, CSF A{beta}{sub 1-42} and total tau (T-tau), as well as the Mini-Mental State Examination (MMSE) score was investigated in 34 subjects with probable AD using step-wise linear regression. FDG uptake was scaled to the pons. Scaled FDG uptake was significantly reduced in the probable AD subjects compared to 17 controls bilaterally in the precuneus/posterior cingulate area, angular gyrus/inferior parietal cortex, inferior temporal/midtemporal cortex, midfrontal cortex, and left caudate. Voxel-based single-subject analysis of the probable AD subjects at p < 0.001 (uncorrected) revealed a total volume of significant hypometabolism ranging from 0 to 452 ml (median 70 ml). The total hypometabolic volume was negatively correlated with the MMSE score, but it was not correlated with the CSF measures. VOI-based step-wise linear regression revealed that scaled FDG uptake in the precuneus/posterior cingulate was negatively correlated with CSF A{beta}{sub 1-42}. Scaled FDG uptake in the caudate was positively correlated with CSF T-tau. The extent and local severity of the reduction in FDG uptake in probable AD subjects are associated with cognitive impairment. In addition, there appears to be a relationship between local FDG uptake and CSF biomarkers which differs between different brain regions. (orig.)

  8. The specific uptake size index for quantifying radiopharmaceutical uptake

    Energy Technology Data Exchange (ETDEWEB)

    Fleming, John S [Department of Medical Physics and Bioengineering, Southampton University Hospitals NHS Trust, Southampton (United Kingdom); Bolt, Livia [Department of Medical Physics and Bioengineering, Southampton University Hospitals NHS Trust, Southampton (United Kingdom); Stratford, Jennifer S [Department of Medical Physics and Bioengineering, Southampton University Hospitals NHS Trust, Southampton (United Kingdom); Kemp, Paul M [Department of Nuclear Medicine, Southampton University Hospitals NHS Trust, Southampton (United Kingdom)

    2004-07-21

    Quantitative indices of radionuclide uptake in an object of interest provide a useful adjunct to qualitative interpretation in the diagnostic application of radionuclide imaging. This note describes a new measure of total uptake of an organ, the specific uptake size index (SUSI). It can either be related in absolute terms to the total activity injected or to the specific activity in a reference region. As it depends on the total activity in the object, the value obtained will not depend on the resolution of the imaging process, as is the case with some other similar quantitative indices. This has been demonstrated in an experiment using simulated images. The application of the index to quantification of dopamine receptor SPECT imaging and parathyroid-thyroid subtraction planar scintigraphy is described. The index is considered to be of potential value in reducing variation in quantitative assessment of uptake in objects with applications in all areas of radionuclide imaging. (note)

  9. Beta-thalassemia

    OpenAIRE

    Origa Raffaella; Galanello Renzo

    2010-01-01

    Abstract Beta-thalassemias are a group of hereditary blood disorders characterized by anomalies in the synthesis of the beta chains of hemoglobin resulting in variable phenotypes ranging from severe anemia to clinically asymptomatic individuals. The total annual incidence of symptomatic individuals is estimated at 1 in 100,000 throughout the world and 1 in 10,000 people in the European Union. Three main forms have been described: thalassemia major, thalassemia intermedia and thalassemia minor...

  10. Alpha and Beta Determinations

    CERN Document Server

    Dunietz, Isard

    1999-01-01

    Because the Bd -> J/psi Ks asymmetry determines only sin(2 beta), a discrete ambiguity in the true value of beta remains. This note reviews how the ambiguity can be removed. Extractions of the CKM angle alpha are discussed next. Some of the methods require very large data samples and will not be feasible in the near future. In the near future, semi-inclusive CP-violating searches could be undertaken, which are reviewed last.

  11. Cellular uptake of metallated cobalamins

    DEFF Research Database (Denmark)

    Tran, Mai Thanh Quynh; Stürup, Stefan; Lambert, Ian Henry

    2016-01-01

    Cellular uptake of vitamin B12-cisplatin conjugates was estimated via detection of their metal constituents (Co, Pt, and Re) by inductively coupled plasma mass spectrometry (ICP-MS). Vitamin B12 (cyano-cob(iii)alamin) and aquo-cob(iii)alamin [Cbl-OH2](+), which differ in the β-axial ligands (CN......(-) and H2O, respectively), were included as control samples. The results indicated that B12 derivatives delivered cisplatin to both cellular cytosol and nuclei with an efficiency of one third compared to the uptake of free cisplatin cis-[Pt(II)Cl2(NH3)2]. In addition, uptake of charged B12 derivatives...

  12. Effect of oral propranolol on splanchnic oxygen uptake and haemodynamics in patients with cirrhosis

    DEFF Research Database (Denmark)

    Bendtsen, Flemming; Henriksen, Jens Henrik; Becker, Povl Ulrik

    1987-01-01

    In order to elucidate the effect of beta-adrenergic blockade on liver metabolism and haemodynamics, splanchnic oxygen uptake, hepatic removal of indocyanine green (ICG) and splanchnic and systemic haemodynamics were studied in 13 patients with cirrhosis before and 1.5-2 h after an oral dose of 80...... mg propranolol. All patients underwent hepatic vein catheterization and had a primed continuous intravenous infusion of ICG. Azygos vein catheterization was performed in six patients. Splanchnic (hepatic-intestinal) oxygen uptake (median control 68 ml/min vs. beta-blockade 56 ml/min, P less than 0...... pressure, stroke volume, and systemic vascular resistance remained essentially unchanged. The results indicate that besides the well-known cardiovascular effects of propranolol, beta-adrenergic blockade may also reduce hepatic metabolic functions as evidenced by the significantly decreased splanchnic...

  13. New classes of alanine racemase inhibitors identified by high-throughput screening show antimicrobial activity against Mycobacterium tuberculosis.

    Directory of Open Access Journals (Sweden)

    Karen G Anthony

    Full Text Available BACKGROUND: In an effort to discover new drugs to treat tuberculosis (TB we chose alanine racemase as the target of our drug discovery efforts. In Mycobacterium tuberculosis, the causative agent of TB, alanine racemase plays an essential role in cell wall synthesis as it racemizes L-alanine into D-alanine, a key building block in the biosynthesis of peptidoglycan. Good antimicrobial effects have been achieved by inhibition of this enzyme with suicide substrates, but the clinical utility of this class of inhibitors is limited due to their lack of target specificity and toxicity. Therefore, inhibitors that are not substrate analogs and that act through different mechanisms of enzyme inhibition are necessary for therapeutic development for this drug target. METHODOLOGY/PRINCIPAL FINDINGS: To obtain non-substrate alanine racemase inhibitors, we developed a high-throughput screening platform and screened 53,000 small molecule compounds for enzyme-specific inhibitors. We examined the 'hits' for structural novelty, antimicrobial activity against M. tuberculosis, general cellular cytotoxicity, and mechanism of enzyme inhibition. We identified seventeen novel non-substrate alanine racemase inhibitors that are structurally different than any currently known enzyme inhibitors. Seven of these are active against M. tuberculosis and minimally cytotoxic against mammalian cells. CONCLUSIONS/SIGNIFICANCE: This study highlights the feasibility of obtaining novel alanine racemase inhibitor lead compounds by high-throughput screening for development of new anti-TB agents.

  14. {beta} - amyloid imaging probes

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Jae Min [Seoul National University College of Medicine, Seoul (Korea, Republic of)

    2007-04-15

    Imaging distribution of {beta} - amyloid plaques in Alzheimer's disease is very important for early and accurate diagnosis. Early trial of the {beta} -amyloid plaques includes using radiolabeled peptides which can be only applied for peripheral {beta} - amyloid plaques due to limited penetration through the blood brain barrier (BBB). Congo red or Chrysamine G derivatives were labeled with Tc-99m for imaging {beta} - amyloid plaques of Alzheimer patient's brain without success due to problem with BBB penetration. Thioflavin T derivatives gave breakthrough for {beta} - amyloid imaging in vivo, and a benzothiazole derivative [C-11]6-OH-BTA-1 brought a great success. Many other benzothiazole, benzoxazole, benzofuran, imidazopyridine, and styrylbenzene derivatives have been labeled with F-18 and I-123 to improve the imaging quality. However, [C-11]6-OH-BTA-1 still remains as the best. However, short half-life of C-11 is a limitation of wide distribution of this agent. So, it is still required to develop an Tc-99m, F-18 or I-123 labeled agent for {beta} - amyloid imaging agent.

  15. Determinants of binding affinity and specificity for the interaction of TEM-1 and SME-1 beta-lactamase with beta-lactamase inhibitory protein.

    Science.gov (United States)

    Zhang, Zhen; Palzkill, Timothy

    2003-11-14

    The hydrolysis of beta-lactam antibiotics by class A beta-lactamases is a common cause of bacterial resistance to these agents. The beta-lactamase inhibitory protein (BLIP) is able to bind and inhibit several class A beta-lactamases, including TEM-1 beta-lactamase and SME-1 beta-lactamase. Although the TEM-1 and SME-1 enzymes share 33% amino acid sequence identity and a similar fold, they differ substantially in surface electrostatic properties and the conformation of a loop-helix region that BLIP binds. Alanine-scanning mutagenesis was performed to identify the residues on BLIP that contribute to its binding affinity for each of these enzymes. The results indicate that the sequence requirements for binding are similar for both enzymes with most of the binding free energy provided by two patches of aromatic residues on the surface of BLIP. Polar residues such as several serines in the interface do not make significant contributions to affinity for either enzyme. In addition, the specificity of binding is significantly altered by mutation of two charged residues, Glu73 and Lys74, that are buried in the structure of the TEM-1.BLIP complex as well as by residues located on two loops that insert into the active site pocket. Based on the results, a E73A/Y50A double mutant was constructed that exhibited a 220,000-fold change in binding specificity for the TEM-1 versus SME-1 enzymes.

  16. Beta cell dynamics: beta cell replenishment, beta cell compensation and diabetes.

    Science.gov (United States)

    Cerf, Marlon E

    2013-10-01

    Type 2 diabetes, characterized by persistent hyperglycemia, arises mostly from beta cell dysfunction and insulin resistance and remains a highly complex metabolic disease due to various stages in its pathogenesis. Glucose homeostasis is primarily regulated by insulin secretion from the beta cells in response to prevailing glycemia. Beta cell populations are dynamic as they respond to fluctuating insulin demand. Beta cell replenishment and death primarily regulate beta cell populations. Beta cells, pancreatic cells, and extra-pancreatic cells represent the three tiers for replenishing beta cells. In rodents, beta cell self-replenishment appears to be the dominant source for new beta cells supported by pancreatic cells (non-beta islet cells, acinar cells, and duct cells) and extra-pancreatic cells (liver, neural, and stem/progenitor cells). In humans, beta cell neogenesis from non-beta cells appears to be the dominant source of beta cell replenishment as limited beta cell self-replenishment occurs particularly in adulthood. Metabolic states of increased insulin demand trigger increased insulin synthesis and secretion from beta cells. Beta cells, therefore, adapt to support their physiology. Maintaining physiological beta cell populations is a strategy for targeting metabolic states of persistently increased insulin demand as in diabetes.

  17. An Optical Overview of Poly[-L-alanine--nitrato-sodium(I] Crystals

    Directory of Open Access Journals (Sweden)

    E. Gallegos-Loya

    2012-01-01

    Full Text Available Single crystals of the semiorganic materials, L-alanine sodium nitrate (LASN and D-alanine sodium nitrate (DASN, were grown from an aqueous solution by slow-evaporation technique. X-ray diffraction (XRD studies were carried for the doped grown crystals. The absorption of these grown crystals was analyzed using UV-Vis-NIR studies, and it was found that these crystals possess minimum absorption from 200 to 1100 nm. An infrared (FTIR spectrum of single crystal has been measured in the 4000–400 cm-1 range. The assignment of the observed vibrational modes to corresponding symmetry type has been performed. A thermogravimetric study was carried out to determine the thermal properties of the grown crystal. The efficiency of second harmonic generation was obtained by a variant of the Kurtz-Perry method.

  18. Dosimetry auditing procedure with alanine dosimeters for light ion beam therapy

    DEFF Research Database (Denmark)

    Ableitinger, Alexander; Vatnitsky, Stanislav; Herrmann, Rochus

    2013-01-01

    fluence in the alanine detector. A pilot run was performed with protons and carbon ions at the Heidelberg Ion Therapy facility (HIT). Results The mean difference of the absolute physical dose measured with the alanine dosimeters compared with the expected dose from the treatment planning system was −2......Background and purpose In the next few years the number of facilities providing ion beam therapy with scanning beams will increase. An auditing process based on an end-to-end test (including CT imaging, planning and dose delivery) could help new ion therapy centres to validate their entire logistic...... chain of radiation delivery. An end-to-end procedure was designed and tested in both scanned proton and carbon ion beams, which may also serve as a dosimetric credentialing procedure for clinical trials in the future. The developed procedure is focused only on physical dose delivery and the validation...

  19. Chiral effects on helicity studied via the energy landscape of short (D, L)-alanine peptides.

    Science.gov (United States)

    Neelamraju, Sridhar; Oakley, Mark T; Johnston, Roy L

    2015-10-28

    The homochirality of natural amino acids facilitates the formation of regular secondary structures such as α-helices and β-sheets. Here, we study the relationship between chirality and backbone structure for the example of hexa-alanine. The most stable stereoisomers are identified through global optimisation. Further, the energy landscape, a database of connected low-energy local minima and transition points, is constructed for various neutral and zwitterionic stereoisomers of hexa-alanine. Three order parameters for partial helicity are applied and metric disconnectivity graphs are presented with partial helicity as a metric. We also apply the Zimm-Bragg model to derive average partial helicities for Ace-(L-Ala)6-NHMe, Ace-(D-Ala-L-Ala)3-NHMe, and Ace-(L-Ala)3-(D-Ala)3-NHMe from the database of local minima and compare with previous studies.

  20. The behaviour of alanine dosimeters at temperatures between 100 and 300 K

    Energy Technology Data Exchange (ETDEWEB)

    Sharpe, P.H.G. [National Physical Laboratory, Teddington TW11 0LW (United Kingdom)], E-mail: peter.sharpe@npl.co.uk; Sephton, J.P.; Gouldstone, C.A. [National Physical Laboratory, Teddington TW11 0LW (United Kingdom)

    2009-07-15

    A cryostat has been constructed to enable irradiations in a MDS Nordion Gammacell 220 irradiator to be carried out at selected temperatures between 100 and 300 K. The principle of operation and the performance of this cryostat are described and results are given of a study into the behaviour of alanine dosimeters at cryogenic temperatures. This work extends previously published data to the region between solid CO{sub 2} and liquid N{sub 2} temperatures and has demonstrated complex dose-dependent behaviour. A sharp discontinuity in the effect of temperature on alanine dosimeter response has been found in the region between 150 and 180 K, with no further influence of irradiation temperature on response observed below this point.

  1. The behaviour of alanine dosimeters at temperatures between 100 and 300 K

    Science.gov (United States)

    Sharpe, P. H. G.; Sephton, J. P.; Gouldstone, C. A.

    2009-07-01

    A cryostat has been constructed to enable irradiations in a MDS Nordion Gammacell 220 irradiator to be carried out at selected temperatures between 100 and 300 K. The principle of operation and the performance of this cryostat are described and results are given of a study into the behaviour of alanine dosimeters at cryogenic temperatures. This work extends previously published data to the region between solid CO 2 and liquid N 2 temperatures and has demonstrated complex dose-dependent behaviour. A sharp discontinuity in the effect of temperature on alanine dosimeter response has been found in the region between 150 and 180 K, with no further influence of irradiation temperature on response observed below this point.

  2. Unusual hydroxyl migration in the fragmentation of β-alanine dication in the gas phase.

    Science.gov (United States)

    Piekarski, Dariusz Grzegorz; Delaunay, Rudy; Maclot, Sylvain; Adoui, Lamri; Martín, Fernando; Alcamí, Manuel; Huber, Bernd A; Rousseau, Patrick; Domaracka, Alicja; Díaz-Tendero, Sergio

    2015-07-14

    We present a combined experimental and theoretical study of the fragmentation of doubly positively charged β-alanine molecules in the gas phase. The dissociation of the produced dicationic molecules, induced by low-energy ion collisions, is analysed by coincidence mass spectrometric techniques; the coupling with ab initio molecular dynamics simulations allows rationalisation of the experimental observations. The present strategy gives deeper insights into the chemical mechanisms of multiply charged amino acids in the gas phase. In the case of the β-alanine dication, in addition to the expected Coulomb explosion and hydrogen migration processes, we have found evidence of hydroxyl-group migration, which leads to unusual fragmentation products, such as hydroxymethyl cation, and is necessary to explain some of the observed dominant channels.

  3. Electronic structure and first hyperpolarizability of poly(2-L-alanine-3-sodium nitrate (I)) crystals

    Indian Academy of Sciences (India)

    A Duarte Moller

    2014-10-01

    Poly(2-L-alanine-3-sodium nitrate (I)), -LASN, crystals have been grown by slow evaporation at room temperature. The nominal size of the crystals obtained by the method was of 500 nm. The UV–Vis spectrum shows a wide range, where absorption is lacking around 532 nm, which is required in order to have the second harmonic emission, when an incident radiation of 1064 nm strikes on the crystal. This guarantees the possible use of the crystal in visible light applications. The transparent nature of the crystal in the visible and infrared regions within the transmission spectrum confirms the nonlinear optical properties of the crystal. Additionally, Fourier transform infrared spectroscopy displays its functional groups which correspond to the poly(2-L-alanine-3-sodium nitrate (I)), where the presence of nitrates in the lattice generally can be identified by their characteristic signature within the 1660–1625, 1300–1255, 870–833 and 763–690 cm-1 range. Single crystal diffraction was carried out in order to determine atomic structure and lattice parameter. Structural parameters were = 5.388(9) Å, = 9.315(15) Å and = 13.63(2) Å. The structure of poly(2-Lalanine-3-sodium nitrate (I)) shown by single crystal diffraction shows an asymmetric unit consisting of one sodium and one nitrate ion and one L-alanine molecule. The coordination geometry around the sodium atom was trigonal bipyramidal, with three bidentate nitrate anions coordinating through their oxygen atoms and two L-alanine molecules, each coordinating through one carboxyl oxygen atom. Electronic structure was obtained by using the Becke–Lee–Yang–Part and Hartree–Fock approximations with hybrid exchangecorrelation three-parameter functional and G-311**G() basis set. Theoretical and experimental results were compared and discussed as having an excellent agreement among them.

  4. A COMPARATIVE STUDY ON THE ACTIVITY OF ALANIN-AMINOTRANSFERASE IN HYPOPHTHALMICHTHYS MOLITRIX AND ARISTICHTHYS NOBILIS

    Directory of Open Access Journals (Sweden)

    Gabriela Vasile

    2006-08-01

    Full Text Available The present paper represents a comparative study on the activity of one aminotransferase - alaninaminotransferase, in the digestive tube of Hypophthalmichthys molitrix (silver carp and Aristichthys nobilis (bighead carp. The enzymatic activity has been determined colorimetrically, with 2, 4 - dinitrophenyl hydrazine, the results obtained being expressed as UE / g / min. It was observed that, comparatively with the alanin-aminotransferase activity recorded in silver carp, in the case of bighead carp, the values recorded are much lower.

  5. [Alanine dehydrogenase of the cyanobacterium Plectonema boryanum in the early period of cyanophage LPP-3 development].

    Science.gov (United States)

    Perepelitsa, S I; Koltukova, N V; Mendzhul, M I

    1995-01-01

    It has been studied how reproduction of LPP-3 in Plectonema boryanum cells influences the alanine dehydrogenase activity. It has been found that immediately after the virus adsorption the enzyme activity falls by 50% and the anabolic reaction is blocked. Physicochemical properties of the enzyme vary as well. An infected cell has one isoenzyme-octamer with pl 9.1-9.2, pH-optimum by action 9-10, molecular weight about 27 kDa.

  6. Structure and vibrational spectra of L-alanine L-alaninium picrate monohydrate

    Science.gov (United States)

    Ghazaryan, V. V.; Fleck, M.; Petrosyan, A. M.

    2012-05-01

    Preparation, crystal and molecular structure as well as vibrational spectra of the crystal L-alanine L-alaninium picrate monohydrate are described. The title crystal is monoclinic, space group P21. The asymmetric unit contains one dimeric (L-Ala⋯L-Ala+) cation, one picrate anion and a water molecule. The O⋯O distance in the dimeric cation is equal to 2.553(2) Å. The IR and Raman spectra are interpreted based on the structure.

  7. Alanine aminotransferase is an inadequate surrogate marker for detecting lamivudine resistance

    Institute of Scientific and Technical Information of China (English)

    Lee; Guan; Lim; Myat; Oo; Aung; Bee; Leng; Seet; Cindy; Tan; Yock; Young; Dan; Yin; Mei; Lee; Dede; Selamat; Sutedja; Mark; Fernandes; Guan; Huei; Lee; Evelyn; Koay; Seng; Gee; Lim

    2010-01-01

    AIM: To investigate the accuracy of serum alanine aminotransferase (ALT) in diagnosing lamivudine resistance and factors that contributed to abnormal serum ALT.METHODS: This was a retrospective study of chronic hepatitis B patients on lamivudine therapy who were followed for 3-mo with liver function tests and hepatitis B virus (HBV) DNA measurement. Lamivudine resistance was defined as HBV DNA ≥ 1 log from nadir on at least 2 occasions, confirmed by genotyping. Serum ALT levels in patients with lamivudine r...

  8. β-alanine supplementation improves isometric endurance of the knee extensor muscles

    Directory of Open Access Journals (Sweden)

    Sale Craig

    2012-06-01

    Full Text Available Abstract Background We examined the effect of four weeks of β-alanine supplementation on isometric endurance of the knee extensors at 45% maximal voluntary isometric contraction (MVIC. Methods Thirteen males (age 23 ± 6 y; height 1.80 ± 0.05 m; body mass 81.0 ± 10.5 kg, matched for pre-supplementation isometric endurance, were allocated to either a placebo (n = 6 or β-alanine (n = 7; 6.4 g·d-1 over 4 weeks supplementation group. Participants completed an isometric knee extension test (IKET to fatigue, at an intensity of 45% MVIC, before and after supplementation. In addition, two habituation tests were completed in the week prior to the pre-supplementation test and a further practice test was completed in the week prior to the post-supplementation test. MVIC force, IKET hold-time, and impulse generated were recorded. Results IKET hold-time increased by 9.7 ± 9.4 s (13.2% and impulse by 3.7 ± 1.3 kN·s-1 (13.9% following β-alanine supplementation. These changes were significantly greater than those in the placebo group (IKET: t(11 = 2.9, p ≤0.05; impulse: t(11 = 3.1, p ≤ 0.05. There were no significant changes in MVIC force in either group. Conclusion Four weeks of β-alanine supplementation at 6.4 g·d-1 improved endurance capacity of the knee extensors at 45% MVIC, which most likely results from improved pH regulation within the muscle cell as a result of elevated muscle carnosine levels.

  9. Densities and solubilities of Glycylglycine and Glycyl-L-Alanine in Aqueous Electrolyte Solutions

    DEFF Research Database (Denmark)

    Breil, Martin Peter; Mollerup, Jørgen; Rudolph, E. Susanne J.

    2004-01-01

    is 1.74 and 4.78 mol/kg of water, respectively. The solubility of glycylglycine in salt solutions of NaCl, Na2SO4, and (NH4)(2)SO4 show a moderate salting-in effect. The solubility of glycyl-L-alanine show a minor or no salting-in effect at low salt concentrations and a moderate salting-out effect...

  10. On the fragmentation of biomolecules: fragmentation of alanine dipeptide along the polypeptide chain

    DEFF Research Database (Denmark)

    Solov'yov, Ilia; Yakubovich, Alexander; Solov'yov, Andrey

    2006-01-01

    . The fragmentation of dipeptide along the polypeptide chain, as well as the interaction between alanines, has been considered. The energy of the system has been analyzed as a function of the distance between fragments for all possible dipeptide fragmentation channels. Analysis of the energy barriers makes...... it possible to estimate the characteristic fragmentation times and to determine the degree of applicability of classical electrodynamics for describing the system energy....

  11. Metalaxyl toxicity, uptake, and distribution in several ornamental plant species.

    Science.gov (United States)

    Wilson, P C; Whitwell, T; Klaine, S J

    2001-01-01

    Phytoremediation depends on the ability of plants to tolerate and assimilate contaminants. This research characterized the interaction between several ornamental plant species and the fungicidal active ingredient, metalaxyl [N-(2,6-dimethylphenyl)-N-(methoxyacetyl)alanine methyl ester]. Species evaluated included sweetflag (Acorus gramineus Sol. ex Aiton), canna (Canna hybrida L. 'Yellow King Humbert'), parrotfeather [Myriophyllum aquaticum (Vell.) Verdc.], and pickerelweed (Pontederia cordata L.). Metalaxyl tolerance levels for each species were determined by exposing plants for 7 d to solutions containing 0, 5, 10, 25, 50, 75, or 100 mg metalaxyl L-1 aqueous nutrient media. Response endpoints included fresh mass production after 7 d exposure and 7 d post-exposure and quantum efficiency using dark-adapted (Fv/Fm) and light-adapted (fluorescence yields) plants. Metalaxyl uptake and distribution within the plant was determined by growing plants in aqueous nutrient media containing 1.18 x 10(6) Bq L-1 [14C]metalaxyl (0.909 mg L-1) for 1, 3, 5, or 7 d. Plant tissues were combusted and analyzed by liquid scintillation counting. Metalaxyl had no effects on the endpoints measured, except for fresh mass production of sweetflag at the 75 and 100 mg L-1 treatment levels. However, leaf necrosis was apparent in most species after 5 d exposure to concentrations greater than 25 mg L-1. Metalaxyl removal from the spiked nutrient media ranged from 15 to 60% during the 7-d exposure period. The majority of metalaxyl removed from the solution was detected within individual plants. In nearly all cases, activity from the radiolabeled pesticide accumulated in the leaves. Uptake of metalaxyl was correlated with water uptake throughout the 7 d. These results suggest that all species examined may be good candidates for incorporation into a phytoremediation scheme for metalaxyl.

  12. Survivability and reactivity of glycine and alanine in early oceans: effects of meteorite impacts.

    Science.gov (United States)

    Umeda, Yuhei; Fukunaga, Nao; Sekine, Toshimori; Furukawa, Yoshihiro; Kakegawa, Takeshi; Kobayashi, Takamichi; Nakazawa, Hiromoto

    2016-01-01

    Prebiotic oceans might have contained abundant amino acids, and were subjected to meteorite impacts, especially during the late heavy bombardment. It is so far unknown how meteorite impacts affected amino acids in the early oceans. Impact experiments were performed under the conditions where glycine was synthesized from carbon, ammonia, and water, using aqueous solutions containing (13)C-labeled glycine and alanine. Selected amino acids and amines in samples were analyzed with liquid chromatography-mass spectrometry (LC/MS). In particular, the (13)C-labeled reaction products were analyzed to distinguish between run products and contaminants. The results revealed that both amino acids survived partially in the early ocean through meteorite impacts, that part of glycine changed into alanine, and that large amounts of methylamine and ethylamine were formed. Fast decarboxylation was confirmed to occur during such impact processes. Furthermore, the formation of n-butylamine, detected only in the samples recovered from the solutions with additional nitrogen and carbon sources of ammonia and benzene, suggests that chemical reactions to form new biomolecules can proceed through marine impacts. Methylamine and ethylamine from glycine and alanine increased considerably in the presence of hematite rather than olivine under similar impact conditions. These results also suggest that amino acids present in early oceans can contribute further to impact-induced reactions, implying that impact energy plays a potential role in the prebiotic formation of various biomolecules, although the reactions are complicated and depend upon the chemical environments as well.

  13. Structural, spectral, thermal, dielectric, mechanical and optical properties of urea L-alanine acetate single crystals

    Science.gov (United States)

    Jaikumar, D.; Kalainathan, S.; Bhagavannarayana, G.

    2010-05-01

    A new organic nonlinear optical crystal, urea L-alanine acetate (ULAA) has been grown by solution growth using slow cooling technique with the vision to improve the properties of the L-alanine crystals. Urea and L-alanine material were mixed in the molar ratio 1:4. Solubility and metastable zone width were determined. Single crystal XRD analyses revealed that the crystal lattice of ULAA is orthorhombic system, primitive lattice with cell parameters a=5.7971 Å, b=6.0391 Å, c=12.3276 Å with space group P2 12 12 1 (D 24). High-resolution X-ray diffraction (HR-XRD) analysis was carried out to study their crystalline perfection. FTIR spectrum was recorded to identify the presence of functional groups and molecular structure was confirmed by 1H NMR spectrum. From the mass spectrum, the ratio of compound formation of ULAA was analyzed. Thermal strength of the grown crystal has been studied using thermo-gravimetric (TG) and differential thermal analysis (DTA). Dielectric measurements reveal that the grown crystals have very low dielectric loss. The mechanical behavior was studied by Vickers microhardness test. The grown crystals were found to be transparent in the entire visible region. Preliminary measurement using Kurtz powder technique with Nd-YAG laser light of wavelength 1064 nm indicates that their second harmonic generation (SHG) efficiency is roughly equal to that of pure KDP.

  14. Heterologous expression of the Bacillus subtilis (natto) alanine dehydrogenase in Escherichia coli and Lactococcus lactis.

    Science.gov (United States)

    Ye, Wei; Huo, Guicheng; Chen, Junliang; Liu, Fei; Yin, Jingyuan; Yang, Lijie; Ma, Xiaolong

    2010-05-30

    The major objective of the present study is to change the alanine production of Lactic acid bacteria by expression of Bacillus subtilis (natto) alanine dehydrogenase (AlaDH), the gene that is not present in Lactic acid. B. subtilis AlaDH gene (ald) was cloned into a pGEX6p-1 and expressed in E. coli JM109. Its enzyme activity was 48.3U/mg at 30 degrees C and 45.2U/mg at 42 degrees C. This ald gene was then cloned into a vector pNZ8148 to generate a vector pNZ8148/ald. The same ald gene was placed downstream of the ldh promoter from Streptococcus thermophilus to generate pNZ273/ldhp/ald. The pNZ8148/ald and pNZ273/ldhp/ald were introduced separately in Lactococcus lactis NZ9000. As a result of over-expressed ald, the production of alanine detected by HPLC in L. lactis NZ9000 carrying pNZ273/ldhp/ald reached 52mug/ml, an approximately 26-fold increase compared to the parent strain L. lactis NZ9000, but not in L. lactis NZ9000 carrying pNZ8148/ald. This study would help strain improvement to be used in dairy fermentation for developing healthy yogurts with sweet taste or other fermented dairy foods. Copyright 2009 Elsevier GmbH. All rights reserved.

  15. Surface chemistry of alanine on Cu{111}: Adsorption geometry and temperature dependence

    Science.gov (United States)

    Baldanza, Silvia; Cornish, Alix; Nicklin, Richard E. J.; Zheleva, Zhasmina V.; Held, Georg

    2014-11-01

    Adsorption of L-alanine on the Cu{111} single crystal surface was investigated as a model system for interactions between small chiral modifier molecules and close-packed metal surfaces. Synchrotron-based X-ray photoelectron spectroscopy (XPS) and near-edge X-ray absorption fine structure (NEXAFS) spectroscopy are used to determine the chemical state, bond coordination and out-of-plane orientation of the molecule on the surface. Alanine adsorbs in its anionic form at room temperature, whilst at low temperature the overlayer consists of anionic and zwitterionic molecules. NEXAFS spectra exhibit a strong angular dependence of the π* resonance associated with the carboxylate group, which allows determining the tilt angle of this group with respect to the surface plane (48° ± 2°) at room temperature. Low-energy electron diffraction (LEED) shows a p(2√{ 13} × 2√{ 13}) R 13 ° superstructure with only one domain, which breaks the mirror symmetry of the substrate and, thus, induces global chirality to the surface. Temperature-programmed XPS (TP-XPS) and temperature-programmed desorption (TPD) experiments indicate that the zwitterionic form converts into the anionic species (alaninate) at 293 K. The latter desorbs/decomposes between 435 K and 445 K.

  16. Paradox of mistranslation of serine for alanine caused by AlaRS recognition dilemma.

    Science.gov (United States)

    Guo, Min; Chong, Yeeting E; Shapiro, Ryan; Beebe, Kirk; Yang, Xiang-Lei; Schimmel, Paul

    2009-12-10

    Mistranslation arising from confusion of serine for alanine by alanyl-tRNA synthetases (AlaRSs) has profound functional consequences. Throughout evolution, two editing checkpoints prevent disease-causing mistranslation from confusing glycine or serine for alanine at the active site of AlaRS. In both bacteria and mice, Ser poses a bigger challenge than Gly. One checkpoint is the AlaRS editing centre, and the other is from widely distributed AlaXps-free-standing, genome-encoded editing proteins that clear Ser-tRNA(Ala). The paradox of misincorporating both a smaller (glycine) and a larger (serine) amino acid suggests a deep conflict for nature-designed AlaRS. Here we show the chemical basis for this conflict. Nine crystal structures, together with kinetic and mutational analysis, provided snapshots of adenylate formation for each amino acid. An inherent dilemma is posed by constraints of a structural design that pins down the alpha-amino group of the bound amino acid by using an acidic residue. This design, dating back more than 3 billion years, creates a serendipitous interaction with the serine OH that is difficult to avoid. Apparently because no better architecture for the recognition of alanine could be found, the serine misactivation problem was solved through free-standing AlaXps, which appeared contemporaneously with early AlaRSs. The results reveal unconventional problems and solutions arising from the historical design of the protein synthesis machinery.

  17. Qualitative analysis of collective mode frequency shifts in L-alanine using terahertz spectroscopy.

    Science.gov (United States)

    Taulbee, Anita R; Heuser, Justin A; Spendel, Wolfgang U; Pacey, Gilbert E

    2009-04-01

    We have observed collective mode frequency shifts in deuterium-substituted L-alanine, three of which have previously only been calculated. Terahertz (THz) absorbance spectra were acquired at room temperature in the spectral range of 66-90 cm(-1), or 2.0-2.7 THz, for L-alanine (L-Ala) and four L-Ala compounds in which hydrogen atoms (atomic mass = 1 amu) were substituted with deuterium atoms (atomic mass = 2 amu): L-Ala-2-d, L-Ala-3,3,3-d(3), L-Ala-2,3,3,3-d(4), and L-Ala-d(7). The absorbance maxima of two L-Ala collective modes in this spectral range were recorded for multiple spectral measurements of each compound, and the magnitude of each collective mode frequency shift due to increased mass of these specific atoms was evaluated for statistical significance. Calculations were performed which predict the THz absorbance frequencies based on the estimated reduced mass of the modes. The shifts in absorbance maxima were correlated with the location(s) of the substituted deuterium atom(s) in the L-alanine molecule, and the atoms contributing to the absorbing delocalized mode in the crystal structure were deduced using statistics described herein. The statistical analyses presented also indicate that the precision of the method allows reproducible frequency shifts as small as 1 cm(-1) or 0.03 THz to be observed and that these shifts are not random error in the measurement.

  18. Identification and expression analyses of the alanine aminotransferase (AlaAT) gene family in poplar seedlings

    Science.gov (United States)

    Xu, Zhiru; Ma, Jing; Qu, Chunpu; Hu, Yanbo; Hao, Bingqing; Sun, Yan; Liu, Zhongye; Yang, Han; Yang, Chengjun; Wang, Hongwei; Li, Ying; Liu, Guanjun

    2017-01-01

    Alanine aminotransferase (AlaAT, E.C.2.6.1.2) catalyzes the reversible conversion of pyruvate and glutamate to alanine and α-oxoglutarate. The AlaAT gene family has been well studied in some herbaceous plants, but has not been well characterized in woody plants. In this study, we identified four alanine aminotransferase homologues in Populus trichocarpa, which could be classified into two subgroups, A and B. AlaAT3 and AlaAT4 in subgroup A encode AlaAT, while AlaAT1 and AlaAT2 in subgroup B encode glutamate:glyoxylate aminotransferase (GGAT), which catalyzes the reaction of glutamate and glyoxylate to α-oxoglutarate and glycine. Four AlaAT genes were cloned from P. simonii × P. nigra. PnAlaAT1 and PnAlaAT2 were expressed predominantly in leaves and induced by exogenous nitrogen and exhibited a diurnal fluctuation in leaves, but was inhibited in roots. PnAlaAT3 and PnAlaAT4 were mainly expressed in roots, stems and leaves, and was induced by exogenous nitrogen. The expression of PnAlaAT3 gene could be regulated by glutamine or its related metabolites in roots. Our results suggest that PnAlaAT3 gene may play an important role in nitrogen metabolism and is regulated by glutamine or its related metabolites in the roots of P. simonii × P. nigra. PMID:28378825

  19. Molecular and phenotypic characterization of transgenic wheat and sorghum events expressing the barley alanine aminotransferase.

    Science.gov (United States)

    Peña, Pamela A; Quach, Truyen; Sato, Shirley; Ge, Zhengxiang; Nersesian, Natalya; Dweikat, Ismail M; Soundararajan, Madhavan; Clemente, Tom

    2017-08-11

    The expression of a barley alanine aminotransferase gene impacts agronomic outcomes in a C3 crop, wheat. The use of nitrogen-based fertilizers has become one of the major agronomic inputs in crop production systems. Strategies to enhance nitrogen assimilation and flux in planta are being pursued through the introduction of novel genetic alleles. Here an Agrobacterium-mediated approach was employed to introduce the alanine aminotransferase from barley (Hordeum vulgare), HvAlaAT, into wheat (Triticum aestivum) and sorghum (Sorghum bicolor), regulated by either constitutive or root preferred promoter elements. Plants harboring the transgenic HvAlaAT alleles displayed increased alanine aminotransferase (alt) activity. The enhanced alt activity impacted height, tillering and significantly boosted vegetative biomass relative to controls in wheat evaluated under hydroponic conditions, where the phenotypic outcome across these parameters varied relative to time of year study was conducted. Constitutive expression of HvAlaAT translated to elevation in wheat grain yield under field conditions. In sorghum, expression of HvAlaAT enhanced enzymatic activity, but no changes in phenotypic outcomes were observed. Taken together these results suggest that positive agronomic outcomes can be achieved through enhanced alt activity in a C3 crop, wheat. However, the variability observed across experiments under greenhouse conditions implies the phenotypic outcomes imparted by the HvAlaAT allele in wheat may be impacted by environment.

  20. Effect of dipeptide of glutamine and alanine on severe traumatic brain injury

    Institute of Scientific and Technical Information of China (English)

    YANG De-lin; XU Jun-fa

    2007-01-01

    Objective: To determine the effect of dipeptide of glutamine and alanine on patients with severe traumatic brain injury. Methods: A total of 46 patients (31 males and 15 females, aged 7-68 years, (47±9.6) years on average) with severe traumatic brain injury were randomized into two groups: Group G (n=23) and Group C (n=23). The patients in Group G received nutritional remedy with the dipeptide of glutamine and alanine, whereas the patients in Group C received routine nutritional therapy only. GCS changes, the length of stay in the neurosurgical intensive care unit (NICU), the mortality,the count of lymphocytes, related complications including lung infection and hemorrhage of alimentary tracts, etc, were examined and recorded. Results: The fatality rate and the length of stay in NICU in Group G was lower than these in Group C (P<0.05), but no obvious difference was found in GCS changes of the patients between the two groups (P>0.05). The patients with lung infection and alimentary tract hemorrhage in Group G were less than those in Group C (P<0.05). The count of lymphocytes in Group G was more than that in Group C (P<0.05), but no difference was found in other nutritional data. Conclusions: Dipeptide of glutamine and alanine can increase the resisting stress and anti-infection ability of patients with severe traumatic brain injury, which can also lower the mortality and shorten the NICU stay.

  1. The effect of irradiation temperatures between ambient and 80 deg. C on the response of alanine dosimeters

    DEFF Research Database (Denmark)

    Sharpe, P.H.G.; Miller, Arne; Sephton, J.P.;

    2009-01-01

    Published data on the effect of irradiation temperature on the response of alanine dosimeters does not extend to the temperatures that may be experienced in high-dose industrial irradiations, particularly in the case of electron beams. We describe here results of the irradiation of alanine...... begins to deviate significantly from linearity and shows marked dose dependence. The effect of this behaviour under conditions typically experienced in industrial processing is evaluated and recommendations made concerning the use of alanine dosimeters at high doses and temperatures....

  2. Association of coatomer proteins with the beta-receptor for platelet-derived growth factor

    DEFF Research Database (Denmark)

    Hansen, Klaus; Rönnstrand, L; Rorsman, C

    1997-01-01

    of intracellular vesicle transport. In order to explore the functional significance of the interaction between alpha- and beta'-COP and the PDGF receptor, a receptor mutant was made in which the conserved histidine residue 928 was mutated to an alanine residue. The mutant receptor, which was unable to bind alpha......The nonreceptor tyrosine kinase Src binds to and is activated by the beta-receptor for platelet-derived growth factor (PDGF). The interaction leads to Src phosphorylation of Tyr934 in the kinase domain of the receptor. In the course of the functional characterization of this phosphorylation, we...... noticed that components of 136 and 97 kDa bound to a peptide from this region of the receptor in a phosphorylation-independent manner. These components have now been purified and identified as alpha- and beta'-coatomer proteins (COPs), respectively. COPs are a family of proteins involved in the regulation...

  3. Water uptake and water supply

    NARCIS (Netherlands)

    Sonneveld, C.; Voogt, W.

    2009-01-01

    The water uptake and the water supply do not directly affect the mineral absorption of plants. However, many connections exist between the management of minerals and water. The most evident of those connections are following

  4. Octreotide Uptake in Parathyroid Adenoma

    Science.gov (United States)

    Karaçavuş, Seyhan; Kula, Mustafa; Cihan Karaca, Züleyha; Ünlühızarcı, Kürşad; Tutuş, Ahmet; Bayram, Fahri; Çoban, Ganime

    2012-01-01

    The patient with a history of bone pain and muscle weakness, was thought to have oncogenic osteomalacia as a result of biochemical investigations and directed to Nuclear Medicine Department for a whole-body bone scintigraphy and 111In-octreotide scintigraphy. There was no focal pathologic tracer uptake, but generalized marked increase in skeletal uptake on bone scintigraphy. Octreotide scintigraphy showed accumulation of octreotide in the region of the left lobe of the thyroid gland in the neck. Thereafter, parathyroid scintigraphy was performed with technetium-99m labeled metroxy-isobutyl-isonitryl (99mTc-MIB) and MIBI scan demonstrated radiotracer uptake at the same location with octreotide scintigraphy. The patient underwent left inferior parathyroidectomy and histopathology confirmed a parathyroid adenoma. Somatostatin receptor positive parathyroid adenoma may show octreotide uptake. Octreotide scintigraphy may be promising and indicate a possibility of using somatostatin analogues for the medical treatment of somatostatin receptor positive Conflict of interest:None declared. PMID:23487397

  5. Radioiodinated Naphthylalanine Derivatives Targeting Pancreatic Beta Cells in Normal and Nonobese Diabetic Mice

    Science.gov (United States)

    Amartey, John K.; Shi, Yufei; Al-Jammaz, Ibrahim; Esguerra, Celestina; Al-Otaibi, Basem; Al-Mohanna, Futwan

    2008-01-01

    An imaging method capable of using a signal from pancreatic beta cells to determine their mass would be of immense value in monitoring the progression of diabetes as well as response to treatment. Somatostatin receptors (SSTRs) are expressed on beta cells and are a potential target for imaging. The main objective of this study was to investigate whether pancreatic beta cells are a target for radiolabeled naphthylalanine derivatives. The molecules were subjected to in vitro and ex vivo evaluations. Pancreatic uptake of radioactivity was lower in nonobese diabetic (NOD) mice than normal mice at all time points investigated (P < .05) and correlated with the number of islets in tissue sections of both control and NOD mice. Immunohistochemical and confocal fluorescent microscopic studies showed colocalization of insulin and the conjugate radioligand in the pancreas. The results demonstrated that pancreatic uptake is receptor-mediated, and that beta cells are the primary target. PMID:18483609

  6. Molecular dynamics simulation of {beta}-sheet formation in self-assembled peptide amphiphile fibers

    Energy Technology Data Exchange (ETDEWEB)

    Lee, One-Sun; Liu Yamei; Schatz, George C., E-mail: schatz@chem.northwestern.edu [Northwestern University, Department of Chemistry (United States)

    2012-08-15

    The influence of amino acid sequence on the secondary structure of peptide amphiphile (PAs) cylindrical micelles and fibers that are self-assembled in solution is studied using molecular dynamics simulations. Simulations for two choices of PAs were performed, starting with structures that have the correct overall shape, but which restructure considerably during the simulation, with one fiber being composed of valine rich PAs and the other of alanine rich PAs. Self-assembly is similar in both simulations, with stable fibers (diameter is 7.7-8 nm) obtained after 40 ns. We find that the valine rich PA fiber has a higher {beta}-sheet population than the alanine rich fiber, and that the number of hydrogen bonds is higher. This behavior of the valine rich fiber is consistent with experimental measurements of higher stiffness, and it shows that stiffness can be varied while still maintaining self-assembly.

  7. Differential sensitivity to beta-cell secretagogues in cultured rat pancreatic islets exposed to human interleukin-1 beta.

    Science.gov (United States)

    Eizirik, D L; Sandler, S; Hallberg, A; Bendtzen, K; Sener, A; Malaisse, W J

    1989-08-01

    The early stages of insulin-dependent diabetes mellitus are characterized by a selective inability to secrete insulin in response to glucose, coupled to a better response to nonnutrient secretagogues. The deficient glucose response may be a result of the autoimmune process directed toward the beta-cells. Interleukin-1 (IL-1) has been suggested to be one possible mediator of immunological damage of the beta-cells. In the present study we characterized the sensitivity of beta-cells to different secretagogues after human recombinant IL-1 beta (rIL-1 beta) exposure. Furthermore, experiments were performed to clarify the biochemical mechanisms behind the defective insulin response observed in these islets. Rat pancreatic islets were isolated and kept in tissue culture (medium RPMI-1640 plus 10% calf serum) for 5 days. The islets were subsequently exposed to 60 pM human recombinant IL-1 beta during 48 h in the same culture conditions as above and examined immediately after IL-1 exposure. The rIL-1 beta-treated islets showed a marked reduction of glucose-stimulated insulin release. Stimulation with arginine plus different glucose concentrations, and leucine plus glutamine partially counteracted the rIL-1 beta-induced reduction of insulin release. The activities of the glycolytic enzymes hexokinase, glucokinase, and glyceraldehyde 3-phosphate dehydrogenase, were similar in control and IL-1-exposed islets. Treatment with IL-1 also did not impair the activities of NADH+- and NADPH+-dependent glutamate dehydrogenase, glutamate-aspartate transaminase, glutamate-alanine transaminase, citrate synthase, and NAD+-linked isocitrate dehydrogenase. The oxidation of D-[6-14C]glucose and L-[U-14C]leucine were decreased by 50% in IL-1-treated islets. Furthermore, there was a significant decrease in the ratios of [2-14C]pyruvate oxidation/[1-14C]pyruvate decarboxylation and L-[U-14C]leucine oxidation/L-[1-14C]leucine decarboxylation, indicating that IL-1 decreases the proportion of

  8. Alanine aminotransferase, gamma-glutamyltransferase (GGT) and all-cause mortality: results from a population-based Danish twins study alanine aminotransferase, GGT and mortality in elderly twins

    DEFF Research Database (Denmark)

    Fraser, Abigail; Thinggaard, Mikael; Christensen, Kaare

    2009-01-01

    Abstract Background/Aims: Alanine aminotransferase (ALT) and gamma-glutamyltransferase (GGT) are widely used markers of liver disease. Several population-based cohort studies have found associations of these liver enzymes with all-cause mortality. None of these studies controlled for genetic...... variation as well as fetal and early life exposure, whether environmental or genetic. Methods: We studied the associations of ALT and GGT with all-cause mortality using data for 686 twins (73-94 years old) included in the Longitudinal Study of Aging Danish Twins. Results: An increase in 1 logged U/L of GGT...... for potential confounders and existing diabetes and cardiovascular disease. Environmental developmental origins may explain the association, but larger twin studies are required to replicate our findings....

  9. Boosted beta regression.

    Directory of Open Access Journals (Sweden)

    Matthias Schmid

    Full Text Available Regression analysis with a bounded outcome is a common problem in applied statistics. Typical examples include regression models for percentage outcomes and the analysis of ratings that are measured on a bounded scale. In this paper, we consider beta regression, which is a generalization of logit models to situations where the response is continuous on the interval (0,1. Consequently, beta regression is a convenient tool for analyzing percentage responses. The classical approach to fit a beta regression model is to use maximum likelihood estimation with subsequent AIC-based variable selection. As an alternative to this established - yet unstable - approach, we propose a new estimation technique called boosted beta regression. With boosted beta regression estimation and variable selection can be carried out simultaneously in a highly efficient way. Additionally, both the mean and the variance of a percentage response can be modeled using flexible nonlinear covariate effects. As a consequence, the new method accounts for common problems such as overdispersion and non-binomial variance structures.

  10. Mechanisms of Ocean Heat Uptake

    Science.gov (United States)

    Garuba, Oluwayemi

    An important parameter for the climate response to increased greenhouse gases or other radiative forcing is the speed at which heat anomalies propagate downward in the ocean. Ocean heat uptake occurs through passive advection/diffusion of surface heat anomalies and through the redistribution of existing temperature gradients due to circulation changes. Atlantic meridional overturning circulation (AMOC) weakens in a warming climate and this should slow the downward heat advection (compared to a case in which the circulation is unchanged). However, weakening AMOC also causes a deep warming through the redistributive effect, thus increasing the downward rate of heat propagation compared to unchanging circulation. Total heat uptake depends on the combined effect of these two mechanisms. Passive tracers in a perturbed CO2 quadrupling experiments are used to investigate the effect of passive advection and redistribution of temperature anomalies. A new passive tracer formulation is used to separate ocean heat uptake into contributions due to redistribution and passive advection-diffusion of surface heating during an ocean model experiment with abrupt increase in surface temperature. The spatial pattern and mechanisms of each component are examined. With further experiments, the effects of surface wind, salinity and temperature changes in changing circulation and the resulting effect on redistribution in the individual basins are isolated. Analysis of the passive advection and propagation path of the tracer show that the Southern ocean dominates heat uptake, largely through vertical and horizontal diffusion. Vertical diffusion transports the tracer across isopycnals down to about 1000m in 100 years in the Southern ocean. Advection is more important in the subtropical cells and in the Atlantic high latitudes, both with a short time scale of about 20 years. The shallow subtropical cells transport the tracer down to about 500m along isopycnal surfaces, below this vertical

  11. Feasibility on using composite gel-alanine dosimetry on the validation of a multiple brain metastasis radiosurgery VMAT technique

    Science.gov (United States)

    Pavoni, J. F.; Neves-Junior, W. F. P.; Silveira, M. A.; Ramos, P. A. M. M.; Haddad, C. M. K.; Baffa, O.

    2015-01-01

    This work presents an end-to-end test using a composite Gel-Alanine phantom, in order to validate 3-dimensionally the dose distribution delivered by a single isocenter VMAT technique on the simultaneous treatment of multiple brain metastases. The results obtained with the gel and alanine dosimeters are consistent with the expected by the treatment planning system, showing the potential of this multidosimetric approach and validating dosimetrically the multiple brain metastases treatment using VMAT.

  12. Double Beta Decay

    CERN Document Server

    Elliott, Steven R

    2011-01-01

    At least one neutrino has a mass of about 50 meV or larger. However, the absolute mass scale for the neutrino remains unknown. Furthermore, the critical question: Is the neutrino its own antiparticle? is unanswered. Studies of double beta decay offer hope for determining the absolute mass scale. In particular, zero-neutrino double beta decay (\\BBz) can address the issues of lepton number conservation, the particle-antiparticle nature of the neutrino, and its mass. A summary of the recent results in \\BBz, and the related technologies will be discussed in the context of the future \\BBz\\ program.

  13. Beta and Gamma Gradients

    DEFF Research Database (Denmark)

    Løvborg, Leif; Gaffney, C. F.; Clark, P. A.;

    1985-01-01

    Experimental and/or theoretical estimates are presented concerning, (i) attenuation within the sample of beta and gamma radiation from the soil, (ii) the gamma dose within the sample due to its own radioactivity, and (iii) the soil gamma dose in the proximity of boundaries between regions...... of differing radioactivity. It is confirmed that removal of the outer 2 mm of sample is adequate to remove influence from soil beta dose and estimates are made of the error introduced by non-removal. Other evaluations include variation of the soil gamma dose near the ground surface and it appears...

  14. The crystal structure of alanine racemase from Streptococcus pneumoniae, a target for structure-based drug design

    Directory of Open Access Journals (Sweden)

    Davlieva Milya

    2011-05-01

    Full Text Available Abstract Background Streptococcus pneumoniae is a globally important pathogen. The Gram-positive diplococcus is a leading cause of pneumonia, otitis media, bacteremia, and meningitis, and antibiotic resistant strains have become increasingly common over recent years.Alanine racemase is a ubiquitous enzyme among bacteria and provides the essential cell wall precursor, D-alanine. Since it is absent in humans, this enzyme is an attractive target for the development of drugs against S. pneumoniae and other bacterial pathogens. Results Here we report the crystal structure of alanine racemase from S. pneumoniae (AlrSP. Crystals diffracted to a resolution of 2.0 Å and belong to the space group P3121 with the unit cell parameters a = b = 119.97 Å, c = 118.10 Å, α = β = 90° and γ = 120°. Structural comparisons show that AlrSP shares both an overall fold and key active site residues with other bacterial alanine racemases. The active site cavity is similar to other Gram positive alanine racemases, featuring a restricted but conserved entryway. Conclusions We have solved the structure of AlrSP, an essential step towards the development of an accurate pharmacophore model of the enzyme, and an important contribution towards our on-going alanine racemase structure-based drug design project. We have identified three regions on the enzyme that could be targeted for inhibitor design, the active site, the dimer interface, and the active site entryway.

  15. Microhydration of Alanine in Gas Phase Studied by Quantum Chemical Method and ABEEMσπ/MM Fluctuating Charge Model

    Institute of Scientific and Technical Information of China (English)

    LU Li-nan; LIU Cui; GONG Li-dong

    2013-01-01

    A fluctuating charge interaction potential function for alanine-water was constructed in the spirit of newly developed ABEEMσπ/MM(atom-bond electronegativity equalization method at the σπ level fused into molecular mechanics).The properties of gaseous neutral alanine-(H2O)n(n=1-7) clusters were systematically investigated by quantum mechanics(QM) and the constructed ABEEMσπ/MM potential,such as conformations,hydrogen bonds (H-bonds),interaction energies,charge distributions,and so on.The results of ABEEMσπ/MM model are in fair agreement with those of QM and available experimental data.For isolated alanine,compared with those of experi-mental structure,the average absolute deviations(AAD) of bond length and bond angle are 0.002 nm and 1.4°,respectively.For alanine-water clusters,the AAD of interaction energies and H-bond lengths are only 3.77 kJ/mol and 0.012 nm,respectively,compared to the results of MP2/aug-cc-pVDZ//MP2/6-311+G** method.The ABEEMσπ charges fluctuate with the changing conformation of the system,and can accurately and reasonably reflect the interpolarization between water and alanine.The presented alanine-water potential function may provide a basis for further simulations on related aqueous solutions of biomolecules.

  16. Combined effect of amino and carboxyl group in α-alanine on seeded precipitation of sodium aluminate solution

    Institute of Scientific and Technical Information of China (English)

    L(U) Bao-lin; CHEN Qi-yuan; YIN Zhou-lan; HU Hui-ping

    2009-01-01

    α-alanine was adopted as a new additive to elucidate the seeded precipitation mechanism of sodium aluminate solution. α-alanine has the inhibitory effect at the initial period of reaction, but the favorable effect in subsequent reaction. The combined effect of amino and carboxyl group in α-alanine was confirmed by investigating the effect of propionic acid, ethamine and the mixture of propionic acid and ethamine (mole ratio 1:1) on the precipitation of sodium aluminate solution, respectively. The inhibitory effect derives from the adsorption of amino or carboxyl group in α-alanine on the active surface sites of gibbsite, which was confirmed by the alleviating inhibitory effects of propionic acid, ethamine and α-alanine due to the double crystal seed mass. The semi-quantitative IR spectrum analysis of the relative concentrations of Al2O(OH)62- with the band at about 550 cm-1 and polynuclear aluminate ion with the bands at about 880 cm-1 and 635 cm-1, indicates that the dynamic balance among some aluminate species present in sodium aluminate solution is broken due to the addition of α-alanine, thus resulting in the change of the seeded precipitation ratio of sodium aluminate solution.

  17. Assessment of Metabolic Changes in Mycobacterium smegmatis Wild-Type and alr Mutant Strains: Evidence of a New Pathway of d-Alanine Biosynthesis.

    Science.gov (United States)

    Marshall, Darrell D; Halouska, Steven; Zinniel, Denise K; Fenton, Robert J; Kenealy, Katie; Chahal, Harpreet K; Rathnaiah, Govardhan; Barletta, Raúl G; Powers, Robert

    2017-03-03

    In mycobacteria, d-alanine is an essential precursor for peptidoglycan biosynthesis. The only confirmed enzymatic pathway to form d-alanine is through the racemization of l-alanine by alanine racemase (Alr, EC 5.1.1.1). Nevertheless, the essentiality of Alr in Mycobacterium tuberculosis and Mycobacterium smegmatis for cell survivability in the absence of d-alanine has been a point of controversy with contradictory results reported in the literature. To address this issue, we examined the effects of alr inactivation on the cellular metabolism of M. smegmatis. The M. smegmatis alr insertion mutant TAM23 exhibited essentially identical growth to wild-type mc(2)155 in the absence of d-alanine. NMR metabolomics revealed drastically distinct phenotypes between mc(2)155 and TAM23. A metabolic switch was observed for TAM23 as a function of supplemented d-alanine. In the absence of d-alanine, the metabolic response directed carbon through an unidentified transaminase to provide the essential d-alanine required for survival. The process is reversed when d-alanine is available, in which the d-alanine is directed to peptidoglycan biosynthesis. Our results provide further support for the hypothesis that Alr is not an essential function of M. smegmatis and that specific Alr inhibitors will have no bactericidal action.

  18. Evaluation of various properties of alternative salt forms of sulfobutylether-beta-cyclodextrin, (SBE)7M-beta-CD.

    Science.gov (United States)

    Sotthivirat, S; Haslam, J L; Stella, V J

    2007-02-07

    The goal of this study was to evaluate alternative salt forms of (SBE)7M-beta-CD (currently the sodium salt). The potential salt form would ideally decrease the rate of (SBE)7M-beta-CD release from osmotic pump formulations and result in an increase in the rate and extent of drug release in osmotic pump tablet and pellet dosage forms. Several (SBE)7M-beta-CD salt forms (potassium, calcium, and two ethylene diamine salt forms) were prepared by either titration or ultrafiltration and characterized by elemental analysis and capillary electrophoresis, CE. The physical properties (water uptake behavior, osmolality, complexation characteristics, etc.) were then compared to the sodium salt form. Although the water isotherm and the binding characteristics using various model drugs were similar among all the salt forms, the calcium salt form appeared to be the best alternative candidate due to its lower osmolality and slower intrinsic dissolution rate.

  19. Regulating the beta cell mass as a strategy for type-2 diabetes treatment.

    Science.gov (United States)

    Song, Imane; Muller, Christo; Louw, Johan; Bouwens, Luc

    2015-01-01

    The incidence of type 2 diabetes (T2D) increases dramatically worldwide and has created an enormous health care burden. Obesity, dyslipidemia and insulin resistance are major risk factors for the development of T2D, but the major factor leading to the disease is failure of the insulin-producing beta cell mass to compensate for increasing insulin demands of the body. Progression of the disease further diminishes the beta cell mass as a result of lipotoxicity and glucotoxicity for which beta cells are particularly sensitive. Hence, treatment aiming to prevent beta cell loss or increase the number of beta cells could inhibit diabetes progression or lead to restoration of normal metabolism. Whereas current and new antidiabetic drugs are mainly targeting insulin secretion and action or glucose uptake, newer interventions must be found that prevent beta cell loss or increase beta cell number. The targets for this are beta cell proliferation, neogenesis and survival. This review examines major evidence from animal experiments suggesting that it is feasible to regulate the beta cell mass by bioactive compounds like growth factors, cytokines, hormones, phytochemicals and small molecules. Often the mode of action remains unclear due to inadequate methods to assess the effects of the compounds on the beta cell dynamics. Furthermore, a major challenge is to identify compounds with sufficient specificity in order to avoid unwanted effects on other cell types. Provided such safety issues can be solved, this may provide a curative approach for diabetes treatment.

  20. Presenilin promotes dietary copper uptake.

    Directory of Open Access Journals (Sweden)

    Adam Southon

    Full Text Available Dietary copper is essential for multicellular organisms. Copper is redox active and required as a cofactor for enzymes such as the antioxidant Superoxide Dismutase 1 (SOD1. Copper dyshomeostasis has been implicated in Alzheimer's disease. Mutations in the presenilin genes encoding PS1 and PS2 are major causes of early-onset familial Alzheimer's disease. PS1 and PS2 are required for efficient copper uptake in mammalian systems. Here we demonstrate a conserved role for presenilin in dietary copper uptake in the fly Drosophila melanogaster. Ubiquitous RNA interference-mediated knockdown of the single Drosophila presenilin (PSN gene is lethal. However, PSN knockdown in the midgut produces viable flies. These flies have reduced copper levels and are more tolerant to excess dietary copper. Expression of a copper-responsive EYFP construct was also lower in the midgut of these larvae, indicative of reduced dietary copper uptake. SOD activity was reduced by midgut PSN knockdown, and these flies were sensitive to the superoxide-inducing chemical paraquat. These data support presenilin being needed for dietary copper uptake in the gut and so impacting on SOD activity and tolerance to oxidative stress. These results are consistent with previous studies of mammalian presenilins, supporting a conserved role for these proteins in mediating copper uptake.

  1. Radioligands for imaging myocardial {alpha}- and &beta;-adrenoceptors

    Energy Technology Data Exchange (ETDEWEB)

    Riemann, B.; Schaefers, M.; Schober, O. [Dept. of Nuclear Medicine, Muenster Univ. (Germany); Law, M.P. [MRC Clinical Sciences Centre, Imperial Coll. School of Science, Technology and Medicine, Hammersmith Hospital, London (United Kingdom); Wichter, T. [Dept. of Cardiology and Angiology, Muenster Univ. (Germany)

    2003-02-01

    Alpha- and beta-adrenoceptors play an important role in the control of heart function. According to their molecular, biological, and pharmacological characteristics, they are subdivided into {alpha}{sub 1}-, {alpha}{sub 2}- and &beta;{sub 1}-, &beta;{sub 2}-, &beta;{sub 3}-, &beta;{sub 4}- adrenoceptors. In cardiac disease, there is often a selective downregulation of &beta;{sub 1}-adrenoceptors associated with a relative increase in &beta;{sub 2}- and {alpha}{sub 1}-adrenoceptors. Functional imaging techniques like single-photon emission tomography (SPECT) and positron emission tomography (PET) provide the unique capability for non-invasive assessment of cardiac adrenoceptors. Radioligands with high specific binding to cardiac {alpha}- and &beta;-adrenoceptors suitable for radiolabelling are required for clinical studies. The non-selective &beta;-adrenoceptor antagonist [{sup 11}C]CGP-12177 was used to quantify &beta;-adrenoceptor density using PET in patients with heart disease. New non-selective ligands (e. g. [{sup 11}C]CGP-12388, [{sup 18}F]CGP-12388, [{sup 11}C]carazolol and [{sup 18}F]fluorocarazolol) are currently evaluated; &beta;{sub 1}-selective radioligands (e. g. [{sup 11}C]CGP-26505, [{sup 11}C]bisoprolol, [{sup 11}C]HX-CH 44) and &beta;{sub 2}-selective radioligands (e. g. [{sup 11}C]formoterol, [{sup 11}C]ICI-118551) were assessed in animals. None of them turned out as suitable for cardiac PET. Potential radioligands for imaging cardiac {alpha}{sub 1}-adrenoceptors are based on prazosin. Whereas [{sup 11}C]prazosin shows low specific binding to myocardium, its derivative [{sup 11}C]GB67 looks more promising. The putative {alpha}{sub 2}-adrenoceptor radioligand [{sup 11}C]MK-912 shows high uptake in rodent myocardium but has not yet been evaluated in man. A number of radioligands were evaluated for assessing cardiac adrenoceptors using PET. New radioligands are needed to provide more insight into cardiac pathophysiology which may influence the

  2. Adjusting ammonium uptake via phosphorylation.

    Science.gov (United States)

    Lanquar, Viviane; Frommer, Wolf B

    2010-06-01

    In plants, AMT/MEP/Rh superfamily mediates high affinity ammonium uptake. AMT/MEP transporters form a trimeric complex, which requires a productive interaction between subunits in order to be functional. The AMT/MEP C-terminal domain is highly conserved in more than 700 AMT homologs from cyanobacteria to higher plants with no cases found to be lacking this domain. AMT1;1 exists in active and inactive states, probably controlled by the spatial positioning of the C-terminus. Ammonium triggers the phosphorylation of a conserved threonine residue (T460) in the C-terminus of AMT1;1 in a time- and concentration-dependent manner. The T460 phosphorylation level correlates with a decrease of root ammonium uptake. We propose that ammonium-induced phosphorylation modulates ammonium uptake as a general mechanism to protect against ammonium toxicity.

  3. Transport of alpha- and beta-D-glucose by the intact human red cell

    Energy Technology Data Exchange (ETDEWEB)

    Carruthers, A.; Melchior, D.L.

    1985-07-16

    The kinetics of alpha- and beta-D-glucose mutarotation and the transport of these anomers by intact human red cells were determined at 0.6 and 36.6 degrees C. The mutarotation coefficients for alpha- and beta-D-glucose in cell-free tris(hydroxymethyl)aminomethane medium (pH 7.4) at 0.6 degrees C are (2.25 +/- 0.2) and (1.73 +/- 0.42) X 10(-3) min-1, respectively, and at 36.6 degrees C are (69 +/- 12) and (75 +/- 5) X 10(-3) min-1, respectively. These values are in good agreement with previous estimates. At 0.6 degrees C, the red cell contains no detectable mutarotase activity. Initial rates of sugar uptake were measured by using radiolabeled D-glucose and time courses of uptake by turbidimetry. The time courses of alpha- and beta-D-glucose and an equilibrium mixture of alpha- and beta-D-glucose infinite-cis entry are identical at 0.66 degrees C (n = 41) where negligible mutarotation is observed. The apparent Ki values for inhibition of radiolabeled D-glucose initial uptake by unlabeled alpha- or beta-D-glucose at 0.6 degrees C are identical (1.6 mM). The calculated Vmax parameters for uptake of the radiolabeled anomers at this temperature are also indistinguishable. The time courses of infinite-cis alpha- and beta-D-glucose uptake at 36.66 degrees C are identical (n = 40). While D-glucose mutarotation is more rapid at this temperature, the anomers of D-glucose are not transported differently by the red cell hexose transfer system.

  4. Lactate, Glucose and Oxygen Uptake in Human Brain During Recovery from Maximal Exercise

    DEFF Research Database (Denmark)

    Kojiro, I.; Schmalbruch, I.K.; Quistorff, B.

    1999-01-01

    Skeletal muscle, brain lactate uptake, brain oxygen uptake, energy metabolism, brain glucose uptake......Skeletal muscle, brain lactate uptake, brain oxygen uptake, energy metabolism, brain glucose uptake...

  5. Concerted modulation of alanine and glutamate metabolism in young Medicago truncatula seedlings under hypoxic stress.

    Science.gov (United States)

    Limami, Anis M; Glévarec, Gaëlle; Ricoult, Claudie; Cliquet, Jean-Bernard; Planchet, Elisabeth

    2008-01-01

    The modulation of primary nitrogen metabolism by hypoxic stress was studied in young Medicago truncatula seedlings. Hypoxic seedlings were characterized by the up-regulation of glutamate dehydrogenase 1 (GDH1) and mitochondrial alanine aminotransferase (mAlaAT), and down-regulation of glutamine synthetase 1b (GS1b), NADH-glutamate synthase (NADH-GOGAT), glutamate dehydrogenase 3 (GDH3), and isocitrate dehydrogenase (ICDH) gene expression. Hypoxic stress severely inhibited GS activity and stimulated NADH-GOGAT activity. GDH activity was lower in hypoxic seedlings than in the control, however, under either normoxia or hypoxia, the in vivo activity was directed towards glutamate deamination. (15)NH(4) labelling showed for the first time that the adaptive reaction of the plant to hypoxia consisted of a concerted modulation of nitrogen flux through the pathways of both alanine and glutamate synthesis. In hypoxic seedlings, newly synthesized (15)N-alanine increased and accumulated as the major amino acid, asparagine synthesis was inhibited, while (15)N-glutamate was synthesized at a similar rate to that in the control. A discrepancy between the up-regulation of GDH1 expression and the down-regulation of GDH activity by hypoxic stress highlighted for the first time the complex regulation of this enzyme by hypoxia. Higher rates of glycolysis and ethanol fermentation are known to cause the fast depletion of sugar stores and carbon stress. It is proposed that the expression of GDH1 was stimulated by hypoxia-induced carbon stress, while the enzyme protein might be involved during post-hypoxic stress contributing to the regeneration of 2-oxoglutarate via the GDH shunt.

  6. Alanine scan of core positions in ubiquitin reveals links between dynamics, stability, and function.

    Science.gov (United States)

    Lee, Shirley Y; Pullen, Lester; Virgil, Daniel J; Castañeda, Carlos A; Abeykoon, Dulith; Bolon, Daniel N A; Fushman, David

    2014-04-03

    Mutations at solvent-inaccessible core positions in proteins can impact function through many biophysical mechanisms including alterations to thermodynamic stability and protein dynamics. As these properties of proteins are difficult to investigate, the impacts of core mutations on protein function are poorly understood for most systems. Here, we determined the effects of alanine mutations at all 15 core positions in ubiquitin on function in yeast. The majority (13 of 15) of alanine substitutions supported yeast growth as the sole ubiquitin. Both the two null mutants (I30A and L43A) were less stable to temperature-induced unfolding in vitro than wild type (WT) but were well folded at physiological temperatures. Heteronuclear NMR studies indicated that the L43A mutation reduces temperature stability while retaining a ground-state structure similar to WT. This structure enables L43A to bind to common ubiquitin receptors in vitro. Many of the core alanine ubiquitin mutants, including one of the null variants (I30A), exhibited an increased accumulation of high-molecular-weight species, suggesting that these mutants caused a defect in the processing of ubiquitin-substrate conjugates. In contrast, L43A exhibited a unique accumulation pattern with reduced levels of high-molecular-weight species and undetectable levels of free ubiquitin. When conjugation to other proteins was blocked, L43A ubiquitin accumulated as free ubiquitin in yeast. Based on these findings, we speculate that ubiquitin's stability to unfolding may be required for efficient recycling during proteasome-mediated substrate degradation. Copyright © 2013 Elsevier Ltd. All rights reserved.

  7. Structural and biochemical analyses of alanine racemase from the multidrug-resistant Clostridium difficile strain 630.

    Science.gov (United States)

    Asojo, Oluwatoyin A; Nelson, Sarah K; Mootien, Sara; Lee, Yashang; Rezende, Wanderson C; Hyman, Daniel A; Matsumoto, Monica M; Reiling, Scott; Kelleher, Alan; Ledizet, Michel; Koski, Raymond A; Anthony, Karen G

    2014-07-01

    Clostridium difficile, a Gram-positive, spore-forming anaerobic bacterium, is the leading cause of infectious diarrhea among hospitalized patients. C. difficile is frequently associated with antibiotic treatment, and causes diseases ranging from antibiotic-associated diarrhea to life-threatening pseudomembranous colitis. The severity of C. difficile infections is exacerbated by the emergence of hypervirulent and multidrug-resistant strains, which are difficult to treat and are often associated with increased mortality rates. Alanine racemase (Alr) is a pyridoxal-5'-phosphate (PLP)-dependent enzyme that catalyzes the reversible racemization of L- and D-alanine. Since D-alanine is an essential component of the bacterial cell-wall peptidoglycan, and there are no known Alr homologs in humans, this enzyme is being tested as an antibiotic target. Cycloserine is an antibiotic that inhibits Alr. In this study, the catalytic properties and crystal structures of recombinant Alr from the virulent and multidrug-resistant C. difficile strain 630 are presented. Three crystal structures of C. difficile Alr (CdAlr), corresponding to the complex with PLP, the complex with cycloserine and a K271T mutant form of the enzyme with bound PLP, are presented. The structures are prototypical Alr homodimers with two active sites in which the cofactor PLP and cycloserine are localized. Kinetic analyses reveal that the K271T mutant CdAlr has the highest catalytic constants reported to date for any Alr. Additional studies are needed to identify the basis for the high catalytic activity. The structural and activity data presented are first steps towards using CdAlr for the development of structure-based therapeutics for C. difficile infections.

  8. Study of pyruvate kinase activity in human astrocytomas - Alanine-inhibition test revisted

    Directory of Open Access Journals (Sweden)

    Javalkar V

    2009-01-01

    Full Text Available Background: Recent studies have confirmed that alterations in the isoenzyme of pyruvate kinase (PK provide tumor cells with selective growth advantage. Aims: Our aim was to establish the mean activity of the enzyme PK in human astrocytomas and to look for any trends in the activity with relation to histological grade. Materials and Methods: The PK (EC 2.7.1.40 activity was measured in the tumor homogenate by spectrophotometric rate determination. ΔAbsorbance at 340 nm (A 340nm per minute was obtained using the maximal linear rate for both the test and the blank. Enzyme activity was estimated in the presence and absence of amino acid alanine. Results: The mean PK level in astrocytomas was 3.5 ± 2.0 mmol/min/mg protein, which was significantly higher (24%; P < 0.001 when compared to 2.8 ± 0.3 mmol/min/mg protein in control brain. Highest PK activity was noted in grade 2 astrocytomas. In controls there was no change in PK activity in the presence of alanine. In grade 2 astrocytomas there was 7% decrease in mean PK activity in the presence of alanine, this difference in grade 3 astrocytomas was 33% and in grade 4 astrocytomas it was 61%. As the tumors were becoming malignant there was a graded increase in the levels of PK inhibition. Conclusions: Mean PK activity was significantly higher in astrocytomas. There was a graded increase in level of PK inhibition as the tumors were becoming more malignant.

  9. Trichoderma .beta.-glucosidase

    Science.gov (United States)

    Dunn-Coleman, Nigel; Goedegebuur, Frits; Ward, Michael; Yao, Jian

    2006-01-03

    The present invention provides a novel .beta.-glucosidase nucleic acid sequence, designated bgl3, and the corresponding BGL3 amino acid sequence. The invention also provides expression vectors and host cells comprising a nucleic acid sequence encoding BGL3, recombinant BGL3 proteins and methods for producing the same.

  10. Roughing up Beta

    DEFF Research Database (Denmark)

    Bollerslev, Tim; Li, Sophia Zhengzi; Todorov, Viktor

    Motivated by the implications from a stylized equilibrium pricing framework, we investigate empirically how individual equity prices respond to continuous, or \\smooth," and jumpy, or \\rough," market price moves, and how these different market price risks, or betas, are priced in the cross-section...

  11. Applied Beta Dosimetry

    Energy Technology Data Exchange (ETDEWEB)

    Rich, B.L.

    1986-01-01

    Measurements of beta and/or nonpenetrating exposure results is complicated and past techniques and capabilities have resulted in significant inaccuracies in recorded results. Current developments have resulted in increased capabilities which make the results more accurate and should result in less total exposure to the work force. Continued development of works in progress should provide equivalent future improvements.

  12. Beta thalassemia - a review

    Directory of Open Access Journals (Sweden)

    R Jha

    2014-09-01

    Full Text Available Thalassemia is a globin gene disorder that results in a diminished rate of synthesis of one or more of the globin chains. About 1.5% of the global population (80 to 90 million people are carriers of beta Thalassemia. More than 200 mutations are described in beta thalassemia. However not all mutations are common in different ethnic groups. The only effective way to reduce burden of thalassemia is to prevent birth of homozygotes. Diagnosis of beta thalassemia can be done by fetal DNA analysis for molecular defects of beta thalassemia or by fetal blood analysis. Hematopoietic stem cell transplantation is the only available curative approach for Thalassemia. Many patients with thalassemia in underdeveloped nations die in childhood or adolescence. Programs that provide acceptable care, including transfusion of safe blood and supportive therapy including chelation must be established.DOI: http://dx.doi.org/10.3126/jpn.v4i8.11609 Journal of Pathology of Nepal; Vol.4,No. 8 (2014 663-671

  13. How stable is a collagen triple helix? An ab initio study on various collagen and beta-sheet forming sequences.

    Science.gov (United States)

    Pálfi, Villo K; Perczel, András

    2008-07-15

    Collagen forms the well characterized triple helical secondary structure, stabilized by interchain H-bonds. Here we have investigated the stability of fully optimized collagen triple helices and beta-pleated sheets by using first principles (ab initio and DFT) calculations so as to determine the secondary structure preference depending on the amino acid composition. Models composed of a total of 18 amino acid residues were studied at six different amino acid compositions: (i) L-alanine only, (ii) glycine only, (iii) L-alanines and glycine, (iv) L-alanines and D-alanine, (v) L-prolines with glycine, (vi) L-proline, L-hydroxyproline, and glycine. The last two, v and vi, were designed to mimic the core part of collagen. Furthermore, ii, iii, and iv model the binding and/or recognition sites of collagen. Finally, i models the G-->A replacement, rare in collagen. All calculated structures show great resemblance to those determined by X-ray crystallography. Calculated triple helix formation affinities correlate well with experimentally determined stabilities derived from melting point (T(m)) data of different collagen models. The stabilization energy of a collagen triple helical structure over that of a beta-pleated sheet is 2.1 kcal mol(-1) per triplet for the [(-Pro-Hyp-Gly-)(2)](3) collagen peptide. This changes to 4.8 kcal mol(-1) per triplet of destabilization energy for the [(-Ala-Ala-Gly-)(2)](3) sequence, known to be disfavored in collagen. The present study proves that by using first principles methods for calculating stabilities of supramolecular complexes, such as collagen and beta-pleated sheets, one can obtain stability data in full agreement with experimental observations, which envisage the applicability of QM in molecular design.

  14. Propylthiouracyl-induced severe liver toxicity: An indication for alanine aminotransferase monitoring?

    Institute of Scientific and Technical Information of China (English)

    M Benyounes; C Sempoux; C Daumerie; J Rahier; AP Geubel

    2006-01-01

    Propylthiouracyl (PTU)-related liver toxicity is likely to occur in about 1% of treated patients. In case of acute or subacute hepatitis, liver failure may occur in about one third. We report two further cases of PTU-induced subacute hepatitis, in whom the delay between occurrence of liver damage after the initiation of treatment, the underestimation of its severity and the delayed withdrawal of the drug were all likely responsible for liver failure.The high incidence of liver toxicity related to PTU, its potential severity and delayed occurrence after initiation of treatment are in favor of monthly alanine aminotransferase monitoring, at least during the first six months of therapy.

  15. Tetrakis-μ-l-alanine-κ8O:O′-bis[tetraaquaterbium(III] hexaperchlorate

    Directory of Open Access Journals (Sweden)

    Musa E. Mohamed

    2010-02-01

    Full Text Available The asymmetric unit of the title compound, [Tb2(C3H7NO24(H2O8](ClO46, contains a dinuclear cation and six perchlorate anions, one of which is disordered. In the cation, the four l-alanine molecules are present in their zwitterionic form and bridge two Tb3+ ions through their carboxylate O atoms. Each Tb atom is also coordinated by four water molecules in a square-antiprismatic geometry. In the crystal structure, the cations and anions are held together via intermolecular O—H...O and N—H...O hydrogen bonds.

  16. Growth and Characterization of Pure and Doped L-Alanine Tartrate Single Crystals

    OpenAIRE

    K. Rajesh; B. Milton Boaz; P. Praveen Kumar

    2013-01-01

    Single crystals of pure and Lanthanum doped L-Alanine Tartrate were grown by slow evaporation method. The cell parameters were determined using single crystal X-ray diffraction method. To improve the physical properties of the LAT crystal, Lanthanum dopant was added by 2 mol%. ICP studies confirm the presence of Lanthanum in the grown LAT crystal. Transparency range of the crystal was determined using UV-VIS-NIR spectrophotometer. The functional groups of pure and doped LAT crystals were a...

  17. Conserved aspartic acid 233 and alanine 231 are not required for poliovirus polymerase function in replicons

    Directory of Open Access Journals (Sweden)

    Freistadt Marion S

    2007-03-01

    Full Text Available Abstract Nucleic acid polymerases have similar structures and motifs. The function of an aspartic acid (conserved in all classes of nucleic acid polymerases in motif A remains poorly understood in RNA-dependent RNA polymerases. We mutated this residue to alanine in a poliovirus replicon. The resulting mutant could still replicate, although at a reduced level. In addition, mutation A231C (also in motif A yielded high levels of replication. Taken together these results show that poliovirus polymerase conserved residues D233 and A231 are not essential to poliovirus replicon function.

  18. Conserved aspartic acid 233 and alanine 231 are not required for poliovirus polymerase function in replicons

    Science.gov (United States)

    Freistadt, Marion S; Eberle, Karen E

    2007-01-01

    Nucleic acid polymerases have similar structures and motifs. The function of an aspartic acid (conserved in all classes of nucleic acid polymerases) in motif A remains poorly understood in RNA-dependent RNA polymerases. We mutated this residue to alanine in a poliovirus replicon. The resulting mutant could still replicate, although at a reduced level. In addition, mutation A231C (also in motif A) yielded high levels of replication. Taken together these results show that poliovirus polymerase conserved residues D233 and A231 are not essential to poliovirus replicon function. PMID:17352827

  19. Beta cell adaptation in pregnancy

    DEFF Research Database (Denmark)

    Nielsen, Jens Høiriis

    2016-01-01

    Pregnancy is associated with a compensatory increase in beta cell mass. It is well established that somatolactogenic hormones contribute to the expansion both indirectly by their insulin antagonistic effects and directly by their mitogenic effects on the beta cells via receptors for prolactin...... and growth hormone expressed in rodent beta cells. However, the beta cell expansion in human pregnancy seems to occur by neogenesis of beta cells from putative progenitor cells rather than by proliferation of existing beta cells. Claes Hellerström has pioneered the research on beta cell growth for decades...... in the expansion of the beta cell mass in human pregnancy, and the relative roles of endocrine factors and nutrients....

  20. Cellular uptake of fluorophore-labeled glyco-DNA-gold nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Witten, Katrin G.; Ruff, Julie [RWTH Aachen University, Institute of Inorganic Chemistry and JARA - Fundamentals of Future Information Technology (Germany); Mohr, Anne; Goertz, Dieter; Recker, Tobias; Rinis, Natalie [RWTH Aachen University, Institute of Biochemistry and Molecular Biology, University Hospital Aachen (Germany); Rech, Claudia; Elling, Lothar [RWTH Aachen University, Laboratory for Biomaterials, Institute of Biotechnology and Helmholtz-Institute for Biomedical Engineering (Germany); Mueller-Newen, Gerhard [RWTH Aachen University, Institute of Biochemistry and Molecular Biology, University Hospital Aachen (Germany); Simon, Ulrich, E-mail: ulrich.simon@ac.rwth-aachen.de [RWTH Aachen University, Institute of Inorganic Chemistry and JARA - Fundamentals of Future Information Technology (Germany)

    2013-10-15

    DNA-functionalized gold nanoparticles (AuNP-DNA) were hybridized with complementary di-N-acetyllactosamine-(di-LacNAc, [3Gal({beta}1-4)GlcNAc({beta}1-]2)-modified oligonucleotides to form glycol-functionalized particles, AuNP-DNA-di-LacNAc. While AuNP-DNA are known to be taken up by cells via scavenger receptors, glycol-functionalized particles have shown to be taken up via asialoglycoprotein receptors (ASGP-R). In this work, the interaction of these new particles with HepG2 cells was analyzed, which express scavenger receptors class B type I (SR-BI) and ASGP-R. To study the contribution of these receptors as potential mediators for cellular uptake, receptor-blocking experiments were performed with d-lactose, a ligand for ASGP-R, Fucoidan, a putative ligand for SR-BI, and a SR-BI blocking antibody. Labeling with Cy5-modified DNA ligands enabled us to monitor the particle uptake by confocal fluorescence microscopy and flow cytometry, in order to discriminate the two putative pathways by competitive binding studies. While SR-BI-antibody and d-lactose had no inhibiting effects on particle uptake Fucoidan led to a complete inhibition. Thus, a receptor-mediated uptake by the two receptors studied could not be proven and therefore other uptake mechanisms have to be considered.

  1. TGF-beta and osteoarthritis.

    NARCIS (Netherlands)

    Blaney Davidson, E.N.; Kraan, P.M. van der; Berg, W.B. van den

    2007-01-01

    OBJECTIVE: Cartilage damage is a major problem in osteoarthritis (OA). Growth factors like transforming growth factor-beta (TGF-beta) have great potential in cartilage repair. In this review, we will focus on the potential therapeutic intervention in OA with TGF-beta, application of the growth facto

  2. Conditions for $\\beta$-perfectness

    NARCIS (Netherlands)

    Keijsper, J.C.M.; Tewes, M.

    2000-01-01

    A $\\beta$-perfect graph is a simple graph $G$ such that $\\chi(G')=\\beta(G')$ for every induced subgraph $G'$ of $G$, where $\\chi(G')$ is the chromatic number of $G'$, and $\\beta(G')$ is defined as the maximum over all induced subgraphs $H$ of $G'$ of the minimum vertex degree in $H$. The vertices of

  3. Misleading Betas: An Educational Example

    Science.gov (United States)

    Chong, James; Halcoussis, Dennis; Phillips, G. Michael

    2012-01-01

    The dual-beta model is a generalization of the CAPM model. In the dual-beta model, separate beta estimates are provided for up-market and down-market days. This paper uses the historical "Anscombe quartet" results which illustrated how very different datasets can produce the same regression coefficients to motivate a discussion of the…

  4. Structural Insights into Substrate Specificity and the anti beta-Elimination Mechanism of Pectate Lyase

    DEFF Research Database (Denmark)

    Seyedarabi, A.; To, T.T.; Ali, S.

    2010-01-01

    Pectate lyases harness anti beta-elimination chemistry to cleave the alpha-1,4 linkage in the homogalacturonan region of plant cell Wall pectin. We have studied the binding of five pectic oligosaccharides to Bacillus subtilis pectate Iyase in crystals of the inactive enzyme in which the catalytic...... base is substituted with alanine (R279A). We discover that the three central subsites (- 1, + 1, and +2) have a profound preference for galacturonate but that the distal subsites call accommodate methylated galactUronate. h Is reasonable to assume therefore that pectate Iyase call cleave pectin...

  5. The effects of moderate drinking and abstinence on serum and urinary beta-hexosaminidase levels.

    Science.gov (United States)

    Kärkkäinen, P; Jokelainen, K; Roine, R; Suokas, A; Salaspuro, M

    1990-02-01

    The effects of moderate alcohol intake on serum (SHEX)- and urinary beta-hexosaminidase (UHEX) were studied in ten healthy volunteers, who ingested 60 g of 100% ethanol daily for 10 days. The drinking period was preceded and followed by an abstinence period. Moderate drinking and abstinence were rapidly and significantly reflected on SHEX, while UHEX levels did not change significantly during the study. Gramma-glutamyl transpeptidase (GGT), aspartate aminotransferase (ASAT) and alanine aminotransferase (ALAT) decreased during the first abstinence period (P less than 0.05), but stayed thereafter at a constant level. It is concluded that SHEX may better reflect recent alcohol consumption than UHEX, GGT, ASAT or ALAT.

  6. Muscle Carnosine Concentration with the Co-Ingestion of Carbohydrate with β-alanine in Male Rats.

    Science.gov (United States)

    Naderi, Alireza; Sadeghi, Mehdi; Sarshin, Amir; Imanipour, Vahid; Nazeri, Seyed Ali; Farkhayi, Fatemeh; Willems, Mark E T

    2017-07-04

    Muscle carnosine is an intracellular buffer. The intake of β-alanine, combined with carbohydrate and protein, enhanced carnosine loading in human muscle. The aim of the present study was to examine if muscle carnosine loading was enhanced by β-alanine intake and co-ingestion of glucose in male rats. Thirty-six male rats were divided into three groups and supplemented for four weeks: β-alanine (βA group, 1.8% β-alanine in drinking water), β-alanine and glucose (βAGL group, 1.8% β-alanine and 5% glucose in drinking water), and control (C group, drinking water). During the supplementation period, rats were exercised (20 m·min(-1), 10 min·day(-1), 4 days·week(-1) for 4 weeks). Muscle carnosine concentration was quantified in soleus (n = 12) and rectus femoris (n = 6) muscles using high-performance liquid chromatography. In soleus muscle, carnosine concentration was 2.24 ± 1.10, 6.12 ± 1.08, and 6.93 ± 2.56 mmol/kg dw for control, βA, and βAGL, respectively. In rectus femoris, carnosine concentration was 2.26 ± 1.31, 7.90 ± 1.66, and 8.59 ± 2.33 mmol/kg dw for control, βA, and βAGL respectively. In each muscle, βA and βAGL resulted in similar carnosine increases compared to the control. In conclusion, β-alanine intake for four weeks, either alone or with glucose co-ingestion, equally increased muscle carnosine content. It appears that the potential insulin response to fluid glucose intake does not affect muscle carnosine loading in male rats.

  7. Unique Aspects of Cryptochrome in Chronobiology and Metabolism, Pancreatic β-Cell Dysfunction, and Regeneration: Research into Cysteine414-Alanine Mutant CRY1.

    Science.gov (United States)

    Okano, Satoshi

    2016-01-01

    Cryptochrome proteins (CRYs), which can bind noncovalently to cofactor (chromophore) flavin adenine dinucleotide (FAD), occur widely among organisms. CRYs play indispensable roles in the generation of circadian rhythm in mammals. Transgenic mice (Tg mice), ubiquitously expressing mouse CRY1 having a mutation in which cysteine414 (the zinc-binding site of CRY1) being replaced with alanine, display unique phenotypes in their circadian rhythms. Moreover, male Tg mice exhibit symptoms of diabetes characterized by beta-cell dysfunction, resembling human maturity onset diabetes of the young (MODY). The lowered proliferation of β-cells is a primary cause of age-dependent β-cell loss. Furthermore, unusually enlarged duct-like structures developed prominently in the Tg mice pancreases. The duct-like structures contained insulin-positive cells, suggesting neogenesis of β-cells in the Tg mice. This review, based mainly on the author's investigation of the unique features of Tg mice, presents reported results and recent findings related to molecular processes associated with mammalian cryptochromes, especially their involvement in the regulation of metabolism. New information is described with emphasis on the aspects of islet architecture, pancreatic β-cell dysfunction, and regeneration.

  8. Unique Aspects of Cryptochrome in Chronobiology and Metabolism, Pancreatic β-Cell Dysfunction, and Regeneration: Research into Cysteine414-Alanine Mutant CRY1

    Directory of Open Access Journals (Sweden)

    Satoshi Okano

    2016-01-01

    Full Text Available Cryptochrome proteins (CRYs, which can bind noncovalently to cofactor (chromophore flavin adenine dinucleotide (FAD, occur widely among organisms. CRYs play indispensable roles in the generation of circadian rhythm in mammals. Transgenic mice (Tg mice, ubiquitously expressing mouse CRY1 having a mutation in which cysteine414 (the zinc-binding site of CRY1 being replaced with alanine, display unique phenotypes in their circadian rhythms. Moreover, male Tg mice exhibit symptoms of diabetes characterized by beta-cell dysfunction, resembling human maturity onset diabetes of the young (MODY. The lowered proliferation of β-cells is a primary cause of age-dependent β-cell loss. Furthermore, unusually enlarged duct-like structures developed prominently in the Tg mice pancreases. The duct-like structures contained insulin-positive cells, suggesting neogenesis of β-cells in the Tg mice. This review, based mainly on the author’s investigation of the unique features of Tg mice, presents reported results and recent findings related to molecular processes associated with mammalian cryptochromes, especially their involvement in the regulation of metabolism. New information is described with emphasis on the aspects of islet architecture, pancreatic β-cell dysfunction, and regeneration.

  9. Unique Aspects of Cryptochrome in Chronobiology and Metabolism, Pancreatic β-Cell Dysfunction, and Regeneration: Research into Cysteine414-Alanine Mutant CRY1

    Science.gov (United States)

    2016-01-01

    Cryptochrome proteins (CRYs), which can bind noncovalently to cofactor (chromophore) flavin adenine dinucleotide (FAD), occur widely among organisms. CRYs play indispensable roles in the generation of circadian rhythm in mammals. Transgenic mice (Tg mice), ubiquitously expressing mouse CRY1 having a mutation in which cysteine414 (the zinc-binding site of CRY1) being replaced with alanine, display unique phenotypes in their circadian rhythms. Moreover, male Tg mice exhibit symptoms of diabetes characterized by beta-cell dysfunction, resembling human maturity onset diabetes of the young (MODY). The lowered proliferation of β-cells is a primary cause of age-dependent β-cell loss. Furthermore, unusually enlarged duct-like structures developed prominently in the Tg mice pancreases. The duct-like structures contained insulin-positive cells, suggesting neogenesis of β-cells in the Tg mice. This review, based mainly on the author's investigation of the unique features of Tg mice, presents reported results and recent findings related to molecular processes associated with mammalian cryptochromes, especially their involvement in the regulation of metabolism. New information is described with emphasis on the aspects of islet architecture, pancreatic β-cell dysfunction, and regeneration. PMID:28105441

  10. Tumor uptake of radioruthenium compounds

    Energy Technology Data Exchange (ETDEWEB)

    Srivastava, S C; Richards, P; Meinken, G E; Larson, S M; Grunbaum, Z

    1980-01-01

    The use of ruthenium-97 as a scintigraphic agent, particularly for tumor localization, is investigated. The tumor uptake of ruthenium chloride and ruthenium-labelled transferrin is evaluated and their application as tumor-imagine agents is compared to gallium-67 citrate. (ACR)

  11. Prostatic uptake of Ga-67

    Energy Technology Data Exchange (ETDEWEB)

    Sullivan, W.T.; Rosen, P.R.; Weiland, F.L.; Ritchey, M.L.

    1984-08-01

    Midline activity low in the pelvis seen on Ga-67 scans is frequently attributed to colonic excretion of radionuclide. Two cases of infectious prostatitis with focal uptake of Ga-67 within the prostate gland are described. A technique of using limited quantities of barium administered by enema and appropriate positional imaging, which localized pelvic activity to the prostate, is described.

  12. Octreotide Uptake in Parathyroid Adenoma

    Directory of Open Access Journals (Sweden)

    Seyhan Karaçavuş

    2012-08-01

    Full Text Available The patient with a history of bone pain and muscle weakness, was thought to have oncogenic osteomalacia as a result of biochemical investigations and directed to Nuclear Medicine Department for a whole-body bone scintigraphy and 111In-octreotide scintigraphy. There was no focal pathologic tracer uptake, but generalized marked increase in skeletal uptake on bone scintigraphy. Octreotide scintigraphy showed accumulation of octreotide in the region of the left lobe of the thyroid gland in the neck. Thereafter, parathyroid scintigraphy was performed with technetium-99m labeled metroxy-isobutyl-isonitryl (99mTc-MIB and MIBI scan demonstrated radiotracer uptake at the same location with octreotide scintigraphy. The patient underwent left inferior parathyroidectomy and histopathology confirmed a parathyroid adenoma. Somatostatin receptor positive parathyroid adenoma may show octreotide uptake. Octreotide scintigraphy may be promising and indicate a possibility of using somatostatin analogues for the medical treatment of somatostatin receptor positive parathyroid tumors. (MIRT 2012;21:77-79

  13. Cellular uptake of metallated cobalamins

    DEFF Research Database (Denmark)

    Tran, MQT; Stürup, Stefan; Lambert, Ian H.;

    2016-01-01

    Cellular uptake of vitamin B12-cisplatin conjugates was estimated via detection of their metal constituents (Co, Pt, and Re) by inductively coupled plasma mass spectrometry (ICP-MS). Vitamin B12 (cyano-cob(iii)alamin) and aquo-cob(iii)alamin [Cbl-OH2](+), which differ in the β-axial ligands (CN(-...

  14. The simultaneous biosynthesis and uptake of amino acids by Lactococcus lactis studied by C-13-labeling experiments

    DEFF Research Database (Denmark)

    Jensen, N.B.S.; Christensen, B.; Nielsen, Jette

    2002-01-01

    Uniformly C-13 labeled glucose was fed to a lactic acid bacterium growing on a defined medium supplemented with all proteinogenic amino acids except glutamate. Aspartate stemming from the protein pool and from the extracellular medium was enriched with C-13 disclosing a substantial de novo...... biosynthesis of this amino acid simultaneous to its uptake from the growth medium and a rapid exchange flux of aspartate over the cellular membrane. Phenylalanine, alanine, and threonine were also synthesized de novo in spite of their presence in the growth medium....

  15. [Effect of nonachlazine on the processes of uptake and release of nordrenaline].

    Science.gov (United States)

    Kaverina, N V; Arefolov, V A; Grigor'eva, E K; Panasiuk, L V

    1976-01-01

    Nonachlazine (2 micrometer) blocked significantly the uptake 1 of endogenic noradrenaline in the myocardial tissues and in adrenergic neurons of vas deferens. The uptake II, as well as the intensity and dynamics of the noradrenaline release were not affected by nonachlazine. These processes resulted in an increase of free noradrenaline concentrations in the synaptic space. The latter seems to be a result of the mediator's passage into the nerve fibers (through axonal membranes) and into the granule, this being due to the nonachlazine-induced block. It is suggested that the metabolic and functional nonachlazine effects are related to the beta-adrenergic receptors stimulation, mediated through the agency of noradrenaline.

  16. Role of tRNAPro in pretransfer editing of alanine by prolyl-tRNA synthetase

    Directory of Open Access Journals (Sweden)

    Boyarshin K. S.

    2013-09-01

    Full Text Available Aim. To characterize the process of tRNA-dependent pretransfer edi- ting of alanine by prolyl-tRNA synthetase of bacteria Enterococcus faecalis (ProRSEf. Methods. Velocity of the editing processes in vitro was determined by ATP hydrolysis by ProRSEf. Pretransfer and posttransfer editing were experimentally separated by site-directed mutagenesis. Results. tRNA-dependent pretransfer editing is characterized by three-fold larger velocity then tRNA-independent editing. Effectivity of the process depends on the presence of 2'-hydroxyle group of A76 tRNAPro. In the absence of tRNAPro selective release of alanyl-AMP occurs simultaneously with tRNA-independent pretransfer editing. Released alanyl-AMP can be re-bound and hydrolyzed. Conclusions. tRNA-dependent pretransfer editing of alanine by ProRSEf is the catalytic mechanism, mediated by 2'-hydroxyl group of A76 tRNAPro. In the absence of tRNAPro tRNA-independent pretransfer editing and selective release of alanyl-AMP occur.

  17. Alanine aminotransferase as a predictor of adverse perinatal outcomes in women with intrahepatic cholestasis of pregnancy.

    Science.gov (United States)

    Ekiz, Ali; Kaya, Basak; Avci, Muhittin Eftal; Polat, Ibrahim; Dikmen, Selin; Yildirim, Gokhan

    2016-01-01

    To evaluate the associations between adverse perinatal outcomes and serum transaminase levels at the time of diagnosis in patients with intrahepatic cholestasis of pregnancy. We performed a retrospective analysis of patients hospitalized for evaluation of intrahepatic cholestasis of pregnancy from January 2013 to June 2014 in a tertiary center. Seventy-one patients were divided into two groups according to the presence (Group I) or absence of adverse perinatal outcomes (Group II). The mean aminotransferase levels and conjugated bilirubin levels at the time of diagnosis were significantly higher in Group I than in Group II. Receiver operating characteristic curve analysis revealed that the alanine aminotransferase level could predict adverse perinatal outcomes with 76.47% sensitivity and 78.38% specificity, and the cut-off value was 95 IU/L. Among patients with intrahepatic cholestasis of pregnancy, those with adverse perinatal outcomes were significantly older, had an earlier diagnosis, and had higher alanine aminotransferase levels. Using the 95-IU/L cut-off value, patients with intrahepatic cholestasis of pregnancy had a 3.54-fold increased risk for adverse perinatal outcomes. Patients with intrahepatic cholestasis of pregnancy and high alanineaminotransferase levels should be followed up for possible adverse perinatal outcomes.

  18. A better parameter in predicting insulin resistance: Obesity plus elevated alanine aminotransferase

    Institute of Scientific and Technical Information of China (English)

    Ping-Hao Chen; Jong-Dar Chen; Yu-Cheng Lin

    2009-01-01

    AIM: To investigate the association of obesity and elevated alanine aminotransferase with insulin resistance and compare these factors with metabolic syndrome.METHODS: We enrolled a total of 1308 male workers aged from 22 to 63 years. Data was extracted from the workers’ periodic health check-ups in hospitals. All cases were from the community of northern Taiwan.This was a cross-sectional observational study from July to September in 2004. We grouped all cases into four groups, based on the quartile of homeostasis model assessment. The top fourth quartile group was defined as the group with insulin resistance. We performed multivariate logistic regression analysis for the odds ratio of the risk factors for insulin resistance.RESULTS: Compared with metabolic syndrome, the coexistence of both factors had a 4.3-fold (95% CI: 2.7-6.8) increased risk, which was more than metabolic syndrome with a 3.6-fold (95% CI: 2.6-5.0) increased risk. The two factors had a synergistic effect. The synergistic index of obesity and elevated alanine aminotransferase (ALT) was 2.1 (95% CI: 1.01-4.3).CONCLUSION: Obesity and elevated ALT are associatedwith insulin resistance. The effects are synergistic.Coexistence of them is better than metabolic syndrome in predicting insulin resistance.

  19. A single glycine-alanine exchange directs ligand specificity of the elephant progestin receptor.

    Directory of Open Access Journals (Sweden)

    Michael Wierer

    Full Text Available The primary gestagen of elephants is 5α-dihydroprogesterone (DHP, which is unlike all other mammals studied until now. The level of DHP in elephants equals that of progesterone in other mammals, and elephants are able to bind DHP with similar affinity to progesterone indicating a unique ligand-binding specificity of the elephant progestin receptor (PR. Using site-directed mutagenesis in combination with in vitro binding studies we here report that this change in specificity is due to a single glycine to alanine exchange at position 722 (G722A of PR, which specifically increases DHP affinity while not affecting binding of progesterone. By conducting molecular dynamics simulations comparing human and elephant PR ligand-binding domains (LBD, we observed that the alanine methyl group at position 722 is able to push the DHP A-ring into a position similar to progesterone. In the human PR, the DHP A-ring position is twisted towards helix 3 of PR thereby disturbing the hydrogen bond pattern around the C3-keto group, resulting in a lower binding affinity. Furthermore, we observed that the elephant PR ligand-binding pocket is more rigid than the human analogue, which probably explains the higher affinity towards both progesterone and DHP. Interestingly, the G722A substitution is not elephant-specific, rather it is also present in five independent lineages of mammalian evolution, suggesting a special role of the substitution for the development of distinct mammalian gestagen systems.

  20. A single glycine-alanine exchange directs ligand specificity of the elephant progestin receptor.

    Science.gov (United States)

    Wierer, Michael; Schrey, Anna K; Kühne, Ronald; Ulbrich, Susanne E; Meyer, Heinrich H D

    2012-01-01

    The primary gestagen of elephants is 5α-dihydroprogesterone (DHP), which is unlike all other mammals studied until now. The level of DHP in elephants equals that of progesterone in other mammals, and elephants are able to bind DHP with similar affinity to progesterone indicating a unique ligand-binding specificity of the elephant progestin receptor (PR). Using site-directed mutagenesis in combination with in vitro binding studies we here report that this change in specificity is due to a single glycine to alanine exchange at position 722 (G722A) of PR, which specifically increases DHP affinity while not affecting binding of progesterone. By conducting molecular dynamics simulations comparing human and elephant PR ligand-binding domains (LBD), we observed that the alanine methyl group at position 722 is able to push the DHP A-ring into a position similar to progesterone. In the human PR, the DHP A-ring position is twisted towards helix 3 of PR thereby disturbing the hydrogen bond pattern around the C3-keto group, resulting in a lower binding affinity. Furthermore, we observed that the elephant PR ligand-binding pocket is more rigid than the human analogue, which probably explains the higher affinity towards both progesterone and DHP. Interestingly, the G722A substitution is not elephant-specific, rather it is also present in five independent lineages of mammalian evolution, suggesting a special role of the substitution for the development of distinct mammalian gestagen systems.

  1. Mineralization of alanine enantiomers in soil treated with heavy metals and nutrients

    Directory of Open Access Journals (Sweden)

    Pavel Formánek

    2011-01-01

    Full Text Available This work deals with the determination of the effect of heavy metals and nutrients applied to the soil on alanine enatiomers mineralization with the main focus on evaluating the effect on L/D alanine respiration rate ratio. This study was initiated because previous research works revealed a change in L/D amino acid respiration under acid- or heavy metal-stress in soil. Generally, D-amino acids artificially supplied to soil are less utilized by microorganisms compared with their L-enantiomers. Stress of soil microorganisms cause decreased discrimination of D-amino acids utilization. Also, previous research showed that an application of fertilizers or combinations of fertilizers may affect the mineralization rate of L-amino acids differently, compared with their D-enantiomers. The results of this study show, that the effect of both heavy metals and nutrients on the L/D ratio was not clear, increasing or decreasing this ratio. Further research is necessary to broaden this study.

  2. Advancements in accuracy of the alanine dosimetry system. Part 2. The influence of the irradiation temperature

    Science.gov (United States)

    Nagy, Vitaly; Puhl, James M.; Desrosiers, Marc F.

    2000-01-01

    Systematic measurements of the temperature coefficient for alanine electron paramagnetic resonance (EPR) response have been performed for irradiation in the temperature range (10-50)°C and in the absorbed dose range (1-100) kGy at the dose rate 9.5 kGy/h. During the 60Co rad -ray irradiation, rad - L-alanine dosimeters were kept in a sealed aluminum holder that provided an effective heat exchange with the temperature-controlled environment. The time between the irradiation and signal measurements was standardized, and a reference sample fixed in the resonant cavity was used to correct the signals for small variations in the spectrometer sensitivity. The temperature coefficient for each dose was determined from approximately 30 experimental points processed by the weighted least-squares technique after the necessary statistical tests were done. The temperature coefficients thus determined were considerably lower than previously reported. The dose dependence of the temperature coefficient features a minimum at (20-30) kGy (about 0.135%/K) with higher values at 1 kGy (0.17%/K) and at 100 kGy ((0.175-0.19) %/K). With the exception of very high doses, no significant distinction was found between the temperature coefficients of Bruker and NIST dosimeters, which differ in shape and binder content.

  3. Design of Deinococcus radiodurans thioredoxin reductase with altered thioredoxin specificity using computational alanine mutagenesis.

    Science.gov (United States)

    Obiero, Josiah; Sanders, David A R

    2011-06-01

    In this study, the X-ray crystal structure of the complex between Escherichia coli thioredoxin reductase (EC TrxR) and its substrate thioredoxin (Trx) was used as a guide to design a Deinococcus radiodurans TrxR (DR TrxR) mutant with altered Trx specificity. Previous studies have shown that TrxRs have higher affinity for cognate Trxs (same species) than that for Trxs from different species. Computational alanine scanning mutagenesis and visual inspection of the EC TrxR-Trx interface suggested that only four residues (F81, R130, F141, and F142) account for the majority of the EC TrxR-Trx interface stability. Individual replacement of equivalent residues in DR TrxR (M84, K137, F148, and F149) with alanine resulted in drastic changes in binding affinity, confirming that the four residues account for most of TrxR-Trx interface stability. When M84 and K137 were changed to match equivalent EC TrxR residues (K137R and M84F), the DR TrxR substrate specificity was altered from its own Trx to that of EC Trx. The results suggest that a small subset of the TrxR-Trx interface residues is responsible for the majority of Trx binding affinity and species-specific recognition.

  4. Ibalizumab-human CD4 receptor interaction: computational alanine scanning molecular dynamics studies.

    Science.gov (United States)

    Su, Zhi-Yuan

    2014-01-01

    Antibody drugs are used in the treatment of many chronic diseases. Recently, however, patients and doctors have encountered problems with drug resistance, and improving the affinity of antibody drugs has therefore become a pressing issue. Ibalizumab is a humanized monoclonal antibody that binds human CD4, the primary receptor for human immunodeficiency virus type 1 (HIV-1). In this study, we sought to identify the key residues of the complementaritydetermining regions (CDRs) of ibalizumab. Virtual alanine mutations (complementarity-determining regions of ibalizumab) were also studied using solvated interaction energies derived from molecular dynamics and the explicit water model. Using 1,000 nanosecond molecular dynamic simulations, we identified six residues: Tyr50 [HCDR2], Tyr53 [HCDR3], Asp58 [HCDR2], Glu95 [HCDR2], and Arg95 [LCDR3]. The Robetta alanine-scanning mutagenesis method and crystallographic information were used to verify our simulations. Our simulated binding affinity of -17.33 kcal/mol is close to the experimentally determined value of -16.48 kcal/mol. Our findings may be useful for protein engineering the structure of the ibalizumab-human CD4 receptor complex. Moreover, the six residues that we identified may play a significant role in the development of bioactive antibody analogues.

  5. Characterization and biocompatibility of organogels based on L-alanine for parenteral drug delivery implants.

    Science.gov (United States)

    Motulsky, Aude; Lafleur, Michel; Couffin-Hoarau, Anne-Claude; Hoarau, Didier; Boury, Frank; Benoit, Jean-Pierre; Leroux, Jean-Christophe

    2005-11-01

    The development of simple and efficient drug delivery systems for the sustained release of peptides/proteins and low molecular weight hydrophilic molecules is an ongoing challenge. The purpose of this work was to prepare and characterize novel biodegradable in situ-forming implants obtained via the self-assembly of L-alanine derivatives in pharmaceutical oils. Six different amphiphilic organogelators based on L-alanine were synthesized. These derivatives could successfully gel various vegetable and synthetic oils approved for parenteral administration. Gelation was thermoreversible, and phase transition temperatures depended on gelator structure, concentration and solvent. Hydrogen bonds and van der Waals interactions were shown to be the main forces implicated in network formation. Selected formulations were then injected subcutaneously in rats for preliminary assessment of biocompatibility. Histopathological analysis of the surrounding tissues revealed mild, chronic inflammation and an overall good biocompatibility profile of the implants over the 8 wk evaluation period. This study demonstrates that in situ-forming organogels represent a potentially promising platform for sustained drug delivery.

  6. [Association of metabolic syndrome markers with abnormal alanine aminotransferase levels in healthy children].

    Science.gov (United States)

    Arancibia, Gabriel; García, Hernán; Jaime, Francisca; Bancalari, Rodrigo; Harris, Paul R

    2012-07-01

    There is a high prevalence of non-alcoholic fatty liver disease (NAFLD) and non-alcoholic steatohepatitis (NASH) among pediatric patients. The identification of clinical predictors of these conditions would allow a timely treatment. To evaluate the relationship between serum alanine aminotransferase levels and parameters of metabolic syndrome in asymptomatic school students without hepatic illness. A randomized sample of 175 children aged between 9 and 14 years (54% females) was selected, from a database of 3010 students living in Santiago, Chile. Weight, height, abdominal circumference, systolic and diastolic blood pressure were measured. A fasting blood sample was obtained to measure glucose, total cholesterol, HDL, LDL-cholesterol, triglycerides, alanine aminotransferase (ALT) and insulin levels. Forty percent of participants were obese, 17% had metabolic syndrome and 13.1% had abnormal ALT levels. Compared with children with normal ALT levels, the latter had significantly higher waist obesity, body mass index, systolic and diastolic blood pressure and triglycerides. However on multivariate analysis, only waist obesity was independently associated with abnormal ALT levels (adjusted odds ratio 3.93, 95% confidence intervals 1.44-10.78, p = 0.008). Only waist obesity was independently associated with abnormal ALT levels in this sample of children.

  7. Differential regulation of chemoattractant-stimulated beta 2, beta 3, and beta 7 integrin activity.

    Science.gov (United States)

    Sadhu, C; Masinovsky, B; Staunton, D E

    1998-06-01

    Leukocyte adhesion to endothelium and extravasation are dynamic processes that require activation of integrins. Chemoattractants such as IL-8 and FMLP are potent activators of leukocyte integrins. To compare the chemoattractant-stimulated activation of three integrins, alpha 4 beta 7, alpha L beta 2, and alpha V beta 3, in the same cellular context, we expressed an IL-8 receptor (IL-8RA) and FMLP receptor (FPR) in the lymphoid cell line JY. Chemoattractants induced a rapid increase in alpha L beta 2- and alpha V beta 3-dependent JY adhesion within 5 min, and it was sustained for 30 min. In contrast, stimulation of alpha 4 beta 7-dependent adhesion was transient, returning to basal levels by 30 min. The activation profiles of the integrins were similar regardless of whether IL-8 or FMLP was used for induction. We also demonstrate that alpha 4 beta 7-dependent adhesion was uniquely responsive to the F actin-disrupting agent cytochalasin D and the protein kinase C (PKC) inhibitor chelerythrin. While alpha V beta 3- and alpha L beta 2-mediated cell adhesion was significantly reduced by cytochalasin D, alpha 4 beta 7-mediated adhesion was enhanced. Chelerythrin inhibited both the IL-8 and PMA activation of alpha L beta 2 and alpha V beta 3. In contrast, inducible alpha 4 beta 7 activity was unaffected, and basal activity was increased. These findings demonstrate that the mechanism of alpha 4 beta 7 regulation by chemoattractants is different from that of alpha L beta 2 and alpha V beta 3 and that it appears to involve distinct cytoskeletal and PKC dependencies. In addition, PKC activity may be a positive or negative regulator of integrin-dependent adhesion.

  8. Pulmonary uptake of morphine (M)

    Energy Technology Data Exchange (ETDEWEB)

    Roerig, D.L.; Bunke, S.S.; Kotrly, K.J.; Dawson, C.A.; Kampine, J.P.

    1986-03-01

    Previously the authors reported less than 5% of M was taken up during the first pass through the human lung. The low uptake of this basic lipophilic amine was further investigated in a single pass isolated perfused rat lung (IPL) in comparison to uptake of radiolabelled H/sub 2/O, antipyrine (A), aminopyrine (AM), nicotine (N) and phenylethylamine (P). The IPL was perfused for 5 min with each drug (5nmol/ml) and effluent collected in 10 sec fractions. Pulmonary extraction was calculated using indocyanine green dye as a non-extractable reference indicator. Accumulation of all compounds in the IPL reached an apparent equilibrium within 4 min. At equilibrium lung/perfusate conc. ratios for H/sub 2/O, A, AM, N, P and M were 1.04, 0.84, 0.85, 1.44, 2.57 and 1.13 respectively. The time course of M uptake differed from the other compounds since initial extraction of M was low (23%) compared to 75%, 53%, 35%, 82% and 86% for H/sub 2/O, A, AM, N and P respectively. Also, the half time to equilibrium for M was longer (50 sec) compared to 18, 21, 26, 19 and 22 sec for H/sub 2/O, A, AM, N and P respectively. The low initial pulmonary extraction of M compared to these compounds followed by greater M extraction during the remainder of drug infusion suggests uptake mechanisms for M different than the flow limited uptake for water and other basic amine drugs.

  9. A comparative study of MP2, B3LYP, RHF and SCC-DFTB force fields in predicting the vibrational spectra of N-acetyl-L-alanine-N'-methyl amide: VA and VCD spectra

    DEFF Research Database (Denmark)

    Bohr, Henrik; Jalkanen, Karl J.; Elstner, M.

    1999-01-01

    Recently we have looked for spectroscopic probes for secondary structural elements in the vibrational spectra of N-acetyl-L-alanine N'-methyl amide (NALANMA), L-alanine (LA), N-acetyl-L-alanyl-L-alanine N'-methyl amide (NALALANMA) and L-alanyl-L-alanine (LALA). Our goal has been to identify...

  10. Beta-thalassemia

    Directory of Open Access Journals (Sweden)

    Origa Raffaella

    2010-05-01

    Full Text Available Abstract Beta-thalassemias are a group of hereditary blood disorders characterized by anomalies in the synthesis of the beta chains of hemoglobin resulting in variable phenotypes ranging from severe anemia to clinically asymptomatic individuals. The total annual incidence of symptomatic individuals is estimated at 1 in 100,000 throughout the world and 1 in 10,000 people in the European Union. Three main forms have been described: thalassemia major, thalassemia intermedia and thalassemia minor. Individuals with thalassemia major usually present within the first two years of life with severe anemia, requiring regular red blood cell (RBC transfusions. Findings in untreated or poorly transfused individuals with thalassemia major, as seen in some developing countries, are growth retardation, pallor, jaundice, poor musculature, hepatosplenomegaly, leg ulcers, development of masses from extramedullary hematopoiesis, and skeletal changes that result from expansion of the bone marrow. Regular transfusion therapy leads to iron overload-related complications including endocrine complication (growth retardation, failure of sexual maturation, diabetes mellitus, and insufficiency of the parathyroid, thyroid, pituitary, and less commonly, adrenal glands, dilated myocardiopathy, liver fibrosis and cirrhosis. Patients with thalassemia intermedia present later in life with moderate anemia and do not require regular transfusions. Main clinical features in these patients are hypertrophy of erythroid marrow with medullary and extramedullary hematopoiesis and its complications (osteoporosis, masses of erythropoietic tissue that primarily affect the spleen, liver, lymph nodes, chest and spine, and bone deformities and typical facial changes, gallstones, painful leg ulcers and increased predisposition to thrombosis. Thalassemia minor is clinically asymptomatic but some subjects may have moderate anemia. Beta-thalassemias are caused by point mutations or, more rarely

  11. Beta-thalassemia.

    Science.gov (United States)

    Galanello, Renzo; Origa, Raffaella

    2010-05-21

    Beta-thalassemias are a group of hereditary blood disorders characterized by anomalies in the synthesis of the beta chains of hemoglobin resulting in variable phenotypes ranging from severe anemia to clinically asymptomatic individuals. The total annual incidence of symptomatic individuals is estimated at 1 in 100,000 throughout the world and 1 in 10,000 people in the European Union. Three main forms have been described: thalassemia major, thalassemia intermedia and thalassemia minor. Individuals with thalassemia major usually present within the first two years of life with severe anemia, requiring regular red blood cell (RBC) transfusions. Findings in untreated or poorly transfused individuals with thalassemia major, as seen in some developing countries, are growth retardation, pallor, jaundice, poor musculature, hepatosplenomegaly, leg ulcers, development of masses from extramedullary hematopoiesis, and skeletal changes that result from expansion of the bone marrow. Regular transfusion therapy leads to iron overload-related complications including endocrine complication (growth retardation, failure of sexual maturation, diabetes mellitus, and insufficiency of the parathyroid, thyroid, pituitary, and less commonly, adrenal glands), dilated myocardiopathy, liver fibrosis and cirrhosis). Patients with thalassemia intermedia present later in life with moderate anemia and do not require regular transfusions. Main clinical features in these patients are hypertrophy of erythroid marrow with medullary and extramedullary hematopoiesis and its complications (osteoporosis, masses of erythropoietic tissue that primarily affect the spleen, liver, lymph nodes, chest and spine, and bone deformities and typical facial changes), gallstones, painful leg ulcers and increased predisposition to thrombosis. Thalassemia minor is clinically asymptomatic but some subjects may have moderate anemia. Beta-thalassemias are caused by point mutations or, more rarely, deletions in the beta

  12. Beta-thalassemia

    Science.gov (United States)

    2010-01-01

    Beta-thalassemias are a group of hereditary blood disorders characterized by anomalies in the synthesis of the beta chains of hemoglobin resulting in variable phenotypes ranging from severe anemia to clinically asymptomatic individuals. The total annual incidence of symptomatic individuals is estimated at 1 in 100,000 throughout the world and 1 in 10,000 people in the European Union. Three main forms have been described: thalassemia major, thalassemia intermedia and thalassemia minor. Individuals with thalassemia major usually present within the first two years of life with severe anemia, requiring regular red blood cell (RBC) transfusions. Findings in untreated or poorly transfused individuals with thalassemia major, as seen in some developing countries, are growth retardation, pallor, jaundice, poor musculature, hepatosplenomegaly, leg ulcers, development of masses from extramedullary hematopoiesis, and skeletal changes that result from expansion of the bone marrow. Regular transfusion therapy leads to iron overload-related complications including endocrine complication (growth retardation, failure of sexual maturation, diabetes mellitus, and insufficiency of the parathyroid, thyroid, pituitary, and less commonly, adrenal glands), dilated myocardiopathy, liver fibrosis and cirrhosis). Patients with thalassemia intermedia present later in life with moderate anemia and do not require regular transfusions. Main clinical features in these patients are hypertrophy of erythroid marrow with medullary and extramedullary hematopoiesis and its complications (osteoporosis, masses of erythropoietic tissue that primarily affect the spleen, liver, lymph nodes, chest and spine, and bone deformities and typical facial changes), gallstones, painful leg ulcers and increased predisposition to thrombosis. Thalassemia minor is clinically asymptomatic but some subjects may have moderate anemia. Beta-thalassemias are caused by point mutations or, more rarely, deletions in the beta

  13. Realized Beta GARCH

    DEFF Research Database (Denmark)

    Hansen, Peter Reinhard; Lunde, Asger; Voev, Valeri Radkov

    2014-01-01

    We introduce a multivariate generalized autoregressive conditional heteroskedasticity (GARCH) model that incorporates realized measures of variances and covariances. Realized measures extract information about the current levels of volatilities and correlations from high-frequency data, which...... is particularly useful for modeling financial returns during periods of rapid changes in the underlying covariance structure. When applied to market returns in conjunction with returns on an individual asset, the model yields a dynamic model specification of the conditional regression coefficient that is known...... as the beta. We apply the model to a large set of assets and find the conditional betas to be far more variable than usually found with rolling-window regressions based exclusively on daily returns. In the empirical part of the paper, we examine the cross-sectional as well as the time variation...

  14. Beta and muon decays

    Energy Technology Data Exchange (ETDEWEB)

    Galindo, A.; Pascual, P.

    1967-07-01

    These notes represent a series of lectures delivered by the authors in the Junta de Energia Nuclear, during the Spring term of 1965. They were devoted to graduate students interested in the Theory of Elementary Particles. Special emphasis was focussed into the computational problems. Chapter I is a review of basic principles (Dirac equation, transition probabilities, final state interactions.) which will be needed later. In Chapter II the four-fermion punctual Interaction is discussed, Chapter III is devoted to the study of beta-decay; the main emphasis is given to the deduction of the formulae corresponding to electron-antineutrino correlation, electron energy spectrum, lifetimes, asymmetry of electrons emitted from polarized nuclei, electron and neutrino polarization and time reversal invariance in beta decay. In Chapter IV we deal with the decay of polarized muons with radiative corrections. Chapter V is devoted to an introduction to C.V.C. theory. (Author)

  15. Magic Baseline Beta Beam

    CERN Document Server

    Agarwalla, Sanjib Kumar; Raychaudhuri, Amitava

    2007-01-01

    We study the physics reach of an experiment where neutrinos produced in a beta-beam facility at CERN are observed in a large magnetized iron calorimeter (ICAL) at the India-based Neutrino Observatory (INO). The CERN-INO distance is close to the so-called "magic" baseline which helps evade some of the parameter degeneracies and allows for a better measurement of the neutrino mass hierarchy and $\\theta_{13}$.

  16. Coroutine Sequencing in BETA

    DEFF Research Database (Denmark)

    Kristensen, Bent Bruun; Madsen, Ole Lehrmann; Møller-Pedersen, Birger;

    In object-oriented programming, a program execution is viewed as a physical model of some real or imaginary part of the world. A language supporting object-oriented programming must therefore contain comprehensive facilities for modeling phenomena and concepts form the application domain. Many ap...... applications in the real world consist of objects carrying out sequential processes. Coroutines may be used for modeling objects that alternate between a number of sequential processes. The authors describe coroutines in BETA...

  17. Polarizable Simulations with Second order Interaction Model (POSSIM) force field: Developing parameters for alanine peptides and protein backbone

    Science.gov (United States)

    Ponomarev, Sergei Y.; Kaminski, George A.

    2011-01-01

    A previously introduced POSSIM (POlarizable Simulations with Second order Interaction Model) force field has been extended to include parameters for alanine peptides and protein backbones. New features were introduced into the fitting protocol, as compared to the previous generation of the polarizable force field for proteins. A reduced amount of quantum mechanical data was employed in fitting the electrostatic parameters. Transferability of the electrostatics between our recently developed NMA model and the protein backbone was confirmed. Binding energy and geometry for complexes of alanine dipeptide with a water molecule were estimated and found in a good agreement with high-level quantum mechanical results (for example, the intermolecular distances agreeing within ca. 0.06Å). Following the previously devised procedure, we calculated average errors in alanine di- and tetra-peptide conformational energies and backbone angles and found the agreement to be adequate (for example, the alanine tetrapeptide extended-globular conformational energy gap was calculated to be 3.09 kcal/mol quantim mechanically and 3.14 kcal/mol with the POSSIM force field). However, we have now also included simulation of a simple alpha-helix in both gas-phase and water as the ultimate test of the backbone conformational behavior. The resulting alanine and protein backbone force field is currently being employed in further development of the POSSIM fast polarizable force field for proteins. PMID:21743799

  18. Regulation of beta cell replication

    DEFF Research Database (Denmark)

    Lee, Ying C; Nielsen, Jens Høiriis

    2008-01-01

    Beta cell mass, at any given time, is governed by cell differentiation, neogenesis, increased or decreased cell size (cell hypertrophy or atrophy), cell death (apoptosis), and beta cell proliferation. Nutrients, hormones and growth factors coupled with their signalling intermediates have been...... suggested to play a role in beta cell mass regulation. In addition, genetic mouse model studies have indicated that cyclins and cyclin-dependent kinases that determine cell cycle progression are involved in beta cell replication, and more recently, menin in association with cyclin-dependent kinase...... inhibitors has been demonstrated to be important in beta cell growth. In this review, we consider and highlight some aspects of cell cycle regulation in relation to beta cell replication. The role of cell cycle regulation in beta cell replication is mostly from studies in rodent models, but whether...

  19. LHCb: $2\\beta_s$ measurement at LHCb

    CERN Multimedia

    Conti, G

    2009-01-01

    A measurement of $2\\beta_s$, the phase of the $B_s-\\bar{B_s}$ oscillation amplitude with respect to that of the ${\\rm b} \\rightarrow {\\rm c^{+}}{\\rm W^{-}}$ tree decay amplitude, is one of the key goals of the LHCb experiment with first data. In the Standard Model (SM), $2\\beta_s$ is predicted to be $0.0360^{+0.0020}_{-0.0016} \\rm rad$. The current constraints from the Tevatron are: $2\\beta_{s}\\in[0.32 ; 2.82]$ at 68$\\%$CL from the CDF experiment and $2\\beta_{s}=0.57^{+0.24}_{-0.30}$ from the D$\\oslash$ experiment. Although the statistical uncertainties are large, these results hint at the possible contribution of New Physics in the $B_s-\\bar{B_s}$ box diagram. After one year of data taking at LHCb at an average luminosity of $\\mathcal{L}\\sim2\\cdot10^{32}\\rm cm^{-2} \\rm s^{-1}$ (integrated luminosity $\\mathcal{L}_{\\rm int}\\sim 2 \\rm fb^{-1}$), the expected statistical uncertainty on the measurement is $\\sigma(2\\beta_s)\\simeq 0.03$. This uncertainty is similar to the $2\\beta_s$ value predicted by the SM.

  20. Nitrogen uptake kinetics of freshly isolated zooxanthellae

    Digital Repository Service at National Institute of Oceanography (India)

    Wafar, M.V.M.; Wafar, S.; Rajkumar, R.

    Zooxanthellae freshly isolated from the coral host Pocillopora damicornis exhibited substrate-saturable uptake kinetics for ammonium, nitrate and urea. Maximum uptake velocity for ammonium [10.1 nmol. ( mu chl-a)./1h/1] was greater than...

  1. Global Transcriptional and Physiological Responses of Saccharomyces cerevisiae to Ammonium, L-Alanine, or L-Glutamine Limitation

    DEFF Research Database (Denmark)

    Usaite, Renata; Patil, Kiran Raosaheb; Grotkjær, Thomas;

    2006-01-01

    The yeast Saccharomyces cerevisiae encounters a range of nitrogen sources at various concentrations in its environment. The impact of these two parameters on transcription and metabolism was studied by growing S. cerevisiae in chemostat cultures with L-glutamine, L-alanine, or L-ammonium in limit......The yeast Saccharomyces cerevisiae encounters a range of nitrogen sources at various concentrations in its environment. The impact of these two parameters on transcription and metabolism was studied by growing S. cerevisiae in chemostat cultures with L-glutamine, L-alanine, or L...... activity in L-alanine-limited cells. The changes in these cells were found to be focused around pyruvate, acetyl coenzyme A, glyoxylate, and alpha-ketoglutarate via increased levels of ALT1, DAL7, PYC1, GDH2, and ADH5 and decreased levels of GDH3, CIT2, and ACS1 transcripts. The transcript profiles were...

  2. Topology of AspT, the Aspartate:Alanine Antiporter of Tetragenococcus halophilus, Determined by Site-Directed Fluorescence Labeling▿ †

    OpenAIRE

    Nanatani, Kei; Fujiki, Takashi; Kanou, Kazuhiko; Takeda-Shitaka, Mayuko; Umeyama, Hideaki; Ye, Liwen; Wang, Xicheng; Nakajima, Tasuku; Uchida, Takafumi; Maloney, Peter C.; Abe, Keietsu

    2007-01-01

    The gram-positive lactic acid bacterium Tetragenococcus halophilus catalyzes the decarboxylation of l-aspartate (Asp) with release of l-alanine (Ala) and CO2. The decarboxylation reaction consists of two steps: electrogenic exchange of Asp for Ala catalyzed by an aspartate:alanine antiporter (AspT) and intracellular decarboxylation of the transported Asp catalyzed by an l-aspartate-β-decarboxylase (AspD). AspT belongs to the newly classified aspartate:alanine exchanger family (transporter cla...

  3. Relationship between impaired glycation and the N-terminal structure of the Hb Görwihl [beta5(A2)Pro-->Ala] variant.

    Science.gov (United States)

    Ito, Shigenori; Nakahari, Takashi; Yamamoto, Daisuke

    2010-01-01

    We studied the structural environment surrounding the beta-N-terminal glycation site of a hemoglobin (Hb) molecule in which the proline residue at beta5(A2) was substituted by alanine in silico. By computer analysis that used Protein Data Bank data (PDB ID: 1BZ0), we tried to clarify the reason for impaired glycation of Hb Görwihl [beta5(A2)Pro-->Ala]. On the basis of the results, we predicted that the glycation site would have the following characteristics: 1) glycation of the beta-N-terminus of Hb is probably accelerated by the neighboring histidine residue at beta2(NA2), which acts as an acid-base catalyst via a phosphate-mediated proton transfer; and 2) the mutation beta5(A2)Pro-->Ala would bring about impaired glycation of the N-terminal residue by forming an electrostatic bond between the alpha amino group of beta1(NA1)Val and beta carboxyl group of beta79(EF3)Asp.

  4. A Tyrosine Residue Along with a Glutamic Acid of the Omega-Like Loop Governs the Beta-Lactamase Activity of MSMEG_4455 in Mycobacterium smegmatis.

    Science.gov (United States)

    Bansal, Ankita; Kar, Debasish; Pandey, Satya Deo; Matcha, Ashok; Kumar, N Ganesh; Nathan, Soshina; Ghosh, Anindya S

    2017-06-01

    Mycobacterial beta-lactamases are involved in exerting beta-lactam resistance, though many of these proteins remain uncharacterized. Here, we have characterized MSMEG_4455 of Mycobacterium smegmatis as a beta-lactamase using molecular, biochemical and mutational techniques. To elucidate its nature in vivo and in vitro, and to predict its structure-function relationship in silico analysis is done. The MSMEG_4455 is cloned and expressed ectopically in a beta-lactamase deficient Escherichia coli mutant to establish the in vivo beta-lactamase like nature via minimum inhibitory concentration (MIC) determination. Likewise the in vivo results, purified soluble form of MSMEG_4455 showed beta-lactam hydrolysis pattern similar to group 2a penicillinase. In silico analyses of MSMEG_4455 reveal glutamic acid (E)193 and tyrosine (Y)194 of omega-like loop might have importance in strengthening hydrogen bond network around the active-site, though involvement of tyrosine is rare for beta-lactamase activity. Accordingly, these residues are mutated to alanine (A) and phenylalanine (F), respectively. The mutated proteins have partially lost their ability to exert beta-lactamase activity both in vivo and in vitro. The Y194F mutation had more prominent effect on the enzymatic activity. Therefore, we infer that Y194 is the key for beta-lactamase activity of MSMEG_4455.

  5. Role of human GABA(A) receptor beta3 subunit in insecticide toxicity.

    Science.gov (United States)

    Ratra, G S; Kamita, S G; Casida, J E

    2001-05-01

    The gamma-aminobutyric acid type A (GABA(A)) receptor is the target for the major insecticides alpha-endosulfan, lindane, and fipronil and for many analogs. Their action as chloride channel blockers is directly measured by binding studies with [(3)H]ethynylbicycloorthobenzoate ([(3)H]EBOB). This study tests the hypothesis that GABA(A) receptor subunit composition determines the sensitivity and selectivity of insecticide toxicity. Human receptor subtypes were expressed individually (alpha1, alpha6, beta1, beta3, and gamma2) and in combination in insect Sf9 cells. Binding parameters were similar for [(3)H]EBOB in the beta3 homooligomer, alpha1beta3gamma2 heterooligomer, and native brain membranes, but toxicological profiles were very different. Surprisingly, alpha-endosulfan, lindane, and fipronil were all remarkably potent on the recombinant beta3 homooligomeric receptor (IC50 values of 0.5-2.4 nM), whereas they were similar in potency on the alpha1beta3gamma2 subtype (IC50 values of 16-33 nM) and highly selective on the native receptor (IC50 values of 7.3, 306, and 2470 nM, respectively). The selectivity order for 29 insecticides and convulsants as IC50 ratios for native/beta3 or alpha1beta3gamma2/beta3 was as follows: fipronil > lindane > 19 other insecticides including alpha-endosulfan and picrotoxinin > 4 trioxabicyclooctanes and dithianes (almost nonselective) > tetramethylenedisulfotetramine, 4-chlorophenylsilatrane, or alpha-thujone. Specificity between mammals and insects at the target site (fipronil > lindane > alpha-endosulfan) paralleled that for toxicity. Potency at the native receptor is more predictive for inhibition of GABA-stimulated chloride uptake than that at the beta3 or alpha1beta3gamma2 receptors. Therefore, the beta3 subunit contains the insecticide target and other subunits differentially modulate the binding to confer compound-dependent specificity and selective toxicity.

  6. Plasmid-Encoded asp Operon Confers a Proton Motive Metabolic Cycle Catalyzed by an Aspartate-Alanine Exchange Reaction

    OpenAIRE

    Abe, Keietsu; Ohnishi, Fumito; Yagi, Kyoko; Nakajima, Tasuku; Higuchi, Takeshi; Sano, Motoaki; Machida, Masayuki; Sarker, Rafiquel I.; Maloney, Peter C.

    2002-01-01

    Tetragenococcus halophila D10 catalyzes the decarboxylation of l-aspartate with nearly stoichiometric release of l-alanine and CO2. This trait is encoded on a 25-kb plasmid, pD1. We found in this plasmid a putative asp operon consisting of two genes, which we designated aspD and aspT, encoding an l-aspartate-β-decarboxylase (AspD) and an aspartate-alanine antiporter (AspT), respectively, and determined the nucleotide sequences. The sequence analysis revealed that the genes of the asp operon i...

  7. High-temperature Raman study of L-alanine, L-threonine and taurine crystals related to thermal decomposition

    Energy Technology Data Exchange (ETDEWEB)

    Cavaignac, A.L.O. [Centro de Ciências Sociais, Saúde e Tecnologia, Universidade Federal do Maranhão, Imperatriz, MA 65900-410 (Brazil); Lima, R.J.C., E-mail: ricardo.lima.ufma@gmail.com [Centro de Ciências Sociais, Saúde e Tecnologia, Universidade Federal do Maranhão, Imperatriz, MA 65900-410 (Brazil); Façanha Filho, P.F. [Centro de Ciências Sociais, Saúde e Tecnologia, Universidade Federal do Maranhão, Imperatriz, MA 65900-410 (Brazil); Moreno, A.J.D. [Coordenação de Ciências Naturais, Universidade Federal do Maranhão, Bacabal, MA 65700-000 (Brazil); Freire, P.T.C. [Departamento de Física, Universidade Federal do Ceará, Fortaleza, CE 60455-760 (Brazil)

    2016-03-01

    In this work high-temperature Raman spectra are used to compare temperature dependence of the lattice mode wavenumber of L-alanine, L-threonine and taurine crystals. Anharmonic effects observed are associated with intermolecular N-H· · ·O hydrogen bond that plays an important role in thermal decomposition process of these materials. Short and strong hydrogen bonds in L-alanine crystal were associated with anharmonic effects in lattice modes leading to low thermal stability compared to taurine crystals. Connection between thermal decomposition process and anharmonic effects is furnished for the first time.

  8. Kinetics and Mechanism of Oxidation of Leucine and Alanine by Ag(III Complex in Alkaline Medium

    Directory of Open Access Journals (Sweden)

    Changying Song

    2008-01-01

    Full Text Available Kinetics and mechanism of oxidation of leucine and alanine by Ag(III complex were studied spectrophotometrically in alkaline medium at constant ion strength. The reaction was in first order with respect to Ag(III complex and amino acids (leucine, alanine. The second-order rate constant, k−, decreased with the increasing in [OH−] and [IO4−]. A plausible mechanism was proposed from the kinetics study, and the rate equations derived from mechanism can explain all experimental phenomena. The activation parameters were calculated at 298.2 K.

  9. Eight-alanine duplication in homeobox D13 in a Chinese family with synpolydactyly.

    Science.gov (United States)

    Xin, Qian; Li, Lin; Li, Jiangxia; Qiu, Rongfang; Guo, Chenhong; Gong, Yaoqin; Liu, Qiji

    2012-05-10

    Human synpolydactyly (SPD), belonging to syndactyly (SD) II, is an inherited autosomal-dominant limb malformation characterized by SD of finger 3 or 4 or toe 4 or 5, usually with digit duplication. Previous studies have demonstrated that homeobox protein D13 (HOXD13) is responsible for this Mendelian disorder. In this paper, we report on a family with SPD - 7 members show typical SPD malformations. We used PCR and Sanger sequencing of DNA from peripheral blood samples and found an 8-Ala expansion in exon 1 of HOXD13 by mutation detection; this variant was absent in unaffected members and in 50 unaffected non-related subjects. This study further confirmed the correlation between SPD and alanine expansion in HOXD13.

  10. Formation Equilibria of Ternary Metal Complexes with Citric Acid and Glutamine (Alanine) in Aqueous Solution

    Institute of Scientific and Technical Information of China (English)

    王进平; 牛春吉; 杨魁跃; 倪嘉缵

    2004-01-01

    The species and their formation constants in the ternary systems were obtained by the Scogs2 software from potentiometric titration data. The Comics software was used to calculate the distribution of species in the ternary systems. MLXH, MLXH2 and MLXH3 are the common species in these systems. The coordination behaviors of the rare earths are very similar and their stability is closely matched. The ternary rare earth complexes are more stable than the corresponding ternary complexes of calcium. The ternary zinc complex with glutamine as the secondary ligand is more stable than the corresponding complexes of rare earths, but the ternary complex with alanine as the secondary ligand shows an inverse trend. The distributions of species in the ternary systems vary with pH changing. A prediction can be made that exogenous rare earths can affect the species of Ca and Zn in human body.

  11. Assessment of an alanine EPR dosimetry technique with enhanced precision and accuracy

    CERN Document Server

    Hayes, R B; Wieser, A; Romanyukha, A A; Hardy, B L; Barrus, J K

    2000-01-01

    Dose reconstruction in the course of a series of blind tests demonstrated that an accuracy of 10 mGy for low doses and 1% for high doses can be achieved using EPR spectroscopy. This was accomplished using a combination of methodologies including polynomial filtration of the EPR spectrum, dosimeter rotation during scanning, use of an EPR standard fixed into the resonator and subtraction of all nonradiogenic signals. Doses were reconstructed over the range of 0.01-1000 Gy using this compound spectral EPR analysis. This EPR technique, being equally applicable to fractionated doses (such as those delivered during multiple radiotherapy treatments), was verified to exhibit dose reciprocity. Irradiated alanine dosimeters which were stored exhibited compound spectral EPR signal fading of ca 3% over 9 months. All error estimates given in this paper are given at the 1 standard deviation level and unless otherwise specified do not account for uncertainties in source calibration.

  12. Ste20-related proline/alanine-rich kinase: A novel regulator of intestinal inflammation

    Institute of Scientific and Technical Information of China (English)

    Yutao Yan; Didier Merlin

    2008-01-01

    Recently, inflammatory bowel disease (IBD) has been the subject of considerable research, with increasing attention being paid to the loss of intestinal epithelial cell barrier function as a mechanism of pathogenesis. Ste20-related proline/alanine-rich kinase (SPAK) is involved in regulating barrier function. SPAK is known to interact with inflammation-related kinases (such as p38, JNK, NKCC1, PKCθ, WNK and MLCK), and with transcription factor AP-1, resulting in diverse biological phenomena, including cell differentiation, cell transformation and proliferation, cytoskeleton rearrangement, and regulation of chloride transport. This review examines the involvement of Ste20-like kinases and downstream mitogen-activated protein kinases (MAPKs) pathways in the pathogenesis and control of intestinal inflammation. The primary focus will be on the molecular features of intestinal inflammation, with an emphasis on the interaction between SPAK and other molecules, and the effect of these interactions on homeostatic maintenance, cell volume regulation and increased cell permeability in intestinal inflammation.

  13. Growth and Characterization of Pure and Doped L-Alanine Tartrate Single Crystals

    Directory of Open Access Journals (Sweden)

    K. Rajesh

    2013-01-01

    Full Text Available Single crystals of pure and Lanthanum doped L-Alanine Tartrate were grown by slow evaporation method. The cell parameters were determined using single crystal X-ray diffraction method. To improve the physical properties of the LAT crystal, Lanthanum dopant was added by 2 mol%. ICP studies confirm the presence of Lanthanum in the grown LAT crystal. Transparency range of the crystal was determined using UV-VIS-NIR spectrophotometer. The functional groups of pure and doped LAT crystals were analyzed by FT-IR spectroscopy. Using Vickers microhardness tester, mechanical strength of the material was found. Dielectric studies of pure and doped LAT single crystals were carried out. The doped LAT crystal is found to have efficiency higher than that of pure LAT crystal.

  14. Growth, Structural And Optical Studies On Bis L-alanine Lithium Chloride (BLALC) Single Crystal

    Science.gov (United States)

    Rose, A. S. J. Lucia; Selvarajan, P.; Perumal, S.

    2011-10-01

    Bis L-alanine Lithium Chloride (BLALC) single crystals were grown successfully by solution method with slow evaporation technique at room temperature. Crystals of size 15 x 9 x 4 mm3 have been obtained in 28 days. The grown crystals were colourless and transparent. Single crystal X-ray diffraction (XRD) study showed that BLALC belongs to orthorhombic system with a non-centro-symmetric space group P212121. The crystallinity of BLALC crystal was confirmed by the powder X-ray diffraction study and diffraction peaks were indexed. The functional groups of the grown crystals have been identified by FTIR studies. UV-visible transmittance spectrum was recorded to study the optical transparency of BLALC crystal. The nonlinear optical (NLO) property of the grown crystal was confirmed by Kurtz-Perry powder technique.

  15. Experimental and DFT computational studies of L-alanine cadmium chloride crystals

    Science.gov (United States)

    Ignatius, I. Cicili; Dheivamalar, S.; Kirubavathi, K.; Selvaraju, K.

    2016-05-01

    In this work, we report the combined experimental and theoretical study on molecular structure and vibrational spectra of nonlinear optical crystal L-alanine cadmium chloride (LACC). The single X-ray diffraction studies have revealed that the compound crystallizes in monoclinic system C2 space group with cell parameters a = 16.270, b = 7.358, c = 7.887 and Z = 4. FTIR and Raman spectra of the nonlinear optical materials LACC have been recorded and analyzed. The optimized geometric bond length and bond angles are obtained with the help of density functional theory (DFT) (B3LYP) calculation. The optimized geometric bond lengths and bond angles obtained by using DFT show good agreement with the experimental data. Using the natural bond orbital analysis the electronic effect and hydrogen bonding were confirmed. The HOMO-LUMO energy gap and the first order hyperpolarizability were calculated and it supports the nonlinear optical activity of LACC crystal.

  16. A Thermochemical Study of the Reaction of Lanthanum Nitrate with Alanine

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The standard molar reaction enthalpy of the solid-solid coordination reaction La(NO3)3 ·6H2O (s) +4Ala(s) (Ala is Alanine)=La(NO3)3 · (Ala)4 · H2O(s) + 5H2O(1) was studied byusing classical solution calorimetry. The molar dissolution enthalpies of the reactants and theproduct of the solid-solid coordination reaction in 2 mol/L HCl were measured by using anisoperibol calorimeter. From the results and other auxiliary quantities, the standard molar formation enthalpy of [La (NO3)3 · (Ala)4 · H2O, s, 298. 15 K] has been determined to be△fHm [La(NO3)3 · (Ala)4 · H2O, s, 298. 15 K]=-3 864. 248 kJ/mol.

  17. Excitatory amino acid b-N-methylamino-L-alanine is a putative environmental neurotoxin

    Directory of Open Access Journals (Sweden)

    VLADIMIR NEDELJKOV

    2011-04-01

    Full Text Available The amino acid b-N-methylamino-L-alanine (L-BMAA has been associated with the amyotrophic lateral sclerosis/parkinsonism-dementia complex in three distinct western Pacific populations. The putative neurotoxin is produced by cyanobacteria, which live symbiotically in the roots of cycad trees. L-BMAA was thought to be a threat only to those few populations whose diet and medicines rely heavily on cycad seeds. However, the recent discovery that cyanobacteria from diverse terrestrial, freshwater, and saltwater ecosystems around the world produce the toxin requires a reassessment of whether it poses a larger health threat. Therefore, it is proposed that monitoring L-BMAA levels in cyanobacteria-contaminated water supplies might be prudent.

  18. Multiple adaptive losses of alanine-glyoxylate aminotransferase mitochondrial targeting in fruit-eating bats.

    Science.gov (United States)

    Liu, Yang; Xu, Huihui; Yuan, Xinpu; Rossiter, Stephen J; Zhang, Shuyi

    2012-06-01

    The enzyme alanine-glyoxylate aminotransferase 1 (AGT) functions to detoxify glyoxylate before it is converted into harmful oxalate. In mammals, mitochondrial targeting of AGT in carnivorous species versus peroxisomal targeting in herbivores is controlled by two signal peptides that correspond to these respective organelles. Differential expression of the mitochondrial targeting sequence (MTS) is considered an adaptation to diet-specific subcellular localization of glyoxylate precursors. Bats are an excellent group in which to study adaptive changes in dietary enzymes; they show unparalleled mammalian dietary diversification as well as independent origins of carnivory, frugivory, and nectarivory. We studied the AGT gene in bats and other mammals with diverse diets and found that the MTS has been lost in unrelated lineages of frugivorous bats. Conversely, species exhibiting piscivory, carnivory, insectivory, and sanguinivory possessed intact MTSs. Detected positive selection in the AGT of ancestral fruit bats further supports adaptations related to evolutionary changes in diet.

  19. Volume dose ratios relevant for alanine dosimetry in small, 6 MV photon beams

    DEFF Research Database (Denmark)

    Cronholm, Rickard O.; Andersen, Claus Erik; Behrens, Claus F.

    2012-01-01

    averaged doses to water (D¯W) and alanine (D¯det) was found to be approximately 1.025 for most situations studied, and a constant ratio is likely to be representative for many applications in radiation therapy. However, D¯W/D¯det was found to be as low as 0.9908 ± 0.0037 in situations where one might...... therapy). To this end, we here present the results of a Monte Carlo simulation study with DOSRZnrc that investigated the influence of field and detector size for small 6 MV photon beams. The study focusses on doses averaged over the volume of the detector rather than point doses.The ratio of volume...

  20. Alanine and proline content modulate global sensitivity to discrete perturbations in disordered proteins.

    Science.gov (United States)

    Perez, Romel B; Tischer, Alexander; Auton, Matthew; Whitten, Steven T

    2014-12-01

    Molecular transduction of biological signals is understood primarily in terms of the cooperative structural transitions of protein macromolecules, providing a mechanism through which discrete local structure perturbations affect global macromolecular properties. The recognition that proteins lacking tertiary stability, commonly referred to as intrinsically disordered proteins (IDPs), mediate key signaling pathways suggests that protein structures without cooperative intramolecular interactions may also have the ability to couple local and global structure changes. Presented here are results from experiments that measured and tested the ability of disordered proteins to couple local changes in structure to global changes in structure. Using the intrinsically disordered N-terminal region of the p53 protein as an experimental model, a set of proline (PRO) and alanine (ALA) to glycine (GLY) substitution variants were designed to modulate backbone conformational propensities without introducing non-native intramolecular interactions. The hydrodynamic radius (R(h)) was used to monitor changes in global structure. Circular dichroism spectroscopy showed that the GLY substitutions decreased polyproline II (PP(II)) propensities relative to the wild type, as expected, and fluorescence methods indicated that substitution-induced changes in R(h) were not associated with folding. The experiments showed that changes in local PP(II) structure cause changes in R(h) that are variable and that depend on the intrinsic chain propensities of PRO and ALA residues, demonstrating a mechanism for coupling local and global structure changes. Molecular simulations that model our results were used to extend the analysis to other proteins and illustrate the generality of the observed PRO and alanine effects on the structures of IDPs. © 2014 Wiley Periodicals, Inc.

  1. Engineering of alanine dehydrogenase from Bacillus subtilis for novel cofactor specificity.

    Science.gov (United States)

    Lerchner, Alexandra; Jarasch, Alexander; Skerra, Arne

    2016-09-01

    The l-alanine dehydrogenase of Bacillus subtilis (BasAlaDH), which is strictly dependent on NADH as redox cofactor, efficiently catalyzes the reductive amination of pyruvate to l-alanine using ammonia as amino group donor. To enable application of BasAlaDH as regenerating enzyme in coupled reactions with NADPH-dependent alcohol dehydrogenases, we alterated its cofactor specificity from NADH to NADPH via protein engineering. By introducing two amino acid exchanges, D196A and L197R, high catalytic efficiency for NADPH was achieved, with kcat /KM  = 54.1 µM(-1)  Min(-1) (KM  = 32 ± 3 µM; kcat  = 1,730 ± 39 Min(-1) ), almost the same as the wild-type enzyme for NADH (kcat /KM  = 59.9 µM(-1)  Min(-1) ; KM  = 14 ± 2 µM; kcat  = 838 ± 21 Min(-1) ). Conversely, recognition of NADH was much diminished in the mutated enzyme (kcat /KM  = 3 µM(-1)  Min(-1) ). BasAlaDH(D196A/L197R) was applied in a coupled oxidation/transamination reaction of the chiral dicyclic dialcohol isosorbide to its diamines, catalyzed by Ralstonia sp. alcohol dehydrogenase and Paracoccus denitrificans ω-aminotransferase, thus allowing recycling of the two cosubstrates NADP(+) and l-Ala. An excellent cofactor regeneration with recycling factors of 33 for NADP(+) and 13 for l-Ala was observed with the engineered BasAlaDH in a small-scale biocatalysis experiment. This opens a biocatalytic route to novel building blocks for industrial high-performance polymers.

  2. Synthesis of {sup 15}N isotope labeled alanine; Sintese da alanina enriquecida com {sup 15}N

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Claudineia R. de; Bendassolli, Jose Albertino; Sant' Ana, Carlos Roberto; Tagliassachi, Romulo Barbieri; Maximo, Everaldo; Prestes, Clelber Vieira [Centro de Energia Nuclear na Agricultura (CENA), Piracicaba, SP (Brazil). Dept. de Isotopos Estaveis]. E-mail: crolivei@cena.usp.br

    2005-07-01

    The application of light chemical elements and their stable isotopes in biological studies have been increased over the last years. The use of {sup 15}N labeled amino acids is an important tool for elucidation of peptides structures. This paper describe a method for the synthesis of {sup 15}N isotope labeled alanine at lower costs than international ones, as well as the details of the recovery system of the nitrogen residues. In the present work an amination of {alpha}-haloacids, with the bromopropionic carboxylic acid and labeled aqua ammonia ({sup 15}NH{sub 3} aq) was carried out. In order to avoid eventually losses of {sup 15}NH{sub 3}, special cares were adopted, since the production cost is high. Although the acquisition cost of the {sup 13}N (radioactive) labeled compounds is lower, the obtained stable tracer will allow the accomplishment of important studies of the nitrogen cycling in living things, less occupational and environment hazards, and the time limitation problems in field studies. The tests took place in triplicates with NH{sub 3} (aq) being employed. With the establishment of the system for {sup 15}NH{sub 3} recovery, an average of 94 % of the ammonia employed in the synthesis process was recovered. The purity of the amino acid was state determined by TLC (Thin Layer Chromatography) and HPLC (High-Performance Liquid Chromatography) with a fluorescence detector. The Rf and the retention time of the synthesized sample were similar the sigma standard. Finally, regarding the established conditions, it was possible to obtain the alanine with a production cost about 40 % lower than the international price. (author)

  3. Alanine mutagenesis of the primary antigenic escape residue cluster, c1, of apical membrane antigen 1.

    Science.gov (United States)

    Dutta, Sheetij; Dlugosz, Lisa S; Clayton, Joshua W; Pool, Christopher D; Haynes, J David; Gasser, Robert A; Batchelor, Adrian H

    2010-02-01

    Antibodies against apical membrane antigen 1 (AMA1) inhibit invasion of Plasmodium merozoites into red cells, and a large number of single nucleotide polymorphisms on AMA1 allow the parasite to escape inhibitory antibodies. The availability of a crystal structure makes it possible to test protein engineering strategies to develop a monovalent broadly reactive vaccine. Previously, we showed that a linear stretch of polymorphic residues (amino acids 187 to 207), localized within the C1 cluster on domain 1, conferred the highest level of escape from inhibitory antibodies, and these were termed antigenic escape residues (AER). Here we test the hypothesis that immunodampening the C1 AER will divert the immune system toward more conserved regions. We substituted seven C1 AER of the FVO strain Plasmodium falciparum AMA1 with alanine residues (ALA). The resulting ALA protein was less immunogenic than the native protein in rabbits. Anti-ALA antibodies contained a higher proportion of cross-reactive domain 2 and domain 3 antibodies and had higher avidity than anti-FVO. No overall enhancement of cross-reactive inhibitory activity was observed when anti-FVO and anti-ALA sera were compared for their ability to inhibit invasion. Alanine mutations at the C1 AER had shifted the immune response toward cross-strain-reactive epitopes that were noninhibitory, refuting the hypothesis but confirming the importance of the C1 cluster as an inhibitory epitope. We further demonstrate that naturally occurring polymorphisms that fall within the C1 cluster can predict escape from cross-strain invasion inhibition, reinforcing the importance of the C1 cluster genotype for antigenic categorization and allelic shift analyses in future phase 2b trials.

  4. Chiral selectivity of amino acid adsorption on chiral surfaces—The case of alanine on Pt

    Energy Technology Data Exchange (ETDEWEB)

    Franke, J.-H.; Kosov, D. S. [Department of Physics, Campus Plaine - CP 231, Université Libre de Bruxelles, 1050 Brussels (Belgium)

    2015-02-07

    We study the binding pattern of the amino acid alanine on the naturally chiral Pt surfaces Pt(531), Pt(321), and Pt(643). These surfaces are all vicinal to the (111) direction but have different local environments of their kink sites and are thus a model for realistic roughened Pt surfaces. Alanine has only a single methyl group attached to its chiral center, which makes the number of possible binding conformations computationally tractable. Additionally, only the amine and carboxyl group are expected to interact strongly with the Pt substrate. On Pt(531), we study the molecule in its pristine as well as its deprotonated form and find that the deprotonated one is more stable by 0.47 eV. Therefore, we study the molecule in its deprotonated form on Pt(321) and Pt(643). As expected, the oxygen and nitrogen atoms of the deprotonated molecule provide a local binding “tripod” and the most stable adsorption configurations optimize the interaction of this “tripod” with undercoordinated surface atoms. However, the interaction of the methyl group plays an important role: it induces significant chiral selectivity of about 60 meV on all surfaces. Hereby, the L-enantiomer adsorbs preferentially to the Pt(321){sup S} and Pt(643){sup S} surfaces, while the D-enantiomer is more stable on Pt(531){sup S}. The binding energies increase with increasing surface density of kink sites, i.e., they are largest for Pt(531){sup S} and smallest for Pt(643){sup S}.

  5. GMXPBSA 2.0: A GROMACS tool to perform MM/PBSA and computational alanine scanning

    Science.gov (United States)

    Paissoni, C.; Spiliotopoulos, D.; Musco, G.; Spitaleri, A.

    2014-11-01

    GMXPBSA 2.0 is a user-friendly suite of Bash/Perl scripts for streamlining MM/PBSA calculations on structural ensembles derived from GROMACS trajectories, to automatically calculate binding free energies for protein-protein or ligand-protein complexes. GMXPBSA 2.0 is flexible and can easily be customized to specific needs. Additionally, it performs computational alanine scanning (CAS) to study the effects of ligand and/or receptor alanine mutations on the free energy of binding. Calculations require only for protein-protein or protein-ligand MD simulations. GMXPBSA 2.0 performs different comparative analysis, including a posteriori generation of alanine mutants of the wild-type complex, calculation of the binding free energy values of the mutant complexes and comparison of the results with the wild-type system. Moreover, it compares the binding free energy of different complexes trajectories, allowing the study the effects of non-alanine mutations, post-translational modifications or unnatural amino acids on the binding free energy of the system under investigation. Finally, it can calculate and rank relative affinity to the same receptor utilizing MD simulations of proteins in complex with different ligands. In order to dissect the different MM/PBSA energy contributions, including molecular mechanic (MM), electrostatic contribution to solvation (PB) and nonpolar contribution to solvation (SA), the tool combines two freely available programs: the MD simulations software GROMACS and the Poisson-Boltzmann equation solver APBS. All the calculations can be performed in single or distributed automatic fashion on a cluster facility in order to increase the calculation by dividing frames across the available processors. The program is freely available under the GPL license. Catalogue identifier: AETQ_v1_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AETQ_v1_0.html Program obtainable from: CPC Program Library, Queen’s University, Belfast, N. Ireland Licensing

  6. Interstrand side chain--side chain interactions in a designed beta-hairpin: significance of both lateral and diagonal pairings.

    Science.gov (United States)

    Syud, F A; Stanger, H E; Gellman, S H

    2001-09-12

    The contributions of interstrand side chain-side chain contacts to beta-sheet stability have been examined with an autonomously folding beta-hairpin model system. RYVEV(D)PGOKILQ-NH2 ((D)P = D-proline, O = ornithine) has previously been shown to adopt a beta-hairpin conformation in aqueous solution, with a two-residue loop at D-Pro-Gly. In the present study, side chains that display interstrand NOEs (Tyr-2, Lys-9, and Leu-11) are mutated to alanine or serine, and the conformational impact of the mutations is assessed. In the beta-hairpin conformation Tyr-2 and Leu-11 are directly across from one another (non-hydrogen bonded pair). This "lateral" juxtaposition of two hydrophobic side chains appears to contribute to beta-hairpin conformational stability, which is consistent with results from other beta-sheet model studies and with statistical analyses of interstrand residue contacts in protein crystal structures. Interaction between the side chains of Tyr-2 and Lys-9 also stabilizes the beta-hairpin conformation. Tyr-2/Lys-9 is a "diagonal" interstrand juxtaposition because these residues are not directly across from one another in terms of the hydrogen bonding registry between the strands. This diagonal interaction arises from the right-handed twist that is commonly observed among beta-sheets. Evidence of diagonal side chain-side chain contacts has been observed in other autonomously folding beta-sheet model systems, but we are not aware of other efforts to determine whether a diagonal interaction contributes to beta-sheet stability.

  7. Study on the role of catalase for uptake of metallic mercury Part 3 In vitro oxidation of metallic mercury by catalase and hydrogen peroxide generated by several oxidase system

    OpenAIRE

    劒持,堅志

    1984-01-01

    In vitro oxidation of metallic mercury by catalase and hydrogen peroxide generated by the glucose-glucose oxidase system, D-alanine-D-amino acid oxidase system and xanthine-xanthine oxidase-superoxide dismutase system was investigated. In vitro oxidation of metallic mercury by catalase and hydrogen peroxide generated by the reaction with glucose and glucose oxidase was observed in erythrocytes and crystalline beef liver catalase solution. The uptake depended on the concentration of glucose ox...

  8. Simultaneous beta and gamma spectroscopy

    Science.gov (United States)

    Farsoni, Abdollah T.; Hamby, David M.

    2010-03-23

    A phoswich radiation detector for simultaneous spectroscopy of beta rays and gamma rays includes three scintillators with different decay time characteristics. Two of the three scintillators are used for beta detection and the third scintillator is used for gamma detection. A pulse induced by an interaction of radiation with the detector is digitally analyzed to classify the type of event as beta, gamma, or unknown. A pulse is classified as a beta event if the pulse originated from just the first scintillator alone or from just the first and the second scintillator. A pulse from just the third scintillator is recorded as gamma event. Other pulses are rejected as unknown events.

  9. Uptake of polychlorinated biphenyls and organochlorine pesticides from soil and air into radishes (Raphanus sativus)

    DEFF Research Database (Denmark)

    Mikes, Ondrej; Cupr, P.; Trapp, Stefan

    2009-01-01

    values were rather constant and varied between 0.01 and 0.22. Resuspended soil particles may facilitate the transport of chemicals from soil to shoots. Elevated POP concentrations found in shoots of radishes grown in the control plot support the hypothesis that the uptake from air was more significant......Uptake of organochlorine pesticides and polychlorinated biphenyls from soil and air into radishes was measured at a heavily contaminated field site. The highest contaminant concentrations were found for DDT and its metabolites, and for beta-hexachlorocyclohexane. Bioconcentration factor (BCF...... for shoots than the one from soil. The uptake of POPs from air was within the range of theoretical values predicted from log K-OA....

  10. Uptake of the glycosphingolipid sulfatide in the gastrointestinal tract and pancreas in vivo and in isolated islets of Langerhans

    Directory of Open Access Journals (Sweden)

    Fredman Pam

    2006-10-01

    Full Text Available Abstract Background The glycosphingolipid sulfatide has previously been found in several mammalian tissues, but information on the uptake of exogenously administered sulfatide in different organs in vivo is limited. In pancreatic beta cells, sulfatide has been shown to be involved in insulin processing and secretion in vitro. In this study, we examined the uptake of exogenously administered sulfatide and its distribution to the pancreatic beta cells. This might encourage future studies of the function(s of sulfatide in beta cell physiology in vivo. Radioactive sulfatide was given orally to mice whereafter the uptake of sulfatide in the gastrointestinal tract and subsequent delivery to the pancreas was examined. Sulfatide uptake in pancreas was also studied in vivo by i.p. administration of radioactive sulfatide in mice, and in vitro in isolated rat islets. Isolated tissue/islets were analysed by scintillation counting, autoradiography and thin-layer chromatography-ELISA. Results Sulfatide was taken up in the gastrointestinal tract for degradation or further transport to other organs. A selective uptake of short chain and/or hydroxylated sulfatide fatty acid isoforms was observed in the small intestine. Exogenously administered sulfatide was found in pancreas after i.p, but not after oral administration. The in vitro studies in isolated rat islets support that sulfatide, independently of its fatty acid length, is endocytosed and metabolised by pancreatic islets. Conclusion Our study supports a selective uptake and/or preservation of sulfatide in the gastrointestinal tract after oral administration and with emphasises on pancreatic sulfatide uptake, i.p. administration results in sulfatide at relevant location.

  11. Beta section Beta: biogeographical patterns of variation and taxonomy.

    NARCIS (Netherlands)

    Letschert, J.P.W.

    1993-01-01

    In Chapter 1 an account is given of the historical subdivision of the genus Beta and its sections, and the relations of the sections are discussed. Emphasis is given to the taxonomic treatment of wild section Beta by various authors. The Linnaean names B. vulgaris L. and B. maritima L. are lectotypi

  12. Lysophosphatidylcholine enhances carotenoid uptake from mixed micelles by Caco-2 human intestinal cells.

    Science.gov (United States)

    Sugawara, T; Kushiro, M; Zhang, H; Nara, E; Ono, H; Nagao, A

    2001-11-01

    Despite the interest in the beneficial roles of dietary carotenoids in human health, little is known about their solubilization from foods to mixed bile micelles during digestion and the intestinal uptake from the micelles. We investigated the absorption of carotenoids solubilized in mixed micelles by differentiated Caco-2 human intestinal cells, which is a useful model for studying the absorption of dietary compounds by intestinal cells. The micelles were composed of 1 micromol/L carotenoids, 2 mmol/L sodium taurocholate, 100 micromol/L monoacylglycerol, 33.3 micromol/L fatty acid and phospholipid (0-200 micromol/L). The phospholipid content of micelles had profound effects on the cellular uptake of carotenoids. Uptake of micellar beta-carotene and lutein was greatly suppressed by phosphatidylcholine (PC) in a dose-dependent manner, whereas lysophosphatidylcholine (lysoPC), the lipolysis product of PC by phospholipase A2 (PLA2), markedly enhanced both beta-carotene and lutein uptake. The addition of PLA2 from porcine pancreas to the medium also enhanced the uptake of carotenoids from micelles containing PC. Caco-2 cells could take up 15 dietary carotenoids, including epoxy carotenoids, such as violaxanthin, neoxanthin and fucoxanthin, from micellar carotenoids, and the uptakes showed a linear correlation with their lipophilicity, defined as the distribution coefficient in 1-octanol/water (log P(ow)). These results suggest that pancreatic PLA2 and lysoPC are important in regulating the absorption of carotenoids in the digestive tract and support a simple diffusion mechanism for carotenoid absorption by the intestinal epithelium.

  13. Increased alanine aminotransferase levels and associated characteristics among newly diagnosed type 2 diabetes patients: Results from the DD2 study

    DEFF Research Database (Denmark)

    Mor, Anil; Thomsen, Reimar W.; Rungby, Jørgen

    Objectives: Elevated levels of serum alanine aminotransferase (ALAT) have been linked with non-alcoholic fatty liver disease (NAFLD), non-alcoholic steatohepatitis (NASH), insulin resistance and the metabolic syndrome in type 2 diabetes (T2D) patients. We examined ALAT levels in newly diagnosed T2D...

  14. Selection and characterization of conditionally active promotors in Lactobacillus plantarum, using alanine racemase as a promotor probe

    NARCIS (Netherlands)

    Bron, P.A.; Hoffer, S.M.; Swam, van I.I.; Vos, de W.M.; Kleerebezem, M.

    2004-01-01

    This paper describes the use of the alr gene, encoding alanine racemase, as a promoter-screening tool for the identification of conditional promoters in Lactobacillus plantarum. Random fragments of the L. plantarum WCFS1 genome were cloned upstream of the promoterless alr gene of Lactococcus lactis

  15. Crystal and molecular structure of N-(4-nitrophenyl)-β-alanine--its vibrational spectra and theoretical calculations.

    Science.gov (United States)

    Marchewka, M K; Drozd, M; Janczak, J

    2011-08-15

    The N-(4-nitrophenyl)-β-alanine in crystalline form directly by the addition of 4-nitroaniline to the acrylic acid in aqueous solution has been obtained. The title β-alanine derivative crystallizes in the P2(1)/c space group of monoclinic system with four molecules per unit cell. The X-ray geometry of β-alanine derivative molecule has been compared with those obtained by molecular orbital calculations corresponding to the gas phase. In the crystal the molecules related by an inversion center interact via symmetrically equivalent O-H···O hydrogen bonds with O···O distance of 2.656(2) Å forming a dimeric structure. The dimers of β-alanine derivative weakly interact via N-H···O hydrogen bonds between the H atom of β-amine groups and one of O atom of nitro groups. The room temperature powder vibrational (infrared and Raman) measurements are in accordance with the X-ray analysis. In aqueous solution of 4-nitroaniline and acrylic acid, the double CC bond of vinyl group of acrylic acid breaks as result of 4-nitroaniline addition.

  16. Expression, crystallization and preliminary X-ray crystallographic analysis of alanine racemase from Acinetobacter baumannii OXA-23.

    Science.gov (United States)

    Nguyen, Dinh-Duc; Ngo, Ho-Phuong-Thuy; Hong, Myoung-ki; Pham, Tan-Viet; Lee, Jung Hun; Lee, Jae Jin; Kwon, Dae Beom; Lee, Sang Hee; Kang, Lin-Woo

    2013-09-01

    Acinetobacter baumannii has received much attention owing to its exceptional ability to develop resistance to currently available antibiotics. Alanine racemase (ALR) catalyzes the racemization of L-alanine to D-alanine with pyridoxal 5'-phosphate (PLP) as a cofactor. The D-alanine product is an essential component of the bacterial cell wall and ALR is a potential target for the development of novel antibacterial drugs. The alr gene from A. baumannii was cloned and the protein (AbALR) was expressed, purified and crystallized. The AbALR crystal diffracted to 2.3 Å resolution and belonged to the primitive orthorhombic space group P2(1)2(1)2(1), with unit-cell parameters a = 55.1, b = 85.0, c = 167.7 Å. Two protomers were present in the asymmetric unit, with a corresponding V(M) value of 2.3 Å(3) Da(-1) and a solvent content of 47.5%.

  17. Preparation and Bioavailability Analysis of Ferrous Bis Alanine Chelate as a New Micronutrient for Treatment of Iron Deficiency Anemia

    Science.gov (United States)

    Zargaran, Marzieh; Saadat, Ebrahim; Dinarvand, Rassoul; Sharifzadeh, Mohammad; Dorkoosh, Farid

    2016-01-01

    Purpose: One of the most nutritional disorders around the world is iron deficiency. A novel iron compound was synthesized by chelating ferrous ions with alanine for prevention and treatment of iron deficiency anemia. Methods: The newly synthesized compound was characterized both qualitatively and quantitatively by Fourier Transform Infrared (FT-IR) spectroscopy. The bioavailability of newly synthesized iron micronutrient was evaluated in four groups of Wistar rats. The group I was a negative control group and the other three groups received three different iron formulations. After 14 days, the blood samples were taken and analyzed accordingly. Results: Calculations showed that more than 91.8% of iron was incorporated in the chelate formulation. In vivo studies showed that serum iron, total iron binding capacity and hemoglobin concentrations were significantly increased in group IV, which received ferrous bis alanine chelate compared with the negative control group (p<0.05) and also group II, which received ferrous sulfate.7H2O (p<0.05). It indicates that the new formulation considerably improves the blood iron status compared with the conventional iron compounds. There were no significant differences (p<0.05) in the serum iron between group IV and group III, which received ferrous bis glycine. Conclusion: The results showed better bioavailability of ferrous bis alanine as a new micronutrient for treatment of iron deficiency anemia in comparison with ferrous sulfate. Ferrous bis alanine could be considered as a suitable supplement for prevention and treatment of iron deficiency anemia. PMID:27766225

  18. Synthesis and characterization of gold/alanine nanocomposites with potential properties for medical application as radiation sensors.

    Science.gov (United States)

    Guidelli, Eder José; Ramos, Ana Paula; Zaniquelli, Maria Elisabete D; Nicolucci, Patricia; Baffa, Oswaldo

    2012-11-01

    Radiation dose assessment is essential for several medical treatments and diagnostic procedures. In this context, nanotechnology has been used in the development of improved radiation sensors, with higher sensitivity as well as smaller sizes and energy dependence. This paper deals with the synthesis and characterization of gold/alanine nanocomposites with varying mass percentage of gold, for application as radiation sensors. Alanine is an excellent stabilizing agent for gold nanoparticles because the size of the nanoparticles does not augment with increasing mass percentage of gold, as evidenced by UV-vis spectroscopy, dynamic light scattering, and transmission electron microscopy. X-ray diffraction patterns suggest that the alanine crystalline orientation undergoes alterations upon the addition of gold nanoparticles. Fourier transform infrared spectroscopy indicates that there is interaction between the gold nanoparticles and the amine group of the alanine molecules, which may be the reason for the enhanced stability of the nanocomposite. The application of the nanocomposites as radiation detectors was evaluated by the electron spin resonance technique. The sensitivity is improved almost 3 times in the case of the nanocomposite containing 3% (w/w) gold, so it can be easily tuned by changing the amount of gold nanoparticles in the nanocomposites, without the size of the nanoparticles influencing the radiation absorption. In conclusion, the featured properties, such as homogeneity, nanoparticle size stability, and enhanced sensitivity, make these nanocomposites potential candidates for the construction of small-sized radiation sensors with tunable sensitivity for application in several medical procedures.

  19. Alanine aminotransferase elevation in obese infants and children: a marker of early onset non alcoholic Fatty liver disease.

    Science.gov (United States)

    Engelmann, Guido; Hoffmann, Georg Friedrich; Grulich-Henn, Juergen; Teufel, Ulrike

    2014-04-01

    Elevated aminotransferases serve as surrogate markers of non-alcoholic fatty liver disease, a feature commonly associated with the metabolic syndrome. Studies on the prevalence of fatty liver disease in obese children comprise small patient samples or focus on those patients with liver enzyme elevation. We have prospectively analyzed liver enzymes in all overweight and obese children coming to our tertiary care centre. In a prospective study 224 healthy, overweight or obese children aged 1 - 12 years were examined. Body Mass Index-Standard Deviation Score, alanine aminotransferase, aspartate aminotransferase and gamma-glutamyl-transpeptidase were measured. Elevated alanine aminotransferase was observed in 29% of children. 26 % of obese and 30 % of overweight children had liver enzyme elevations. Obese children had significantly higher alanine aminotransferase levels than overweight children (0.9 vs. 0.7 times the Upper Limit of Normal; P = 0.04). Elevation of liver enzymes appears in 29 % obese children in a tertiary care centre. Absolute alanine aminotransferase levels are significantly higher in obese than in overweight children. Even obese children with normal liver enzymes show signs of fatty liver disease as demonstrated by liver enzymes at the upper limit of normal.

  20. Preparation and Bioavailability Analysis of Ferrous Bis Alanine Chelate as a New Micronutrient for Treatment of Iron Deficiency Anemia.

    Science.gov (United States)

    Zargaran, Marzieh; Saadat, Ebrahim; Dinarvand, Rassoul; Sharifzadeh, Mohammad; Dorkoosh, Farid

    2016-09-01

    Purpose: One of the most nutritional disorders around the world is iron deficiency. A novel iron compound was synthesized by chelating ferrous ions with alanine for prevention and treatment of iron deficiency anemia. Methods: The newly synthesized compound was characterized both qualitatively and quantitatively by Fourier Transform Infrared (FT-IR) spectroscopy. The bioavailability of newly synthesized iron micronutrient was evaluated in four groups of Wistar rats. The group I was a negative control group and the other three groups received three different iron formulations. After 14 days, the blood samples were taken and analyzed accordingly. Results: Calculations showed that more than 91.8% of iron was incorporated in the chelate formulation. In vivo studies showed that serum iron, total iron binding capacity and hemoglobin concentrations were significantly increased in group IV, which received ferrous bis alanine chelate compared with the negative control group (pferrous sulfate.7H2O (pferrous bis glycine. Conclusion: The results showed better bioavailability of ferrous bis alanine as a new micronutrient for treatment of iron deficiency anemia in comparison with ferrous sulfate. Ferrous bis alanine could be considered as a suitable supplement for prevention and treatment of iron deficiency anemia.

  1. Cyclic modular beta-sheets.

    Science.gov (United States)

    Woods, R Jeremy; Brower, Justin O; Castellanos, Elena; Hashemzadeh, Mehrnoosh; Khakshoor, Omid; Russu, Wade A; Nowick, James S

    2007-03-07

    The development of peptide beta-hairpins is problematic, because folding depends on the amino acid sequence and changes to the sequence can significantly decrease folding. Robust beta-hairpins that can tolerate such changes are attractive tools for studying interactions involving protein beta-sheets and developing inhibitors of these interactions. This paper introduces a new class of peptide models of protein beta-sheets that addresses the problem of separating folding from the sequence. These model beta-sheets are macrocyclic peptides that fold in water to present a pentapeptide beta-strand along one edge; the other edge contains the tripeptide beta-strand mimic Hao [JACS 2000, 122, 7654] and two additional amino acids. The pentapeptide and Hao-containing peptide strands are connected by two delta-linked ornithine (deltaOrn) turns [JACS 2003, 125, 876]. Each deltaOrn turn contains a free alpha-amino group that permits the linking of individual modules to form divalent beta-sheets. These "cyclic modular beta-sheets" are synthesized by standard solid-phase peptide synthesis of a linear precursor followed by solution-phase cyclization. Eight cyclic modular beta-sheets 1a-1h containing sequences based on beta-amyloid and macrophage inflammatory protein 2 were synthesized and characterized by 1H NMR. Linked cyclic modular beta-sheet 2, which contains two modules of 1b, was also synthesized and characterized. 1H NMR studies show downfield alpha-proton chemical shifts, deltaOrn delta-proton magnetic anisotropy, and NOE cross-peaks that establish all compounds but 1c and 1g to be moderately or well folded into a conformation that resembles a beta-sheet. Pulsed-field gradient NMR diffusion experiments show little or no self-association at low (

  2. DNA UPTAKE BY TRANSFORMABLE BACTERIA

    Energy Technology Data Exchange (ETDEWEB)

    LACKS,S.A.

    1999-09-07

    The various processes of DNA uptake by cells can be categorized as: viral DNA entry, conjugation, or transformation. Within each category, a variety of mechanisms have been found. However, considerable similarities occur among the different mechanisms of conjugation and, especially, transformation. All of these natural mechanisms of DNA transfer are quite elaborate and involve multiple protein components, as the case may be, of the virus, the donor cell, and the recipient cell. The mechanisms of viral infection and conjugation will be discussed mainly with respect to their relevance to transformation.

  3. DNA Uptake by Transformable Bacteria

    Energy Technology Data Exchange (ETDEWEB)

    Lacks, Sanford A.

    1999-03-31

    The various processes of DNA uptake by cells can be categorized as: viral DNA entry, conjugation, or transformation. Within each category, a variety of mechanisms have been found. However, considerable similarities occur among the different mechanisms of conjugation and, especially, transformation. All of these natural mechanisms of DNA transfer are quite elaborate and involve multiple protein components, as the case may be, of the virus, the donor cell, and the recipient cell. The mechanisms of viral infection and conjugation will be discussed mainly with respect to their relevance to transformation.

  4. Enhancement of glucose uptake in skeletal muscle L6 cells and insulin secretion in pancreatic hamster-insulinoma-transfected cells by application of non-thermal plasma jet

    Science.gov (United States)

    Kumar, Naresh; Kaushik, Nagendra K.; Park, Gyungsoon; Choi, Eun H.; Uhm, Han S.

    2013-11-01

    Type-II diabetes Mellitus is characterized by defects in insulin action on peripheral tissues, such as skeletal muscle, adipose tissue, and liver and pancreatic beta cells. Since the skeletal muscle accounts for approximately 75% of insulin-stimulated glucose-uptake in our body, impaired insulin secretion from defected beta cell plays a major role in the afflicted glucose homoeostasis. It was shown that the intracellular reactive oxygen species and nitric oxide level was increased by non-thermal-plasma treatment in ambient air. These increased intracellular reactive species may enhance glucose uptake and insulin secretion through the activation of intracellular calcium (Ca+) and cAMP production.

  5. Xanthophylls are preferentially taken up compared with beta-carotene by retinal cells via a SRBI-dependent mechanism.

    Science.gov (United States)

    During, Alexandrine; Doraiswamy, Sundari; Harrison, Earl H

    2008-08-01

    The purpose of this study was to investigate the mechanisms by which carotenoids [xanthophylls vs. beta-carotene(beta-C)] are taken up by retinal pigment epithelial (RPE) cells. The human RPE cell line, ARPE-19, was used. When ARPE-19 cells were fully differentiated (7-9 weeks), the xanthophylls lutein (LUT) and zeaxanthin (ZEA) were taken up by cells to an extent 2-fold higher than beta-C (P < 0.05). At 9 weeks, cellular uptakes were 1.6, 2.5, and 3.2%, respectively, for beta-C, LUT, and ZEA. Similar extents were observed when carotenoids were delivered in either Tween 40 or "chylomicrons" produced by Caco-2 cells. Differentiated ARPE-19 cells did not exhibit any detectable beta-C 15,15'-oxygenase activity or convert exogenous beta-C into vitamin A. When using specific antibodies against the lipid transporters cluster determinant 36 (CD36) and scavenger receptor class B type I (SR-BI), cellular uptake of beta-C and ZEA were significantly decreased (40-60%) with anti-SR-BI but not with anti-CD36. Small interfering RNA transfection for SR-BI led to marked knockdown of SR-BI protein expression (approximately 90%), which resulted in decreased beta-C and ZEA uptakes by 51% and 87%, respectively. Thus, the present data show that RPE cells preferentially take up xanthophylls versus the carotene by a process that appears to be entirely SR-BI-dependent for ZEA and partly so for beta-C. This mechanism may explain, in part, the preferential accumulation of xanthophylls in the macula of the retina.

  6. Ceramide formation is involved in Lactobacillus acidophilus-induced IFN-beta response in dendritic cells

    DEFF Research Database (Denmark)

    Fuglsang, Eva; Henningsen, Louise; Frøkiær, Hanne

    of sphingomyelin to ceramide by acid sphingomyelinase (ASMase) at the outer leaflet of the PM is a key event in endocytosis of gram-positive Lactobacillus acidophilus (L. acidophilus) and the subsequent induction of IFN-beta in DCs and, as the gram-negative Escherichia coli (E. coli) does not induce appreciable...... amounts of IFN-beta, the ASMase activity would affect endocytosis and the ensuing cytokine response of L. acidophilus and E. coli differently. SMase or an inhibitor of ASMase and acid ceramidase, chlorpromazine (CPZ), was added to DCs prior to stimulation with either of the bacteria. Endocytosis...... of fluorescent bacteria +/- FITC-dextran was measured by flow cytometry and gene expression and cytokine response of IFN-beta and IL-12 was measured by qPCR and ELISA, respectively. Addition of SMase increased the uptake of L. acidophilus and L. acidophilus-induced IL-12/IFN-beta but showed no effect...

  7. Amino acid metabolism of Astacus leptodactylus Esch.—III. Studies on the biosynthesis of α- and β-alanine from aspartate

    NARCIS (Netherlands)

    Marrewijk, W.J.A. van; Zandee, D.I.

    1975-01-01

    1. 1. Six hours after injection of 1- or 4-14C-aspartate into the crayfish Astacus leptodactylus almost all radioactivity incorporated was found in the amino acids. 2. 2. From both precursors only the amino acids α-alanine and glutamic acid were labelled. The biosynthesis of α-alanine from aspartat

  8. De Novo Alanine Synthesis by Bacteroids of Mesorhizobium loti Is Not Required for Nitrogen Transfer in the Determinate Nodules of Lotus corniculatus

    OpenAIRE

    Kumar, Shalini; Bourdès, Alexandre; Poole, Philip

    2005-01-01

    Deletion of both alanine dehydrogenase genes (aldA) in Mesorhizobium loti resulted in the loss of AldA enzyme activity from cultured bacteria and bacteroids but had no effect on the symbiotic performance of Lotus corniculatus plants. Thus, neither indeterminate pea nodules nor determinate L. corniculatus nodules export alanine as the sole nitrogen secretion product.

  9. De novo alanine synthesis by bacteroids of Mesorhizobium loti is not required for nitrogen transfer in the determinate nodules of Lotus corniculatus.

    Science.gov (United States)

    Kumar, Shalini; Bourdès, Alexandre; Poole, Philip

    2005-08-01

    Deletion of both alanine dehydrogenase genes (aldA) in Mesorhizobium loti resulted in the loss of AldA enzyme activity from cultured bacteria and bacteroids but had no effect on the symbiotic performance of Lotus corniculatus plants. Thus, neither indeterminate pea nodules nor determinate L. corniculatus nodules export alanine as the sole nitrogen secretion product.

  10. Developing a dosimetry system with alanine at University of Santiago de Compostela; Desarrollo de un sistema de dosimetria con alamina en la Universidad de Santiago de Compostela

    Energy Technology Data Exchange (ETDEWEB)

    Gago Arias, M. A.; Gomez Rodriguez, F.; Gonzalez Castano, D. M.; Peteiro Vilaseco, E.; Lodeiro Remesar, C.

    2013-07-01

    This paper presents the studies realized for the calibration, absorbed dose in water, the signal of Electron Paramagnetic Resonance of dosimeters of alanine, necessary step for the implementation of a service of dosimetry with alanine, traced to the secondary pattern of the Radio physics laboratory (RPL), and linked to the service of resonance Para Magnetic of the University of Santiago de Compostela. (Author)

  11. Effects of β-alanine administration on selected parameters of oxidative stress and phosphoryltransfer network in cerebral cortex and cerebellum of rats

    NARCIS (Netherlands)

    Gemelli, Tanise; de Andrade, Rodrigo Binkowski; Rojas, Denise Bertin; Bonorino, Nariélle Ferner; Mazzola, Priscila Nicolao; Tortorelli, Lucas Silva; Funchal, Cláudia; Filho, Carlos Severo Dutra; Wannmacher, Clovis Milton Duval

    2013-01-01

    β-Alanine is a β-amino acid derivative of the degradation of pyrimidine uracil and precursor of the oxidative substrate acetyl-coenzyme A (acetyl-CoA). The accumulation of β-alanine occurs in β-alaninemia, an inborn error of metabolism. Patients with β-alaninemia may develop neurological abnormaliti

  12. Reconfiguration of N Metabolism upon Hypoxia Stress and Recovery: Roles of Alanine Aminotransferase (AlaAT) and Glutamate Dehydrogenase (GDH)

    Science.gov (United States)

    Diab, Houssein; Limami, Anis M.

    2016-01-01

    In the context of climatic change, more heavy precipitation and more frequent flooding and waterlogging events threaten the productivity of arable farmland. Furthermore, crops were not selected to cope with flooding- and waterlogging-induced oxygen limitation. In general, low oxygen stress, unlike other abiotic stresses (e.g., cold, high temperature, drought and saline stress), received little interest from the scientific community and less financial support from stakeholders. Accordingly, breeding programs should be developed and agronomical practices should be adapted in order to save plants’ growth and yield—even under conditions of low oxygen availability (e.g., submergence and waterlogging). The prerequisite to the success of such breeding programs and changes in agronomical practices is a good knowledge of how plants adapt to low oxygen stress at the cellular and the whole plant level. In the present paper, we summarized the recent knowledge on metabolic adjustment in general under low oxygen stress and highlighted thereafter the major changes pertaining to the reconfiguration of amino acids syntheses. We propose a model showing (i) how pyruvate derived from active glycolysis upon hypoxia is competitively used by the alanine aminotransferase/glutamate synthase cycle, leading to alanine accumulation and NAD+ regeneration. Carbon is then saved in a nitrogen store instead of being lost through ethanol fermentative pathway. (ii) During the post-hypoxia recovery period, the alanine aminotransferase/glutamate dehydrogenase cycle mobilizes this carbon from alanine store. Pyruvate produced by the reverse reaction of alanine aminotransferase is funneled to the TCA cycle, while deaminating glutamate dehydrogenase regenerates, reducing equivalent (NADH) and 2-oxoglutarate to maintain the cycle function. PMID:27258319

  13. Experimental determination of the energy response of alanine pellets in the high dose rate 192Ir spectrum

    Science.gov (United States)

    Schaeken, B.; Cuypers, R.; Goossens, J.; Van den Weyngaert, D.; Verellen, D.

    2011-10-01

    An experimental determination of the energy correction factor for alanine/paraffin pellets in the 192Ir spectrum at varying distances from the source is presented. Alanine dosimeters were irradiated in water under full scatter conditions with a high dose rate (HDR) 192Ir source (Flexisource), using a dedicated holder. Up to six line sources (catheters) fit in a regular pattern at fixed radial distances from the holder axis, the alanine detector being placed at the centre of the holder. The HDR source was stepping every 0.5 cm within a trocar needle within ± 3.0 cm around the medial plane through the detector in order to achieve dose homogeneity within the detector volume. The energy correction factor of alanine/paraffin pellets in 192Ir relative to 60Co was experimentally determined as the inverse ratio of the dose to water measured in water around the 192Ir source to the dose to water calculated in water using the TG-43 formalism. The pellets were read out with a Bruker EMXmicro spectrometer (X-band). The amplitude of the central line in the alanine absorption spectrum from pellets irradiated within the 192Ir spectrum was directly compared with the amplitude from 60Co-irradiated pellets. The energy correction factors of Harwell pellets irradiated in the 192Ir spectrum are 1.029 ± 0.02, 1.027 ± 0.02 and 1.045 ± 0.02 at a mean weighted source-detector distance of 2.0, 2.9 and 5.3 cm, respectively. The experimentally obtained values for the energy response are 1.3% lower compared to the theoretical values for radial distances smaller than 3 cm.

  14. Reconfiguration of N Metabolism upon Hypoxia Stress and Recovery: Roles of Alanine Aminotransferase (AlaAT and Glutamate Dehydrogenase (GDH

    Directory of Open Access Journals (Sweden)

    Houssein Diab

    2016-05-01

    Full Text Available In the context of climatic change, more heavy precipitation and more frequent flooding and waterlogging events threaten the productivity of arable farmland. Furthermore, crops were not selected to cope with flooding- and waterlogging-induced oxygen limitation. In general, low oxygen stress, unlike other abiotic stresses (e.g., cold, high temperature, drought and saline stress, received little interest from the scientific community and less financial support from stakeholders. Accordingly, breeding programs should be developed and agronomical practices should be adapted in order to save plants’ growth and yield—even under conditions of low oxygen availability (e.g., submergence and waterlogging. The prerequisite to the success of such breeding programs and changes in agronomical practices is a good knowledge of how plants adapt to low oxygen stress at the cellular and the whole plant level. In the present paper, we summarized the recent knowledge on metabolic adjustment in general under low oxygen stress and highlighted thereafter the major changes pertaining to the reconfiguration of amino acids syntheses. We propose a model showing (i how pyruvate derived from active glycolysis upon hypoxia is competitively used by the alanine aminotransferase/glutamate synthase cycle, leading to alanine accumulation and NAD+ regeneration. Carbon is then saved in a nitrogen store instead of being lost through ethanol fermentative pathway. (ii During the post-hypoxia recovery period, the alanine aminotransferase/glutamate dehydrogenase cycle mobilizes this carbon from alanine store. Pyruvate produced by the reverse reaction of alanine aminotransferase is funneled to the TCA cycle, while deaminating glutamate dehydrogenase regenerates, reducing equivalent (NADH and 2-oxoglutarate to maintain the cycle function.

  15. The best-beta CAPM

    NARCIS (Netherlands)

    Zou, L.

    2006-01-01

    The issue of 'best-beta' arises as soon as potential errors in the Sharpe-Lintner-Black capital asset pricing model (CAPM) are acknowledged. By incorporating a target variable into the investor preferences, this study derives a best-beta CAPM (BCAPM) that maintains the CAPM's theoretical appeal and

  16. Beta decay of Cu-56

    NARCIS (Netherlands)

    Borcea, R; Aysto, J; Caurier, E; Dendooven, P; Doring, J; Gierlik, M; Gorska, M; Grawe, H; Hellstrom, M; Janas, Z; Jokinen, A; Karny, M; Kirchner, R; La Commara, M; Langanke, K; Martinez-Pinedo, G; Mayet, P; Nieminen, A; Nowacki, F; Penttila, H; Plochocki, A; Rejmund, M; Roeckl, E; Schlegel, C; Schmidt, K; Schwengner, R; Sawicka, M

    2001-01-01

    The proton-rich isotope Cu-56 was produced at the GSI On-Line Mass Separator by means of the Si-28(S-32, p3n) fusion-evaporation reaction. Its beta -decay properties were studied by detecting beta -delayed gamma rays and protons. A half-Life of 93 +/- 3 ms was determined for Cu-56. Compared to the p

  17. Integration of BETA with Eclipse

    DEFF Research Database (Denmark)

    Andersen, Peter; Madsen, Ole Lehrmann; Enevoldsen, Mads Brøgger

    2004-01-01

    This paper presents language interoperability issues appearing in order to implement support for the BETA language in the Java-based Eclipse integrated development environment. One of the challenges is to implement plug-ins in BETA and be able to load them in Eclipse. In order to do this, some form...

  18. Beta cell adaptation in pregnancy

    DEFF Research Database (Denmark)

    Nielsen, Jens Høiriis

    2016-01-01

    Pregnancy is associated with a compensatory increase in beta cell mass. It is well established that somatolactogenic hormones contribute to the expansion both indirectly by their insulin antagonistic effects and directly by their mitogenic effects on the beta cells via receptors for prolactin and...

  19. Measurements of sin 2 $\\beta$

    CERN Document Server

    Tricomi, A

    2000-01-01

    A review of the most recent measurements of the CP violating parameter sin 2 beta from LEP and CDF is reported. These yield an average value of sin 2 beta =0.91+or-0.35, giving a confidence level that CP violation in the B system has been observed of almost 99%. (10 refs).

  20. Beta-hemolytic streptococcal bacteremia

    DEFF Research Database (Denmark)

    Nielsen, Hans Ulrik; Kolmos, Hans Jørn; Frimodt-Møller, Niels

    2002-01-01

    Bacteremia with beta-hemolytic Streptococci groups A, B, C and G has a mortality rate of approximately 20%. In this study we analyzed the association of various patient risk factors with mortality. Records from 241 patients with beta-hemolytic streptococcal bacteremia were reviewed with particular...