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Sample records for residues included arginine

  1. Chemical modification of arginine residues in the lactose repressor

    International Nuclear Information System (INIS)

    Whitson, P.A.; Matthews, K.S.

    1987-01-01

    The lactose repressor protein was chemically modified with 2,3-butanedione and phenylglyoxal. Arginine reaction was quantitated by either amino aced analysis or incorporation of 14 C-labeled phenylglyoxal. Inducer binding activity was unaffected by the modification of arginine residues, while both operator and nonspecific DNA binding activities were diminished, although to differing degrees. The correlation of the decrease in DNA binding activities with the modification of ∼ 1-2 equiv of arginine per monomer suggests increased reactivity of a functionally essential residue(s). For both reagents, operator DNA binding activity was protected by the presence of calf thymus DNA, and the extent of reaction with phenylglyoxal was simultaneously diminished. This protection presumably results from steric restriction of reagent access to an arginine(s) that is (are) essential for DNA binding interactions. These experiments suggest that there is (are) an essential reactive arginine(s) critical for repressor binding to DNA

  2. Symmetric allosteric mechanism of hexameric Escherichia coli arginine repressor exploits competition between L-arginine ligands and resident arginine residues.

    Directory of Open Access Journals (Sweden)

    Rebecca Strawn

    2010-06-01

    Full Text Available An elegantly simple and probably ancient molecular mechanism of allostery is described for the Escherichia coli arginine repressor ArgR, the master feedback regulator of transcription in L-arginine metabolism. Molecular dynamics simulations with ArgRC, the hexameric domain that binds L-arginine with negative cooperativity, reveal that conserved arginine and aspartate residues in each ligand-binding pocket promote rotational oscillation of apoArgRC trimers by engagement and release of hydrogen-bonded salt bridges. Binding of exogenous L-arginine displaces resident arginine residues and arrests oscillation, shifting the equilibrium quaternary ensemble and promoting motions that maintain the configurational entropy of the system. A single L-arg ligand is necessary and sufficient to arrest oscillation, and enables formation of a cooperative hydrogen-bond network at the subunit interface. The results are used to construct a free-energy reaction coordinate that accounts for the negative cooperativity and distinctive thermodynamic signature of L-arginine binding detected by calorimetry. The symmetry of the hexamer is maintained as each ligand binds, despite the conceptual asymmetry of partially-liganded states. The results thus offer the first opportunity to describe in structural and thermodynamic terms the symmetric relaxed state predicted by the concerted allostery model of Monod, Wyman, and Changeux, revealing that this state is achieved by exploiting the dynamics of the assembly and the distributed nature of its cohesive free energy. The ArgR example reveals that symmetry can be maintained even when binding sites fill sequentially due to negative cooperativity, which was not anticipated by the Monod, Wyman, and Changeux model. The molecular mechanism identified here neither specifies nor requires a pathway for transmission of the allosteric signal through the protein, and it suggests the possibility that binding of free amino acids was an early

  3. Hexa-arginine enhanced uptake and residualization of selective high affinity ligands by Raji lymphoma cells

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    Mirick Gary

    2009-04-01

    Full Text Available Abstract Background A variety of arginine-rich peptide sequences similar to those found in viral proteins have been conjugated to other molecules to facilitate their transport into the cytoplasm and nucleus of targeted cells. The selective high affinity ligand (SHAL (DvLPBaPPP2LLDo, which was developed to bind only to cells expressing HLA-DR10, has been conjugated to one of these peptide transduction domains, hexa-arginine, to assess the impact of the peptide on SHAL uptake and internalization by Raji cells, a B-cell lymphoma. Results An analog of the SHAL (DvLPBaPPP2LLDo containing a hexa-arginine peptide was created by adding six D-arginine residues sequentially to a lysine inserted in the SHAL's linker. SHAL binding, internalization and residualization by Raji cells expressing HLA-DR10 were examined using whole cell binding assays and confocal microscopy. Raji cells were observed to bind two fold more 111In-labeled hexa-arginine SHAL analog than Raji cells treated with the parent SHAL. Three fold more hexa-arginine SHAL remained associated with the Raji cells after washing, suggesting that the peptide also enhanced residualization of the 111In transported into cells. Confocal microscopy showed both SHALs localized in the cytoplasm of Raji cells, whereas a fraction of the hexa-arginine SHAL localized in the nucleus. Conclusion The incorporation of a hexa-D-arginine peptide into the linker of the SHAL (DvLPBaPPP2LLDo enhanced both the uptake and residualization of the SHAL analog by Raji cells. In contrast to the abundant cell surface binding observed with Lym-1 antibody, the majority of (DvLPBaPPP2LArg6AcLLDo and the parent SHAL were internalized. Some of the internalized hexa-arginine SHAL analog was also associated with the nucleus. These results demonstrate that several important SHAL properties, including uptake, internalization, retention and possibly intracellular distribution, can be enhanced or modified by conjugating the SHALs to a

  4. Arginine residues are more effective than lysine residues in eliciting the cellular uptake of onconase.

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    Sundlass, Nadia K; Raines, Ronald T

    2011-11-29

    Onconase is an amphibian member of the pancreatic ribonuclease family of enzymes that is in clinical trials for the treatment of cancer. Onconase, which has an abundance of lysine residues, is internalized by cancer cells through endocytosis in a mechanism similar to that of cell-penetrating peptides. Here, we compare the effect of lysine versus arginine residues on the biochemical attributes necessary for Onconase to elicit its cytotoxic activity. In the variant R-Onconase, 10 of the 12 lysine residues in Onconase are replaced with arginine, leaving only the two active-site lysines intact. Cytometric assays quantifying internalization showed a 3-fold increase in the internalization of R-Onconase compared with Onconase. R-Onconase also showed greater affinity for heparin and a 2-fold increase in ribonucleolytic activity. Nonetheless, arginine substitution endowed only a slight increase in toxicity toward human cancer cells. Analysis of denaturation induced with guanidine-HCl showed that R-Onconase has less conformational stability than does the wild-type enzyme; moreover, R-Onconase is more susceptible to proteolytic degradation. These data indicate that arginine residues are more effective than lysine in eliciting cellular internalization but can compromise other aspects of protein structure and function.

  5. Interaction of arginine, lysine, and guanidine with surface residues of lysozyme: implication to protein stability.

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    Shah, Dhawal; Shaikh, Abdul Rajjak

    2016-01-01

    Additives are widely used to suppress aggregation of therapeutic proteins. However, the molecular mechanisms of effect of additives to stabilize proteins are still unclear. To understand this, we herein perform molecular dynamics simulations of lysozyme in the presence of three commonly used additives: arginine, lysine, and guanidine. These additives have different effects on stability of proteins and have different structures with some similarities; arginine and lysine have aliphatic side chain, while arginine has a guanidinium group. We analyze atomic contact frequencies to study the interactions of the additives with individual residues of lysozyme. Contact coefficient, quantified from contact frequencies, is helpful in analyzing the interactions with the guanidine groups as well as aliphatic side chains of arginine and lysine. Strong preference for contacts to the additives (over water) is seen for the acidic followed by polar and the aromatic residues. Further analysis suggests that the hydration layer around the protein surface is depleted more in the presence of arginine, followed by lysine and guanidine. Molecular dynamics simulations also reveal that the internal dynamics of protein, as indicated by the lifetimes of the hydrogen bonds within the protein, changes depending on the additives. Particularly, we note that the side-chain hydrogen-bonding patterns within the protein differ with the additives, with several side-chain hydrogen bonds missing in the presence of guanidine. These results collectively indicate that the aliphatic chain of arginine and lysine plays a critical role in the stabilization of the protein.

  6. Camphorquinone-10-sulfonic acid and derivatives: convenient reagents for reversible modification of arginine residues.

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    Pande, C S; Pelzig, M; Glass, J D

    1980-02-01

    Camphorquinone-10-sulfonic acid hydrate was prepared by the action of selenous acid on camphor-10-sulfonic acid. Camphorquinone-10-sulfonylnorleucine was prepared either from the sulfonic acid via the sulfonyl chloride or by selenous acid oxidation of camphor-10-sulfonylnorleucine. These reagents are useful for specific, reversible modification of the guanidino groups of arginine residues. Camphorquinonesulfonic acid is a crystalline water-soluble reagent that is especially suitable for use with small arginine-containing molecules, because the sulfonic acid group of the reagent is a convenient handle for analytical and preparative separation of products. Camphorquinonesulfonylnorleucine is more useful for work with large polypeptides and proteins, because hydrolysates of modified proteins may be analyzed for norleucine to determine the extent of arginine modification. The adducts of the camphorquinone derivatives with the guanidino group are stable to 0.5 M hydroxylamine solutions at pH 7, the recommended conditions for cleavage of the corresponding cyclohexanedione adducts. At pH 8-9 the adducts of the camphorquinone derivatives with the guanidino group are cleaved by o-phenylenediamine. The modification and regeneration of arginine, of the dipeptide arginylaspartic acid, of ribonuclease S-peptide, and of soybean trypsin inhibitor are presented as demonstrations of the use of the reagents. The use of camphorquinonesulfonyl chloride to prepare polymers containing arginine-specific ligands is discussed.

  7. Camphorquinone-10-sulfonic acid and derivatives: Convenient reagents for reversible modification of arginine residues

    OpenAIRE

    Pande, Chandra S.; Pelzig, Michal; Glass, John D.

    1980-01-01

    Camphorquinone-10-sulfonic acid hydrate was prepared by the action of selenous acid on camphor-10-sulfonic acid. Camphorquinone-10-sulfonylnorleucine was prepared either from the sulfonic acid via the sulfonyl chloride or by selenous acid oxidation of camphor-10-sulfonylnorleucine. These reagents are useful for specific, reversible modification of the guanidino groups of arginine residues. Camphorquinonesulfonic acid is a crystalline water-soluble reagent that is especially suitable for use w...

  8. Probing the disparate effects of arginine and lysine residues on antimicrobial peptide/bilayer association.

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    Rice, A; Wereszczynski, J

    2017-10-01

    Antimicrobial peptides (AMPs) are key components of the innate immune response and represent promising templates for the development of broad-spectrum alternatives to conventional antibiotics. Most AMPs are short, cationic peptides that interact more strongly with negatively charged prokaryotic membranes than net neutral eukaryotic ones. Both AMPs and synthetic analogues with arginine-like side chains are more active against bacteria than those with lysine-like amine groups, though the atomistic mechanism for this increase in potency remains unclear. To examine this, we conducted comparative molecular dynamics simulations of a model negatively-charged membrane system interacting with two mutants of the AMP KR-12: one with lysine residues mutated to arginines (R-KR12) and one with arginine residues mutated to lysine (K-KR12). Simulations show that both partition analogously to the bilayer and display similar preferences for hydrogen bonding with the anionic POPGs. However, R-KR12 binds stronger to the bilayer than K-KR12 and forms significantly more hydrogen bonds, leading to considerably longer interaction times. Additional simulations with methylated R-KR12 and charge-modified K-KR12 mutants show that the extensive interaction seen in the R-KR12 system is partly due to arginine's strong atomic charge distribution, rather than being purely an effect of the greater number of hydrogen bond donors. Finally, free energy simulations reveal that both peptides are disordered in solution but form an amphipathic α-helix when inserted into the bilayer headgroup region. Overall, these results highlight the role of charge and hydrogen bond strength in peptide bilayer insertion, and offer potential insights for designing more potent analogues in the future. Copyright © 2017 Elsevier B.V. All rights reserved.

  9. Computational prediction of methylation types of covalently modified lysine and arginine residues in proteins.

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    Deng, Wankun; Wang, Yongbo; Ma, Lili; Zhang, Ying; Ullah, Shahid; Xue, Yu

    2017-07-01

    Protein methylation is an essential posttranslational modification (PTM) mostly occurs at lysine and arginine residues, and regulates a variety of cellular processes. Owing to the rapid progresses in the large-scale identification of methylation sites, the available data set was dramatically expanded, and more attention has been paid on the identification of specific methylation types of modification residues. Here, we briefly summarized the current progresses in computational prediction of methylation sites, which provided an accurate, rapid and efficient approach in contrast with labor-intensive experiments. We collected 5421 methyllysines and methylarginines in 2592 proteins from the literature, and classified most of the sites into different types. Data analyses demonstrated that different types of methylated proteins were preferentially involved in different biological processes and pathways, whereas a unique sequence preference was observed for each type of methylation sites. Thus, we developed a predictor of GPS-MSP, which can predict mono-, di- and tri-methylation types for specific lysines, and mono-, symmetric di- and asymmetrical di-methylation types for specific arginines. We critically evaluated the performance of GPS-MSP, and compared it with other existing tools. The satisfying results exhibited that the classification of methylation sites into different types for training can considerably improve the prediction accuracy. Taken together, we anticipate that our study provides a new lead for future computational analysis of protein methylation, and the prediction of methylation types of covalently modified lysine and arginine residues can generate more useful information for further experimental manipulation. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  10. Fluorescence histochemistry of peptide hormone-producing cells: observations on the phenanthrenequinone method for the demonstration of arginine residues.

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    Sundler, F; Håkanson, R

    1978-07-12

    Phenanthrenequinone is a sensitive and specific fluorescence histochemical reagent for monosubstituted guanidines. It is probable that it selectively demonstrates the guanidino group of arginine residues of proteins and peptides. Phenanthrenequinone induces moderate to intense fluorescence in gastric chief cells, parenchymal cells of the pancreas, and certain peptide hormone-producing cell types such as the GH cells of the adenohypophysis and the glucagon cells of the pancreatic islets. Similar fluorescence spectra were obtained from an arginine-containing peptide in a histochemical model and from the GH cells of the adenohypophysis following exposure to phenanthrenequinone. We conclude that the cells demonstrated with this reagent store peptides or proteins rich in arginine.

  11. Structure-sweetness relationship in egg white lysozyme: role of lysine and arginine residues on the elicitation of lysozyme sweetness.

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    Masuda, Tetsuya; Ide, Nobuyuki; Kitabatake, Naofumi

    2005-10-01

    Lysozyme is one of the sweet-tasting proteins. To clarify the structure-sweetness relationship and the basicity-sweetness relationship in lysozyme, we have generated lysozyme mutants with Pichia systems. Alanine substitution of lysine residues demonstrated that two out of six lysine residues, Lys13 and Lys96, are required for lysozyme sweetness, while the remaining four lysine residues do not play a significant role in the perception of sweetness. Arginine substitution of lysine residues revealed that the basicity, but not the shape, of the side chain plays a significant role in sweetness. Single alanine substitutions of arginine residues showed that three arginine residues, Arg14, Arg21, and Arg73, play significant roles in lysozyme sweetness, whereas Arg45, Arg68, Arg125 and chemical modification by 1,2-cyclohexanedione did not affect sweetness. From investigation of the charge-specific mutations, we found that the basicity of a broad surface region formed by five positively charged residues, Lys13, Lys96, Arg14, Arg21, and Arg73, is required for lysozyme sweetness. Differences in the threshold values among sweet-tasting proteins might be caused by the broadness and/or the density of charged residues on the protein surface.

  12. Diversity-oriented synthesis of azapeptides with basic amino acid residues: aza-lysine, aza-ornithine, and aza-arginine.

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    Traoré, Mariam; Doan, Ngoc-Duc; Lubell, William D

    2014-07-03

    Aza-peptides with basic amino acid residues (lysine, ornithine, arginine) and derivatives were synthesized by an effective approach featuring alkylation of a hydrazone-protected aza-glycine residue with α-bromo ω-chloro propane and butane to provide the corresponding alkyl chloride side chains. Displacement of the chloride with azide and various amines gave entry to azaOrn, azaLys, and azaArg containing peptides as demonstrated by the solution and solid-phase syntheses of 29 examples, including an aza-library of Growth Hormone Releasing Peptide-6 analogs.

  13. Model studies on protein glycation: influence of cysteine on the reactivity of arginine and lysine residues toward glyoxal.

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    Schwarzenbolz, Uwe; Mende, Susann; Henle, Thomas

    2008-04-01

    Mixtures of N alpha-hippurylarginin, N alpha-hippuryllysine, and glyoxal were incubated in the absence and presence of N alpha-acetylcysteine in order to assess the individual reactivity of these nucleophilic amino acid residues. The incubations were performed under atmospheric and high hydrostatic pressure (400 MPa), and, at the same time, beta-casein was reacted with glyoxal. The results showed that arginine is the main partner for glyoxal in the absence of cysteine, whereas a lysine derivatization was not apparent. In the presence of cysteine, however, arginine was almost completely protected from the reaction, whereas a noticeable formation of lysine derivatives, mainly carboxymethyllysine, was observed. Based on these findings, a reaction mechanism is proposed to explain the influence of cysteine on the reaction.

  14. Immunoglobulin-G Glycation by Fructose Leads to Structural Perturbations and Drop Off in Free Lysine and Arginine Residues.

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    Faisal, Mohammad; Alatar, Abdulrahman A; Ahmad, Saheem

    2017-01-01

    Non-enzymatic glycation is the addition of free carbonyl group of reducing sugar to the free amino groups of proteins and leads to the formation of early glycation products and further into advanced glycation end products (AGEs). Fructose reacts rapidly with the free amino groups of proteins to form AGEs. AGEs are believed to be involved in the pathogenesis of several diseases, particularly in diabetic complications. In this study, IgG was glycated with fructose monosaccharide at 10 mM concentration for varying time interval. The reaction mixture was kept at 37ºC. The early glycation of IgG was done by nitroblue tetrazolium assay (NBT), and the generation of AGEs was done by the extent of side chain modifications (lysine and arginine), Nε-carboxymethyl lysine, pentosidine and carbonyl content. The decrease in free lysine and arginine residues suggests that protein 'IgG' has undergone modification specifically on epsilon amino groups of lysine and arginine. Additionally, their fluorescence and absorbance characteristics were also systematically studied. The results suggest that the maximum Amadori product (ketoamine content) was formed on sixth day of the incubation. The conformational structural perturbation was observed within the glycated IgG protein as studied by using various physicochemical techniques. This study reports structural perturbation, formation of various intermediates and AGEs. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  15. Residue-specific pK(a) determination of lysine and arginine side chains by indirect N-15 and C-13 NMR spectroscopy : Application to apo calmodulin

    NARCIS (Netherlands)

    Andre, Ingemar; Linse, Sara; Mulder, Frans A. A.

    2007-01-01

    Electrostatic interactions in proteins can be probed experimentally through determination of residue-specific acidity constants, We describe here triple-resonance NMR techniques for direct determination of lysine and arginine side-chain protonation states in proteins. The experiments are based on

  16. Effect of repeated pesticide applications on soil properties in cotton fields: II. Insecticide residues and impact on dehydrogenase and arginine deaminase activities

    International Nuclear Information System (INIS)

    Vig, K.; Singh, D.K.; Agarwal, H.C.; Dhawan, A.K.; Dureja, P.

    2001-01-01

    Insecticides were applied sequentially at recommended dosages post crop emergence in cotton fields and soil was sampled at regular intervals after each treatment. Soil was analysed for insecticide residues and activity of the enzymes dehydrogenase and arginine deaminase. Insecticide residues detected in the soil were in small quantities and they did not persist for long. Only endosulfan leached below 15 cm. Insecticides had only temporary effects on enzyme activities which disappeared either before the next insecticide treatment or by the end of the experimental period. (author)

  17. Conserved lysin and arginin residues in the extracellular loop of P2X(3) receptors are involved in agonist binding.

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    Fischer, Wolfgang; Zadori, Zoltan; Kullnick, Yvonne; Gröger-Arndt, Helke; Franke, Heike; Wirkner, Kerstin; Illes, Peter; Mager, Peter P

    2007-12-08

    Wild-type human (h) P2X(3) receptors expressed in HEK293 cells responded to the prototypic agonist alpha,beta-methylene ATP (alpha,beta-meATP) with rapidly desensitizing inward currents and an increase in the intracellular Ca(2+) concentration. In contrast to electrophysiological recordings, Ca(2+) microfluorimetry showed a lower maximum of the concentration-response curve of alpha,beta-meATP in the transiently than in the permanently transfected HEK293 cells. However, the concentrations causing 50% of the maximum possible effect (EC(50) values) were identical, when measured with either method. In order to determine the role of certain conserved, positively charged amino acids in the nucleotide binding domains (NBD-1-4) of hP2X(3) receptors for agonist binding, the lysine-63, -65, -176 and -299 as well as the arginine-281 and -295 residues were substituted by the neutral amino acid alanine. We observed no effect of alpha,beta-meATP at the K63A, K176A, R295A, and K299A mutants, and a marked decrease of agonist potency at the K65A and R281A mutants. The P2X(3) receptor antagonist 2',3'-O-trinitrophenyl-ATP (TNP-ATP) blocked the effect of alpha,beta-meATP at the wild-type hP2X(3) receptor with lower affinity than at the mutant K65A, indicating an interference of this mutation with the docking of the antagonist with its binding sites. The use of confocal fluorescence microscopy in conjunction with an antibody raised against the extracellular loop of the hP2X(3) receptor documented the expression of all mutants in the plasma membrane of HEK293 cells. Eventually, we modelled the possible agonist and antagonist binding sites NBD-1-4 of the hP2X(3) subunit by using structural bioinformatics. This model is in complete agreement with the available data and integrates results from mutagenesis studies with geometry optimization of the tertiary structure predictions of the receptor.

  18. Contributions of the substrate-binding arginine residues to maleate-induced closure of the active site of Escherichia coli aspartate aminotransferase.

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    Matharu, A; Hayashi, H; Kagamiyama, H; Maras, B; John, R A

    2001-03-01

    Crystallography shows that aspartate aminotransferase binds dicarboxylate substrate analogues by bonds to Arg292 and Arg386, respectively [Jager, J, Moser, M. Sauder, U. & Jansonius, J. N. (1994) J. Mol. Biol., 239, 285-305]. The contribution of each interaction to the conformational change that the enzyme undergoes when it binds ligands via these residues, is assessed by probing mutant forms of the enzyme lacking either or both arginines. The probes used are NaH(3)BCN which reduces the cofactor imine, the reactive substrate analogue, cysteine sulfinate and proteolysis by trypsin. The unreactive substrate analogue, maleate, is used to induce closure. Each single mutant reacted only 2.5-fold more slowly with NaH(3)BCN than the wild-type indicating that charge repulsion by the arginines contributes little to maintaining the open conformation. Maleate lowered the rate of reduction of the wild-type enzyme more than 300-fold but had little effect on the reaction of the mutant enzymes indicating that the ability of this dicarboxylate analogue to bridge the arginines precisely makes the major contribution to closure. The R292L mutant reacted 20 times more rapidly with cysteine sulfinate than R386L but 5 x 10(4) times more slowly than the wild-type enzyme, consistent with the proposal that enzyme's catalytic abilities are not developed unless closure is induced by bridging of the arginines. Proteolysis of the mutants with trypsin showed that, in the wild-type enzyme, the bonds most susceptible to trypsin are those contributed by Arg292 and Arg386. Proteolysis of the next most susceptible bond, at Arg25 in the double mutant, was protected by maleate demonstrating the presence of an additional site on the enzyme for binding dicarboxylates.

  19. /sup 13/C nuclear magnetic resonance study of the interaction of ligands with arginine residues in dihydrofolate reductase

    Energy Technology Data Exchange (ETDEWEB)

    Cocco, L. (Univ. of Iowa, Iowa City); Blakley, R.L.; Walker, T.E.; London, R.E.

    1977-01-01

    /sup 13/C NMR spectra of Streptococcus faecium dihydrofolate reductase containing (/sup 13/C-guanidino) arginine and ligand complexes with the labeled enzyme are reported. The spectrum of the native enzyme shows 5 well-resolved resonances (the enzyme contains 8 Arg) with a chemical shift range of 1.2 ppM. Addition of ligands to the enzyme produces distinct changes in the enzyme spectrum, and demonstrates that /sup 13/C NMR of labeled protein can be used in studies of protein-ligand interactions. An example of the use of /sup 13/C-depleted material is also presented.

  20. Roles of Arginine and Lysine Residues in the Translocation of a Cell-Penetrating Peptide from 13C, 31P and 19F Solid-State NMR

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    Su, Yongchao; Doherty, Tim; Waring, Alan J.; Ruchala, Piotr; Hong, Mei

    2009-01-01

    Cell-penetrating peptides (CPPs) are small cationic peptides that cross the cell membrane while carrying macromolecular cargoes. We use solid-state NMR to investigate the structure and lipid interaction of two cationic residues, Arg10 and Lys13, in the CPP penetratin. 13C chemical shifts indicate that Arg10 adopts a rigid β-strand conformation in the liquid-crystalline state of anionic lipid membranes. This behavior contrasts with all other residues observed so far in this peptide, which adopt a dynamic β-turn conformation with coil-like chemical shifts at physiological temperature. Low-temperature 13C-31P distances between the peptide and the lipid phosphates indicate that both the Arg10 guanidinium Cζ and the Lys13 Cε lie in close proximity to the lipid 31P (4.0 - 4.2 Å), proving the existence of charge-charge interaction for both Arg10 and Lys13 in the gel-phase membrane. However, since lysine substitution in CPPs are known to reduce their translocation ability, we propose that low temperature stabilizes both lysine and arginine interactions with the phosphates, whereas at high temperature the lysine-phosphate interaction is much weaker than the arginine-phosphate interaction. This is supported by the unusually high rigidity of the Arg10 sidechain and its β-strand conformation at high temperature. The latter is proposed to be important for ion pair formation by allowing close approach of the lipid headgroups to guanidinium sidechains. 19F and 13C spin diffusion experiments indicate that penetratin is oligomerized into β-sheets in gel-phase membranes. These solid-state NMR data indicate that guanidinium-phosphate interactions exist in penetratin, and guanidinium groups play a stronger structural role than ammonium groups in the lipid-assisted translocation of CPPs across liquid-crystalline cell membranes. PMID:19364134

  1. Roles of arginine and lysine residues in the translocation of a cell-penetrating peptide from (13)C, (31)P, and (19)F solid-state NMR.

    Science.gov (United States)

    Su, Yongchao; Doherty, Tim; Waring, Alan J; Ruchala, Piotr; Hong, Mei

    2009-06-02

    Cell-penetrating peptides (CPPs) are small cationic peptides that cross the cell membrane while carrying macromolecular cargoes. We use solid-state NMR to investigate the structure and lipid interaction of two cationic residues, Arg(10) and Lys(13), in the CPP penetratin. (13)C chemical shifts indicate that Arg(10) adopts a rigid beta-strand conformation in the liquid-crystalline state of anionic lipid membranes. This behavior contrasts with all other residues observed so far in this peptide, which adopt a dynamic beta-turn conformation with coil-like chemical shifts at physiological temperature. Low-temperature (13)C-(31)P distances between the peptide and the lipid phosphates indicate that both the Arg(10) guanidinium Czeta atom and the Lys(13) Cepsilon atom are close to the lipid (31)P (4.0-4.2 A), proving the existence of charge-charge interaction for both Arg(10) and Lys(13) in the gel-phase membrane. However, since lysine substitution in CPPs is known to weaken their translocation ability, we propose that the low temperature stabilizes interactions of both lysine and arginine with the phosphates, whereas at high temperatures, the lysine-phosphate interaction is much weaker than the arginine-phosphate interaction. This is supported by the unusually high rigidity of the Arg(10) side chain and its beta-strand conformation at high temperatures. The latter is proposed to be important for ion pair formation by allowing close approach of the lipid headgroups to guanidinium side chains. (19)F and (13)C spin diffusion experiments indicate that penetratin is oligomerized into beta-sheets in gel-phase membranes. These solid-state NMR data indicate that guanidinium-phosphate interactions exist in penetratin, and guanidinium groups play a stronger structural role than ammonium groups in the lipid-assisted translocation of CPPs across liquid-crystalline cell membranes.

  2. The arginine residue within the C-terminal active core of Bombyx mori pheromone biosynthesis-activating neuropeptide (PBAN is essential for receptor binding and activation

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    Takeshi eKawai

    2012-03-01

    Full Text Available In most lepidopteran insects, the biosynthesis of sex pheromones is regulated by pheromone biosynthesis activating neuropeptide (PBAN. Bombyx mori PBAN (BomPBAN consists of 33 amino acid residues and contains a C-terminus FSPRLamide motif as the active core. Among neuropeptides containing the FXPRLamide motif, the arginine (Arg, R residue two positions from the C-terminus is highly conserved across several neuropeptides, which can be designated as RXamide peptides. The purpose of this study was to reveal the role of the Arg residue in the BomPBAN active core. We synthesized a ten-residue peptide corresponding to the C-terminal part of BomPBAN with a series of point mutants at the 2nd position (ie, Arg from the C-terminus, termed the C2 position, and measured their efficacy in stimulating Ca2+ influx in insect cells concomitantly expressing a fluorescent PBAN receptor chimera (PBANR-EGFP and loaded with the fluorescent Ca2+ indicator, Fura Red-AM. PBAN analogs with the C2 position replaced with alanine (Ala, A, aspartic acid (Asp, D, serine (Ser, S or L-2-aminooctanoic acid (Aoc decreased PBAN-like activity. RC2A (SKTRYFSPALamide and RC2D (SKTRYFSPDLamide had the lowest activity and could not inhibit the activity of PBAN C10 (SKTRYFSPRLamide. We also prepared Rhodamine Red-labeled PBAN analogs of the mutants and examined their ability to bind PBANR. In contrast to 100 nM Rhodamine Red-PBAN C10, none of the mutants at the same concentration exhibited PBANR binding. Taken together, our results demonstrate that the C2 Arg residue in BomPBAN is essential for PBANR binding and activation.

  3. Pesticide residues in grapes from vineyards included in integrated pest management in Slovenia.

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    Cesnik, H Basa; Gregorcic, A; Cus, F

    2008-04-01

    Although the list of pesticides used in integrated pest management (IPM) in grape growing and their annual application rates are limited, we are still confronted with the problem of pesticide residues in grapes. This paper presents the results of pesticide monitoring of 47 samples of wine grapes (Vitis vinifera L.) from the 2006 vintage from vineyards included in IPM. The grape samples were analysed for the presence of 67 pesticides. Among them 20 were allowed in IPM in 2006. Grapes were sampled at harvest. Two internal analytical methods were used for the determination of pesticides: gas chromatography-mass spectrometry (GC-MS) method for the determination of dithiocarbamates and a multi-residue GC-MS method. One grape sample (2.1%) contained no residues or they were below the limit of detection, 28 samples (59.6%) contained residues lower or equal than maximum residue levels (MRLs), and 18 samples (38.3%) exceeded national MRLs for cyprodinil (the concentration range was 0.03-0.40 mg kg(-1) of cyprodinil) and fludioxonil (concentration was 0.03 mg kg(-1) of fludioxonil). Multiple residues were found in 41 samples (87.2%). The highest number of pesticides detected per sample was seven. No violation of pesticides allowed in IPM was observed. Folpet (97.9%), cyprodinil (51.1%), dithiocarbamates (44.7%), chlorothalonil (23.4%), chlorpyriphos (19.1%) and pyrimethanil (14.9%) were the most frequently found pesticides in grapes. Risk assessment showed that the exceeded concentrations of cyprodinil and fludioxonil did not represent any risk for consumer's health (the national estimate of short-term intake as a percentage of the acceptable daily intake was below 100%).

  4. Dietary arginine and linear growth

    DEFF Research Database (Denmark)

    van Vught, Anneke J A H; Dagnelie, Pieter C; Arts, Ilja C W

    2013-01-01

    and slopes were defined to estimate the association between arginine intake and growth velocity, including the following covariates: sex; age; baseline height; energy intake; puberty stage at 7-year follow-up and intervention/control group. The association between arginine intake and growth velocity......The amino acid arginine is a well-known growth hormone (GH) stimulator and GH is an important modulator of linear growth. The aim of the present study was to investigate the effect of dietary arginine on growth velocity in children between 7 and 13 years of age. Data from the Copenhagen School...

  5. Simulation of Weld Mechanical Behavior to Include Welding-Induced Residual Stress and Distortion: Coupling of SYSWELD and Abaqus Codes

    Science.gov (United States)

    2015-11-01

    Memorandum Simulation of Weld Mechanical Behavior to Include Welding-Induced Residual Stress and Distortion: Coupling of SYSWELD and Abaqus Codes...Weld Mechanical Behavior to Include Welding-Induced Residual Stress and Distortion: Coupling of SYSWELD and Abaqus Codes by Charles R. Fisher...Welding- Induced Residual Stress and Distortion: Coupling of SYSWELD and Abaqus Codes 5a. CONTRACT NUMBER N/A 5b. GRANT NUMBER N/A 5c

  6. Chemical mechanisms of histone lysine and arginine modifications.

    Science.gov (United States)

    Smith, Brian C; Denu, John M

    2009-01-01

    Histone lysine and arginine residues are subject to a wide array of post-translational modifications including methylation, citrullination, acetylation, ubiquitination, and sumoylation. The combinatorial action of these modifications regulates critical DNA processes including replication, repair, and transcription. In addition, enzymes that modify histone lysine and arginine residues have been correlated with a variety of human diseases including arthritis, cancer, heart disease, diabetes, and neurodegenerative disorders. Thus, it is important to fully understand the detailed kinetic and chemical mechanisms of these enzymes. Here, we review recent progress towards determining the mechanisms of histone lysine and arginine modifying enzymes. In particular, the mechanisms of S-adenosyl-methionine (AdoMet) dependent methyltransferases, FAD-dependent demethylases, iron dependent demethylases, acetyl-CoA dependent acetyltransferases, zinc dependent deacetylases, NAD(+) dependent deacetylases, and protein arginine deiminases are covered. Particular attention is paid to the conserved active-site residues necessary for catalysis and the individual chemical steps along the catalytic pathway. When appropriate, areas requiring further work are discussed.

  7. Simulation of Weld Mechanical Behavior to Include Welding Induced Residual Stress and Distortion: Coupling of SYSWELD and Abaqus Codes

    Science.gov (United States)

    2015-11-01

    data .  scaleFactor: Scale factor to convert SYSWELD units to units in Abaqus analysis for field of interest. A help description can be obtained by...Memorandum Simulation of Weld Mechanical Behavior to Include Welding-Induced Residual Stress and Distortion: Coupling of SYSWELD and Abaqus Codes...Weld Mechanical Behavior to Include Welding-Induced Residual Stress and Distortion: Coupling of SYSWELD and Abaqus Codes by Charles R. Fisher

  8. High-resolution X-ray and NMR structures of the SMN Tudor domain : conformational variation in the binding site for symmetrically dimethylated arginine residues

    NARCIS (Netherlands)

    Sprangers, Remco; Groves, Matthew R; Sinning, Irmgard; Sattler, Michael

    2003-01-01

    The SMN protein, which is linked to spinal muscular atrophy (SMA), plays an important role in the assembly of the spliceosomal small nuclear ribonucleoprotein complexes. This function requires binding of SMN to the arginine-glycine (RG) rich C-terminal tails of the Sm proteins, which contain

  9. A novel mutation affecting the arginine-137 residue of AVPR2 in dizygous twins leads to nephrogenic diabetes insipidus and attenuated urine exosome aquaporin-2

    DEFF Research Database (Denmark)

    Hinrichs, Gitte R; Houlberg Hansen, Louise; Nielsen, Maria R

    2016-01-01

    of inappropriate antidiuresis or congenital X-linked nephrogenic diabetes insipidus. We present a novel mutation in codon 137 within AVPR2 with substitution of glycine for arginine in male dizygotic twins. Nephrogenic diabetes insipidus was demonstrated by water deprivation test and resistance to vasopressin...

  10. Effects of L-arginine on intestinal development and endogenous ...

    African Journals Online (AJOL)

    Jane

    2011-08-01

    Aug 1, 2011 ... the underlying mechanism includes dietary L-arginine supplementation which regulated the productions of intestinal polyamine in jejunum, and stimulated endogenous arginine-synthesizing enzymes in neonatal piglets. Key words: Neonatal pig, L-arginine, intestinal development, arginine-synthetases.

  11. Design of A District Heating System Including The Upgrading of Residual Industrial Waste Heat

    NARCIS (Netherlands)

    Falcao, P.W.; Mesbah, A.; Suherman, M.V.; Wennekes, S.

    2005-01-01

    This study was aimed to evaluate the feasibility of using a waste heat stream from DSM for a District Heating System. A conceptual design was carried out with emphasis on the unit for upgrading the residual waste heat. Having reviewed heat pump technology, mechanical heat pump was found to be the

  12. Economic values of production and functional traits, including residual feed intake, in Finnish milk production.

    Science.gov (United States)

    Hietala, P; Wolfová, M; Wolf, J; Kantanen, J; Juga, J

    2014-02-01

    Improving the feed efficiency of dairy cattle has a substantial effect on the economic efficiency and on the reduction of harmful environmental effects of dairy production through lower feeding costs and emissions from dairy farming. To assess the economic importance of feed efficiency in the breeding goal for dairy cattle, the economic values for the current breeding goal traits and the additional feed efficiency traits for Finnish Ayrshire cattle under production circumstances in 2011 were determined. The derivation of economic values was based on a bioeconomic model in which the profit of the production system was calculated, using the generated steady state herd structure. Considering beef production from dairy farms, 2 marketing strategies for surplus calves were investigated: (A) surplus calves were sold at a young age and (B) surplus calves were fattened on dairy farms. Both marketing strategies were unprofitable when subsidies were not included in the revenues. When subsidies were taken into account, a positive profitability was observed in both marketing strategies. The marginal economic values for residual feed intake (RFI) of breeding heifers and cows were -25.5 and -55.8 €/kg of dry matter per day per cow and year, respectively. The marginal economic value for RFI of animals in fattening was -29.5 €/kg of dry matter per day per cow and year. To compare the economic importance among traits, the standardized economic weight of each trait was calculated as the product of the marginal economic value and the genetic standard deviation; the standardized economic weight expressed as a percentage of the sum of all standardized economic weights was called relative economic weight. When not accounting for subsidies, the highest relative economic weight was found for 305-d milk yield (34% in strategy A and 29% in strategy B), which was followed by protein percentage (13% in strategy A and 11% in strategy B). The third most important traits were calving

  13. Simulation of Spread of African Swine Fever, Including the Effects of Residues from Dead Animals

    DEFF Research Database (Denmark)

    Hisham Beshara Halasa, Tariq; Boklund, Anette; Bøtner, Anette

    2016-01-01

    the subclinical stage and are fully infectious during the clinical stage. ASF virus (ASFV) infection through residues of dead animals in the slurries was also modeled in an exponentially fading-out pattern. Low and high transmission rates for ASFV were tested in the model. Robustness analysis was carried out......To study the spread of African swine fever (ASF) within a pig unit and the impact of unit size on ASF spread, a simulation model was created. In the model, an animal can be in one of the following stages: susceptible, latent, subclinical, clinical, or recovered. Animals can be infectious during...... in order to study the impact of uncertain parameters on model predictions. The results showed that the disease may fade out within the pig unit without a major outbreak. Furthermore, they showed that spread of ASFV is dependent on the infectiousness of subclinical animals and the residues of dead animals...

  14. A 1H NMR spectroscopic study on the tryptophan residues of lysozyme included by glucosyl-β-cyclodextrin

    Science.gov (United States)

    Yamamoto, Tatsuyuki; Kobayashi, Teruya; Yoshikiyo, Keisuke; Matsui, Yoshihisa; Takahashi, Tetsuya; Aso, Yuji

    2009-02-01

    A 1H NMR spectroscopic study showed that the side chains of Trp residues of chicken egg white lysozyme in an aqueous solution are included by Glucosyl-β-cyclodextrin (G1-β-CD). The 1H NMR signals due to Trp residues shifted with the addition of G1-β-CD. The addition of methyl α- D-glucopyranoside, which has no inclusion ability, gave different effect on the shift of 1H NMR signals. The 1H NMR signals due to Cys64 and Ile98 were also influenced to a considerable extent with the addition of G1-β-CD, suggesting that these hydrophobic amino acid residues are also included by the CD. The chemical shift values of 1H NMR signals, due to indole rings of tryptophan residues, changed more with the addition of G1-β-CD. The magnitudes of the chemical shift change were different depending on their locations in the protein. The chemical shift values of 1H NMR signals, due to those Trp residues in the active site of the lysozyme were smaller than those locating at relatively near the surface of the protein.

  15. Pesticide residues in grapes from integrated production of the Slovene origin The CORRECTED TITLE is: Pesticide residues in grapes from vineyards included in integrated pest management in Slovenia.

    OpenAIRE

    Baša Česnik , Helena; Gregorčič , Ana; Čuš , Franc

    2008-01-01

    Abstract Although the list of pesticides used in integrated pest management (IPM) in grape growing and their annual application rates are limited, we are still confronted with the problem of pesticide residues in grapes. The paper presents the results of pesticide monitoring in 47 samples of wine grapes (Vitis vinifera L.) of the 2006 vintage from the vineyards included in IPM. The grape samples were analysed for the presence of 67 pesticides. Among them, 20 were allowed in IPM in ...

  16. The roles of selected arginine and lysine residues of TAFI (Pro-CPU) in its activation to TAFIa by the thrombin-thrombomodulin complex.

    Science.gov (United States)

    Wu, Chengliang; Kim, Paul Y; Manuel, Reg; Seto, Marian; Whitlow, Marc; Nagashima, Mariko; Morser, John; Gils, Ann; Declerck, Paul; Nesheim, Michael E

    2009-03-13

    Thrombomodulin (TM) increases the catalytic efficiency of thrombin (IIa)-mediated activation of thrombin-activable fibrinolysis inhibitor (TAFI) 1250-fold. Negatively charged residues of the C-loop of TM-EGF-like domain 3 are required for TAFI activation. Molecular models suggested several positively charged residues of TAFI with which the C-loop residues could interact. Seven TAFI mutants were constructed to determine if these residues are required for efficient TAFI activation. TAFI wild-type or mutants were activated in the presence or absence of TM and the kinetic parameters of TAFI activation were determined. When the three consecutive lysine residues in the activation peptide of TAFI were substituted with alanine (K42/43/44A), the catalytic efficiencies for TAFI activation with TM decreased 8-fold. When other positively charged surface residues of TAFI (Lys-133, Lys-211, Lys-212, Arg-220, Lys-240, or Arg-275) were mutated to alanine, the catalytic efficiencies for TAFI activation with TM decreased by 1.7-2.7-fold. All decreases were highly statistically significant. In the absence of TM, catalytic efficiencies ranged from 2.8-fold lower to 1.24-fold higher than wild-type. None of these, except the 2.8-fold lower value, was statistically significant. The average half-life of the TAFIa mutants was 8.1+/-0.6 min, and that of wild type was 8.4+/-0.3 min at 37 degrees C. Our data show that these residues are important in the activation of TAFI by IIa, especially in the presence of TM. Whether the mutated residues promote a TAFI-TM or TAFI-IIa interaction remains to be determined. In addition, these residues do not influence spontaneous inactivation of TAFIa.

  17. L-arginine biosensors: A comprehensive review

    Directory of Open Access Journals (Sweden)

    Neelam Verma

    2017-12-01

    Full Text Available Arginine has been considered as the most potent nutraceutics discovered ever, due to its powerful healing property, and it's been known to scientists as the Miracle Molecule. Arginine detection in fermented food products is necessary because, high level of arginine in foods forms ethyl carbamate (EC during the fermentation process. Therefore, L-arginine detection in fermented food products is very important as a control measure for quality of fermented foods, food supplements and beverages including wine. In clinical analysis arginine detection is important due to their enormous inherent versatility in various metabolic pathways, topmost in the synthesis of Nitric oxide (NO and tumor growth. A number of methods are being used for arginine detection, but biosensors technique holds prime position due to rapid response, high sensitivity and high specificity. However, there are many problems still to be addressed, including selectivity, real time analysis and interference of urea presence in the sample. In the present review we aim to emphasize the significant role of arginine in human physiology and foods. A small attempt has been made to discuss the various techniques used for development of arginine biosensor and how these techniques affect their performance. The choice of transducers for arginine biosensor ranges from optical, pH sensing, ammonia gas sensing, ammonium ion-selective, conductometric and amperometric electrodes because ammonia is formed as a final product.

  18. L-Arginine

    Science.gov (United States)

    ... with this combination.Talk with your health provider.Sildenafil (Viagra)Sildenafil (Viagra) can lower blood pressure. L-arginine can also lower blood pressure. Taking sildenafil (Viagra) and L-arginine together might cause the ...

  19. PKCepsilon stimulated arginine methylation of RIP140 for its nuclear-cytoplasmic export in adipocyte differentiation.

    Directory of Open Access Journals (Sweden)

    Pawan Gupta

    2008-07-01

    Full Text Available Receptor interacting protein 140 (RIP140 is a versatile transcriptional co-repressor that plays roles in diverse metabolic processes including fat accumulation in adipocytes. Previously we identified three methylated arginine residues in RIP140, which rendered its export to the cytoplasm; but it was unclear what triggered RIP140 arginine methylation.In this study, we determined the activated PKCepsilon as the specific trigger for RIP140 arginine methylation and its subsequent export. We identified two PKCepsilon-phosphorylated residues of RIP140, Ser-102 and Ser-1003, which synergistically stimulated direct binding of RIP140 by 14-3-3 that recruited protein arginine methyl transferase 1 to methylate RIP140. The methylated RIP140 then preferentially recruited exportin 1 for nuclear export. As a result, the nuclear gene-repressive activity of RIP140 was reduced. In RIP140 null adipocyte cultures, the defect in fat accumulation was effectively rescued by the phosphorylation-deficient mutant RIP140 that resided predominantly in the nucleus, but less so by the phospho-mimetic RIP140 that was exported to the cytoplasm.This study uncovers a novel means, via a cascade of protein modifications, to inactivate, or suppress, the nuclear action of an important transcription coregulator RIP140, and delineates the first specific phosphorylation-arginine methylation cascade that could alter protein subcellular distribution and biological activity.

  20. Arginine-rich cell-penetrating peptide-modified extracellular vesicles for active macropinocytosis induction and efficient intracellular delivery.

    Science.gov (United States)

    Nakase, Ikuhiko; Noguchi, Kosuke; Aoki, Ayako; Takatani-Nakase, Tomoka; Fujii, Ikuo; Futaki, Shiroh

    2017-05-16

    Extracellular vesicles (EVs) including exosomes have been shown to play crucial roles in cell-to-cell communication because of their ability to carry biofunctional molecules (e.g., microRNAs and enzymes). EVs also have pharmaceutical advantages and are highly anticipated to be a next-generation intracellular delivery tool. Here, we demonstrate an experimental technique that uses arginine-rich cell-penetrating peptide (CPP)-modified EVs to induce active macropinocytosis for effective cellular EV uptake. Modification of arginine-rich CPPs on the EV membrane resulted in the activation of the macropinocytosis pathway, and the number of arginine residues in the peptide sequences affected the cellular EV uptake efficiency. Consequently, the ribosome-inactivating protein saporin-encapsulated EVs modified with hexadeca-arginine (R16) peptide effectively attained anti-cancer activity.

  1. Parkinsonism-associated protein DJ-1/Park7 is a major protein deglycase that repairs methylglyoxal- and glyoxal-glycated cysteine, arginine, and lysine residues.

    Science.gov (United States)

    Richarme, Gilbert; Mihoub, Mouadh; Dairou, Julien; Bui, Linh Chi; Leger, Thibaut; Lamouri, Aazdine

    2015-01-16

    Glycation is an inevitable nonenzymatic covalent reaction between proteins and endogenous reducing sugars or dicarbonyls (methylglyoxal, glyoxal) that results in protein inactivation. DJ-1 was reported to be a multifunctional oxidative stress response protein with poorly defined function. Here, we show that human DJ-1 is a protein deglycase that repairs methylglyoxal- and glyoxal-glycated amino acids and proteins by acting on early glycation intermediates and releases repaired proteins and lactate or glycolate, respectively. DJ-1 deglycates cysteines, arginines, and lysines (the three major glycated amino acids) of serum albumin, glyceraldehyde-3-phosphate dehydrogenase, aldolase, and aspartate aminotransferase and thus reactivates these proteins. DJ-1 prevented protein glycation in an Escherichia coli mutant deficient in the DJ-1 homolog YajL and restored cell viability in glucose-containing media. These results suggest that DJ-1-associated Parkinsonism results from excessive protein glycation and establishes DJ-1 as a major anti-glycation and anti-aging protein. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

  2. Stress and Fatigue Life Modeling of Cannon Breech Closures Including Effects of Material Strength and Residual Stress

    National Research Council Canada - National Science Library

    Underwood, John

    2000-01-01

    ...; overload residual stress. Modeling of applied and residual stresses at the location of the fatigue failure site is performed by elastic-plastic finite element analysis using ABAQUS and by solid...

  3. Arginine-aromatic interactions and their effects on arginine-induced solubilization of aromatic solutes and suppression of protein aggregation

    KAUST Repository

    Shah, Dhawal

    2011-09-21

    We examine the interaction of aromatic residues of proteins with arginine, an additive commonly used to suppress protein aggregation, using experiments and molecular dynamics simulations. An aromatic-rich peptide, FFYTP (a segment of insulin), and lysozyme and insulin are used as model systems. Mass spectrometry shows that arginine increases the solubility of FFYTP by binding to the peptide, with the simulations revealing the predominant association of arginine to be with the aromatic residues. The calculations further show a positive preferential interaction coefficient, Γ XP, contrary to conventional thinking that positive Γ XP\\'s indicate aggregation rather than suppression of aggregation. Simulations with lysozyme and insulin also show arginine\\'s preference for aromatic residues, in addition to acidic residues. We use these observations and earlier results reported by us and others to discuss the possible implications of arginine\\'s interactions with aromatic residues on the solubilization of aromatic moieties and proteins. Our results also highlight the fact that explanations based purely on Γ XP, which measures average affinity of an additive to a protein, could obscure or misinterpret the underlying molecular mechanisms behind additive-induced suppression of protein aggregation. © 2011 American Institute of Chemical Engineers (AIChE).

  4. Enthalpy-driven interactions with sulfated glycosaminoglycans promote cell membrane penetration of arginine peptides.

    Science.gov (United States)

    Takechi-Haraya, Yuki; Nadai, Ryo; Kimura, Hitoshi; Nishitsuji, Kazuchika; Uchimura, Kenji; Sakai-Kato, Kumiko; Kawakami, Kohsaku; Shigenaga, Akira; Kawakami, Toru; Otaka, Akira; Hojo, Hironobu; Sakashita, Naomi; Saito, Hiroyuki

    2016-06-01

    The first step of cell membrane penetration of arginine peptides is thought to occur via electrostatic interactions between positive charges of arginine residues and negative charges of sulfated glycosaminoglycans (GAGs) on the cell surface. However, the molecular interaction of arginine peptides with GAG still remains unclear. Here, we compared the interactions of several arginine peptides of Tat, R8, and Rev and their analogues with heparin in relation to the cell membrane penetration efficiency. The high-affinity binding of arginine peptides to heparin was shown to be driven by large favorable enthalpy contributions, possibly reflecting multidentate hydrogen bondings of arginine residues with sulfate groups of heparin. Interestingly, the lysine peptides in which all arginine residues are substituted with lysine residues exhibited negligible binding enthalpy despite of their considerable binding to heparin. In CHO-K1 cells, arginine peptides exhibited a great cell-penetrating ability whereas their corresponding lysine peptides did not penetrate into cells. The degree of cell penetration of arginine peptides markedly decreased by the chlorate treatment of cells which prevents the sulfation of GAG chains. Significantly, the cell penetration efficiency of arginine peptides was found to be correlated with the favorable enthalpy of binding to heparin. These results suggest that the enthalpy-driven strong interaction with sulfated GAGs such as heparan sulfate plays a critical role in the efficient cell membrane penetration of arginine peptides. Copyright © 2016 Elsevier B.V. All rights reserved.

  5. Effect of replacing the aspartic acid/glutamic acid residues of bullfrog sialic acid binding lectin with asparagine/glutamine and arginine on the inhibition of cell proliferation in murine leukemia P388 cells.

    Science.gov (United States)

    Ogawa, Yuko; Iwama, Masanori; Ohgi, Kazuko; Tsuji, Tsutomu; Irie, Masachika; Itagaki, Tadashi; Kobayashi, Hiroko; Inokuchi, Norio

    2002-06-01

    The sialic acid binding lectin from bullfrog oocytes (cSBL) is known to have anti-tumor activity. In a previous report, to elucidate the relationship between the net charge and anti-tumor activity of cSBL, we examined the effect of chemical modifications of cSBL with a water-soluble carbodiimide in the presence of various nucleophiles. The results suggested that the anti-tumor activity and internalization into tumor cells increased with an increase in the net charge of cSBL. However, in the chemically modified cSBL, a modification site was observed on average in two of the carboxyl groups of cSBL. To confirm these previous results and to determine which modified carboxyl group contributes to the increase in anti-tumor activity, we prepared mutants with substitutions of Asn/Gln and Arg at three acidic amino acid residues of cSBL and studied their anti-tumor activity and internalization efficiency. The results showed the enhancing effect of charge on anti-tumor activity and internalization, and suggested that the replacement of D24 and E88 of cSBL with arginine is more effective than that of E97. The double mutant D24RE88R showed comparable anti-tumor activity to the ethylenediamine-modified cSBL reported previously. The mutant was well-characterized as a pure cSBL derivative suitable for studying the mechanism of the anti-tumor action of cSBL.

  6. Arginine methylation regulates the p53 response

    DEFF Research Database (Denmark)

    Jansson, Martin; Durant, Stephen T; Cho, Er-Chieh

    2008-01-01

    Activation of the p53 tumour suppressor protein in response to DNA damage leads to apoptosis or cell-cycle arrest. Enzymatic modifications are widely believed to affect and regulate p53 activity. We describe here a level of post-translational control that has an important functional consequence...... on the p53 response. We show that the protein arginine methyltransferase (PRMT) 5, as a co-factor in a DNA damage responsive co-activator complex that interacts with p53, is responsible for methylating p53. Arginine methylation is regulated during the p53 response and affects the target gene specificity...... of p53. Furthermore, PRMT5 depletion triggers p53-dependent apoptosis. Thus, methylation on arginine residues is an underlying mechanism of control during the p53 response....

  7. Bioenergy from crops and biomass residues: a consequential life-cycle assessment including land-use changes

    DEFF Research Database (Denmark)

    Tonini, Davide; Astrup, Thomas Fruergaard

    demonstrated that algae represent an interesting alternative to terrestrial energy crops. This study provides GHG emission factors for a wide number of bioenergy scenarios. The aim is to inform decision/policy makers on the environmental consequences of producing biofuels from different sources...... generation biofuels produced from residual biomass promise important environmental savings. However, since these residues are today in-use for specific purposes (e.g., feeding), a detailed modelling of the consequences (e.g., on the feed-market) induced by their diversion to energy should be performed...... at identifying all the consequences associated with the establishment of bioenergy systems compared with the reference (current use of fossil and biomass resource). The modelling was facilitated with the LCA-model EASETECH. The functional unit was 1 unit-energy produced (i.e., 1 kWh electricity, 1 MJ heat or 1...

  8. Freeze-Drying of L-Arginine/Sucrose-Based Protein Formulations, Part 2: Optimization of Formulation Design and Freeze-Drying Process Conditions for an L-Arginine Chloride-Based Protein Formulation System.

    Science.gov (United States)

    Stärtzel, Peter; Gieseler, Henning; Gieseler, Margit; Abdul-Fattah, Ahmad M; Adler, Michael; Mahler, Hanns-Christian; Goldbach, Pierre

    2015-12-01

    We recently reported that the presence of chloride counter ions in freeze-dried l-arginine/sucrose formulations provided the greatest protein stability, but led to low collapse temperatures and glass transition temperatures of the freeze concentrates. The objectives of this study were to identify l-arginine chloride-based formulations and optimize freeze-drying process conditions to deliver a freeze-dried product with good physical quality attributes (including cake appearance, residual moisture, and reconstitution time). Additional properties were tested such as thermal properties, cake microstructure, and protein physical stability. Excipient concentrations were varied with and without a model protein (bovine serum albumin, BSA). Formulations were frozen with and without annealing or with and without controlled nucleation. Primary drying was conducted at high and low shelf temperature. Cakes with least defects and optimum physical attributes were achieved when protein to excipient ratios were high. Controlled nucleation led to elegant cakes for most systems at a low shelf temperature. Replacing BSA by a monoclonal antibody showed that protein (physical) stability was slightly improved under stress storage temperature (i.e., 40°C) in the presence of a low concentration of l-arginine in a sucrose-based formulation. At higher l-arginine concentrations, cake defects increased. Using optimized formulation design, addition of l-arginine chloride to a sucrose-based formulation provided elegant cakes and benefits for protein stability. © 2015 Wiley Periodicals, Inc. and the American Pharmacists Association.

  9. Loss of the arginine methyltranserase PRMT7 causes syndromic intellectual disability with microcephaly and brachydactyly.

    Science.gov (United States)

    Kernohan, K D; McBride, A; Xi, Y; Martin, N; Schwartzentruber, J; Dyment, D A; Majewski, J; Blaser, S; Boycott, K M; Chitayat, D

    2017-05-01

    Post-translational protein modifications exponentially expand the functional complement of proteins encoded by the human genome. One such modification is the covalent addition of a methyl group to arginine or lysine residues, which is used to regulate a substantial proportion of the proteome. Arginine and lysine methylation are catalyzed by protein arginine methyltransferase (PRMTs) and protein lysine methyltransferase proteins (PKMTs), respectively; each methyltransferase has a specific set of target substrates. Here, we report a male with severe intellectual disability, facial dysmorphism, microcephaly, short stature, brachydactyly, cryptorchidism and seizures who was found to have a homozygous 15,309 bp deletion encompassing the transcription start site of PRMT7, which we confirmed is functionally a null allele. We show that the patient's cells have decreased levels of protein arginine methylation, and that affected proteins include the essential histones, H2B and H4. Finally, we demonstrate that patient cells have altered Wnt signaling, which may have contributed to the skeletal abnormalities. Our findings confirm the recent disease association of PRMT7, expand the phenotypic manifestations of this disorder and provide insight into the molecular pathogenesis of this new condition. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  10. Remission of diabetes mellitus in cats cannot be predicted by the arginine stimulation test

    OpenAIRE

    Tschuor, F

    2011-01-01

    Background: Responsiveness of β-cells to arginine persists the longest during diabetes progression, making the intravenous arginine stimulation test (IVAST) a useful tool to assess residual insulin and glucagon secretion. Hypothesis: Diabetic cats with and without remission will have different arginine-induced insulin or glucagon response. Animals: 17 cats with diabetes, 7 healthy cats. Methods: Response to IVAST was assessed by calculating insulin and glucagon area under the c...

  11. The Role of Protein Arginine Methyltransferases in Inflammatory Responses

    Directory of Open Access Journals (Sweden)

    Ji Hye Kim

    2016-01-01

    Full Text Available Protein arginine methyltransferases (PRMTs mediate the methylation of a number of protein substrates of arginine residues and serve critical functions in many cellular responses, including cancer development, progression, and aggressiveness, T-lymphocyte activation, and hepatic gluconeogenesis. There are nine members of the PRMT family, which are divided into 4 types (types I–IV. Although most PRMTs do not require posttranslational modification (PTM to be activated, fine-tuning modifications, such as interactions between cofactor proteins, subcellular compartmentalization, and regulation of RNA, via micro-RNAs, seem to be required. Inflammation is an essential defense reaction of the body to eliminate harmful stimuli, including damaged cells, irritants, or pathogens. However, chronic inflammation can eventually cause several types of diseases, including some cancers, atherosclerosis, rheumatoid arthritis, and periodontitis. Therefore, inflammation responses should be well modulated. In this review, we briefly discuss the role of PRMTs in the control of inflammation. More specifically, we review the roles of four PRMTs (CARM1, PRMT1, PRMT5, and PRMT6 in modulating inflammation responses, particularly in terms of modulating the transcriptional factors or cofactors related to inflammation. Based on the regulatory roles known so far, we propose that PRMTs should be considered one of the target molecule groups that modulate inflammatory responses.

  12. Reduced arginine availability and nitric oxide production

    NARCIS (Netherlands)

    Hallemeesch, M. M.; Lamers, W. H.; Deutz, N. E. P.

    2002-01-01

    The precursor for nitric oxide (NO) synthesis is the amino acid arginine. Reduced arginine availability may limit NO production. Arginine availability for NO synthesis may be regulated by de novo arginine production from citrulline, arginine transport across the cell membrane, and arginine breakdown

  13. Mammalian protein arginine methyltransferase 7 (PRMT7) specifically targets RXR sites in lysine- and arginine-rich regions.

    Science.gov (United States)

    Feng, You; Maity, Ranjan; Whitelegge, Julian P; Hadjikyriacou, Andrea; Li, Ziwei; Zurita-Lopez, Cecilia; Al-Hadid, Qais; Clark, Amander T; Bedford, Mark T; Masson, Jean-Yves; Clarke, Steven G

    2013-12-27

    The mammalian protein arginine methyltransferase 7 (PRMT7) has been implicated in roles of transcriptional regulation, DNA damage repair, RNA splicing, cell differentiation, and metastasis. However, the type of reaction that it catalyzes and its substrate specificity remain controversial. In this study, we purified a recombinant mouse PRMT7 expressed in insect cells that demonstrates a robust methyltransferase activity. Using a variety of substrates, we demonstrate that the enzyme only catalyzes the formation of ω-monomethylarginine residues, and we confirm its activity as the prototype type III protein arginine methyltransferase. This enzyme is active on all recombinant human core histones, but histone H2B is a highly preferred substrate. Analysis of the specific methylation sites within intact histone H2B and within H2B and H4 peptides revealed novel post-translational modification sites and a unique specificity of PRMT7 for methylating arginine residues in lysine- and arginine-rich regions. We demonstrate that a prominent substrate recognition motif consists of a pair of arginine residues separated by one residue (RXR motif). These findings will significantly accelerate substrate profile analysis, biological function study, and inhibitor discovery for PRMT7.

  14. Mammalian Protein Arginine Methyltransferase 7 (PRMT7) Specifically Targets RXR Sites in Lysine- and Arginine-rich Regions*

    Science.gov (United States)

    Feng, You; Maity, Ranjan; Whitelegge, Julian P.; Hadjikyriacou, Andrea; Li, Ziwei; Zurita-Lopez, Cecilia; Al-Hadid, Qais; Clark, Amander T.; Bedford, Mark T.; Masson, Jean-Yves; Clarke, Steven G.

    2013-01-01

    The mammalian protein arginine methyltransferase 7 (PRMT7) has been implicated in roles of transcriptional regulation, DNA damage repair, RNA splicing, cell differentiation, and metastasis. However, the type of reaction that it catalyzes and its substrate specificity remain controversial. In this study, we purified a recombinant mouse PRMT7 expressed in insect cells that demonstrates a robust methyltransferase activity. Using a variety of substrates, we demonstrate that the enzyme only catalyzes the formation of ω-monomethylarginine residues, and we confirm its activity as the prototype type III protein arginine methyltransferase. This enzyme is active on all recombinant human core histones, but histone H2B is a highly preferred substrate. Analysis of the specific methylation sites within intact histone H2B and within H2B and H4 peptides revealed novel post-translational modification sites and a unique specificity of PRMT7 for methylating arginine residues in lysine- and arginine-rich regions. We demonstrate that a prominent substrate recognition motif consists of a pair of arginine residues separated by one residue (RXR motif). These findings will significantly accelerate substrate profile analysis, biological function study, and inhibitor discovery for PRMT7. PMID:24247247

  15. Effect of methylation on the side-chain pKa value of arginine.

    Science.gov (United States)

    Evich, Marina; Stroeva, Ekaterina; Zheng, Yujun George; Germann, Markus W

    2016-02-01

    Arginine methylation is important in biological systems. Recent studies link the deregulation of protein arginine methyltransferases with certain cancers. To assess the impact of methylation on interaction with other biomolecules, the pKa values of methylated arginine variants were determined using NMR data. The pKa values of monomethylated, symmetrically dimethylated, and asymmetrically dimethylated arginine are similar to the unmodified arginine (14.2 ± 0.4). Although the pKa value has not been significantly affected by methylation, consequences of methylation include changes in charge distribution and steric effects, suggesting alternative mechanisms for recognition. © 2015 The Protein Society.

  16. Homoarginine Levels are Regulated by L-Arginine:Glycine Amidinotransferase and Affect Stroke Outcome: Results from Human and Murine Studies

    NARCIS (Netherlands)

    Choe, C.-U.; Atzler, D.; Wild, P.S.; Carter, A.M.; B\\"oger, R.H.; Ojeda, F.; Simova, O.; Stockebrand, M.; Lackner, K.; Nabuurs, C.; Marescau, B.; Streichert, T.; M\\"uller, C.; L\\"uneburg, N.; Deyn, P.P. de; Benndorf, R.A.; Baldus, S.; Gerloff, C.; Blankenberg, S.; Heerschap, A.; Grant, P.J.; Magnus, T.; Zeller, T.; Isbrandt, D.; Schwedhelm, E.

    2013-01-01

    Endogenous arginine homologues, including homoarginine, have been identified as novel biomarkers for cardiovascular disease and outcomes. Our studies of human cohorts and a confirmatory murine model associated the arginine homologue homoarginine and its metabolism in stroke pathology and

  17. Arginine: New Insights into Growth Performance and Urinary Metabolomic Profiles of Rats

    Directory of Open Access Journals (Sweden)

    Guangmang Liu

    2016-08-01

    Full Text Available Arginine regulates growth performance, nutrient metabolism and health effects, but the underlying mechanism remains unknown. This study aims to investigate the effect of dietary arginine supplementation on rat growth performance and urinary metabolome through 1H-NMR spectroscopy. Twenty rats were randomly assigned to two groups supplemented with 0% or 1.0% l-arginine for 4 weeks. Urine samples were analyzed through NMR-based metabolomics. Arginine supplementation significantly increased the urine levels of 4-aminohippurate, acetate, creatine, creatinine, ethanolamine, formate, hippurate, homogentisate, indoxyl sulfate, and phenylacetyglycine. Conversely, arginine decreased the urine levels of acetamide, β-glucose, cirtulline, ethanol, glycine, isobutyrate, lactate, malonate, methymalonate, N-acetylglutamate, N-methylnicotinamide, and propionate. Results suggested that arginine can alter common systemic metabolic processes, including energy metabolism, amino acid metabolism, and gut microbiota metabolism. Moreover, the results also imply a possible physiological role of the metabolism in mediating the arginine supplementation-supported growth of rats.

  18. l-Arginine-Dependent Epigenetic Regulation of Interleukin-10, but Not Transforming Growth Factor-β, Production by Neonatal Regulatory T Lymphocytes

    OpenAIRE

    Kuender D. Yang; Kuender D. Yang; Kuender D. Yang; Te-Yao Hsu; Hong-Ren Yu; Ching-Chang Tsai; Ling-Sai Chang; Hsin-Chun Huang; Hsin-Hsin Cheng; Jiu-Yao Wang; Jiu-Yao Wang; Jiunn-Ming Sheen; Ho-Chang Kuo; Kai-Sheng Hsieh; Ying-Hsien Huang

    2017-01-01

    A growing number of diseases in humans, including trauma, certain cancers, and infection, are known to be associated with l-arginine deficiency. In addition, l-arginine must be supplemented by diet during pregnancy to aid fetal development. In conditions of l-arginine depletion, T cell proliferation is impaired. We have previously shown that neonatal blood has lower l-arginine levels than adult blood, which is associated with poor neonatal lymphocyte proliferation, and that l-arginine enhance...

  19. A sensitive multi-residue method for the determination of 35 micropollutants including pharmaceuticals, iodinated contrast media and pesticides in water.

    Science.gov (United States)

    Valls-Cantenys, Carme; Scheurer, Marco; Iglesias, Mònica; Sacher, Frank; Brauch, Heinz-Jürgen; Salvadó, Victoria

    2016-09-01

    A sensitive, multi-residue method using solid-phase extraction followed by liquid chromatography-tandem mass spectrometry (LC-MS/MS) was developed to determine a representative group of 35 analytes, including corrosion inhibitors, pesticides and pharmaceuticals such as analgesic and anti-inflammatory drugs, five iodinated contrast media, β-blockers and some of their metabolites and transformation products in water samples. Few other methods are capable of determining such a broad range of contrast media together with other analytes. We studied the parameters affecting the extraction of the target analytes, including sorbent selection and extraction conditions, their chromatographic separation (mobile phase composition and column) and detection conditions using two ionisation sources: electrospray ionisation (ESI) and atmospheric pressure chemical ionisation (APCI). In order to correct matrix effects, a total of 20 surrogate/internal standards were used. ESI was found to have better sensitivity than APCI. Recoveries ranging from 79 to 134 % for tap water and 66 to 144 % for surface water were obtained. Intra-day precision, calculated as relative standard deviation, was below 34 % for tap water and below 21 % for surface water, groundwater and effluent wastewater. Method quantification limits (MQL) were in the low ng L(-1) range, except for the contrast agents iomeprol, amidotrizoic acid and iohexol (22, 25.5 and 17.9 ng L(-1), respectively). Finally, the method was applied to the analysis of 56 real water samples as part of the validation procedure. All of the compounds were detected in at least some of the water samples analysed. Graphical Abstract Multi-residue method for the determination of micropollutants including pharmaceuticals, iodinated contrast media and pesticides in waters by LC-MS/MS.

  20. Role of arginine and lysine in the antimicrobial mechanism of histone-derived antimicrobial peptides.

    Science.gov (United States)

    Cutrona, Kara J; Kaufman, Bethany A; Figueroa, Dania M; Elmore, Donald E

    2015-12-21

    Translocation of cell-penetrating peptides is often promoted by increased content of arginine or other guanidinium groups. However, relatively little research has considered the role of these functional groups on antimicrobial peptide activity. This study compared the activity of three histone-derived antimicrobial peptides-buforin II, DesHDAP1, and parasin-with variants that contain only lysine or arginine cationic residues. These peptides operate via different mechanisms as parasin causes membrane permeabilization while buforin II and DesHDAP1 translocate into bacteria. For all peptides, antibacterial activity increased with increased arginine content. Higher arginine content increased permeabilization for parasin while it improved translocation for buforin II and DesHDAP1. These observations provide insight into the relative importance of arginine and lysine in these antimicrobial peptides. Copyright © 2015 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.

  1. Signifiance of Arginine 20 in the 2A protease for swine vesicular disease virus pathogenicity

    DEFF Research Database (Denmark)

    Inoue, Toru; Zhang, Zhidong; Wang, Leyuan

    2007-01-01

    of the 2A protease is particularly significant. Inoculation of pigs with mutant viruses containing single amino acid substitutions at this residue leads to the appearance of revertants, often containing an arginine at this position encoded by an AGA codon, one of six codons for this residue. The properties...

  2. Mannitol/l-Arginine-Based Formulation Systems for Freeze Drying of Protein Pharmaceuticals: Effect of the l-Arginine Counter Ion and Formulation Composition on the Formulation Properties and the Physical State of Mannitol.

    Science.gov (United States)

    Stärtzel, Peter; Gieseler, Henning; Gieseler, Margit; Abdul-Fattah, Ahmad M; Adler, Michael; Mahler, Hanns-Christian; Goldbach, Pierre

    2016-10-01

    Previous studies have shown that protein storage stability in freeze-dried l-arginine-based systems improved in the presence of chloride ions. However, chloride ions reduced the glass transition temperature of the freeze concentrate (Tg') and made freeze drying more challenging. In this study, l-arginine was freeze dried with mannitol to obtain partially crystalline solids that can be freeze dried in a fast process and result in elegant cakes. We characterized the effect of different l-arginine counter ions on physicochemical properties of mannitol compared with mannitol/sucrose systems. Thermal properties of formulations with different compositions were correlated to thermal history during freeze drying and to physicochemical properties (cake appearance, residual moisture, reconstitution time, crystallinity). Partially crystalline solids were obtained even at the highest l-arginine level (mannitol:l-arginine of 2:1) used in this study. All l-arginine-containing formulations yielded elegant cakes. Only cakes containing l-arginine chloride and succinate showed a surface "crust" formed by phase separation. X-ray powder diffraction showed that inhibition of mannitol crystallization was stronger for l-arginine compared with sucrose and varied with the type of l-arginine counter ion. The counter ion affected mannitol polymorphism and higher levels of mannitol hemi-hydrate were obtained at high levels of l-arginine chloride. Copyright © 2016 American Pharmacists Association®. Published by Elsevier Inc. All rights reserved.

  3. Oral supplementation with a combination of L-citrulline and L-arginine rapidly increases plasma L-arginine concentration and enhances NO bioavailability.

    Science.gov (United States)

    Morita, Masahiko; Hayashi, Toshio; Ochiai, Masayuki; Maeda, Morihiko; Yamaguchi, Tomoe; Ina, Koichiro; Kuzuya, Masafumi

    2014-11-07

    Chronic supplementation with L-citrulline plus L-arginine has been shown to exhibit anti-atherosclerotic effects. However, the short-term action of this combination on the nitric oxide (NO)-cGMP pathway remains to be elucidated. The objective of the present study was to investigate the acute effects of a combination of oral L-citrulline and L-arginine on plasma L-arginine and NO levels, as well as on blood circulation. Rats or New Zealand white rabbits were treated orally with L-citrulline, or L-arginine, or a combination of each at half dosage. Following supplementation, plasma levels of L-arginine, NOx, cGMP and changes in blood circulation were determined sequentially. L-Citrulline plus L-arginine supplementation caused a more rapid increase in plasma L-arginine levels and marked enhancement of NO bioavailability, including plasma cGMP concentrations, than with dosage with the single amino acids. Blood flow in the central ear artery in rabbits was also significantly increased by L-citrulline plus L-arginine administration as compared with the control. Our data show for the first time that a combination of oral L-citrulline and L-arginine effectively and rapidly augments NO-dependent responses at the acute stage. This approach may have clinical utility for the regulation of cardiovascular function in humans. Copyright © 2014 The Authors. Published by Elsevier Inc. All rights reserved.

  4. Protein arginine deiminase 2 binds calcium in an ordered fashion: implications for inhibitor design.

    Science.gov (United States)

    Slade, Daniel J; Fang, Pengfei; Dreyton, Christina J; Zhang, Ying; Fuhrmann, Jakob; Rempel, Don; Bax, Benjamin D; Coonrod, Scott A; Lewis, Huw D; Guo, Min; Gross, Michael L; Thompson, Paul R

    2015-04-17

    Protein arginine deiminases (PADs) are calcium-dependent histone-modifying enzymes whose activity is dysregulated in inflammatory diseases and cancer. PAD2 functions as an Estrogen Receptor (ER) coactivator in breast cancer cells via the citrullination of histone tail arginine residues at ER binding sites. Although an attractive therapeutic target, the mechanisms that regulate PAD2 activity are largely unknown, especially the detailed role of how calcium facilitates enzyme activation. To gain insights into these regulatory processes, we determined the first structures of PAD2 (27 in total), and through calcium-titrations by X-ray crystallography, determined the order of binding and affinity for the six calcium ions that bind and activate this enzyme. These structures also identified several PAD2 regulatory elements, including a calcium switch that controls proper positioning of the catalytic cysteine residue, and a novel active site shielding mechanism. Additional biochemical and mass-spectrometry-based hydrogen/deuterium exchange studies support these structural findings. The identification of multiple intermediate calcium-bound structures along the PAD2 activation pathway provides critical insights that will aid the development of allosteric inhibitors targeting the PADs.

  5. Field Measurements of Trace Gases and Aerosols Emitted by Undersampled Combustion Sources Including Wood and Dung Cooking Fires, Garbage and Crop Residue Burning, and Indonesian Peat Fires

    Science.gov (United States)

    Stockwell, C.; Jayarathne, T. S.; Goetz, D.; Simpson, I. J.; Selimovic, V.; Bhave, P.; Blake, D. R.; Cochrane, M. A.; Ryan, K. C.; Putra, E. I.; Saharjo, B.; Stone, E. A.; DeCarlo, P. F.; Yokelson, R. J.

    2017-12-01

    Field measurements were conducted in Nepal and in the Indonesian province of Central Kalimantan to improve characterization of trace gases and aerosols emitted by undersampled combustion sources. The sources targeted included cooking with a variety of stoves, garbage burning, crop residue burning, and authentic peat fires. Trace gas and aerosol emissions were studied using a land-based Fourier transform infrared spectrometer, whole air sampling, photoacoustic extinctiometers (405 and 870nm), and filter samples that were analyzed off-line. These measurements were used to calculate fuel-based emission factors (EFs) for up to 90 gases, PM2.5, and PM2.5 constituents. The aerosol optical data measured included EFs for the scattering and absorption coefficients, the single scattering albedo (at 870 and 405 nm), as well as the absorption Ångström exponent. The emissions varied significantly by source, although light absorption by both brown and black carbon (BrC and BC, respectively) was important for all non-peat sources. For authentic peat combustion, the emissions of BC were negligible and absorption was dominated by organic aerosol. The field results from peat burning were in reasonable agreement with recent lab measurements of smoldering Kalimantan peat and compare well to the limited data available from other field studies. The EFs can be used with estimates of fuel consumption to improve regional emissions inventories and assessments of the climate and health impacts of these undersampled sources.

  6. Structures of Bacterial Biosynthetic Arginine Decarboxylases

    Energy Technology Data Exchange (ETDEWEB)

    F Forouhar; S Lew; J Seetharaman; R Xiao; T Acton; G Montelione; L Tong

    2011-12-31

    Biosynthetic arginine decarboxylase (ADC; also known as SpeA) plays an important role in the biosynthesis of polyamines from arginine in bacteria and plants. SpeA is a pyridoxal-5'-phosphate (PLP)-dependent enzyme and shares weak sequence homology with several other PLP-dependent decarboxylases. Here, the crystal structure of PLP-bound SpeA from Campylobacter jejuni is reported at 3.0 {angstrom} resolution and that of Escherichia coli SpeA in complex with a sulfate ion is reported at 3.1 {angstrom} resolution. The structure of the SpeA monomer contains two large domains, an N-terminal TIM-barrel domain followed by a {beta}-sandwich domain, as well as two smaller helical domains. The TIM-barrel and {beta}-sandwich domains share structural homology with several other PLP-dependent decarboxylases, even though the sequence conservation among these enzymes is less than 25%. A similar tetramer is observed for both C. jejuni and E. coli SpeA, composed of two dimers of tightly associated monomers. The active site of SpeA is located at the interface of this dimer and is formed by residues from the TIM-barrel domain of one monomer and a highly conserved loop in the {beta}-sandwich domain of the other monomer. The PLP cofactor is recognized by hydrogen-bonding, {pi}-stacking and van der Waals interactions.

  7. Xenoestrogens regulate the activity of arginine methyltransferases.

    Science.gov (United States)

    Cheng, Donghang; Bedford, Mark T

    2011-01-24

    Arginine methylation is a common post-translational modification that has been strongly implicated in transcriptional regulation. The arginine methyltransferases (PRMTs) were first reported as transcriptional coactivators for the estrogen and androgen receptors. Compounds that inhibit these enzymes will provide us with valuable tools for dissecting the roles of these enzymes in cells, and will possibly also have therapeutic applications. In order to identify such inhibitors of the PRMTs, we have previously performed a high-throughput screen using a small molecule library. These compounds were named arginine methyltransferase inhibitors (AMIs). The majority of these inhibitors were polyphenols, and one in particular (AMI-18) shared additional features with a group of known xenoestrogens. We, thus, tested a panel of xenoestrogens and found that a number of them possess the ability to inhibit PRMT activity, in vitro. These inhibitors primarily target CARM1, and include licochalcone A, kepone, benzyl 4-hydroxybenzoate, and tamoxifen. We developed a cell-based reporter system for CARM1 activity, and showed that tamoxifen (IC(50) =30 μM) inhibits this PRMT. The ability of these compounds to regulate the activity of transcriptional coactivators may be an unappreciated mechanism of action for xenoestrogens, and might also explain the efficacy of high-dose tamoxifen treatment on estrogen receptor negative cancers. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Optimization of biological and instrumental detection of explosives and ignitable liquid residues including canines, SPME/ITMS and GC/MSn

    Science.gov (United States)

    Furton, Kenneth G.; Harper, Ross J.; Perr, Jeannette M.; Almirall, Jose R.

    2003-09-01

    A comprehensive study and comparison is underway using biological detectors and instrumental methods for the rapid detection of ignitable liquid residues (ILR) and high explosives. Headspace solid phase microextraction (SPME) has been demonstrated to be an effective sampling method helping to identify active odor signature chemicals used by detector dogs to locate forensic specimens as well as a rapid pre-concentration technique prior to instrumental detection. Common ignitable liquids and common military and industrial explosives have been studied including trinitrotoluene, tetryl, RDX, HMX, EGDN, PETN and nitroglycerine. This study focuses on identifying volatile odor signature chemicals present, which can be used to enhance the level and reliability of detection of ILR and explosives by canines and instrumental methods. While most instrumental methods currently in use focus on particles and on parent organic compounds, which are often involatile, characteristic volatile organics are generally also present and can be exploited to enhance detection particularly for well-concealed devices. Specific examples include the volatile odor chemicals 2-ethyl-1-hexanol and cyclohexanone, which are readily available in the headspace of the high explosive composition C-4; whereas, the active chemical cyclo-1,3,5-trimethylene-2,4,6-trinitramine (RDX) is not. The analysis and identification of these headspace 'fingerprint' organics is followed by double-blind dog trials of the individual components using certified teams in an attempt to isolate and understand the target compounds to which dogs are sensitive. Studies to compare commonly used training aids with the actual target explosive have also been undertaken to determine their suitability and effectiveness. The optimization of solid phase microextraction (SPME) combined with ion trap mobility spectrometry (ITMS) and gas chromatography/mass spectrometry/mass spectrometry (GC/MSn) is detailed including interface development

  9. Biomarkers of arginine and lysine excess.

    Science.gov (United States)

    Luiking, Yvette C; Deutz, Nicolaas E P

    2007-06-01

    Arginine supplementation is used in several disease states. In arginine-deficient states, supplementation is a logical choice of therapy. However, the definition of an arginine-deficient state is complex. For example, plasma arginine levels could be within normal range but intracellular arginine levels could be reduced because of membrane transport problems. Lysine competes with arginine for transport into the cell. In these situations, arginine supplementation of higher than required levels is proposed. Arginine has several important functions in metabolism as it is a precursor of metabolically active components such as nitric oxide (NO), ornithine, creatine, and polyamines. Supplementing arginine in excess could potentially overstimulate metabolism via enhanced production of NO. NO is a reactive component that, via production of radicals, will inactivate proteins. NO is also a powerful vasodilator, which could lead to severe hemodynamic instability. A good marker for excess supplementation of arginine or lysine could be an increased or reduced production rate of NO. However, NO production is difficult to measure because NO is a very labile component and is rapidly oxidized in blood. Stable isotope-labeled arginine and citrulline are used to trace the arginine-NO route. During supplementation of arginine in septic pigs or patients in septic shock, NO production, measured with stable isotope technology, is enhanced.

  10. Diffusion-weighted MR imaging including bi-exponential fitting for the detection of recurrent or residual tumour after (chemo)radiotherapy for laryngeal and hypopharyngeal cancers

    Energy Technology Data Exchange (ETDEWEB)

    Tshering Vogel, Dechen W.; Vermathen, Peter; Thoeny, Harriet C. [University of Bern, Department of Diagnostic, Interventional and Paediatric Radiology, Inselspital, Bern (Switzerland); Zbaeren, Peter [University of Bern, Department of Oto-Rhino-Laryngology, Head and Neck Surgery, Inselspital, Bern (Switzerland); Geretschlaeger, Andreas [University of Bern, Department of Radiation Oncology, Inselspital, Bern (Switzerland); Keyzer, Frederik de [University Hospitals Leuven, Department of Radiology, Leuven (Belgium)

    2013-02-15

    To assess whether diffusion-weighted magnetic resonance imaging (DW-MRI) including bi-exponential fitting helps to detect residual/recurrent tumours after (chemo)radiotherapy of laryngeal and hypopharyngeal carcinoma. Forty-six patients with newly-developed/worsening symptoms after (chemo)radiotherapy for laryngeal/hypopharyngeal cancers were prospectively imaged using conventional MRI and axial DW-MRI. Qualitative (visual assessment) and quantitative analysis (mono-exponentially: total apparent diffusion coefficient [ADC{sub T}], and bi-exponentially: perfusion fraction [F{sub P}] and true diffusion coefficient [ADC{sub D}]) were performed. Diffusion parameters of tumour versus post-therapeutic changes were compared, with final diagnosis based on histopathology and follow-up. Mann-Whitney U test was used for statistical analysis. Qualitative DW-MRI combined with morphological images allowed the detection of tumour with a sensitivity of 94% and specificity 100%. ADC{sub T} and ADC{sub D} values were lower in tumour with values 120 {+-} 49 x 10{sup -5} mm{sup 2}/s and 113 {+-} 50 x 10{sup -5} mm{sup 2}/s, respectively, compared with post-therapeutic changes with values 182 {+-} 41 x 10{sup -5} mm{sup 2}/s (P < 0.0002) and 160 {+-} 47 x 10{sup -5} mm{sup 2}/s (P < 0.003), respectively. F{sub P} values were significantly lower in tumours than in non-tumours (13 {+-} 9% versus 31 {+-} 16%, P < 0.0002), with F{sub P} being the best quantitative parameter for differentiation between post-therapeutic changes and recurrence. DW-MRI in combination with conventional MRI substantially improves detection and exclusion of tumour in patients with laryngeal and hypopharyngeal cancers after treatment with (chemo)radiotherapy on both qualitative and quantitative analysis, with F{sub P} being the best quantitative parameter in this context. (orig.)

  11. Regulation of Arginine-Ornithine Exchange and the Arginine Deiminase Pathway in Streptococcus lactis

    NARCIS (Netherlands)

    POOLMAN, B; DRIESSEN, AJM; KONINGS, WN

    1987-01-01

    Streptococcus lactis metabolizes arginine by the argiqine deiminase (ADI) pathway. Resting cells of S. lactis grown in the presence of galactose and arginine maintain a high intracellular ornithine pool in the absence of arginine and other exogenous energy sources. Addition of arginine results in a

  12. The arginine-ornithine antiporter ArcD contributes to biological fitness of Streptococcus suis

    Directory of Open Access Journals (Sweden)

    Marcus eFulde

    2014-08-01

    Full Text Available The arginine-ornithine antiporter (ArcD is part of the Arginine Deiminase System (ADS, a catabolic, energy-providing pathway found in a variety of different bacterial species, including the porcine zoonotic pathogen Streptococcus suis. The ADS has recently been shown to play a role in the pathogenicity of S. suis, in particular in its survival in host cells. The contribution of arginine and arginine transport mediated by ArcD, however, has yet to be clarified. In the present study, we showed by experiments using [U-13C6]arginine as a tracer molecule that S. suis is auxotrophic for arginine and that bacterial growth depends on the uptake of extracellular arginine. To further study the role of ArcD in arginine metabolism, we generated an arcD-specific mutant strain and characterized its growth compared to the wild-type (WT strain, a virulent serotype 2 strain. The mutant strain showed a markedly reduced growth rate in chemically defined media supplemented with arginine when compared to the WT strain, indicating that ArcD promotes arginine uptake. To further evaluate the in vivo relevance of ArcD, we studied the intracellular bacterial survival of the arcD mutant strain in an epithelial cell culture infection model. The mutant strain was substantially attenuated, and its reduced intracellular survival rate correlated with a lower ability to neutralize the acidified environment. Based on these results, we propose that ArcD, by its function as an arginine-ornithine antiporter, is important for supplying arginine as substrate of the ADS and, thereby, contributes to biological fitness and virulence of S. suis in the host.

  13. Effects of L-arginine pretreatment on nitric oxide metabolism and hepatosplanchnic perfusion during porcine endotoxemia.

    Science.gov (United States)

    Poeze, Martijn; Bruins, Maaike J; Kessels, Fons; Luiking, Yvette C; Lamers, Wouter H; Deutz, Nicolaas E P

    2011-06-01

    Sepsis is accompanied by an increased need for and a decreased supply of arginine, reflecting a condition of arginine deficiency. The objective was to evaluate the effects of l-arginine pretreatment on arginine-nitric oxide (NO) production and hepatosplanchnic perfusion during subsequent endotoxemia. In a randomized controlled trial, pigs (20-25 kg) received 3 μg . kg(-1) . min(-1) lipopolysaccharide (LPS; 5 endotoxin units/ng) intravenously and saline resuscitation. l-Arginine (n = 8; 5.3 μmol . kg(-1) . min(-1)) or saline (n = 8) was infused starting 12 h before LPS infusion and continued for 24 h after the endotoxin infusion ended. Whole-body appearance rates, portal-drained viscera (PDV), and liver fluxes of arginine, citrulline, NO, and arginine de novo synthesis were measured by using stable-isotope infusion of [(15)N(2)]arginine and [(13)C-(2)H(2)]citrulline. Hepatosplanchnic perfusion was assessed by using a primed continuous infusion of para-aminohippuric acid and jejunal intramucosal partial pressure of carbon dioxide and was related to systemic hemodynamics. Arginine supplementation before LPS increased whole-body NO production in the PDV but not in the liver. Furthermore, it increased blood flow in the portal vein but not in the aorta and hepatic artery. During endotoxin infusion, arginine pretreatment was associated with an increased whole-body arginine appearance and NO production in the gut. Additional effects included a preserved mean arterial pressure, the prevention of an increase in pulmonary arterial pressure, an attenuated metabolic acidosis, and an attenuated increase in the intramucosal partial pressure of carbon dioxide. Arginine treatment starting before endotoxemia appears to be beneficial because it improves hepatosplanchnic perfusion and oxygenation during prolonged endotoxemia, probably through an enhancement in NO synthesis, without causing deleterious systemic side effects.

  14. 8-year retrospective analysis of intravenous arginine therapy for acute metabolic strokes in pediatric mitochondrial disease.

    Science.gov (United States)

    Ganetzky, Rebecca D; Falk, Marni J

    2018-03-01

    Intravenous (IV) arginine has been reported to ameliorate acute metabolic stroke symptoms in adult patients with Mitochondrial Encephalopathy with Lactic Acidosis and Stroke-like Episodes (MELAS) syndrome, where its therapeutic benefit is postulated to result from arginine acting as a nitric oxide donor to reverse vasospasm. Further, reduced plasma arginine may occur in mitochondrial disease since the biosynthesis of arginine's precursor, citrulline, requires ATP. Metabolic strokes occur across a wide array of primary mitochondrial diseases having diverse molecular etiologies that are likely to share similar pathophysiologic mechanisms. Therefore, IV arginine has been increasingly used for the acute clinical treatment of metabolic stroke across a broad mitochondrial disease population. We performed retrospective analysis of a large cohort of subjects who were under 18 years of age at IRB #08-6177 study enrollment and had molecularly-confirmed primary mitochondrial disease (n = 71, excluding the common MELAS m.3243A>G mutation). 9 unrelated subjects in this cohort received acute arginine IV treatment for one or more stroke-like episodes (n = 17 total episodes) between 2009 and 2016 at the Children's Hospital of Philadelphia. Retrospectively reviewed data included subject genotype, clinical symptoms, age, arginine dosing, neuroimaging (if performed), prophylactic therapies, and adverse events. Genetic etiologies of subjects who presented with acute metabolic strokes included 4 mitochondrial DNA (mtDNA) pathogenic point mutations, 1 mtDNA deletion, and 4 nuclear gene disorders. Subject age ranged from 19 months to 23 years at the time of any metabolic stroke episode (median, 8 years). 3 subjects had recurrent stroke episodes. 70% of subjects were on prophylactic arginine or citrulline therapy at the time of a stroke-like episode. IV arginine was initiated on initial presentation in 65% of cases. IV arginine was given for 1-7 days (median, 1 day). A

  15. Arginine homeostasis in allergic asthma

    NARCIS (Netherlands)

    Maarsingh, Harm; Zaagsma, Johan; Meurs, Herman

    2008-01-01

    Allergic asthma is a chronic disease characterized by early and late asthmatic reactions, airway hyperresponsiveness, airway inflammation and airway remodelling. Changes in L-arginine homeostasis may contribute to all these features of asthma by decreased nitric oxide (NO) production and increased

  16. Large-Scale Identification of the Arginine Methylome by Mass Spectrometry

    DEFF Research Database (Denmark)

    Sylvestersen, Kathrine B; Nielsen, Michael L

    2015-01-01

    , prefractionation using strong cation exchange, and identification using liquid chromatography coupled to tandem mass spectrometry. A strategy for relative quantification is described using stable isotope labeling by amino acids in cell culture (SILAC). Approaches for analysis of arginine methylation site occupancy......The attachment of one or more methylation groups to the side chain of arginine residues is a regulatory mechanism for cellular proteins. Recent advances in mass spectrometry-based characterization allow comprehensive identification of arginine methylation sites by peptide-level enrichment...... strategies. Described in this unit is a 4-day protocol for enrichment of arginine-methylated peptides and subsequent identification of thousands of distinct sites by mass spectrometry. Specifically, the protocol explains step-by-step sample preparation, enrichment using commercially available antibodies...

  17. Arginine kinase in Phytomonas, a trypanosomatid parasite of plants.

    Science.gov (United States)

    Canepa, Gaspar E; Carrillo, Carolina; Miranda, Mariana R; Sayé, Melisa; Pereira, Claudio A

    2011-09-01

    Phytomonas are trypanosomatid plant parasites closely related to parasites that cause several human diseases. Little is known about the biology of these organisms including aspects of their metabolism. Arginine kinase (E.C. 2.7.3.3) is a phosphotransferase which catalyzes the interconversion between the phosphagen phosphoarginine and ATP. This enzyme is present in some invertebrates and is a homolog of another widely distributed phosphosphagen kinase, creatine kinase. In this work, a single canonical arginine kinase isoform was detected in Phytomonas Jma by enzymatic activity assays, PCR, and Western Blot. This arginine kinase is very similar to the canonical isoforms found in T. cruzi and T. brucei, presenting about 70% of amino acid sequence identity and a very similar molecular weight (40kDa). The Phytomonas phosphagen system seems to be very similar to T. cruzi, which has only one isoform, or T. brucei (three isoforms); establishing a difference with other trypanosomatids, such as Leishmania, which completely lacks phosphagen kinases, probably by the presence of the arginine-consuming enzyme, arginase. Finally, phylogenetic analysis suggests that Kinetoplastids' arginine kinase was acquired, during evolution, from the arthropod vectors by horizontal gene transfer. Copyright © 2011 Elsevier Inc. All rights reserved.

  18. Analysis of arginine and lysine methylation utilizing peptide separations at neutral pH and electron transfer dissociation mass spectrometry.

    Science.gov (United States)

    Snijders, Ambrosius P L; Hung, Ming-Lung; Wilson, Stuart A; Dickman, Mark J

    2010-01-01

    Arginine and lysine methylation are widespread protein post-translational modifications. Peptides containing these modifications are difficult to retain using traditional reversed-phase liquid chromatography because they are intrinsically basic/hydrophilic and often fragment poorly during collision induced fragmentation (CID). Therefore, they are difficult to analyze using standard proteomic workflows. To overcome these caveats, we performed peptide separations at neutral pH, resulting in increased retention of the hydrophilic/basic methylated peptides before identification using MS/MS. Alternatively trifluoroacetic acid (TFA) was used for increased trapping of methylated peptides. Electron-transfer dissociation (ETD) mass spectrometry was then used to identify and characterize methylated residues. In contrast to previous reports utilizing ETD for arginine methylation, we observed significant amount of side-chain fragmentation. Using heavy methyl stable isotope labeling with amino acids in cell culture it was shown that, similar to CID, a loss of monomethylamine or dimethylamine from the arginine methylated side-chain during ETD can be used as a diagnostic to determine the type of arginine methylation. CID of lysine methylated peptides does not lead to significant neutral losses, but ETD is still beneficial because of the high charge states of such peptides. The developed LC MS/MS methods were successfully applied to tryptic digests of a number of methylated proteins, including splicing factor proline-glutamine-rich protein (SFPQ), RNA and export factor-binding protein 2 (REF2-I) and Sul7D, demonstrating significant advantages over traditional LC MS/MS approaches. 2010 American Society for Mass Spectrometry. Published by Elsevier Inc. All rights reserved.

  19. Long term exposure to L-arginine accelerates endothelial cell senescence through arginase-II and S6K1 signaling.

    OpenAIRE

    Xiong Yuyan; Fru Michael Forbiteh; Yu Yi; Montani Jean-Pierre; Ming Xiu-Fen; Yang Zhihong

    2014-01-01

    L arginine supplementation is proposed to improve health status or as adjunct therapy for diseases including cardiovascular diseases. However controversial results and even detrimental effects of L arginine supplementation are reported. We investigate potential mechanisms of L arginine induced detrimental effects on vascular endothelial cells. Human endothelial cells were exposed to a physiological (0.1 mmol/L) or pharmacological (0.5 mmol/L) concentration of L arginine for 30 minutes (acute)...

  20. Long term exposure to L-arginine accelerates endothelial cell senescence through arginase-II and S6K1 signaling

    OpenAIRE

    Xiong, Yuyani; Fru, Michael Forbiteh; Yu, Yi; Montani, Jean-Pierre; Ming, Xiu-Fen; Yang, Zhihong

    2014-01-01

    L-arginine supplementation is proposed to improve health status or as adjunct therapy for diseases including cardiovascular diseases. However, controversial results and even detrimental effects of L-arginine supplementation are reported. We investigate potential mechanisms of L-arginine-induced detrimental effects on vascular endothelial cells. Human endothelial cells were exposed to a physiological (0.1 mmol/L) or pharmacological (0.5 mmol/L) concentration of L-arginine for 30 minutes (acute...

  1. Regulation of Skeletal Muscle Plasticity by Protein Arginine Methyltransferases and Their Potential Roles in Neuromuscular Disorders

    Directory of Open Access Journals (Sweden)

    Derek W. Stouth

    2017-11-01

    Full Text Available Protein arginine methyltransferases (PRMTs are a family of enzymes that catalyze the methylation of arginine residues on target proteins, thereby mediating a diverse set of intracellular functions that are indispensable for survival. Indeed, full-body knockouts of specific PRMTs are lethal and PRMT dysregulation has been implicated in the most prevalent chronic disorders, such as cancers and cardiovascular disease (CVD. PRMTs are now emerging as important mediators of skeletal muscle phenotype and plasticity. Since their first description in muscle in 2002, a number of studies employing wide varieties of experimental models support the hypothesis that PRMTs regulate multiple aspects of skeletal muscle biology, including development and regeneration, glucose metabolism, as well as oxidative metabolism. Furthermore, investigations in non-muscle cell types strongly suggest that proteins, such as peroxisome proliferator-activated receptor-γ coactivator-1α, E2F transcription factor 1, receptor interacting protein 140, and the tumor suppressor protein p53, are putative downstream targets of PRMTs that regulate muscle phenotype determination and remodeling. Recent studies demonstrating that PRMT function is dysregulated in Duchenne muscular dystrophy (DMD, spinal muscular atrophy (SMA, and amyotrophic lateral sclerosis (ALS suggests that altering PRMT expression and/or activity may have therapeutic value for neuromuscular disorders (NMDs. This review summarizes our understanding of PRMT biology in skeletal muscle, and identifies uncharted areas that warrant further investigation in this rapidly expanding field of research.

  2. Buried lysine, but not arginine, titrates and alters transmembrane helix tilt.

    Science.gov (United States)

    Gleason, Nicholas J; Vostrikov, Vitaly V; Greathouse, Denise V; Koeppe, Roger E

    2013-01-29

    The ionization states of individual amino acid residues of membrane proteins are difficult to decipher or assign directly in the lipid-bilayer membrane environment. We address this issue for lysines and arginines in designed transmembrane helices. For lysines (but not arginines) at two locations within dioleoyl-phosphatidylcholine bilayer membranes, we measure pK(a) values below 7.0. We find that buried charged lysine, in fashion similar to arginine, will modulate helix orientation to maximize its own access to the aqueous interface or, if occluded by aromatic rings, may cause a transmembrane helix to exit the lipid bilayer. Interestingly, the influence of neutral lysine (vis-à-vis leucine) upon helix orientation also depends upon its aqueous access. Our results suggest that changes in the ionization states of particular residues will regulate membrane protein function and furthermore illustrate the subtle complexity of ionization behavior with respect to the detailed lipid and protein environment.

  3. Resolution and quantification of arginine, monomethylarginine, asymmetric dimethylarginine, and symmetric dimethylarginine in plasma using HPLC with internal calibration

    Science.gov (United States)

    Alkaitis, Matthew S.; Nardone, Glenn; Chertow, Jessica H.

    2015-01-01

    Abstract NG,NG‐dimethyl‐l‐arginine (asymmetric dimethylarginine, ADMA),NG‐monomethyl‐l‐arginine (l‐NMMA) and NG,N G’‐dimethyl‐l‐arginine (symmetric dimethylarginine, SDMA) are released during hydrolysis of proteins containing methylated arginine residues. ADMA and l‐NMMA inhibit nitric oxide synthase by competing with l‐arginine substrate. All three methylarginine derivatives also inhibit arginine transport. To enable investigation of methylarginines in diseases involving impaired nitric oxide synthesis, we developed a high‐performance liquid chromatography (HPLC) assay to simultaneously quantify arginine, ADMA, l‐NMMA and SDMA. Our assay requires 12 μL of plasma and is ideal for applications where sample availability is limited. We extracted arginine and methylarginines with mixed‐mode cation‐exchange columns, using synthetic monoethyl‐l‐arginine as an internal standard. Metabolites were derivatized with ortho‐phthaldialdeyhde and 3‐mercaptopropionic acid, separated by reverse‐phase HPLC and quantified with fluorescence detection. Standard curve linearity was ≥0.9995 for all metabolites. Inter‐day coefficient of variation (CV) values were ≤5% for arginine, ADMA and SDMA in human plasma and for arginine and ADMA in mouse plasma. The CV value for l‐NMMA was higher in human (10.4%) and mouse (15.8%) plasma because concentrations were substantially lower than ADMA and SDMA. This assay provides unique advantages of small sample volume requirements, excellent separation of target metabolites from contaminants and validation for both human and mouse plasma samples. © 2015 The Authors Biomedical Chromatography published by John Wiley & Sons, Ltd. PMID:26130049

  4. The second case of a young man with L-arginine-induced acute pancreatitis.

    Science.gov (United States)

    Binet, Quentin; Dufour, Inès; Agneessens, Emmanuel; Debongnie, Jean-Claude; Aouattah, Tarik; Covas, Angélique; Coche, Jean-Charles; De Koninck, Xavier

    2018-04-21

    Dietary supplementation of arginine has been used by numerous world-class athletes and professional bodybuilders over the past 30 years. L-Arginine indeed enhances muscular power and general performance via maintaining ATP level. However, L-arginine is also known to induce acute pancreatitis in murine models. We report the case of young man presenting with upper abdominal pain and increased serum lipase levels. Contrast-enhanced computed tomography confirms a mild acute pancreatitis. Common etiologies have been ruled out and toxicological anamnestic screening reveals the intake of protein powder. This is, to the best of our knowledge, the second case in human of arginine-induced acute pancreatitis. This case report suggests that every patient presenting with acute pancreatitis without obvious etiology should be evaluated for the intake of toxics other than alcohol, including L-arginine.

  5. Symmetric Allosteric Mechanism of Hexameric Escherichia coli Arginine Repressor Exploits Competition between L-Arginine Ligands and Resident Arginine Residues

    Czech Academy of Sciences Publication Activity Database

    Strawn, R.; Melicherčík, Milan; Green, M.; Stockner, T.; Carey, J.; Ettrich, Rüdiger

    2010-01-01

    Roč. 6, č. 6 (2010), s. 1-12 ISSN 1553-734X R&D Projects: GA MŠk(CZ) LC06010; GA ČR GAP207/10/1934 Institutional research plan: CEZ:AV0Z60870520 Keywords : molecular-dynamics simulations * free-energy calculations * structural basis * DNA-binding domain * bacillus-stearothermophilus * T4 lysozyme * proteins * hemoglobin * model * affinity Subject RIV: EH - Ecology, Behaviour Impact factor: 5.515, year: 2010

  6. Monomeric Corynebacterium glutamicum N-acetyl glutamate kinase maintains sensitivity to L-arginine but has a lower intrinsic catalytic activity.

    Science.gov (United States)

    Huang, Yuanyuan; Li, Cheng; Zhang, Hao; Liang, Shuli; Han, Shuangyan; Lin, Ying; Yang, Xiaorong; Zheng, Suiping

    2016-02-01

    N-acetyl glutamate kinase (NAGK) is a key enzyme in the synthesis of L-arginine, and L-arginine-sensitive NAGK typically has hexameric architecture. Defining the relationship between this architecture and L-arginine inhibition can provide a foundation to identify the key amino acids involved in the allosteric regulation network of L-arginine. In the present study, the key amino acids in the N-terminal helix (N-helix) of Corynebacterium glutamicum (Cg) NAGK required for hexamer formation were determined using structural homology modeling and site-directed mutagenesis. It was also verified that hexameric architecture is required for the positive cooperativity of inhibition by L-arginine and for efficient catalysis, but that it is not the determinant of inhibition by L-arginine. Monomeric mutants retained a similar sensitivity to L-arginine as the hexameric form, indicating that monomers contain an independent, sensitive signal transduction network of L-arginine to mediate allosteric regulation. Mutation studies of CgNAGKs also revealed that amino acid residues 18-23 of the N-helix are required for inhibition by L-arginine, and that E19 may be an essential amino acid influencing the apparent affinity of L-arginine. Collectively, these studies may illuminate the basic mechanism of metabolic homeostasis of C. glutamicum.

  7. Gas-phase salt bridge interactions between glutamic acid and arginine

    NARCIS (Netherlands)

    Jaeqx, S.; Oomens, J.; Rijs, A.M.

    2013-01-01

    The gas-phase side chain-side chain (SC-SC) interaction and possible proton transfer between glutamic acid (Glu) and arginine (Arg) residues are studied under low-temperature conditions in an overall neutral peptide. Conformation-specific IR spectra, obtained with the free electron laser FELIX, in

  8. Arginine Coordination in Enzymatic Phosphoryl Transfer: Evaluation of the Effect of Arg166 Mutations in Escherichia Coli Alkaline Phosphatase

    International Nuclear Information System (INIS)

    O'Brien, P.J.; Lassila, J.K.; Fenn, T.D.; Zalatan, J.G.; Herschlag, D.

    2008-01-01

    Arginine residues are commonly found in the active sites of enzymes catalyzing phosphoryl transfer reactions. Numerous site-directed mutagenesis experiments establish the importance of these residues for efficient catalysis, but their role in catalysis is not clear. To examine the role of arginine residues in the phosphoryl transfer reaction, we have measured the consequences of mutations to arginine 166 in Escherichia coli alkaline phosphatase on hydrolysis of ethyl phosphate, on individual reaction steps in the hydrolysis of the covalent enzyme-phosphoryl intermediate, and on thio substitution effects. The results show that the role of the arginine side chain extends beyond its positive charge, as the Arg166Lys mutant is as compromised in activity as Arg166Ser. Through measurement of individual reaction steps, we construct a free energy profile for the hydrolysis of the enzyme-phosphate intermediate. This analysis indicates that the arginine side chain strengthens binding by ∼3 kcal/mol and provides an additional 1-2 kcal/mol stabilization of the chemical transition state. A 2.1 (angstrom) X-ray diffraction structure of Arg166Ser AP is presented, which shows little difference in enzyme structure compared to the wild-type enzyme but shows a significant reorientation of the bound phosphate. Altogether, these results support a model in which the arginine contributes to catalysis through binding interactions and through additional transition state stabilization that may arise from complementarity of the guanidinum group to the geometry of the trigonal bipyramidal transition state

  9. Physiological implications of arginine metabolism in plants

    Directory of Open Access Journals (Sweden)

    Gudrun eWinter

    2015-07-01

    Full Text Available Nitrogen is a limiting resource for plant growth in most terrestrial habitats since large amounts of nitrogen are needed to synthesize nucleic acids and proteins. Among the 21 proteinogenic amino acids, arginine has the highest nitrogen to carbon ratio, which makes it especially suitable as a storage form of organic nitrogen. Synthesis in chloroplasts via ornithine is apparently the only operational pathway to provide arginine in plants, and the rate of arginine synthesis is tightly regulated by various feedback mechanisms in accordance with the overall nutritional status. While several steps of arginine biosynthesis still remain poorly characterized in plants, much wider attention has been paid to inter- and intracellular arginine transport as well as arginine-derived metabolites. A role of arginine as alternative source besides glutamate for proline biosynthesis is still discussed controversially and may be prevented by differential subcellular localization of enzymes. Apparently, arginine is a precursor for nitric oxide (NO, although the molecular mechanism of NO production from arginine remains unclear in higher plants. In contrast, conversion of arginine to polyamines is well documented, and in several plant species also ornithine can serve as a precursor for polyamines. Both NO and polyamines play crucial roles in regulating developmental processes as well as responses to biotic and abiotic stress. It is thus conceivable that arginine catabolism serves on the one hand to mobilize nitrogen storages, while on the other hand it may be used to fine-tune development and defense mechanisms against stress. This review summarizes the recent advances in our knowledge about arginine metabolism, with a special focus on the model plant Arabidopsis thaliana, and pinpoints still unresolved critical questions.

  10. Convergent evolution of the arginine deiminase pathway : the ArcD and ArcE arginine/ornithine exchangers

    NARCIS (Netherlands)

    Noens, Elke E E; Lolkema, Juke S

    2016-01-01

    The arginine deiminase (ADI) pathway converts L-arginine into L-ornithine and yields 1 mol of ATP per mol of L-arginine consumed. The L-arginine/L-ornithine exchanger in the pathway takes up L-arginine and excretes L-ornithine from the cytoplasm. Analysis of the genomes of 1281 bacterial species

  11. Comparative study of two ATP : L-arginine phosphotransferases of molecular weight 84 000.

    Science.gov (United States)

    Thiem, N V; Lacombe, G; Thoai, N V

    1975-01-23

    Solen ensisensis muscle arginine kinase (ATP : L-arginine phosphotransferase, EC 2.7.3.3) was isolated in an homogeneous state. Its molecular weight was found to be about 80 000. The properties of this enzyme were compared with those of arginine kinase from Sipunculus nudus, an enzyme which also has a molecular weight of about 80 000. Both enzymes have several reactive thiol groups (8 thiol groups in the Solen kinase and 12 in the Sipunculus enzyme were titrateable with 5,5'-dithio-bis-(2-nitrobenzoic) acid and histidine residues (both enzymes have 6 reactive histidine residues). These kinases were, therefore, highly susceptible to oxidation. Both enzymes show the same pH optimum and absolute specificity towards the guanidine substrate, L-arginine. The reaction kinetics of both enzymes are of the sequential type. In the presence of alpha-aminoacids of Mg2+-ADP, similar spectral effects were obtained. The enzymes differ in their enzymic activities and in their rate of recovery following urea denaturation. The most important difference that appeared to be a special feature of the Sipunculus enzyme is that the spectrum of the Mg2+-ADP-enzyme complex is strongly intensified by L-arginine.

  12. A study on the effect of surface lysine to arginine mutagenesis on protein stability and structure using green fluorescent protein.

    Science.gov (United States)

    Sokalingam, Sriram; Raghunathan, Govindan; Soundrarajan, Nagasundarapandian; Lee, Sun-Gu

    2012-01-01

    Two positively charged basic amino acids, arginine and lysine, are mostly exposed to protein surface, and play important roles in protein stability by forming electrostatic interactions. In particular, the guanidinium group of arginine allows interactions in three possible directions, which enables arginine to form a larger number of electrostatic interactions compared to lysine. The higher pKa of the basic residue in arginine may also generate more stable ionic interactions than lysine. This paper reports an investigation whether the advantageous properties of arginine over lysine can be utilized to enhance protein stability. A variant of green fluorescent protein (GFP) was created by mutating the maximum possible number of lysine residues on the surface to arginines while retaining the activity. When the stability of the variant was examined under a range of denaturing conditions, the variant was relatively more stable compared to control GFP in the presence of chemical denaturants such as urea, alkaline pH and ionic detergents, but the thermal stability of the protein was not changed. The modeled structure of the variant indicated putative new salt bridges and hydrogen bond interactions that help improve the rigidity of the protein against different chemical denaturants. Structural analyses of the electrostatic interactions also confirmed that the geometric properties of the guanidinium group in arginine had such effects. On the other hand, the altered electrostatic interactions induced by the mutagenesis of surface lysines to arginines adversely affected protein folding, which decreased the productivity of the functional form of the variant. These results suggest that the surface lysine mutagenesis to arginines can be considered one of the parameters in protein stability engineering.

  13. Asymmetric dimethylarginine and L-arginine levels in neonatal sepsis and septic shock.

    Science.gov (United States)

    Aydemir, Ozge; Ozcan, Beyza; Yucel, Husniye; Bas, Ahmet Yagmur; Demirel, Nihal

    2015-05-01

    Nitric oxide (NO) formed by the enzyme NO synthase (NOS) from L-arginine, is an important mediator for pathogen elimination. Being a potent vasodilator NO is implicated in hypotension and decreased organ perfusion in sepsis. Asymmetric dimethylarginine (ADMA) is an endogenous NOS inhibitor. We investigated ADMA and L-arginine levels in neonatal sepsis and their relation to disease severity. A prospective controlled study was conducted including 31 neonates with sepsis and 20 controls. Serum ADMA and L-arginine levels were measured within 24 h of sepsis diagnosis. Clinical and laboratory data including clinical risk index for babies (CRIB) score, presence of septic shock, organ dysfunction and death were recorded. L-arginine and ADMA levels were higher in neonates with sepsis compared to controls (p = 0.029 and p = 0.001, respectively). Neonates with septic shock had higher ADMA levels compared to septic neonates without shock (p = 0.026) and controls (p L-arginine levels were higher in neonates with septic shock compared to septic neonates without shock (p = 0.012) and controls (p L-arginine and ADMA levels. ADMA levels were correlated with CRIB score (rho = 0.320, p = 0.025). L-arginine and ADMA levels are elevated in neonatal sepsis and even higher levels are observed in septic shock.

  14. Protein substrates of the arginine methyltransferase Hmt1 identified by proteome arrays.

    Science.gov (United States)

    Low, Jason K K; Im, Hogune; Erce, Melissa A; Hart-Smith, Gene; Snyder, Michael P; Wilkins, Marc R

    2016-02-01

    Arginine methylation on nonhistone proteins is associated with a number of cellular processes including RNA splicing, protein localization, and the formation of protein complexes. In this manuscript, Saccharomyces cerevisiae proteome arrays carrying 4228 proteins were used with an antimethylarginine antibody to first identify 88 putatively arginine-methylated proteins. By treating the arrays with recombinant arginine methyltransferase Hmt1, 42 proteins were found to be possible substrates of this enzyme. Analysis of the putative arginine-methylated proteins revealed that they were predominantly nuclear or nucleolar in localization, consistent with the localization of Hmt1. Many are involved in known methylarginine-associated functions, such as RNA processing and ribonucleoprotein complex biogenesis, yet others are of newer classes, namely RNA/DNA helicases and tRNA-associated proteins. Using ex vivo methylation and MS/MS, a set of 12 proteins (Brr1, Dia4, Hts1, Mpp10, Mrd1, Nug1, Prp43, Rpa43, Rrp43, Spp381, Utp4, and Npl3), including the RNA helicase Prp43 and tRNA ligases Dia4 and Hts1, were all validated as Hmt1 substrates. Interestingly, the majority of these also had human orthologs, or family members, that have been documented elsewhere to carry arginine methylation. These results confirm arginine methylation as a widespread modification and Hmt1 as the major arginine methyltransferase in the S. cerevisiae cell. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Arginine and Citrulline for the Treatment of MELAS Syndrome

    Directory of Open Access Journals (Sweden)

    Ayman W. El-Hattab MD, FACMG

    2017-03-01

    Full Text Available Mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes (MELAS syndrome is a maternally inherited mitochondrial disease with a broad spectrum of manifestations. In addition to impaired energy production, nitric oxide (NO deficiency occurs in MELAS syndrome and leads to impaired blood perfusion in microvasculature that can contribute to several complications including stroke-like episodes, myopathy, and lactic acidosis. The supplementation of NO precursors, L-arginine and L-citrulline, increases NO production and hence can potentially have therapeutic utility in MELAS syndrome. L-citrulline raises NO production to a greater extent than L-arginine; therefore, L-citrulline may have a better therapeutic effect. The clinical effect of L-citrulline has not yet been studied and clinical studies on L-arginine, which are limited, only evaluated the stroke-like episodes’ aspects of the disease. Controlled studies are still needed to assess the clinical effects of L-arginine and L-citrulline on different aspects of MELAS syndrome.

  16. Crystal structure of arginine methyltransferase 6 from Trypanosoma brucei.

    Directory of Open Access Journals (Sweden)

    Chongyuan Wang

    Full Text Available Arginine methylation plays vital roles in the cellular functions of the protozoan Trypanosoma brucei. The T. brucei arginine methyltransferase 6 (TbPRMT6 is a type I arginine methyltransferase homologous to human PRMT6. In this study, we report the crystal structures of apo-TbPRMT6 and its complex with the reaction product S-adenosyl-homocysteine (SAH. The structure of apo-TbPRMT6 displays several features that are different from those of type I PRMTs that were structurally characterized previously, including four stretches of insertion, the absence of strand β15, and a distinct dimerization arm. The comparison of the apo-TbPRMT6 and SAH-TbPRMT6 structures revealed the fine rearrangements in the active site upon SAH binding. The isothermal titration calorimetry results demonstrated that SAH binding greatly increases the affinity of TbPRMT6 to a substrate peptide derived from bovine histone H4. The western blotting and mass spectrometry results revealed that TbPRMT6 methylates bovine histone H4 tail at arginine 3 but cannot methylate several T. brucei histone tails. In summary, our results highlight the structural differences between TbPRMT6 and other type I PRMTs and reveal that the active site rearrangement upon SAH binding is important for the substrate binding of TbPRMT6.

  17. Arginine requirement and apparent absence of a lysine-arginine antagonist in fingerling channel catfish.

    Science.gov (United States)

    Robinson, E H; Wilson, R P; Poe, W E

    1981-01-01

    A series of growth studies, utilizing casein-gelatin based diets supplemented with crystalline amino acids, were conducted to determine the arginine requirement for fingerling channel catfish (Ictalurus punctatus) and to evaluate the effects of excessive levels of dietary lysine and arginine. Weight gain and feed efficiency data indicate the arginine requirement to be 1.03 +/- 0.07% and 1.00 +/- 0.06% of the dry diet, respectively. Based on growth this corresponds to 4.29% of the dietary protein. There was no evidence of an arginine-lysine antagonism when excess lysine was fed in diets adequate or marginal in arginine. Similarly, growth and feed efficiency data suggest the lack of an antagonism when excess arginine is added to diets marginal in lysine. Apparently channel catfish are not as sensitive to disproportionate lysine and arginine levels as are other animals.

  18. Enteral Glutamine Administration in Critically Ill Nonseptic Patients Does Not Trigger Arginine Synthesis

    Directory of Open Access Journals (Sweden)

    Mechteld A. R. Vermeulen

    2016-01-01

    Full Text Available Glutamine supplementation in specific groups of critically ill patients results in favourable clinical outcome. Enhancement of citrulline and arginine synthesis by glutamine could serve as a potential mechanism. However, while receiving optimal enteral nutrition, uptake and enteral metabolism of glutamine in critically ill patients remain unknown. Therefore we investigated the effect of a therapeutically relevant dose of L-glutamine on synthesis of L-citrulline and subsequent L-arginine in this group. Ten versus ten critically ill patients receiving full enteral nutrition, or isocaloric isonitrogenous enteral nutrition including 0.5 g/kg L-alanyl-L-glutamine, were studied using stable isotopes. A cross-over design using intravenous and enteral tracers enabled splanchnic extraction (SE calculations. Endogenous rate of appearance and SE of glutamine citrulline and arginine was not different (SE controls versus alanyl-glutamine: glutamine 48 and 48%, citrulline 33 versus 45%, and arginine 45 versus 42%. Turnover from glutamine to citrulline and arginine was not higher in glutamine-administered patients. In critically ill nonseptic patients receiving adequate nutrition and a relevant dose of glutamine there was no extra citrulline or arginine synthesis and glutamine SE was not increased. This suggests that for arginine synthesis enhancement there is no need for an additional dose of glutamine when this population is adequately fed. This trial is registered with NTR2285.

  19. Modelling the residual stresses and microstructural evolution in Friction Stir Welding of AA2024-T3 including the Wagner-Kampmann precipitation model

    DEFF Research Database (Denmark)

    Sonne, Mads Rostgaard; Hattel, Jesper Henri

    In this work, a numerical finite element model for friction stir welding of 2024-T3 aluminum alloy, consisting of a heat transfer analysis and a sequentially coupled quasi-static stress analysis is proposed. Metallurgical softening of the material is properly considered and included...

  20. PRMT5: A novel regulator of Hepatitis B virus replication and an arginine methylase of HBV core.

    Directory of Open Access Journals (Sweden)

    Barbora Lubyova

    Full Text Available In mammals, protein arginine methyltransferase 5, PRMT5, is the main type II enzyme responsible for the majority of symmetric dimethylarginine formation in polypeptides. Recent study reported that PRMT5 restricts Hepatitis B virus (HBV replication through epigenetic repression of HBV DNA transcription and interference with encapsidation of pregenomic RNA. Here we demonstrate that PRMT5 interacts with the HBV core (HBc protein and dimethylates arginine residues within the arginine-rich domain (ARD of the carboxyl-terminus. ARD consists of four arginine rich subdomains, ARDI, ARDII, ARDIII and ARDIV. Mutation analysis of ARDs revealed that arginine methylation of HBc required the wild-type status of both ARDI and ARDII. Mass spectrometry analysis of HBc identified multiple potential ubiquitination, methylation and phosphorylation sites, out of which lysine K7 and arginines R150 (within ARDI and R156 (outside ARDs were shown to be modified by ubiquitination and methylation, respectively. The HBc symmetric dimethylation appeared to be linked to serine phosphorylation and nuclear import of HBc protein. Conversely, the monomethylated HBc retained in the cytoplasm. Thus, overexpression of PRMT5 led to increased nuclear accumulation of HBc, and vice versa, down-regulation of PRMT5 resulted in reduced levels of HBc in nuclei of transfected cells. In summary, we identified PRMT5 as a potent controller of HBc cell trafficking and function and described two novel types of HBc post-translational modifications (PTMs, arginine methylation and ubiquitination.

  1. Inversion of allosteric effect of arginine on N-acetylglutamate synthase, a molecular marker for evolution of tetrapods

    Directory of Open Access Journals (Sweden)

    Cabrera-Luque Juan

    2008-09-01

    Full Text Available Abstract Background The efficient conversion of ammonia, a potent neurotoxin, into non-toxic metabolites was an essential adaptation that allowed animals to move from the aquatic to terrestrial biosphere. The urea cycle converts ammonia into urea in mammals, amphibians, turtles, snails, worms and many aquatic animals and requires N-acetylglutamate (NAG, an essential allosteric activator of carbamylphosphate synthetase I (CPSI in mammals and amphibians, and carbamylphosphate synthetase III (CPSIII in fish and invertebrates. NAG-dependent CPSI and CPSIII catalyze the formation of carbamylphosphate in the first and rate limiting step of ureagenesis. NAG is produced enzymatically by N-acetylglutamate synthase (NAGS, which is also found in bacteria and plants as the first enzyme of arginine biosynthesis. Arginine is an allosteric inhibitor of microbial and plant NAGS, and allosteric activator of mammalian NAGS. Results Information from mutagenesis studies of E. coli and P. aeruginosa NAGS was combined with structural information from the related bacterial N-acetylglutamate kinases to identify four residues in mammalian NAGS that interact with arginine. Substitutions of these four residues were engineered in mouse NAGS and into the vertebrate-like N-acetylglutamate synthase-kinase (NAGS-K of Xanthomonas campestris, which is inhibited by arginine. All mutations resulted in arginine losing the ability to activate mouse NAGS, and inhibit X. campestris NAGS-K. To examine at what point in evolution inversion of arginine effect on NAGS occur, we cloned NAGS from fish and frogs and examined the arginine response of their corresponding proteins. Fish NAGS were partially inhibited by arginine and frog NAGS were activated by arginine. Conclusion Difference in arginine effect on bacterial and mammalian NAGS most likely stems from the difference in the type of conformational change triggered by arginine binding to these proteins. The change from arginine

  2. Hepatic adaptation compensates inactivation of intestinal arginine biosynthesis in suckling mice.

    Directory of Open Access Journals (Sweden)

    Vincent Marion

    Full Text Available Suckling mammals, including mice, differ from adults in the abundant expression of enzymes that synthesize arginine from citrulline in their enterocytes. To investigate the importance of the small-intestinal arginine synthesis for whole-body arginine production in suckling mice, we floxed exon 13 of the argininosuccinate synthetase (Ass gene, which codes for a key enzyme in arginine biosynthesis, and specifically and completely ablated Ass in enterocytes by crossing Ass (fl and Villin-Cre mice. Unexpectedly, Ass (fl/fl /VilCre (tg/- mice showed no developmental impairments. Amino-acid fluxes across the intestine, liver, and kidneys were calculated after determining the blood flow in the portal vein, and hepatic and renal arteries (86%, 14%, and 33%, respectively, of the transhepatic blood flow in 14-day-old mice. Relative to control mice, citrulline production in the splanchnic region of Ass (fl/fl /VilCre (tg/- mice doubled, while arginine production was abolished. Furthermore, the net production of arginine and most other amino acids in the liver of suckling control mice declined to naught or even changed to consumption in Ass (fl/fl /VilCre (tg/- mice, and had, thus, become remarkably similar to that of post-weaning wild-type mice, which no longer express arginine-biosynthesizing enzymes in their small intestine. The adaptive changes in liver function were accompanied by an increased expression of genes involved in arginine metabolism (Asl, Got1, Gpt2, Glud1, Arg1, and Arg2 and transport (Slc25a13, Slc25a15, and Slc3a2, whereas no such changes were found in the intestine. Our findings suggest that the genetic premature deletion of arginine synthesis in enterocytes causes a premature induction of the post-weaning pattern of amino-acid metabolism in the liver.

  3. The effects of L-arginine, D-arginine, L-name and methylene blue on channa striatus-induced peripheral antinociception in mice.

    Science.gov (United States)

    Zakaria, Zainul Amiruddin; Sulaiman, Mohd Rosian; Somchit, Muhammad Nazrul; Jais, Abdul Manan Mat; Ali, Daud Israf

    2005-08-03

    To determine the involvement of nitric oxide/cyclic guanosine monophosphate (NO/cGMP) pathway in aqueous supernatant of haruan (Channa striatus) fillet (ASH) antinociception using the acetic acid-induced abdominal constriction test. The ASH was prepared by soaking fresh haruan fillet in chloroform:methanol (CM) (2/1 (v/v)) for 72 h followed by evaporation of the upper layer supernatant to remove any solvent residues. The supernatant was then subjected to a freeze-drying process (48 h) followed by doses preparation. Subcutaneous (SC) administration of ASH alone (0.170, 0.426 and 1.704 mg/kg) exhibited a dose-dependent antinociception. On the other hand, 20 mg/kg (SC) of L-arginine and MB exhibited a significant nociception and antinociception, while D-arginine and L-NAME did not produce any effect at all. Pre-treatment with L-arginine was found to significantly reverse the three respective doses of ASH antinociception; pre-treatment with D-arginine did not produce any significant change in the ASH activity; pre-treatment with L-NAME only significantly increased the 0.170 and 0.426 mg/kg ASH antinociception; and pre-treatment with MB significantly enhanced the respective doses of ASH antinociception, respectively. Furthermore, co-treatment with L-NAME significantly enhanced the L-arginine reversal effect on 0.426 mg/kg ASH antinociception. In addition, MB significantly reversed the L-arginine nociception on 0.426 mg/kg ASH. These finding suggest ASH antinociception involves the nitric oxide (NO)/cyclic guanosine monophosphate (cGMP) pathway. The presence of NO was found to reverse ASH antinociceptive activity while blocking of cGMP system enhanced it.

  4. Short Arginine Motifs Drive Protein Stickiness in the Escherichia coli Cytoplasm.

    Science.gov (United States)

    Kyne, Ciara; Crowley, Peter B

    2017-09-19

    Although essential to numerous biotech applications, knowledge of molecular recognition by arginine-rich motifs in live cells remains limited. 1 H, 15 N HSQC and 19 F NMR spectroscopies were used to investigate the effects of C-terminal -GR n (n = 1-5) motifs on GB1 interactions in Escherichia coli cells and cell extracts. While the "biologically inert" GB1 yields high-quality in-cell spectra, the -GR n fusions with n = 4 or 5 were undetectable. This result suggests that a tetra-arginine motif is sufficient to drive interactions between a test protein and macromolecules in the E. coli cytoplasm. The inclusion of a 12 residue flexible linker between GB1 and the -GR 5 motif did not improve detection of the "inert" domain. In contrast, all of the constructs were detectable in cell lysates and extracts, suggesting that the arginine-mediated complexes were weak. Together these data reveal the significance of weak interactions between short arginine-rich motifs and the E. coli cytoplasm and demonstrate the potential of such motifs to modify protein interactions in living cells. These interactions must be considered in the design of (in vivo) nanoscale assemblies that rely on arginine-rich sequences.

  5. Residual deposits (residual soil)

    International Nuclear Information System (INIS)

    Khasanov, A.Kh.

    1988-01-01

    Residual soil deposits is accumulation of new formate ore minerals on the earth surface, arise as a result of chemical decomposition of rocks. As is well known, at the hyper genes zone under the influence of different factors (water, carbonic acid, organic acids, oxygen, microorganism activity) passes chemical weathering of rocks. Residual soil deposits forming depends from complex of geologic and climatic factors and also from composition and physical and chemical properties of initial rocks

  6. Effects of l-arginine pretreatment on nitric oxide metabolism and hepatosplanchnic perfusion during porcine endotoxemia1234

    Science.gov (United States)

    Bruins, Maaike J; Kessels, Fons; Luiking, Yvette C; Lamers, Wouter H; Deutz, Nicolaas EP

    2011-01-01

    Background: Sepsis is accompanied by an increased need for and a decreased supply of arginine, reflecting a condition of arginine deficiency. Objective: The objective was to evaluate the effects of l-arginine pretreatment on arginine–nitric oxide (NO) production and hepatosplanchnic perfusion during subsequent endotoxemia. Design: In a randomized controlled trial, pigs (20–25 kg) received 3 μg ⋅ kg−1 ⋅ min−1 lipopolysaccharide (LPS; 5 endotoxin units/ng) intravenously and saline resuscitation. l-Arginine (n = 8; 5.3 μmol ⋅ kg−1 ⋅ min−1) or saline (n = 8) was infused starting 12 h before LPS infusion and continued for 24 h after the endotoxin infusion ended. Whole-body appearance rates, portal-drained viscera (PDV), and liver fluxes of arginine, citrulline, NO, and arginine de novo synthesis were measured by using stable-isotope infusion of [15N2]arginine and [13C-2H2]citrulline. Hepatosplanchnic perfusion was assessed by using a primed continuous infusion of para-aminohippuric acid and jejunal intramucosal partial pressure of carbon dioxide and was related to systemic hemodynamics. Results: Arginine supplementation before LPS increased whole-body NO production in the PDV but not in the liver. Furthermore, it increased blood flow in the portal vein but not in the aorta and hepatic artery. During endotoxin infusion, arginine pretreatment was associated with an increased whole-body arginine appearance and NO production in the gut. Additional effects included a preserved mean arterial pressure, the prevention of an increase in pulmonary arterial pressure, an attenuated metabolic acidosis, and an attenuated increase in the intramucosal partial pressure of carbon dioxide. Conclusion: Arginine treatment starting before endotoxemia appears to be beneficial because it improves hepatosplanchnic perfusion and oxygenation during prolonged endotoxemia, probably through an enhancement in NO synthesis, without causing deleterious systemic side effects. PMID

  7. THE ARGININE AND PREARGININE GROUPS IN EDESTIN.

    Science.gov (United States)

    Simms, H S

    1930-09-20

    The author corroborates the data of Schmidt showing that the dissociation index of the third group of arginine is pK(3)' = 12.5. New titration data of edestin have been obtained in very alkaline solutions and show that there is a corresponding group with a titration index of pG' = 12.0, but present in much less quantity than can account for the arginine found on hydrolysis. The data support the theory that the combination of strong base or strong acid with proteins is produced by the formation of salts with the "extra groups" of those trivalent amino acids which can be isolated from the protein, with the exception of arginine. Arginine contributes to the titration curve in much smaller amount than is found on hydrolysis. This deficiency in the arginine group may be accounted for by the basic group in proteins having a titration index of pG' = 3.8 to 4.6 (depending on the protein), which apparently yields arginine on hydrolysis, and may properly be called prearginine.

  8. Supplementation of bovine embryo culture medium with L-arginine improves embryo quality via nitric oxide production.

    Science.gov (United States)

    Santana, Priscila Di Paula Bessa; Silva, Thiago Velasco Guimarães; da Costa, Nathália Nogueira; da Silva, Bruno Barauna; Carter, Timothy Frederick; Cordeiro, Marcela da Silva; da Silva, Bruno José Martins; Santos, Simone do Socorro Damasceno; Herculano, Anderson Manoel; Adona, Paulo Roberto; Ohashi, Otávio Mitio; Miranda, Moysés dos Santos

    2014-10-01

    Nitric oxide (NO) is a cell-signaling molecule that regulates a variety of molecular pathways. We investigated the role of NO during preimplantation embryonic development by blocking its production with an inhibitor or supplementing in vitro bovine embryo cultures with its natural precursor, L-arginine, over different periods. Endpoints evaluated included blastocyst rates, development kinetics, and embryo quality. Supplementation with the NO synthase inhibitor N-Nitro-L-arginine-methyl ester (L-NAME) from Days 1 to 8 of culture decreased blastocyst (P L-arginine decreased blastocyst rates (P L-arginine improved embryo hatching rates (P supplementing the embryo culture medium with L-arginine favors preimplantation development of bovine embryos. © 2014 Wiley Periodicals, Inc.

  9. A lysine-to-arginine mutation on NEDD8 markedly reduces the activity of cullin RING E3 ligase through the impairment of neddylation cascades.

    Science.gov (United States)

    Sui, Yiyan; Liu, Yaobin; Xu, Guoqiang

    2015-06-12

    Neural-precursor-cell-expressed developmentally down-regulated 8 (NEDD8) is a ubiquitin-like modifier, which forms covalent conjugates on lysines of its substrates. This post-translational modification, neddylation, plays important roles in tumor cell proliferation and viability. Ubiquitin can form diverse polyubiquitin chains, on its seven lysines, which play important functions in various biological processes. However, the roles of lysines in NEDD8 have not been explored. Here, we generated nine NEDD8 point mutants, each with one lysine replaced by an arginine, to study the putative function of lysines in NEDD8. Our experiments discover that Lys27 in NEDD8 is a critical residue for protein neddylation. Replacement of this residue with arginine almost completely eliminates the conjugation of NEDD8 to its substrates. Furthermore, we find that the K27R mutant impairs NEDD8 conjugation to the E2 enzyme, which normally forms thioester bonds for further transferring NEDD8 to its ligases and substrates. Therefore, this mutation completely inhibits global protein neddylation, including neddylation of cullin family proteins, resulting in decreased activity of cullin-RING E3 ligases. This work sheds new light on the roles of NEDD8 lysines on neddylation cascades and provides a dominant negative mutant for the study of neddylation and its biological functions. Copyright © 2015 Elsevier Inc. All rights reserved.

  10. CcpA regulates arginine biosynthesis in Staphylococcus aureus through repression of proline catabolism.

    Directory of Open Access Journals (Sweden)

    Austin S Nuxoll

    Full Text Available Staphylococcus aureus is a leading cause of community-associated and nosocomial infections. Imperative to the success of S. aureus is the ability to adapt and utilize nutrients that are readily available. Genomic sequencing suggests that S. aureus has the genes required for synthesis of all twenty amino acids. However, in vitro experimentation demonstrates that staphylococci have multiple amino acid auxotrophies, including arginine. Although S. aureus possesses the highly conserved anabolic pathway that synthesizes arginine via glutamate, we demonstrate here that inactivation of ccpA facilitates the synthesis of arginine via the urea cycle utilizing proline as a substrate. Mutations within putA, rocD, arcB1, argG and argH abolished the ability of S. aureus JE2 ccpA::tetL to grow in the absence of arginine, whereas an interruption in argJBCF, arcB2, or proC had no effect. Furthermore, nuclear magnetic resonance demonstrated that JE2 ccpA::ermB produced (13C(5 labeled arginine when grown with (13C(5 proline. Taken together, these data support the conclusion that S. aureus synthesizes arginine from proline during growth on secondary carbon sources. Furthermore, although highly conserved in all sequenced S. aureus genomes, the arginine anabolic pathway (ArgJBCDFGH is not functional under in vitro growth conditions. Finally, a mutation in argH attenuated virulence in a mouse kidney abscess model in comparison to wild type JE2 demonstrating the importance of arginine biosynthesis in vivo via the urea cycle. However, mutations in argB, argF, and putA did not attenuate virulence suggesting both the glutamate and proline pathways are active and they, or their pathway intermediates, can complement each other in vivo.

  11. Kidney Mass Reduction Leads to l-Arginine Metabolism-Dependent Blood Pressure Increase in Mice.

    Science.gov (United States)

    Pillai, Samyuktha Muralidharan; Seebeck, Petra; Fingerhut, Ralph; Huang, Ji; Ming, Xiu-Fen; Yang, Zhihong; Verrey, François

    2018-02-25

    Uninephrectomy (UNX) is performed for various reasons, including kidney cancer or donation. Kidneys being the main site of l-arginine production in the body, we tested whether UNX mediated kidney mass reduction impacts l-arginine metabolism and thereby nitric oxide production and blood pressure regulation in mice. In a first series of experiments, we observed a significant increase in arterial blood pressure 8 days post-UNX in female and not in male mice. Further experimental series were performed in female mice, and the blood pressure increase was confirmed by telemetry. l-citrulline, that is used in the kidney to produce l-arginine, was elevated post-UNX as was also asymmetric dimethylarginine, an inhibitor of nitric oxide synthase that competes with l-arginine and is a marker for renal failure. Interestingly, the UNX-induced blood pressure increase was prevented by supplementation of the diet with 5% of the l-arginine precursor, l-citrulline. Because l-arginine is metabolized in the kidney and other peripheral tissues by arginase-2, we tested whether the lack of this metabolic pathway also compensates for decreased l-arginine production in the kidney and/or for local nitric oxide synthase inhibition and consecutive blood pressure increase. Indeed, upon uninephrectomy, arginase-2 knockout mice (Arg-2 -/- ) neither displayed an increase in asymmetric dimethylarginine and l-citrulline plasma levels nor a significant increase in blood pressure. UNX leads to a small increase in blood pressure that is prevented by l-citrulline supplementation or arginase deficiency, 2 measures that appear to compensate for the impact of kidney mass reduction on l-arginine metabolism. © 2018 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley.

  12. Arginine phosphorylation marks proteins for degradation by a Clp protease.

    Science.gov (United States)

    Trentini, Débora Broch; Suskiewicz, Marcin Józef; Heuck, Alexander; Kurzbauer, Robert; Deszcz, Luiza; Mechtler, Karl; Clausen, Tim

    2016-11-03

    Protein turnover is a tightly controlled process that is crucial for the removal of aberrant polypeptides and for cellular signalling. Whereas ubiquitin marks eukaryotic proteins for proteasomal degradation, a general tagging system for the equivalent bacterial Clp proteases is not known. Here we describe the targeting mechanism of the ClpC-ClpP proteolytic complex from Bacillus subtilis. Quantitative affinity proteomics using a ClpP-trapping mutant show that proteins phosphorylated on arginine residues are selectively targeted to ClpC-ClpP. In vitro reconstitution experiments demonstrate that arginine phosphorylation by the McsB kinase is required and sufficient for the degradation of substrate proteins. The docking site for phosphoarginine is located in the amino-terminal domain of the ClpC ATPase, as resolved at high resolution in a co-crystal structure. Together, our data demonstrate that phosphoarginine functions as a bona fide degradation tag for the ClpC-ClpP protease. This system, which is widely distributed across Gram-positive bacteria, is functionally analogous to the eukaryotic ubiquitin-proteasome system.

  13. IMMUNOSUPPRESSIVE EFFECTS OF ARGININE DEIMINASE FROM STREPTOCOCCUS PYOGENES

    Directory of Open Access Journals (Sweden)

    E. A. Starikova

    2015-01-01

    Full Text Available Many pathogens use metabolic pathway of arginine for successful dissemination. Bacterial arginine deiminase hydrolyzes arginine to form one molecule of ammonia and two molecules of ATP. The activity of the enzyme contributes to the improvement of survival of pathogenic bacteria in conditions of low pH at the site of infection or in phagolysosome, as well as in anaerobic conditions, and also leads to deficiency of arginine. Metabolism of arginine plays an important role in regulating the functions of immune system cells in mammals. Arginine is a substrate of enzymes NOS and arginase. Arginine depletion, potentially contributs to immunosuppression. The review analyzed the literature data on the effect of streptococcal arginine deiminase on the metabolism of arginine eukaryotic cells, and discusses immunosuppressive action of the enzyme.

  14. How Common Is Disorder? Occurrence of Disordered Residues in Four Domains of Life

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    Mikhail Yu. Lobanov

    2015-08-01

    Full Text Available Disordered regions play important roles in protein adaptation to challenging environmental conditions. Flexible and disordered residues have the highest propensities to alter the protein packing. Therefore, identification of disordered/flexible regions is important for structural and functional analysis of proteins. We used the IsUnstruct program to predict the ordered or disordered status of residues in 122 proteomes, including 97 eukaryotic and 25 large bacterial proteomes larger than 2,500,000 residues. We found that bacterial and eukaryotic proteomes contain comparable fraction of disordered residues, which was 0.31 in the bacterial and 0.38 in the eukaryotic proteomes. Additional analysis of the total of 1540 bacterial proteomes of various sizes yielded a smaller fraction of disordered residues, which was only 0.26. Together, the results showed that the larger is the size of the proteome, the larger is the fraction of the disordered residues. A continuous dependence of the fraction of disordered residues on the size of the proteome is observed for four domains of life: Eukaryota, Bacteria, Archaea, and Viruses. Furthermore, our analysis of 122 proteomes showed that the fraction of disordered residues increased with increasing the length of homo-repeats for polar, charged, and small residues, and decreased for hydrophobic residues. The maximal fraction of disordered residues was obtained for proteins containing lysine and arginine homo-repeats. The minimal fraction was found in valine and leucine homo-repeats. For 15-residue long homo-repeats these values were 0.2 (for Val and Leu and 0.7 (for Lys and Arg.

  15. Arginine and Lysine Transporters Are Essential for Trypanosoma brucei.

    OpenAIRE

    Mathieu, Christoph; Pereira de Macêdo, Juan; Hürlimann, Daniel; Wirdnam, Corina; Haindrich, Alexander; Suter, Marianne; González Salgado, Amaia; Schmidt, Remo; Inbar, Ehud; Mäser, Pascal; Bütikofer, Peter; Zilberstein, Dan; Rentsch, Doris

    2017-01-01

    For Trypanosoma brucei arginine and lysine are essential amino acids and therefore have to be imported from the host. Heterologous expression in Saccharomyces cerevisiae mutants identified cationic amino acid transporters among members of the T. brucei AAAP (amino acid/auxin permease) family. TbAAT5-3 showed high affinity arginine uptake (K m 3.6 ? 0.4 ?M) and high selectivity for L-arginine. L-arginine transport was reduced by a 10-times excess of L-arginine, homo-arginine, canavanine or arg...

  16. A Heparin Binding Motif Rich in Arginine and Lysine is the Functional Domain of YKL-40

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    Nipaporn Ngernyuang

    2018-02-01

    Full Text Available The heparin-binding glycoprotein YKL-40 (CHI3L1 is intimately associated with microvascularization in multiple human diseases including cancer and inflammation. However, the heparin-binding domain(s pertinent to the angiogenic activity have yet been identified. YKL-40 harbors a consensus heparin-binding motif that consists of positively charged arginine (R and lysine (K (RRDK; residues 144–147; but they don't bind to heparin. Intriguingly, we identified a separate KR-rich domain (residues 334–345 that does display strong heparin binding affinity. A short synthetic peptide spanning this KR-rich domain successfully competed with YKL-40 and blocked its ability to bind heparin. Three individual point mutations, where alanine (A substituted for K or R (K337A, K342A, R344A, led to remarkable decreases in heparin-binding ability and angiogenic activity. In addition, a neutralizing anti-YKL-40 antibody that targets these residues and prevents heparin binding impeded angiogenesis in vitro. MDA-MB-231 breast cancer cells engineered to express ectopic K337A, K342A or R344A mutants displayed reduced tumor development and compromised tumor vessel formation in mice relative to control cells expressing wild-type YKL-40. These data reveal that the KR-rich heparin-binding motif is the functional heparin-binding domain of YKL-40. Our findings shed light on novel molecular mechanisms underlying endothelial cell angiogenesis promoted by YKL-40 in a variety of diseases.

  17. A Heparin Binding Motif Rich in Arginine and Lysine is the Functional Domain of YKL-40.

    Science.gov (United States)

    Ngernyuang, Nipaporn; Yan, Wei; Schwartz, Lawrence M; Oh, Dennis; Liu, Ying-Bin; Chen, Hongzhuan; Shao, Rong

    2018-02-01

    The heparin-binding glycoprotein YKL-40 (CHI3L1) is intimately associated with microvascularization in multiple human diseases including cancer and inflammation. However, the heparin-binding domain(s) pertinent to the angiogenic activity have yet been identified. YKL-40 harbors a consensus heparin-binding motif that consists of positively charged arginine (R) and lysine (K) (RRDK; residues 144-147); but they don't bind to heparin. Intriguingly, we identified a separate KR-rich domain (residues 334-345) that does display strong heparin binding affinity. A short synthetic peptide spanning this KR-rich domain successfully competed with YKL-40 and blocked its ability to bind heparin. Three individual point mutations, where alanine (A) substituted for K or R (K337A, K342A, R344A), led to remarkable decreases in heparin-binding ability and angiogenic activity. In addition, a neutralizing anti-YKL-40 antibody that targets these residues and prevents heparin binding impeded angiogenesis in vitro. MDA-MB-231 breast cancer cells engineered to express ectopic K337A, K342A or R344A mutants displayed reduced tumor development and compromised tumor vessel formation in mice relative to control cells expressing wild-type YKL-40. These data reveal that the KR-rich heparin-binding motif is the functional heparin-binding domain of YKL-40. Our findings shed light on novel molecular mechanisms underlying endothelial cell angiogenesis promoted by YKL-40 in a variety of diseases. Copyright © 2018 The Authors. Published by Elsevier Inc. All rights reserved.

  18. Arginine Adjunctive Therapy in Active Tuberculosis

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    Aliasghar Farazi

    2015-01-01

    Full Text Available Background. Dietary supplementation has been used as a mechanism to augment the immune system. Adjunctive therapy with L-arginine has the potential to improve outcomes in active tuberculosis. Methods. In a randomized clinical trial 63 participants with smear-positive pulmonary tuberculosis in Markazi Province of Iran were given arginine or placebo for 4 weeks in addition to conventional chemotherapy. The final treatment success, sputum conversion, weight gain, and clinical symptoms after one and two months were considered as primary outcomes and secondary outcomes were ESR, CRP, and Hg. Data were collected and analyzed with SPSS software (ver. 18. Results. Arginine supplementation reduced constitutional symptoms (P=0.032 in patients with smear-positive TB at the end of the first month of treatment. Arginine treated patients had significantly increased BMI at the end of the first and second months of treatment (P=0.032 and P=0.04 and a reduced CRP at the end of the first month of treatment (P=0.03 versus placebo group. Conclusion. Arginine is useful as an adjunctive therapy in patients with active tuberculosis, in which the effects are more likely mediated by the increased production of nitric oxide and improved constitutional symptoms and weight gain. This trial is registered with Clinical Trials Registry of Iran: IRCT201211179855N2.

  19. Increased L-arginine Production by Site-directed Mutagenesis of N-acetyl-L-glutamate Kinase and proB Gene Deletion in Corynebacterium crenatum.

    Science.gov (United States)

    Zhang, Bin; Wan, Fang; Qiu, Yu Lou; Chen, Xue Lan; Tang, Li; Chen, Jin Cong; Xiong, Yong Hua

    2015-12-01

    In Corynebacterium crenatum, the adjacent D311 and D312 of N-acetyl-L-glutamate kinase (NAGK), as a key rate-limiting enzyme of L-arginine biosynthesis under substrate regulatory control by arginine, were initially replaced with two arginine residues to investigate the L-arginine feedback inhibition for NAGK. NAGK enzyme expression was evaluated using a plasmid-based method. Homologous recombination was employed to eliminate the proB. The IC50 and enzyme activity of NAGK M4, in which the D311R and D312R amino acid substitutions were combined with the previously reported E19R and H26E substitutions, were 3.7-fold and 14.6% higher, respectively, than those of the wild-type NAGK. NAGK M4 was successfully introduced into the C. crenatum MT genome without any genetic markers; the L-arginine yield of C. crenatum MT-M4 was 26.2% higher than that of C. crenatum MT. To further improve upon the L-arginine yield, we constructed the mutant C. crenatum MT-M4 proB. The optimum concentration of L-proline was also investigated in order to determine its contribution to L-arginine yield. After L-proline was added to the medium at 10 mmol/L, the L-arginine yield reached 16.5 g/L after 108 h of shake-flask fermentation, approximately 70.1% higher than the yield attained using C. crenatum MT. Feedback inhibition of L-arginine on NAGK in C. crenatum is clearly alleviated by the M4 mutation of NAGK, and deletion of the proB in C. crenatum from MT to M4 results in a significant increase in arginine production. Copyright © 2015 The Editorial Board of Biomedical and Environmental Sciences. Published by China CDC. All rights reserved.

  20. Effect of L-arginine and sildenafil citrate on intrauterine growth restriction fetuses: a meta-analysis.

    Science.gov (United States)

    Chen, Juncao; Gong, Xiaoyuan; Chen, Pingyang; Luo, Kaiju; Zhang, Xiuquan

    2016-08-16

    Intrauterine growth restriction (IUGR) is associated with perinatal morbidity and mortality. Several clinical trials have reported L-arginine and sildenafil citrate had effect on intrauterine growth restriction fetuses. A meta-analysis of available randomized controlled trials (RCTs) was conducted to investigate the effects of L-arginine and sildenafil citrate on major clinical outcomes of IUGR fetuses. Systematically searched Medline, Embase, the Cochrane Library, and Clinical Trials, references of retrieved articles, and conference proceedings from 1960 to 2015. We included randomized controlled trials assessing the effects of L-arginine and sildenafil citrate on IUGR. Outcomes analyzed were the birth weight, gestational age at labor, Apgar score at 1and 5 min, the ratio of NRDS, the ratio of ICH and neonatal death, etc. Ten trials were included. Nine trials (576 patients) compared L-arginine with either placebo or no intervention. In the L-arginine treatment groups of the L-arginine trials, there was a significant increase in fetal birth weight (SMD 0.41, 95 % CI [0.24,0.58]), gestational age (SMD 0.30, 95 % CI [0.07,0.54]); L-arginine treatment group have a significant reduction in the ratio of neonatal respiratory distress syndrome (P = 0.009), intracranial hemorrhage of fetuses (P = 0.002), but the number of included studies and people on these outcomes are small. As only one trial (41 patients) compared sildenafil citrate with placebo, it was too small for reliable conclusions about possible differential effects could be drawn. The results of this meta-analysis showed that L-arginine increased birth weight and prolonged gestational age at labor of IUGR fetuses. However, further large-scale RCTs are needed to adequately assess the effect of L-arginine and Sildenafil citrate on clinical outcomes, because the number of study may be small.

  1. l-Arginine Modifies the Exopolysaccharide Matrix and Thwarts Streptococcus mutans Outgrowth within Mixed-Species Oral Biofilms.

    Science.gov (United States)

    He, Jinzhi; Hwang, Geelsu; Liu, Yuan; Gao, Lizeng; Kilpatrick-Liverman, LaTonya; Santarpia, Peter; Zhou, Xuedong; Koo, Hyun

    2016-10-01

    of the most prevalent and costly infectious diseases worldwide, caused by a biofilm formed on tooth surfaces. Novel strategies that compromise the ability of virulent species to assemble and maintain pathogenic biofilms could be an effective alternative to conventional antimicrobials that indiscriminately kill other oral species, including commensal bacteria. l-Arginine at 1.5% has been shown to be clinically effective in modulating cariogenic biofilms via alkali production by arginolytic bacteria. Using a mixed-species ecological model, we show new mechanisms by which l-arginine disrupts the process of biofilm matrix assembly and the dynamic microbial interactions that are associated with cariogenic biofilm development, without impacting the bacterial viability. These results may aid in the development of enhanced methods to control biofilms using l-arginine. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

  2. Three consecutive arginines are important for the mycobacterial peptide deformylase enzyme activity.

    Science.gov (United States)

    Saxena, Rahul; Kanudia, Pavitra; Datt, Manish; Dar, Haider Hussain; Karthikeyan, Subramanian; Singh, Balvinder; Chakraborti, Pradip K

    2008-08-29

    Genes encoding the peptide deformylase enzyme (def) are present in all eubacteria and are involved in the deformylation of the N-formyl group of newly synthesized polypeptides during protein synthesis. We compared the amino acid sequences of this enzyme in different mycobacterial species and found that they are highly conserved (76% homology with 62% identity); however, when this comparison was extended to other eubacterial homologs, it emerged that the mycobacterial proteins have an insertion region containing three consecutive arginine residues (residues 77-79 in Mycobacterium tuberculosis peptide deformylase (mPDF)). Here, we demonstrate that these three arginines are important for the activity of mPDF. Circular dichroism studies of wild-type mPDF and of mPDF containing individual conservative substitutions (R77K, R78K, or R79K) or combined substitutions incorporated into a triple mutant (R77K/R78K/R79K) indicate that such mutations cause mPDF to undergo structural alterations. Molecular modeling of mPDF suggests that the three arginines are distal to the active site. Molecular dynamics simulations of wild-type and mutant mPDF structures indicate that the arginines may be involved in the stabilization of substrate binding pocket residues for their proper interaction with peptide(s). Treatment with 5'-phosphothiorate-modified antisense oligodeoxyribonucleotides directed against different regions of def from M. tuberculosis inhibits growth of Mycobacterium smegmatis in culture. Taken together, these results hold out the possibility of future design of novel mycobacteria-specific PDF inhibitors.

  3. [L-arginine and male infertility].

    Science.gov (United States)

    Scibona, M; Meschini, P; Capparelli, S; Pecori, C; Rossi, P; Menchini Fabris, G F

    1994-12-01

    The clinical efficacy and acceptance of L-arginina HCL was tested in 40 infertile men. All of these men had a normal number of spermatozoa (> 20 million/ml), but a decreased motility; this decreased motility was not due to infection or to immunological disorders. The treatment consisted of 80 ml of 10% L-arginine HCL administered daily per os for 6 months. L-arginine HCL showed to be able to improve the motility of spermatozoa without any side-effects.

  4. Arginine and Citrulline and the Immune Response in Sepsis

    Science.gov (United States)

    Wijnands, Karolina A.P.; Castermans, Tessy M.R.; Hommen, Merel P.J.; Meesters, Dennis M.; Poeze, Martijn

    2015-01-01

    Arginine, a semi-essential amino acid is an important initiator of the immune response. Arginine serves as a precursor in several metabolic pathways in different organs. In the immune response, arginine metabolism and availability is determined by the nitric oxide synthases and the arginase enzymes, which convert arginine into nitric oxide (NO) and ornithine, respectively. Limitations in arginine availability during inflammatory conditions regulate macrophages and T-lymfocyte activation. Furthermore, over the past years more evidence has been gathered which showed that arginine and citrulline deficiencies may underlie the detrimental outcome of inflammatory conditions, such as sepsis and endotoxemia. Not only does the immune response contribute to the arginine deficiency, also the impaired arginine de novo synthesis in the kidney has a key role in the eventual observed arginine deficiency. The complex interplay between the immune response and the arginine-NO metabolism is further underscored by recent data of our group. In this review we give an overview of physiological arginine and citrulline metabolism and we address the experimental and clinical studies in which the arginine-citrulline NO pathway plays an essential role in the immune response, as initiator and therapeutic target. PMID:25699985

  5. Arginine and Citrulline and the Immune Response in Sepsis

    Directory of Open Access Journals (Sweden)

    Karolina A.P. Wijnands

    2015-02-01

    Full Text Available Arginine, a semi-essential amino acid is an important initiator of the immune response. Arginine serves as a precursor in several metabolic pathways in different organs. In the immune response, arginine metabolism and availability is determined by the nitric oxide synthases and the arginase enzymes, which convert arginine into nitric oxide (NO and ornithine, respectively. Limitations in arginine availability during inflammatory conditions regulate macrophages and T-lymfocyte activation. Furthermore, over the past years more evidence has been gathered which showed that arginine and citrulline deficiencies may underlie the detrimental outcome of inflammatory conditions, such as sepsis and endotoxemia. Not only does the immune response contribute to the arginine deficiency, also the impaired arginine de novo synthesis in the kidney has a key role in the eventual observed arginine deficiency. The complex interplay between the immune response and the arginine-NO metabolism is further underscored by recent data of our group. In this review we give an overview of physiological arginine and citrulline metabolism and we address the experimental and clinical studies in which the arginine-citrulline NO pathway plays an essential role in the immune response, as initiator and therapeutic target.

  6. Effects of L-arginine on intestinal development and endogenous ...

    African Journals Online (AJOL)

    Arginine and its metabolites (citrulline and ornithine) were elevated, additionally, dietary supplementation with 0.8% L-arginine markedly enhanced jejunal villus height, villus area on day 11 and D-xylose absorption rate on day 19. Dietary supplementation with 0.8% L-arginine increased (P<0.05) activities of maltose and ...

  7. Mutational analysis to identify the residues essential for the inhibition of N-acetyl glutamate kinase of Corynebacterium glutamicum.

    Science.gov (United States)

    Huang, Yuanyuan; Zhang, Hao; Tian, Hongming; Li, Cheng; Han, Shuangyan; Lin, Ying; Zheng, Suiping

    2015-09-01

    N-acetyl glutamate kinase (NAGK) is a key enzyme in the synthesis of L-arginine that is inhibited by its end product L-arginine in Corynebacterium glutamicum (C. glutamicum). In this study, the potential binding sites of arginine and the residues essential for its inhibition were identified by homology modeling, inhibitor docking, and site-directed mutagenesis. The allosteric inhibition of NAGK was successfully alleviated by a mutation, as determined through analysis of mutant enzymes, which were overexpressed in vivo in C. glutamicum ATCC14067. Analysis of the mutant enzymes and docking analysis demonstrated that residue W23 positions an arginine molecule, and the interaction between arginine and residues L282, L283, and T284 may play an important role in the remote inhibitory process. Based on the results of the docking analysis of the effective mutants, we propose a linkage mechanism for the remote allosteric regulation of NAGK activity, in which residue R209 may play an essential role. In this study, the structure of the arginine-binding site of C. glutamicum NAGK (CgNAGK) was successfully predicted and the roles of the relevant residues were identified, providing new insight into the allosteric regulation of CgNAGK activity and a solid platform for the future construction of an optimized L-arginine producing strain.

  8. Low plasma arginine:asymmetric dimethyl arginine ratios predict mortality after intracranial aneurysm rupture

    DEFF Research Database (Denmark)

    Staalsø, Jonatan Myrup; Bergström, Anita; Edsen, Troels

    2013-01-01

    Asymmetrical dimethylarginine (ADMA), an endogenous inhibitor of nitric oxide synthases, predicts mortality in cardiovascular disease and has been linked to cerebral vasospasm after aneurysmal subarachnoid hemorrhage (SAH). In this prospective study, we assessed whether circulating ADMA, arginine...

  9. Genome-wide association reveals that common genetic variation in the kallikrein-kinin system is associated with serum L-arginine levels

    NARCIS (Netherlands)

    Zhang, Weihua; Jerneren, Fredrik; Lehne, Benjamin C.; Chen, Ming-Huei; Luben, Robert N.; Johnston, Carole; Elshorbagy, Amany; Eppinga, Ruben N.; Scott, William R.; Adeyeye, Elizabeth; Scott, James; Boeger, Rainer H.; Khaw, Kay-Tee; van der Harst, Pim; Wareham, Nicholas J.; Vasan, Ramachandran S.; Chambers, John C.; Refsum, Helga; Kooner, Jaspal S.

    2016-01-01

    L-arginine is the essential precursor of nitric oxide, and is involved in multiple key physiological processes, including vascular and immune function. The genetic regulation of blood L-arginine levels is largely unknown. We performed a genome-wide association study (GWAS) to identify genetic

  10. Lysine and arginine requirements of Salminus brasiliensis

    Directory of Open Access Journals (Sweden)

    Jony Koji Dairiki

    2013-08-01

    Full Text Available The objective of this work was to determine the dietary lysine (DL and dietary arginine (DA requirements of dourado (Salminus brasiliensis, through dose-response trials using the amino acid profiles of whole carcasses as a reference. Two experiments were carried out in a completely randomized design (n=4. In the first experiment, groups of 12 feed-conditioned dourado juveniles (11.4±0.2 g were stocked in 60 L cages placed in 300 L plastic indoor tanks in a closed circulation system. Fish were fed for 60 days on diets containing 1.0, 1.5, 2.0, 2.5, 3.0, or 3.5 % dietary lysine. In the second experiment, dourado juveniles (27.0±0.8 g were fed for 60 days on semipurified diets containing arginine at 1.0, 1.5, 2.0, 2.5 or 3.0%, in similar conditions to those of the first experiment. Optimal DL requirements, as determined by broken-line analysis method for final weight, weight gain and specific growth rate, were 2.15% DL or 5% lysine in dietary protein, and 1.48% DA or 3.43% arginine in dietary protein. The best feed conversion ratio is attained with 2.5% DL or 5.8% lysine in dietary protein and 1.4% DA or 3.25% arginine in dietary protein.

  11. Estimation of Plasma Arginine Vasopressin Concentration Using ...

    African Journals Online (AJOL)

    The purpose of this study was to estimate plasma arginine vasopressin (PAVP) using thirst perception (TP) and plasma osmolality (POSM) values before and at 60 minutes in control or euhydrate (group A, 0.0 ml/kg body weight of distilled water), hydrated (group B, 7.1ml/kg body weight of distilled water) and dehydrated ...

  12. Differences in DNA condensation and release by lysine and arginine homopeptides govern their DNA delivery efficiencies.

    Science.gov (United States)

    Mann, Anita; Thakur, Garima; Shukla, Vasundhara; Singh, Anand Kamal; Khanduri, Richa; Naik, Rangeetha; Jiang, Yang; Kalra, Namita; Dwarakanath, B S; Langel, Ulo; Ganguli, Munia

    2011-10-03

    Designing of nanocarriers that can efficiently deliver therapeutic DNA payload and allow its smooth intracellular release for transgene expression is still a major constraint. The optimization of DNA nanocarriers requires thorough understanding of the chemical and structural characteristics of the vector-nucleic acid complexes and its correlation with the cellular entry, intracellular state and transfection efficiency. L-lysine and L-arginine based cationic peptides alone or in conjugation with other vectors are known to be putative DNA delivery agents. Here we have used L-lysine and L-arginine homopeptides of three different lengths and probed their DNA condensation and release properties by using a multitude of biophysical techniques including fluorescence spectroscopy, gel electrophoresis and atomic force microscopy. Our results clearly showed that although both lysine and arginine based homopeptides condense DNA via electrostatic interactions, they follow different pattern of DNA condensation and release in vitro. While lysine homopeptides condense DNA to form both monomolecular and multimolecular complexes and show differential release of DNA in vitro depending on the peptide length, arginine homopeptides predominantly form multimolecular complexes and show complete DNA release for all peptide lengths. The cellular uptake of the complexes and their intracellular state (as observed through flow cytometry and fluorescence microscopy) seem to be controlled by the peptide chemistry. The difference in the transfection efficiency of lysine and arginine homopeptides has been rationalized in light of these observations.

  13. L-Arginine Modulates T Cell Metabolism and Enhances Survival and Anti-tumor Activity.

    Science.gov (United States)

    Geiger, Roger; Rieckmann, Jan C; Wolf, Tobias; Basso, Camilla; Feng, Yuehan; Fuhrer, Tobias; Kogadeeva, Maria; Picotti, Paola; Meissner, Felix; Mann, Matthias; Zamboni, Nicola; Sallusto, Federica; Lanzavecchia, Antonio

    2016-10-20

    Metabolic activity is intimately linked to T cell fate and function. Using high-resolution mass spectrometry, we generated dynamic metabolome and proteome profiles of human primary naive T cells following activation. We discovered critical changes in the arginine metabolism that led to a drop in intracellular L-arginine concentration. Elevating L-arginine levels induced global metabolic changes including a shift from glycolysis to oxidative phosphorylation in activated T cells and promoted the generation of central memory-like cells endowed with higher survival capacity and, in a mouse model, anti-tumor activity. Proteome-wide probing of structural alterations, validated by the analysis of knockout T cell clones, identified three transcriptional regulators (BAZ1B, PSIP1, and TSN) that sensed L-arginine levels and promoted T cell survival. Thus, intracellular L-arginine concentrations directly impact the metabolic fitness and survival capacity of T cells that are crucial for anti-tumor responses. Copyright © 2016 The Author(s). Published by Elsevier Inc. All rights reserved.

  14. Converting the Yeast Arginine Can1 Permease to a Lysine Permease*

    Science.gov (United States)

    Ghaddar, Kassem; Krammer, Eva-Maria; Mihajlovic, Natalija; Brohée, Sylvain; André, Bruno; Prévost, Martine

    2014-01-01

    Amino acid uptake in yeast cells is mediated by about 16 plasma membrane permeases, most of which belong to the amino acid-polyamine-organocation (APC) transporter family. These proteins display various substrate specificity ranges. For instance, the general amino acid permease Gap1 transports all amino acids, whereas Can1 and Lyp1 catalyze specific uptake of arginine and lysine, respectively. Although Can1 and Lyp1 have different narrow substrate specificities, they are close homologs. Here we investigated the molecular rules determining the substrate specificity of the H+-driven arginine-specific permease Can1. Using a Can1-Lyp1 sequence alignment as a guideline and a three-dimensional Can1 structural model based on the crystal structure of the bacterial APC family arginine/agmatine antiporter, we introduced amino acid substitutions liable to alter Can1 substrate specificity. We show that the single substitution T456S results in a Can1 variant transporting lysine in addition to arginine and that the combined substitutions T456S and S176N convert Can1 to a Lyp1-like permease. Replacement of a highly conserved glutamate in the Can1 binding site leads to variants (E184Q and E184A) incapable of any amino acid transport, pointing to a potential role for this glutamate in H+ coupling. Measurements of the kinetic parameters of arginine and lysine uptake by the wild-type and mutant Can1 permeases, together with docking calculations for each amino acid in their binding site, suggest a model in which residues at positions 176 and 456 confer substrate selectivity at the ligand-binding stage and/or in the course of conformational changes required for transport. PMID:24448798

  15. Butyroyl-arginine as a potent virus inactivation agent.

    Science.gov (United States)

    Katsuyama, Yukiko; Yamasaki, Hisashi; Tsujimoto, Kazuko; Koyama, A Hajime; Ejima, Daisuke; Arakawa, Tsutomu

    2008-09-01

    Virus inactivation is a critical step in the manufacturing of recombinant therapeutic proteins, in particular antibodies, using mammalian expression systems. We have shown in the previous paper that arginine is effective in inactivation of herpes simplex virus type 1 (HSV-1) and influenza virus at low temperature under mildly acidic pH, i.e., above pH 4.0; above this pH, conformational changes of most antibodies are negligible. We have here extended virus inactivation study of arginine to other enveloped viruses, such as Sendai virus and Newcastle Disease Virus (NDV), and observed that arginine was ineffective against both viruses under the similar conditions, i.e., on ice and above pH 4.0. However, an arginine derivative, butyroyl-arginine, showed a strong virucidal potency against Sendai virus, leading to a 4log reduction in virus yield at pH 4.0, but not against NDV. In addition, although arginine and butyroyl-arginine were equally effective against influenza virus having a cleaved form of hemagglutinin spike proteins, only butyroyl-arginine was significantly effective against the same virus, but having an uncleaved hemagglutinin spike proteins. Furthermore, butyroyl-arginine was more effective than arginine against HSV-1 at pH 4.5; i.e., it has a broader pH spectrum than does arginine.

  16. How does spa treatment affect cardiovascular function and vascular endothelium in patients with generalized osteoarthritis? A pilot study through plasma asymmetric di-methyl arginine (ADMA) and L-arginine/ADMA ratio

    Science.gov (United States)

    Karaarslan, Fatih; Ozkuk, Kagan; Seringec Karabulut, Serap; Bekpinar, Seldag; Karagulle, Mufit Zeki; Erdogan, Nergis

    2017-12-01

    The study aims to investigate the effect of spa treatment on vascular endothelium and clinical symptoms of generalized osteoarthritis. Forty generalized osteoarthritis (GOA) patients referred to a government spa hospital, and 40 GOA patients followed on university hospital locomotor system disease ambulatory clinics were included as study and control groups, respectively. Study group received spa treatment including thermal water baths, physical therapy modalities, and exercises. Control group was followed with home exercises for 15 days. Plasma ADMA, L-arginine, L-arginine/ADMA ratio, routine blood analyses, 6-min walking test, including fingertip O2 saturation, systolic/diastolic blood pressure, and pulse rate, were measured at the beginning and at the end of treatment. Groups were evaluated with VAS pain, patient, and physician global assessment; HAQ; and WOMAC at the beginning, at the end, and after 1 month of treatment. In study group, L-arginine and L-arginine/ADMA ratio showed statistically significant increase after treatment. Plasma ADMA levels did not change. There is no significant difference in intergroup comparison. Study group displayed statistically significant improvements in all clinical parameters. The study showed that spa treatment does not cause any harm to the vascular endothelium through ADMA. Significant increase in plasma L-arginine and L-arginine/ADMA ratio suggests that balneotherapy may play a preventive role on cardiovascular diseases. Balneotherapy provides meaningful improvements on clinical parameters of GOA.

  17. A randomized pilot study of L-arginine infusion in severe falciparum malaria: preliminary safety, efficacy and pharmacokinetics.

    Directory of Open Access Journals (Sweden)

    Tsin W Yeo

    Full Text Available Decreased nitric oxide (NO and hypoargininemia are associated with severe falciparum malaria and may contribute to severe disease. Intravenous L-arginine increases endothelial NO in moderately-severe malaria (MSM without adverse effects. The safety, efficacy and pharmacokinetics of L-arginine or other agents to improve NO bioavailability in severe malaria have not been assessed.In an open-label pilot study of L-arginine in adults with severe malaria (ARGISM-1 Study, patients were randomized to 12 g L-arginine hydrochloride or saline over 8 hours together with intravenous artesunate. Vital signs, selected biochemical measures (including blood lactate and L-arginine and endothelial NO bioavailability (using reactive hyperemia peripheral arterial tonometry [RH-PAT] were assessed serially. Pharmacokinetic analyses of L-arginine concentrations were performed using NONMEM.Six patients received L-arginine and two saline infusions. There were no deaths in either group. There were no changes in mean systolic (SBP and diastolic blood pressure (DBP or other vital signs with L-arginine, although a transient but clinically unimportant mean maximal decrease in SBP of 14 mmHg was noted. No significant changes in mean potassium, glucose, bicarbonate, or pH were seen, with transient mean maximal increases in plasma potassium of 0.3 mmol/L, and mean maximal decreases in blood glucose of 0.8 mmol/L and bicarbonate of 2.3 mEq/L following L-arginine administration. There was no effect on lactate clearance or RH-PAT index. Pharmacokinetic modelling (n = 4 showed L-arginine concentrations 40% lower than predicted from models developed in MSM.In the first clinical trial of an adjunctive treatment aimed at increasing NO bioavailability in severe malaria, L-arginine infused at 12 g over 8 hours was safe, but did not improve lactate clearance or endothelial NO bioavailability. Future studies may require increased doses of L-arginine.ClinicalTrials.gov NCT00616304.

  18. A Randomized Pilot Study of L-Arginine Infusion in Severe Falciparum Malaria: Preliminary Safety, Efficacy and Pharmacokinetics

    Science.gov (United States)

    Yeo, Tsin W.; Lampah, Daniel A.; Rooslamiati, Indri; Gitawati, Retno; Tjitra, Emiliana; Kenangalem, Enny; Price, Ric N.; Duffull, Stephen B.; Anstey, Nicholas M.

    2013-01-01

    Background Decreased nitric oxide (NO) and hypoargininemia are associated with severe falciparum malaria and may contribute to severe disease. Intravenous L-arginine increases endothelial NO in moderately-severe malaria (MSM) without adverse effects. The safety, efficacy and pharmacokinetics of L-arginine or other agents to improve NO bioavailability in severe malaria have not been assessed. Methods In an open-label pilot study of L-arginine in adults with severe malaria (ARGISM-1 Study), patients were randomized to 12 g L-arginine hydrochloride or saline over 8 hours together with intravenous artesunate. Vital signs, selected biochemical measures (including blood lactate and L-arginine) and endothelial NO bioavailability (using reactive hyperemia peripheral arterial tonometry [RH-PAT]) were assessed serially. Pharmacokinetic analyses of L-arginine concentrations were performed using NONMEM. Results Six patients received L-arginine and two saline infusions. There were no deaths in either group. There were no changes in mean systolic (SBP) and diastolic blood pressure (DBP) or other vital signs with L-arginine, although a transient but clinically unimportant mean maximal decrease in SBP of 14 mmHg was noted. No significant changes in mean potassium, glucose, bicarbonate, or pH were seen, with transient mean maximal increases in plasma potassium of 0.3 mmol/L, and mean maximal decreases in blood glucose of 0.8 mmol/L and bicarbonate of 2.3 mEq/L following L-arginine administration. There was no effect on lactate clearance or RH-PAT index. Pharmacokinetic modelling (n = 4) showed L-arginine concentrations 40% lower than predicted from models developed in MSM. Conclusion In the first clinical trial of an adjunctive treatment aimed at increasing NO bioavailability in severe malaria, L-arginine infused at 12 g over 8 hours was safe, but did not improve lactate clearance or endothelial NO bioavailability. Future studies may require increased doses of L-arginine. Trial

  19. Proteomic analysis of arginine methylation sites in human cells reveals dynamic regulation during transcriptional arrest

    DEFF Research Database (Denmark)

    Sylvestersen, Kathrine B; Horn, Heiko; Jungmichel, Stephanie

    2014-01-01

    mono-methylation (MMA) sites. We thereby identify 1,027 site-specific MMA sites on 494 human proteins, discovering numerous novel mono-methylation targets and confirming the majority of currently known MMA substrates. Nuclear RNA-binding proteins involved in RNA processing, RNA localization......, transcription, and chromatin remodeling are predominantly found modified with MMA. Despite this, MMA sites prominently are located outside RNA-binding domains as compared to the proteome-wide distribution of arginine residues. Quantification of arginine methylation in cells treated with Actinomycin D uncovers...... strong site-specific regulation of MMA sites during transcriptional arrest. Interestingly, several MMA sites are down-regulated after a few hours of transcriptional arrest. In contrast, the corresponding di-methylation or protein expression level is not altered in expression, confirming that MMA sites...

  20. Mapping arginine methylation in the human body and cardiac disease.

    Science.gov (United States)

    Onwuli, Donatus O; Rigau-Roca, Laura; Cawthorne, Chris; Beltran-Alvarez, Pedro

    2017-01-01

    Arginine methylation (ArgMe) is one of the most ubiquitous PTMs, and hundreds of proteins undergo ArgMe in, for example, brain. However, the scope of ArgMe in many tissues, including the heart, is currently underexplored. Here, we aimed to (i) identify proteins undergoing ArgMe in human organs, and (ii) expose the relevance of ArgMe in cardiac disease. The publicly available proteomic data is used to search for ArgMe in 13 human tissues. To induce H9c2 cardiac-like cell hypertrophy glucose is used. The results show that ArgMe is mainly tissue-specific; nevertheless, the authors suggest an embryonic origin of core ArgMe events. In the heart, 103 mostly novel ArgMe sites in 58 nonhistone proteins are found. The authors provide compelling evidence that cardiac protein ArgMe is relevant to cardiomyocyte ontology, and important for proper cardiac function. This is highlighted by the fact that genetic mutations affecting methylated arginine positions are often associated with cardiac disease, including hypertrophic cardiomyopathy. The pilot experimental data suggesting significant changes in ArgMe profiles of H9c2 cells upon induction of cell hypertrophy using glucose is provided. The work calls for in-depth investigation of ArgMe in normal and diseased tissues using methods including clinical proteomics. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. l-arginine and l-NMMA for assessing cerebral endothelial dysfunction in ischaemic cerebrovascular disease

    DEFF Research Database (Denmark)

    Karlsson, William K; Sørensen, Caspar G; Kruuse, Christina

    2017-01-01

    Endothelial dysfunction (ED), in particular cerebral ED, may be an essential biomarker for ischaemic cerebrovascular disease. However, there is no consensus on methods to best estimate cerebral ED. In this systematic review, we evaluate the use of l-arginine and NG -monomethyl-l-arginine (l......-NMMA) for assessment of cerebral ED. A systematic search of PubMed, EMBASE and the Cochrane Library was done. We included studies investigating cerebrovascular response to l-arginine or l-NMMA in human subjects with vascular risk factors or ischaemic cerebrovascular disease. Seven studies (315 subjects) were eligible...... according to inclusion and exclusion criteria. Studies investigated the effect of age (n=2), type 2 diabetes mellitus (DM) (n=1), cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) (n=1), leukoaraiosis (n=1), and prior ischaemic stroke or transient ischaemic...

  2. Remission of diabetes mellitus in cats cannot be predicted by the arginine stimulation test.

    Science.gov (United States)

    Tschuor, F; Zini, E; Schellenberg, S; Wenger, M; Kaufmann, K; Furrer, D; Lutz, T A; Reusch, C E

    2011-01-01

    Cats with diabetes mellitus frequently achieve clinical remission, suggesting residual β-cell function. Responsiveness of β-cells to arginine persists the longest during diabetes progression, making the intravenous arginine stimulation test (IVAST) a useful tool to assess residual insulin and glucagon secretion. Diabetic cats with and without remission will have different arginine-induced insulin or glucagon response. Seventeen cats with diabetes, 7 healthy cats. Blood samples collected on admission and during subsequent IVAST. Glucose, insulin, and glucagon were measured. Response to IVAST was assessed by calculating the insulin and glucagon area under the curve (AUC) and the AUC glucagon-to-insulin ratio. Diabetic cats were treated with insulin and were followed for 18 weeks. Remission was defined as normoglycemia and disappearance of clinical signs of diabetes for ≥4 weeks, without requiring insulin. Seven diabetic cats (41%) achieved remission. On admission, blood glucose concentration was significantly lower in cats with remission (median, 389 mg/dL; range, 342-536 mg/dL) than in those without remission (median, 506 mg/dL; range, 266-738 mg/dL). After IVAST, diabetic cats with remission had higher AUC glucagon-to-insulin ratios (median, 61; range, 34-852) than did cats without remission (median, 26; range, 20-498); glucose, insulin, and glucagon AUCs were not different. Diabetic cats had lower insulin AUC than did healthy cats but comparable glucagon AUC. Diabetic cats with and without remission have similar arginine-stimulated insulin secretion on admission. Although cats with remission had lower blood glucose concentrations and higher AUC glucagon-to-insulin ratios, large overlap between groups prevents use of these parameters in clinical practice. Copyright © 2010 by the American College of Veterinary Internal Medicine.

  3. l-Arginine-Dependent Epigenetic Regulation of Interleukin-10, but Not Transforming Growth Factor-β, Production by Neonatal Regulatory T Lymphocytes

    Science.gov (United States)

    Yu, Hong-Ren; Tsai, Ching-Chang; Chang, Ling-Sai; Huang, Hsin-Chun; Cheng, Hsin-Hsin; Wang, Jiu-Yao; Sheen, Jiunn-Ming; Kuo, Ho-Chang; Hsieh, Kai-Sheng; Huang, Ying-Hsien; Yang, Kuender D.; Hsu, Te-Yao

    2017-01-01

    A growing number of diseases in humans, including trauma, certain cancers, and infection, are known to be associated with l-arginine deficiency. In addition, l-arginine must be supplemented by diet during pregnancy to aid fetal development. In conditions of l-arginine depletion, T cell proliferation is impaired. We have previously shown that neonatal blood has lower l-arginine levels than adult blood, which is associated with poor neonatal lymphocyte proliferation, and that l-arginine enhances neonatal lymphocyte proliferation through an interleukin (IL)-2-independent pathway. In this study, we have further investigated how exogenous l-arginine enhances neonatal regulatory T-cells (Tregs) function in relation to IL-10 production under epigenetic regulation. Results showed that cord blood mononuclear cells (CBMCs) produced higher levels of IL-10 than adult peripheral blood mononuclear cells (PBMCs) by phytohemagglutinin stimulation but not by anti-CD3/anti-CD28 stimulation. Addition of exogenous l-arginine had no effect on transforming growth factor-β production by PBMCs or CBMCs, but enhanced IL-10 production by neonatal CD4+CD25+FoxP3+ Tregs. Further studies showed that IL-10 promoter DNA hypomethylation, rather than histone modification, corresponded to the l-arginine-induced increase in IL-10 production by neonatal CD4+ T cells. These results suggest that l-arginine modulates neonatal Tregs through the regulation of IL-10 promoter DNA methylation. l-arginine supplementation may correct the Treg function in newborns with l-arginine deficiency. PMID:28487700

  4. l-Arginine-Dependent Epigenetic Regulation of Interleukin-10, but Not Transforming Growth Factor-β, Production by Neonatal Regulatory T Lymphocytes

    Directory of Open Access Journals (Sweden)

    Kuender D. Yang

    2017-04-01

    Full Text Available A growing number of diseases in humans, including trauma, certain cancers, and infection, are known to be associated with l-arginine deficiency. In addition, l-arginine must be supplemented by diet during pregnancy to aid fetal development. In conditions of l-arginine depletion, T cell proliferation is impaired. We have previously shown that neonatal blood has lower l-arginine levels than adult blood, which is associated with poor neonatal lymphocyte proliferation, and that l-arginine enhances neonatal lymphocyte proliferation through an interleukin (IL-2-independent pathway. In this study, we have further investigated how exogenous l-arginine enhances neonatal regulatory T-cells (Tregs function in relation to IL-10 production under epigenetic regulation. Results showed that cord blood mononuclear cells (CBMCs produced higher levels of IL-10 than adult peripheral blood mononuclear cells (PBMCs by phytohemagglutinin stimulation but not by anti-CD3/anti-CD28 stimulation. Addition of exogenous l-arginine had no effect on transforming growth factor-β production by PBMCs or CBMCs, but enhanced IL-10 production by neonatal CD4+CD25+FoxP3+ Tregs. Further studies showed that IL-10 promoter DNA hypomethylation, rather than histone modification, corresponded to the l-arginine-induced increase in IL-10 production by neonatal CD4+ T cells. These results suggest that l-arginine modulates neonatal Tregs through the regulation of IL-10 promoter DNA methylation. l-arginine supplementation may correct the Treg function in newborns with l-arginine deficiency.

  5. An Efficient Method for the Synthesis of Peptoids with Mixed Lysine-type/Arginine-type Monomers and Evaluation of Their Anti-leishmanial Activity.

    Science.gov (United States)

    Bolt, Hannah L; Denny, Paul W; Cobb, Steven L

    2016-11-02

    This protocol describes the manual solid-phase synthesis of linear peptoids that contain two differently functionalized cationic monomers. In this procedure amino functionalized 'lysine' and guanido functionalized 'arginine' peptoid monomers can be included within the same peptoid sequence. This procedure uses on-resin (N-(1-(4,4-dimethyl-2,6-dioxocyclohexylidene)ethyl) or Dde protection, orthogonal conditions to the Boc protection of lysine monomers. Subsequent deprotection allows an efficient on-resin guanidinylation reaction to form the arginine residues. The procedure is compatible with the commonly used submonomer method of peptoid synthesis, allowing simple peptoids to be made using common laboratory equipment and commercially available reagents. The representative synthesis, purification and characterization of two mixed peptoids is described. The evaluation of these compounds as potential anti-infectives in screening assays against Leishmania mexicana is also described. The protozoan parasite L. mexicana is a causative agent of cutaneous leishmaniasis, a neglected tropical disease that affects up to 12 million people worldwide.

  6. L-arginine and Vitamin D Adjunctive Therapies in Pulmonary Tuberculosis: A Randomised, Double-Blind, Placebo-Controlled Trial

    Science.gov (United States)

    Ralph, Anna P.; Waramori, Govert; Pontororing, Gysje J.; Kenangalem, Enny; Wiguna, Andri; Tjitra, Emiliana; Sandjaja; Lolong, Dina B.; Yeo, Tsin W.; Chatfield, Mark D.; Soemanto, Retno K.; Bastian, Ivan; Lumb, Richard; Maguire, Graeme P.; Eisman, John; Price, Ric N.; Morris, Peter S.; Kelly, Paul M.; Anstey, Nicholas M.

    2013-01-01

    Background Vitamin D (vitD) and L-arginine have important antimycobacterial effects in humans. Adjunctive therapy with these agents has the potential to improve outcomes in active tuberculosis (TB). Methods In a 4-arm randomised, double-blind, placebo-controlled factorial trial in adults with smear-positive pulmonary tuberculosis (PTB) in Timika, Indonesia, we tested the effect of oral adjunctive vitD 50,000 IU 4-weekly or matching placebo, and L-arginine 6.0 g daily or matching placebo, for 8 weeks, on proportions of participants with negative 4-week sputum culture, and on an 8-week clinical score (weight, FEV1, cough, sputum, haemoptysis). All participants with available endpoints were included in analyses according to the study arm to which they were originally assigned. Adults with new smear-positive PTB were eligible. The trial was registered at ClinicalTrials.gov NCT00677339. Results 200 participants were enrolled, less than the intended sample size: 50 received L-arginine + active vitD, 49 received L-arginine + placebo vit D, 51 received placebo L-arginine + active vitD and 50 received placebo L-arginine + placebo vitD. According to the factorial model, 99 people received arginine, 101 placebo arginine, 101 vitamin D, 99 placebo vitamin D. Results for the primary endpoints were available in 155 (4-week culture) and 167 (clinical score) participants. Sputum culture conversion was achieved by week 4 in 48/76 (63%) participants in the active L-arginine versus 48/79 (61%) in placebo L-arginine arms (risk difference −3%, 95% CI −19 to 13%), and in 44/75 (59%) in the active vitD versus 52/80 (65%) in the placebo vitD arms (risk difference 7%, 95% CI −9 to 22%). The mean clinical outcome score also did not differ between study arms. There were no effects of the interventions on adverse event rates including hypercalcaemia, or other secondary outcomes. Conclusion Neither vitD nor L-arginine supplementation, at the doses administered and with the power attained

  7. L-arginine and vitamin D adjunctive therapies in pulmonary tuberculosis: a randomised, double-blind, placebo-controlled trial.

    Directory of Open Access Journals (Sweden)

    Anna P Ralph

    Full Text Available Vitamin D (vitD and L-arginine have important antimycobacterial effects in humans. Adjunctive therapy with these agents has the potential to improve outcomes in active tuberculosis (TB.In a 4-arm randomised, double-blind, placebo-controlled factorial trial in adults with smear-positive pulmonary tuberculosis (PTB in Timika, Indonesia, we tested the effect of oral adjunctive vitD 50,000 IU 4-weekly or matching placebo, and L-arginine 6.0 g daily or matching placebo, for 8 weeks, on proportions of participants with negative 4-week sputum culture, and on an 8-week clinical score (weight, FEV1, cough, sputum, haemoptysis. All participants with available endpoints were included in analyses according to the study arm to which they were originally assigned. Adults with new smear-positive PTB were eligible. The trial was registered at ClinicalTrials.gov NCT00677339.200 participants were enrolled, less than the intended sample size: 50 received L-arginine + active vitD, 49 received L-arginine + placebo vit D, 51 received placebo L-arginine + active vitD and 50 received placebo L-arginine + placebo vitD. According to the factorial model, 99 people received arginine, 101 placebo arginine, 101 vitamin D, 99 placebo vitamin D. Results for the primary endpoints were available in 155 (4-week culture and 167 (clinical score participants. Sputum culture conversion was achieved by week 4 in 48/76 (63% participants in the active L-arginine versus 48/79 (61% in placebo L-arginine arms (risk difference -3%, 95% CI -19 to 13%, and in 44/75 (59% in the active vitD versus 52/80 (65% in the placebo vitD arms (risk difference 7%, 95% CI -9 to 22%. The mean clinical outcome score also did not differ between study arms. There were no effects of the interventions on adverse event rates including hypercalcaemia, or other secondary outcomes.Neither vitD nor L-arginine supplementation, at the doses administered and with the power attained, affected TB outcomes

  8. Effects of arginine on multimodal anion exchange chromatography.

    Science.gov (United States)

    Hirano, Atsushi; Arakawa, Tsutomu; Kameda, Tomoshi

    2015-12-01

    The effects of arginine on binding and elution properties of a multimodal anion exchanger, Capto adhere, were examined using bovine serum albumin (BSA) and a monoclonal antibody against interleukin-8 (mAb-IL8). Negatively charged BSA was bound to the positively charged Capto adhere and was readily eluted from the column with a stepwise or gradient elution using 1M NaCl at pH 7.0. For heat-treated BSA, small oligomers and remaining monomers were also eluted using a NaCl gradient, whereas larger oligomers required arginine for effective elution. The positively charged mAb-IL8 was bound to Capto adhere at pH 7.0. Arginine was also more effective for elution of the bound mAb-IL8 than was NaCl. The results imply that arginine interacts with the positively charged Capto adhere. The mechanism underlying the interactions of arginine with Capto adhere was examined by calculating the binding free energy between an arginine molecule and a Capto adhere ligand in water through molecular dynamics simulations. The overall affinity of arginine for Capto adhere is attributed to the hydrophobic and π-π interactions between an arginine side chain and the aromatic moiety of the ligand as well as hydrogen bonding between arginine and the ligand hydroxyl group, which may account for the characteristics of protein elution using arginine. Copyright © 2015 Elsevier Inc. All rights reserved.

  9. Preparation of arginine (guanide 14C)

    International Nuclear Information System (INIS)

    Pichat, L.; Baret, C.

    1960-01-01

    Reaction of anhydrous ammoniac at 800 deg. C on 14 CO 3 Ba gives rise to barium cyanamide 14 C with a yield of about 98 per cent. Addition on H 2 S on cyanamide 14 C leads to thiourea 14 C with a 85 per cent yield, which is quantitatively transformed into S-ethyl-isothiouronium iodide by treatment with methyl iodide. This 14 C-isothiouronium salt is used to introduce 14 C guanide group in α-N-tosyl-ornithine; tosyl group in α-N-tosyl-arginine thus obtained is then removed by hydrolysis with hydrochloric acid. Arginine is separated as flavianic acid salt and is purified on exchange resin Dowex-50. The overall yield based on 14 CO 3 Ba is 25 per cent. (author) [fr

  10. Comparison of Arginine Hydrochloride and Acetazolamide for the Correction of Metabolic Alkalosis in Pediatric Patients.

    Science.gov (United States)

    Heble, Daniel E; Oschman, Alexandra; Sandritter, Tracy L

    Metabolic alkalosis is a common acid-base disturbance occurring in critically ill pediatric patients. Acetazolamide and arginine hydrochloride are pharmacologic agents used at our institution for patients refractory to first-line therapy or those unable to tolerate fluid replacement. The objective of this retrospective review was to determine if a course of arginine hydrochloride or acetazolamide was more effective at correcting metabolic alkalosis within a 24-hour period. Patients included received a course of acetazolamide or arginine hydrochloride for metabolic alkalosis with a repeat metabolic panel 18-30 hours after treatment initiation. Exclusion criteria consisted of previous treatment with either drug within 24 hours or a documented metabolic disorder. Efficacy was determined by proportion of patients achieving resolution of metabolic alkalosis (treatment success: serum CO2 96 mmol/L). Additionally, mean change in serum bicarbonate and chloride concentrations was assessed. Thirty-four patients met inclusion criteria, 19 patients received acetazolamide and 15 patients received arginine hydrochloride. Treatment success was similar in patients receiving acetazolamide and arginine hydrochloride (37% vs. 7%, P = 0.053). Correction of serum bicarbonate was observed in more patients treated with acetazolamide (42% vs. 7%, P = 0.047). Both groups had a similar increase in mean serum chloride concentration (5.7 ± 5.3 vs. 4.4 ± 4.4 mmol/L, P = 0.458). Mean decrease in serum bicarbonate concentration was equivalent between groups (5.6 ± 5.2 vs. 2.8 ± 4.7, mmol/L, P = 0.110). Acetazolamide and arginine hydrochloride appear to be equally effective in correcting metabolic alkalosis in critically ill pediatric patients.

  11. Residuation theory

    CERN Document Server

    Blyth, T S; Sneddon, I N; Stark, M

    1972-01-01

    Residuation Theory aims to contribute to literature in the field of ordered algebraic structures, especially on the subject of residual mappings. The book is divided into three chapters. Chapter 1 focuses on ordered sets; directed sets; semilattices; lattices; and complete lattices. Chapter 2 tackles Baer rings; Baer semigroups; Foulis semigroups; residual mappings; the notion of involution; and Boolean algebras. Chapter 3 covers residuated groupoids and semigroups; group homomorphic and isotone homomorphic Boolean images of ordered semigroups; Dubreil-Jacotin and Brouwer semigroups; and loli

  12. The role of arginine and arginine-metabolizing enzymes during Giardia – host cell interactions in vitro

    Science.gov (United States)

    2013-01-01

    Background Arginine is a conditionally essential amino acid important in growing individuals and under non-homeostatic conditions/disease. Many pathogens interfere with arginine-utilization in host cells, especially nitric oxide (NO) production, by changing the expression of host enzymes involved in arginine metabolism. Here we used human intestinal epithelial cells (IEC) and three different isolates of the protozoan parasite Giardia intestinalis to investigate the role of arginine and arginine-metabolizing enzymes during intestinal protozoan infections. Results RNA expression analyses of major arginine-metabolizing enzymes revealed the arginine-utilizing pathways in human IECs (differentiated Caco-2 cells) grown in vitro. Most genes were constant or down-regulated (e.g. arginase 1 and 2) upon interaction with Giardia, whereas inducible NO synthase (iNOS) and ornithine decarboxylase (ODC) were up-regulated within 6 h of infection. Giardia was shown to suppress cytokine-induced iNOS expression, thus the parasite has both iNOS inducing and suppressive activities. Giardial arginine consumption suppresses NO production and the NO-degrading parasite protein flavohemoglobin is up-regulated in response to host NO. In addition, the secreted, arginine-consuming giardial enzyme arginine deiminase (GiADI) actively reduces T-cell proliferation in vitro. Interestingly, the effects on NO production and T cell proliferation could be reversed by addition of external arginine or citrulline. Conclusions Giardia affects the host’s arginine metabolism on many different levels. Many of the effects can be reversed by addition of arginine or citrulline, which could be a beneficial supplement in oral rehydration therapy. PMID:24228819

  13. Effect of in ovo injection with L-arginine on productive and ...

    African Journals Online (AJOL)

    This study evaluated the influence of administering different levels of L-arginine into eggs of 0-day-old Japanese quail embryos. On day 0 of incubation, 480 eggs (120 for each treatment group) were injected with 0% arginine (C group), 1% arginine (T1), 2% arginine (T2) or 3% arginine (T3). After hatching, 336 quail chicks ...

  14. PRmePRed: A protein arginine methylation prediction tool.

    Directory of Open Access Journals (Sweden)

    Pawan Kumar

    Full Text Available Protein methylation is an important Post-Translational Modification (PTMs of proteins. Arginine methylation carries out and regulates several important biological functions, including gene regulation and signal transduction. Experimental identification of arginine methylation site is a daunting task as it is costly as well as time and labour intensive. Hence reliable prediction tools play an important task in rapid screening and identification of possible methylation sites in proteomes. Our preliminary assessment using the available prediction methods on collected data yielded unimpressive results. This motivated us to perform a comprehensive data analysis and appraisal of features relevant in the context of biological significance, that led to the development of a prediction tool PRmePRed with better performance. The PRmePRed perform reasonably well with an accuracy of 84.10%, 82.38% sensitivity, 83.77% specificity, and Matthew's correlation coefficient of 66.20% in 10-fold cross-validation. PRmePRed is freely available at http://bioinfo.icgeb.res.in/PRmePRed/.

  15. Nuclear magnetic resonance studies on bacterial dihydrofolate reductase containing (guanidino-/sup 13/C)arginine. [Streptococcus

    Energy Technology Data Exchange (ETDEWEB)

    Cocco, L.; Blakley, R.L.; Walker, T.E.; London, R.E.; Matwiyoff, N.A.

    1978-10-03

    Dihydrofolate reductase labeled with (guanidino-/sup 13/C)arginine has been purified from Streptococcus faecium and /sup 13/C nuclear magnetic resonance spectra of the enzyme and its complexes with various ligands have been recorded. Resonances of the eight residues are resolved into 4 to 6 peaks with chemical shifts over a range of 1.2 ppM. There appear to be two classes of residues: those with chemical shifts very close to that of free (guanidino-/sup 13/C)arginine (class 1); and those with significantly different shifts (class 2). Spin-lattice relaxation times (T/sub 1/), measured in H/sub 2/O, for residues of class 1 are approximately 50% greater than the values for residues of the second class. In D/sub 2/O the T/sub 1/ values for both classes of residues are essentially the same and approximately twice the values obtained in H/sub 2/O for residues of class 1. The temperature-dependent behavior of T/sub 1/ for residues of class 2, together with the small nuclear Overhauser enhancement values, and the difference in line width in H/sub 2/O vs. D/sub 2/O are consistent with the assumption that the internal motion of these residues is slow relative to the overall rotational motion of the protein. An overall rotational correlation time for the protein of 20 ns has been estimated from the data for these immobilized residues. Class 1 residues appear to have a significant degree of internal motion and are probably accessible to solvent, whereas class 2 residues are probably inaccessible.

  16. Pretreatment and Treatment With L-Arginine Attenuate Weight Loss and Bacterial Translocation in Dextran Sulfate Sodium Colitis.

    Science.gov (United States)

    Andrade, Maria Emília Rabelo; Santos, Rosana das Graças Carvalho Dos; Soares, Anne Danieli Nascimento; Costa, Kátia Anunciação; Fernandes, Simone Odília Antunes; de Souza, Cristina Maria; Cassali, Geovanni Dantas; de Souza, Adna Luciana; Faria, Ana Maria Caetano; Cardoso, Valbert Nascimento

    2016-11-01

    Imbalances in a variety of factors, including genetics, intestinal flora, and mucosal immunity, can contribute to the development of ulcerative colitis and its side effects. This study evaluated the effects of pretreatment or treatment with arginine by oral administration on intestinal permeability, bacterial translocation (BT), and mucosal intestinal damage due to colitis. C57BL/6 mice were distributed into 4 groups: standard diet and water (C: control group), standard diet and dextran sodium sulfate (DSS) solution (Col: colitis group), 2% L-arginine supplementation for 7 days prior to DSS administration and during disease induction (PT: pretreated group), and 2% L-arginine supplementation during disease induction (T: treated group). Colitis was induced by administration of 1.5% DSS for 7 days. After 14 days, intestinal permeability and BT were evaluated; colons were collected for histologic analysis and determination of cytokines; feces were collected for measurement of immunoglobulin A (IgA). The Col group showed increased intestinal permeability (C vs Col: P supplemented groups (PT and T), this amino acid tended to decrease intestinal permeability. Arginine decreased BT to liver during PT (P < .05) and to blood, liver, spleen, and lung during T (P < .05). Histologic analysis showed that arginine preserved the intestinal mucosa and tended to decreased inflammation. Arginine attenuates weight loss and BT in mice with colitis. © 2015 American Society for Parenteral and Enteral Nutrition.

  17. Supplementation with L-arginine does not influence arterial blood pressure in healthy people: a randomized, double blind, trial.

    Science.gov (United States)

    Ast, J; Cieślewicz, A R; Korzeniowska, K; Bogdański, P; Kazmierczak, E; Olszewski, J; Skołuda, A; Jabłecka, A

    2011-12-01

    It cannot be excluded that supplementation with L-arginine, by improving function of endothelium and hypotensive effect, can be advantegeous in prevention of cardiovascular diseases in healthy people. However, reports about hypotensive effect of L-arginine in healthy people are unclear. Moreover, no research including ambulatory blood pressure measurement (ABPM) has been conducted so far. Therefore, the aim of our study was to show if 4-week supplementation of healthy people with L-arginine influences blood pressure measured with ABPM. The study was carried out on 19 healthy people randomized to 6 g/24-hour, 12 g/24-hours of L-arginine or placebo. ABPM was carried out 4 times: before randomization, after 2 and 4 weeks of supplementation and 2 weeks after finishing supplementation. It was found that 4 weeks of supplementation of healthy people with L-arginine (6 or 12 g/24-hour) led to nonsignificant decrease of systolic and diastolic blood pressure; the decrease was greater during night. These findings showed that supplementation with L-arginine is not necessarily advantageous in healthy people.

  18. A glutamate/aspartate switch controls product specificity in a protein arginine methyltransferase

    Energy Technology Data Exchange (ETDEWEB)

    Debler, Erik W.; Jain, Kanishk; Warmack, Rebeccah A.; Feng, You; Clarke, Steven G.; Blobel, Günter; Stavropoulos, Pete

    2016-02-08

    Trypanosoma brucei PRMT7 (TbPRMT7) is a protein arginine methyltransferase (PRMT) that strictly monomethylates various substrates, thus classifying it as a type III PRMT. However, the molecular basis of its unique product specificity has remained elusive. Here, we present the structure of TbPRMT7 in complex with its cofactor product S-adenosyl-L-homocysteine (AdoHcy) at 2.8 Å resolution and identify a glutamate residue critical for its monomethylation behavior. TbPRMT7 comprises the conserved methyltransferase and β-barrel domains, an N-terminal extension, and a dimerization arm. The active site at the interface of the N-terminal extension, methyltransferase, and β-barrel domains is stabilized by the dimerization arm of the neighboring protomer, providing a structural basis for dimerization as a prerequisite for catalytic activity. Mutagenesis of active-site residues highlights the importance of Glu181, the second of the two invariant glutamate residues of the double E loop that coordinate the target arginine in substrate peptides/proteins and that increase its nucleophilicity. Strikingly, mutation of Glu181 to aspartate converts TbPRMT7 into a type I PRMT, producing asymmetric dimethylarginine (ADMA). Isothermal titration calorimetry (ITC) using a histone H4 peptide showed that the Glu181Asp mutant has markedly increased affinity for monomethylated peptide with respect to the WT, suggesting that the enlarged active site can favorably accommodate monomethylated peptide and provide sufficient space for ADMA formation. In conclusion, these findings yield valuable insights into the product specificity and the catalytic mechanism of protein arginine methyltransferases and have important implications for the rational (re)design of PRMTs.

  19. A Designed Tryptophan- and Lysine/Arginine-Rich Antimicrobial Peptide with Therapeutic Potential for Clinical Antibiotic-Resistant Candida albicans Vaginitis.

    Science.gov (United States)

    Jin, Lin; Bai, Xuewei; Luan, Ning; Yao, Huimin; Zhang, Zhiye; Liu, Weihui; Chen, Yan; Yan, Xiuwen; Rong, Mingqiang; Lai, Ren; Lu, Qiumin

    2016-03-10

    New therapeutic agents for Candida albicans vaginitis are urgently awaiting to be developed because of the increasing antibiotic resistance of C. albicans. Antimicrobial peptides (AMPs) are one of the most promising choices for next-generation antibiotics. In this study, novel peptides were designed based on snake venom antimicrobial peptide cathelicidin-BF to promote anti-C. albicans activity and decrease side-effects. The designing strategies include substitutions of charged or hydrophobic amino acid residues for noncharged polar residues to promote antimicrobial activity and insertion of a hydrophobic residue in the hydrophilic side of the helix structure to reduce hemolysis. A designed tryptophan and lysine/arginine-rich cationic peptide 4 (ZY13) (VKRWKKWRWKWKKWV-NH2) exhibited excellent antimicrobial activity against either common strain or clinical isolates of antibiotic-resistant C. albicans with little hemolysis. Peptide 4 showed significant therapeutic effects on vaginitis in mice induced by the infection of clinical antibiotic-resistant C. albicans. The approaches herein might be useful for designing of AMPs.

  20. Structural Basis for Recognizing Phosphoarginine and Evolving Residue-Specific Protein Phosphatases in Gram-Positive Bacteria

    Directory of Open Access Journals (Sweden)

    Jakob Fuhrmann

    2013-06-01

    Full Text Available Many cellular pathways are regulated by the competing activity of protein kinases and phosphatases. The recent identification of arginine phosphorylation as a protein modification in bacteria prompted us to analyze the molecular basis of targeting phospho-arginine. In this work, we characterize an annotated tyrosine phosphatase, YwlE, that counteracts the protein arginine kinase McsB. Strikingly, structural studies of YwlE reaction intermediates provide a direct view on a captured arginine residue. Together with biochemical data, the crystal structures depict the evolution of a highly specific phospho-arginine phosphatase, with the use of a size-and-polarity filter for distinguishing phosphorylated arginine from other phosphorylated side chains. To confirm the proposed mechanism, we performed bioinformatic searches for phosphatases, employing a similar selectivity filter, and identified a protein in Drosophila melanogaster exhibiting robust arginine phosphatase activity. In sum, our findings uncover the molecular framework for specific targeting of phospho-arginine and suggest that protein arginine (dephosphorylation may be relevant in eukaryotes.

  1. Mass spectrometry-based identification and characterisation of lysine and arginine methylation in the human proteome.

    Science.gov (United States)

    Bremang, Michael; Cuomo, Alessandro; Agresta, Anna Maria; Stugiewicz, Magdalena; Spadotto, Valeria; Bonaldi, Tiziana

    2013-09-01

    Protein methylation is a post-translational modification (PTM) by which a variable number of methyl groups are transferred to lysine and arginine residues within proteins. Despite increased interest in this modification due to its reversible nature and its emerging role in a diverse set of biological pathways beyond chromatin, global identification of protein methylation has remained an unachieved goal. To characterise sites of lysine and arginine methylation beyond histones, we employed an approach that combines heavy methyl stable isotope labelling by amino acids in cell culture (hmSILAC) with high-resolution mass spectrometry-based proteomics. Through a broad evaluation of immuno-affinity enrichment and the application of two classical protein separation techniques prior to mass spectrometry, to nucleosolic and cytosolic fractions separately, we identified a total of 501 different methylation types, on 397 distinct lysine and arginine sites, present on 139 unique proteins. Our results considerably extend the number of known in vivo methylation sites and indicate their significant presence on several protein complexes involved at all stages of gene expression, from chromatin remodelling and transcription to splicing and translation. In addition, we describe the potential of the hmSILAC approach for accurate relative quantification of methylation levels between distinct functional states.

  2. Characterization of four arginine kinases in the ciliate Paramecium tetraurelia: Investigation on the substrate inhibition mechanism.

    Science.gov (United States)

    Yano, Daichi; Suzuki, Takaya; Hirokawa, Saki; Fuke, Kyoko; Suzuki, Tomohiko

    2017-08-01

    The ciliate Paramecium tetraurelia contains four arginine kinase genes (AK1-4). We detected cDNA for only three of the AKs (AK1-3) via PCR. Recombinant AK1-4 were expressed in Escherichia coli and their kinetics parameters determined. AK3 showed typical substrate inhibition toward arginine, and enzymatic activity markedly decreased when arginine concentration increased. This is the first example of substrate inhibition in wild-type phosphagen kinases. To explore the substrate inhibition mechanism, site-directed mutations were generated, targeting the amino acid sequence D-D-S-Q-V at positions 77-81 in P. tetraurelia AK3. Among the mutants, substrate inhibition was lost remarkably in the S79A mutant. In spite of high amino acid sequence identity (91%) between P. tetraurelia AK3 and AK4, the enzymatic activity of AK4 was less by 3% than that of AK3. We noticed that the conservative G298 was unusually replaced by R in P. tetraurelia AK4, and we constructed two mutants, R298G/AK4 and G298R/AK3. Enzymatic activity of the former mutant was comparable with that of the wild-type AK3, whereas that of the latter mutant was dramatically reduced. Thus, we concluded that the significantly low activity of P. tetraurelia AK4 is due to the residue R298. Copyright © 2017 Elsevier B.V. All rights reserved.

  3. Promoting siRNA delivery via enhanced cellular uptake using an arginine-decorated amphiphilic dendrimer

    Science.gov (United States)

    Liu, Xiaoxuan; Liu, Cheng; Zhou, Jiehua; Chen, Chao; Qu, Fanqi; Rossi, John J.; Rocchi, Palma; Peng, Ling

    2015-02-01

    RNA interference (RNAi) with small interfering RNA (siRNA) is expected to offer an attractive means to specifically and efficiently silence disease-associated genes for treating various diseases provided that safe and efficient delivery systems are available. In this study, we have established an arginine-decorated amphiphilic dendrimer composed of a hydrophobic alkyl chain and a hydrophilic PAMAM dendron bearing arginine terminals as nonviral vector for siRNA delivery. Indeed, this dendrimer proved to be very effective at delivering siRNAs in human prostate cancer PC-3 cells and in human hematopoietic CD34+ stem cells, leading to improved gene silencing compared to the corresponding nonarginine decorated dendrimer. Further investigation confirmed that this dendrimer was granted with the capacity to form stable nanoparticles with siRNA and significantly enhance cellular uptake of siRNA. In addition, this dendrimer revealed no discernible cytotoxicity. All these findings demonstrate that decoration of the dendrimer surface with arginine residues is indeed a useful strategy to improve the delivery ability of dendrimers.

  4. A lysine-to-arginine mutation on NEDD8 markedly reduces the activity of cullin RING E3 ligase through the impairment of neddylation cascades

    Energy Technology Data Exchange (ETDEWEB)

    Sui, Yiyan; Liu, Yaobin; Xu, Guoqiang, E-mail: gux2002@suda.edu.cn

    2015-06-12

    Neural-precursor-cell-expressed developmentally down-regulated 8 (NEDD8) is a ubiquitin-like modifier, which forms covalent conjugates on lysines of its substrates. This post-translational modification, neddylation, plays important roles in tumor cell proliferation and viability. Ubiquitin can form diverse polyubiquitin chains, on its seven lysines, which play important functions in various biological processes. However, the roles of lysines in NEDD8 have not been explored. Here, we generated nine NEDD8 point mutants, each with one lysine replaced by an arginine, to study the putative function of lysines in NEDD8. Our experiments discover that Lys27 in NEDD8 is a critical residue for protein neddylation. Replacement of this residue with arginine almost completely eliminates the conjugation of NEDD8 to its substrates. Furthermore, we find that the K27R mutant impairs NEDD8 conjugation to the E2 enzyme, which normally forms thioester bonds for further transferring NEDD8 to its ligases and substrates. Therefore, this mutation completely inhibits global protein neddylation, including neddylation of cullin family proteins, resulting in decreased activity of cullin-RING E3 ligases. This work sheds new light on the roles of NEDD8 lysines on neddylation cascades and provides a dominant negative mutant for the study of neddylation and its biological functions. - Highlights: • Lys27 in NEDD8 is critical for protein neddylation. • NEDD8 K27R mutant impairs the NEDD8 conjugation. • NEDD8 K27R mutant significantly reduces the activity of cullin-RING E3 ligases.

  5. Intricate Effects of α-Amino and Lysine Modifications on Arginine Methylation of the N-Terminal Tail of Histone H4.

    Science.gov (United States)

    Fulton, Melody D; Zhang, Jing; He, Maomao; Ho, Meng-Chiao; Zheng, Y George

    2017-07-18

    Chemical modifications of the DNA and nucleosomal histones tightly control the gene transcription program in eukaryotic cells. The "histone code" hypothesis proposes that the frequency, combination, and location of post-translational modifications (PTMs) of the core histones compose a complex network of epigenetic regulation. Currently, there are at least 23 different types and >450 histone PTMs that have been discovered, and the PTMs of lysine and arginine residues account for a crucial part of the histone code. Although significant progress has been achieved in recent years, the molecular basis for the histone code is far from being fully understood. In this study, we investigated how naturally occurring N-terminal acetylation and PTMs of histone H4 lysine-5 (H4K5) affect arginine-3 methylation catalyzed by both type I and type II PRMTs at the biochemical level. Our studies found that acylations of H4K5 resulted in decreased levels of arginine methylation by PRMT1, PRMT3, and PRMT8. In contrast, PRMT5 exhibits an increased rate of arginine methylation upon H4K5 acetylation, propionylation, and crotonylation, but not upon H4K5 methylation, butyrylation, or 2-hydroxyisobutyrylation. Methylation of H4K5 did not affect arginine methylation by PRMT1 or PRMT5. There was a small increase in the rate of arginine methylation by PRMT8. Strikingly, a marked increase in the rate of arginine methylation was observed for PRMT3. Finally, N-terminal acetylation reduced the rate of arginine methylation by PRMT3 but had little influence on PRMT1, -5, and -8 activity. These results together highlight the underlying mechanistic differences in substrate recognition among different PRMTs and pave the way for the elucidation of the complex interplay of histone modifications.

  6. A comparison of DNA compaction by arginine and lysine peptides: A physical basis for arginine rich protamines

    OpenAIRE

    DeRouchey, Jason; Hoover, Brandon; Rau, Donald C

    2013-01-01

    Protamines are small, highly positively charged peptides used to package DNA to very high densities in sperm nuclei. Tight DNA packing is considered essential to minimize DNA damage by mutagens and reactive oxidizing species. A striking and general feature of protamines is the almost exclusive use of arginine over lysine for the positive charge to neutralize DNA. We have investigated whether this preference for arginine might arise from a difference in DNA condensation by arginine and lysine ...

  7. Modulating short tryptophan- and arginine-rich peptides activity by substitution with histidine.

    Science.gov (United States)

    Bacalum, Mihaela; Janosi, Lorant; Zorila, Florina; Tepes, Ana-Maria; Ionescu, Cristina; Bogdan, Elena; Hadade, Niculina; Craciun, Liviu; Grosu, Ion; Turcu, Ioan; Radu, Mihai

    2017-07-01

    High antimicrobial efficacy of short tryptophan-and arginine-rich peptides makes them good candidates in the fight against pathogens. Substitution of tryptophan and arginine by histidine could be used to modulate the peptides efficacy by optimizing their structures. The peptide (RRWWRWWRR), reported to showed good antimicrobial efficacy, was used as template, seven new analogs being designed substituting tryptophan or arginine with histidine. The peptides' efficacy was tested against E. coli, B. subtilis and S. aureus. The cytotoxicity and hemolytic effect were evaluated and the therapeutic index was inferred for each peptide. Atomic force microscopy and molecular simulation were used to analyze the effects of peptides on bacterial membrane. The substitution of tryptophan by histidine proved to strongly modulate the antimicrobial activity, mainly by changing the peptide-to-membrane binding energy. The substitution of arginine has low effect on the antimicrobial efficacy. The presence of histidine residue reduced the cytotoxic and hemolytic activity of the peptides in some cases maintaining the same efficacy against bacteria. The peptides' antimicrobial activity was correlated to the 3D-hydrophobic moment and to a simple structure-based packing parameter. The results show that some of these peptides have the potential to become good candidates to fight against bacteria. The substitution by histidine proved to fine tune the therapeutic index allowing the optimization of the peptide structure mainly by changing its binding energy and 3D-hydrophobic moment. The short tryptophan reach peptides therapeutic index can be maximized using the histidine substitution to optimize their structure. Copyright © 2017 Elsevier B.V. All rights reserved.

  8. Transient Kinetics Define a Complete Kinetic Model for Protein Arginine Methyltransferase 1*

    Science.gov (United States)

    Hu, Hao; Luo, Cheng; Zheng, Y. George

    2016-01-01

    Protein arginine methyltransferases (PRMTs) are the enzymes responsible for posttranslational methylation of protein arginine residues in eukaryotic cells, particularly within the histone tails. A detailed mechanistic model of PRMT-catalyzed methylation is currently lacking, but it is essential for understanding the functions of PRMTs in various cellular pathways and for efficient design of PRMT inhibitors as potential treatments for a range of human diseases. In this work, we used stopped-flow fluorescence in combination with global kinetic simulation to dissect the transient kinetics of PRMT1, the predominant type I arginine methyltransferase. Several important mechanistic insights were revealed. The cofactor and the peptide substrate bound to PRMT1 in a random manner and then followed a kinetically preferred pathway to generate the catalytic enzyme-cofactor-substrate ternary complex. Product release proceeded in an ordered fashion, with peptide dissociation followed by release of the byproduct S-adenosylhomocysteine. Importantly, the dissociation rate of the monomethylated intermediate from the ternary complex was much faster than the methyl transfer. Such a result provided direct evidence for distributive arginine dimethylation, which means the monomethylated substrate has to be released to solution and rebind with PRMT1 before it undergoes further methylation. In addition, cofactor binding involved a conformational transition, likely an open-to-closed conversion of the active site pocket. Further, the histone H4 peptide bound to the two active sites of the PRMT1 homodimer with differential affinities, suggesting a negative cooperativity mechanism of substrate binding. These findings provide a new mechanistic understanding of how PRMTs interact with their substrates and transfer methyl groups. PMID:27834681

  9. Effects of 7 days of arginine-alpha-ketoglutarate supplementation on blood flow, plasma L-arginine, nitric oxide metabolites, and asymmetric dimethyl arginine after resistance exercise.

    Science.gov (United States)

    Willoughby, Darryn S; Boucher, Tony; Reid, Jeremy; Skelton, Garson; Clark, Mandy

    2011-08-01

    Arginine-alpha-ketoglutarate (AAKG) supplements are alleged to increase nitric oxide production, thereby resulting in vasodilation during resistance exercise. This study sought to determine the effects of AAKG supplementation on hemodynamics and brachial-artery blood flow and the circulating levels of L-arginine, nitric oxide metabolites (NOx; nitrate/nitrite), asymmetric dimethyl arginine (ADMA), and L-arginine:ADMA ratio after resistance exercise. Twenty-four physically active men underwent 7 days of AAKG supplementation with 12 g/day of either NO(2) Platinum or placebo (PLC). Before and after supplementation, a resistance-exercise session involving the elbow flexors was performed involving 3 sets of 15 repetitions with 70-75% of 1-repetition maximum. Data were collected immediately before, immediately after (PST), and 30 min after (30PST) each exercise session. Data were analyzed with factorial ANOVA (p L-arginine was increased in the NO(2) group (p = .001). NOx was shown to increase in both groups at PST (p = .001) and at 30PST (p = .001) but was not different between groups. ADMA was not affected between tests (p = .26) or time points (p = .31); however, the L-arginine:ADMA ratio was increased in the NO(2) group (p = .03). NO(2) Platinum increased plasma L-arginine levels; however, the effects observed in hemodynamics, brachial-artery blood flow, and NOx can only be attributed to the resistance exercise.

  10. The effects on plasma L-arginine levels of combined oral L-citrulline and L-arginine supplementation in healthy males.

    Science.gov (United States)

    Suzuki, Takashi; Morita, Masahiko; Hayashi, Toshio; Kamimura, Ayako

    2017-02-01

    We investigated the effects of combining 1 g of l-citrulline and 1 g of l-arginine as oral supplementation on plasma l-arginine levels in healthy males. Oral l-citrulline plus l-arginine supplementation more efficiently increased plasma l-arginine levels than 2 g of l-citrulline or l-arginine, suggesting that oral l-citrulline and l-arginine increase plasma l-arginine levels more effectively in humans when combined.

  11. Effect of arginine deficiency on arginine-dependent post-translational protein modifications in mice

    NARCIS (Netherlands)

    Kwikkers, Karin L.; Ruijter, Jan M.; Labruyère, Wil T.; McMahon, Kathryn K.; Lamers, Wouter H.

    2005-01-01

    Transgenic mice that overexpress arginase-I in their small-intestinal enterocytes suffer from a pronounced, but selective decrease in circulating arginine levels during the suckling period, resulting in impaired growth and development of hair, muscle and immune system. In the present study, we

  12. Weissella halotolerans W22 combines arginine deiminase and ornithine decarboxylation pathways and converts arginine to putrescine

    NARCIS (Netherlands)

    Pereira, C. I.; San Romao, M. V.; Lolkema, J. S.; Barreto Crespo, M. T.; Baretto Crespo, M.

    2009-01-01

    Aims: To demonstrate that the meat food strain Weissella halotolerans combines an ornithine decarboxylation pathway and an arginine deiminase (ADI) pathway and is able to produce putrescine, a biogenic amine. Evidence is shown that these two pathways produce a proton motive force (PMF). Methods and

  13. Arginine and Lysine Transporters Are Essential for Trypanosoma brucei.

    Science.gov (United States)

    Mathieu, Christoph; Macêdo, Juan P; Hürlimann, Daniel; Wirdnam, Corina; Haindrich, Alexander C; Suter Grotemeyer, Marianne; González-Salgado, Amaia; Schmidt, Remo S; Inbar, Ehud; Mäser, Pascal; Bütikofer, Peter; Zilberstein, Dan; Rentsch, Doris

    2017-01-01

    For Trypanosoma brucei arginine and lysine are essential amino acids and therefore have to be imported from the host. Heterologous expression in Saccharomyces cerevisiae mutants identified cationic amino acid transporters among members of the T. brucei AAAP (amino acid/auxin permease) family. TbAAT5-3 showed high affinity arginine uptake (Km 3.6 ± 0.4 μM) and high selectivity for L-arginine. L-arginine transport was reduced by a 10-times excess of L-arginine, homo-arginine, canavanine or arginine-β-naphthylamide, while lysine was inhibitory only at 100-times excess, and histidine or ornithine did not reduce arginine uptake rates significantly. TbAAT16-1 is a high affinity (Km 4.3 ± 0.5 μM) and highly selective L-lysine transporter and of the compounds tested, only L-lysine and thialysine were competing for L-lysine uptake. TbAAT5-3 and TbAAT16-1 are expressed in both procyclic and bloodstream form T. brucei and cMyc-tagged proteins indicate localization at the plasma membrane. RNAi-mediated down-regulation of TbAAT5 and TbAAT16 in bloodstream form trypanosomes resulted in growth arrest, demonstrating that TbAAT5-mediated arginine and TbAAT16-mediated lysine transport are essential for T. brucei. Growth of induced RNAi lines could partially be rescued by supplementing a surplus of arginine or lysine, respectively, while addition of both amino acids was less efficient. Single and double RNAi lines indicate that additional low affinity uptake systems for arginine and lysine are present in T. brucei.

  14. Leishmania metacaspase: an arginine-specific peptidase.

    Science.gov (United States)

    Martin, Ricardo; Gonzalez, Iveth; Fasel, Nicolas

    2014-01-01

    The purpose of this chapter is to give insights into metacaspase of Leishmania protozoan parasites as arginine-specific cysteine peptidase. The physiological role of metacaspase in Leishmania is still a matter of debate, whereas its peptidase enzymatic activity has been well characterized. Among the different possible expression systems, metacaspase-deficient yeast cells (Δyca1) have been instrumental in studying the activity of Leishmania major metacaspase (LmjMCA). Here, we describe techniques for purification of LmjMCA and its activity measurement, providing a platform for further identification of LmjMCA substrates.

  15. Functional and neurochemical profile of place learning after L-nitro-arginine in the rat

    DEFF Research Database (Denmark)

    Mogensen, Jesper; Wörtwein, Gitta; Hasman, Andreas

    1995-01-01

    Neurobiology, nitrogenoxid (NO), place learning, rotte, L-Nitro-Arginin, funktionel genopretning......Neurobiology, nitrogenoxid (NO), place learning, rotte, L-Nitro-Arginin, funktionel genopretning...

  16. L-arginine induces relaxation of rat aorta possibly through non-endothelial nitric oxide formation.

    OpenAIRE

    Moritoki, H.; Ueda, H.; Yamamoto, T.; Hisayama, T.; Takeuchi, S.

    1991-01-01

    1. The relaxation of rings of rat thoracic aorta induced by L-arginine and its derivatives was investigated. 2. L-Arginine (0.3-100 microM), but not D-arginine, induced relaxation of the arteries, which was detectable after 2 h and maximal after 4-6 h on its repeated application; it was endothelium-independent. 3. L-Arginine methyl ester, N alpha-benzoyl L-arginine and L-homo-arginine had essentially similar effects to those of L-arginine. 4. NG-nitro L-arginine methyl ester (L-NAME, 3 microM...

  17. L-arginine supplementation and risk factors of cardiovascular diseases in healthy men: a double-blind randomized clinical trial.

    Science.gov (United States)

    Pahlavani, Naseh; Jafari, Mostafa; Sadeghi, Omid; Rezaei, Masoud; Rasad, Hamid; Rahdar, Hossein Ali; Entezari, Mohammad Hasan

    2014-01-01

    Context: The effect of L-arginine on risk factors of cardiovascular diseases (CVD) has mostly focused on western countries. Since cardiovascular diseases is the second cause of death in Iran and, as far as we are aware, there have been no studies about the effect of L-arginine on CVD risk factors, the aim of this trial was to assess the effects of L-arginine supplementation on CVD risk factors in healthy men. Objective:  The purpose of this study was to evaluate the effect of low-dose L-arginine supplementation on CVD risk factors (lipid profile, blood sugar and blood pressure) in Iranian healthy men. Design, setting, participants:  We conducted a double-blind randomized controlled trial in 56 patients selected from sport clubs at the Isfahan University of Medical Science between November 2013 and December 2013. Interventions: Healthy men received L-arginine supplementation (2000 mg daily) in the intervention group or placebo (2000 mg maltodextrin daily) in the control group for 45 days. Main outcome measure:  The primary outcome measures were we measured the levels of fasting blood sugar, blood pressure and lipid profile including triglyceride (TG), cholesterol, LDL and HDL in healthy subjects. It was hypothesized that these measures would be significantly improved in those receiving L-arginine supplementation. at the beginning and end of the study. Results:  In this trial, we had complete data for 52 healthy participants with mean age of 20.85±4.29 years. At the end of study, fasting blood sugar (P=0.001) and lipid profile (triglycerideTG (PL-arginine group but we found no significant change in the placebo group. In addition, the reduction of fasting blood sugar and lipid profile in L-arginine was significant compared with placebo group. No significant changes were found about systolic (P=0.81) and diastolic blood pressure either in L-arginine or placebo group. (P=0.532). Conclusion : The use of L-arginine significantly improved outcomes compared to placebo.

  18. L-arginine supplementation and risk factors of cardiovascular diseases in healthy men: a double-blind randomized clinical trial

    Science.gov (United States)

    Pahlavani, Naseh; Jafari, Mostafa; Sadeghi, Omid; Rezaei, Masoud; Rasad, Hamid; Rahdar, Hossein Ali; Entezari, Mohammad Hasan

    2017-01-01

    Context: The effect of L-arginine on risk factors of cardiovascular diseases (CVD) has mostly focused on western countries. Since cardiovascular diseases is the second cause of death in Iran and, as far as we are aware, there have been no studies about the effect of L-arginine on CVD risk factors, the aim of this trial was to assess the effects of L-arginine supplementation on CVD risk factors in healthy men. Objective: The purpose of this study was to evaluate the effect of low-dose L-arginine supplementation on CVD risk factors (lipid profile, blood sugar and blood pressure) in Iranian healthy men. Design, setting, participants: We conducted a double-blind randomized controlled trial in 56 patients selected from sport clubs at the Isfahan University of Medical Science between November 2013 and December 2013. Interventions: Healthy men received L-arginine supplementation (2000 mg daily) in the intervention group or placebo (2000 mg maltodextrin daily) in the control group for 45 days. Main outcome measure: The primary outcome measures were we measured the levels of fasting blood sugar, blood pressure and lipid profile including triglyceride (TG), cholesterol, LDL and HDL in healthy subjects. It was hypothesized that these measures would be significantly improved in those receiving L–arginine supplementation. at the beginning and end of the study. Results: In this trial, we had complete data for 52 healthy participants with mean age of 20.85±4.29 years. At the end of study, fasting blood sugar (P=0.001) and lipid profile (triglycerideTG (PL-arginine group but we found no significant change in the placebo group. In addition, the reduction of fasting blood sugar and lipid profile in L-arginine was significant compared with placebo group. No significant changes were found about systolic (P=0.81) and diastolic blood pressure either in L-arginine or placebo group. (P=0.532). Conclusion: The use of L-arginine significantly improved outcomes compared to placebo

  19. Comparative functional properties of engineered cationic antimicrobial peptides consisting exclusively of tryptophan and either lysine or arginine.

    Science.gov (United States)

    Deslouches, Berthony; Hasek, Mary L; Craigo, Jodi K; Steckbeck, Jonathan D; Montelaro, Ronald C

    2016-06-01

    We previously reported a series of de novo engineered cationic antibiotic peptides (eCAPs) consisting exclusively of arginine and tryptophan (WR) that display potent activity against diverse multidrug-resistant (MDR) bacterial strains. In this study, we sought to examine the influence of arginine compared to lysine on antibacterial properties by direct comparison of the WR peptides (8-18 residues) with a parallel series of engineered peptides containing only lysine and tryptophan. WR and WK series were compared for antibacterial activity by bacterial killing and growth inhibition assays and for mechanism of peptide-bacteria interactions by surface plasmon resonance and flow cytometry. Mammalian cytotoxicity was also assessed by flow cytometry, haemolytic and tetrazolium-based assays. The shortest arginine-containing peptides (8 and 10 mers) displayed a statistically significant increase in activity compared to the analogous lysine-containing peptides. The WR and WK peptides achieved maximum antibacterial activity at the 12-mer peptide (WK12 or WR12). Further examination of antibacterial mechanisms of the optimally active 12-mer peptides using surface plasmon resonance and flow cytometry demonstrates stronger interactions with Pseudomonasaeruginosa, greater membrane permeabilizing activity, and lower inhibitory effects of divalent cations on activity and membrane permeabilization properties of WR12 compared to WK12 (P arginine, compared to lysine, can indeed yield enhanced antibacterial activity to minimize the required length to achieve functional antimicrobial peptides.

  20. Effect of the Basic Residue on the Energetics, Dynamics and Mechanisms of Gas- Phase Fragmentation of Protonated Peptides

    Energy Technology Data Exchange (ETDEWEB)

    Laskin, Julia; Yang, Zhibo; Song, Tao; Lam, Corey; Chu, Ivan K.

    2010-11-17

    The effect of the basic residue on the energetics, dynamics and mechanisms of backbone fragmentation of protonated peptides was investigated. Time- and collision energy-resolved surface-induced dissociation (SID) of singly protonated peptides with the N-terminal arginine residue and their analogs, in which arginine is replaced with less basic lysine and histidine residues was examined using in a specially configured Fourier transform ion cyclotron resonance mass spectrometer (FT-ICR MS). SID experiments demonstrated very different kinetics of formation of several primary product ions of peptides with and without arginine residue. The energetics and dynamics of these pathways were determined from the RRKM modeling of the experimental data. Comparison between the kinetics and energetics of fragmentation of arginine-containing peptides and the corresponding methyl ester derivatives provides important information on the effect of dissociation pathways involving salt bridge (SB) intermediates on the observed fragmentation behavior. It is found that because pathways involving SB intermediates are characterized by low threshold energies, they efficiently compete with classical oxazolone pathways of arginine-containing peptides on a long timescale of the FT-ICR instrument. In contrast, fragmentation of histidine- and lysine-containing peptides is largely determined by classical oxazolone pathways. Because SB pathways are characterized by negative activation entropies, fragmentation of arginine-containing peptides is kinetically hindered and observed at higher collision energies as compared to their lysine- and histidine-containing analogs.

  1. Residue processing

    Energy Technology Data Exchange (ETDEWEB)

    Gieg, W.; Rank, V.

    1942-10-15

    In the first stage of coal hydrogenation, the liquid phase, light and heavy oils were produced; the latter containing the nonliquefied parts of the coal, the coal ash, and the catalyst substances. It was the problem of residue processing to extract from these so-called let-down oils that which could be used as pasting oils for the coal. The object was to obtain a maximum oil extraction and a complete removal of the solids, because of the latter were returned to the process they would needlessly burden the reaction space. Separation of solids in residue processing could be accomplished by filtration, centrifugation, extraction, distillation, or low-temperature carbonization (L.T.C.). Filtration or centrifugation was most suitable since a maximum oil yield could be expected from it, since only a small portion of the let-down oil contained in the filtration or centrifugation residue had to be thermally treated. The most satisfactory centrifuge at this time was the Laval, which delivered liquid centrifuge residue and centrifuge oil continuously. By comparison, the semi-continuous centrifuges delivered plastic residues which were difficult to handle. Various apparatus such as the spiral screw kiln and the ball kiln were used for low-temperature carbonization of centrifuge residues. Both were based on the idea of carbonization in thin layers. Efforts were also being made to produce electrode carbon and briquette binder as by-products of the liquid coal phase.

  2. Nutritional consequences of interspecies differences in arginine and lysine metabolism.

    Science.gov (United States)

    Ball, Ronald O; Urschel, Kristine L; Pencharz, Paul B

    2007-06-01

    Differences in lysine and arginine requirements among various species such as omnivores (humans, pigs, rats, dogs), carnivores (cats), herbivores (rabbits, horses), ruminants (cattle), poultry, and fish, are covered in detail in this article. Although lysine is classified as an indispensable amino acid across species, the classification of arginine as either an indispensable or dispensable amino acid is more ambiguous because of differences among species in rates of de novo arginine synthesis. Because lysine is most often the limiting amino acid in the diet, its requirement has been extensively studied. By use of the ideal protein concept, the requirements of the other indispensable amino acids can be extrapolated from the lysine requirement. The successful use of this concept in pigs is compared with potential application of the ideal protein concept in humans. The current dietary arginine requirement varies widely among species, with ruminants, rabbits, and rats having relatively low requirements and carnivores, fish, and poultry having high requirements. Interspecies differences in metabolic arginine utilization and reasons for different rates of de novo arginine synthesis are reviewed in detail, as these are the primary determinants of the dietary arginine requirement. There is presently no dietary requirement for humans of any age, although this needs to be reassessed, particularly in neonates. A thorough understanding of the factors contributing to the lysine and arginine requirements in different species will be useful in our understanding of human amino acid requirements.

  3. L-Arginine Attenuates Diabetic Nephropathy In Streptozotocin ...

    African Journals Online (AJOL)

    ... renal activities of glutathione peroxidase(GPx),superoxide dismutase(SOD), LDH, aldose reductase(AR),sorbitol dehydrogenase(SDH), levels of renal glutathione(GSH) and NOx in the diabetic group treated with L-arginine. It can be concluded that L-arginine supplementation may become a promising solution to reduce ...

  4. The do's and don'ts of arginine supplementation

    African Journals Online (AJOL)

    properties, there has been increased effort in defining possible clinical uses for arginine.3. Furthermore, the ... endogenous daily production of 15–20 g occurs via the citrulline intestinal-renal axis.2. A large proportion .... sepsis, the endogenous synthesis of arginine from the amino acid citrulline, is reduced to one third of the ...

  5. Arginine, citrulline and nitric oxide metabolism in sepsis

    Science.gov (United States)

    Arginine has vasodilatory effects, via its conversion by nitric oxide (NO) synthase into NO, and immunomodulatory actions that play important roles in sepsis. Protein breakdown affects arginine availability, and the release of asymmetric dimethylarginine, an inhibitor of NO synthase, may therefore a...

  6. Redox specificity of 2-hydroxyacid-coupled NAD(+/NADH dehydrogenases: a study exploiting "reactive" arginine as a reporter of protein electrostatics.

    Directory of Open Access Journals (Sweden)

    Pooja Gupta

    Full Text Available With "reactive" arginine as a kinetic reporter, 2-hydroxyacid dehydrogenases are assessed in basis of their specialization as NAD(+-reducing or NADH-oxidizing enzymes. Specifically, M4 and H4 lactate dehydrogenases (LDHs and cytoplasmic and mitochondrial malate dehydrogenases (MDHs are compared to assess if their coenzyme specificity may involve electrostatics of cationic or neutral nicotinamide structure as the basis. The enzymes from diverse eukaryote and prokaryote sources thus are assessed in "reactivity" of functionally-critical arginine as a function of salt concentration and pH. Electrostatic calculations were performed on "reactive" arginines and found good correspondence with experiment. The reductive and oxidative LDHs and MDHs are assessed in their count over ionizable residues and in placement details of the residues in their structures as proteins. The variants found to be high or low in ΔpKa of "reactive" arginine are found to be also strong or weak cations that preferentially oxidize NADH (neutral nicotinamide structure or reduce NAD(+ (cationic nicotinamide structure. The ionized groups of protein structure may thus be important to redox specificity of the enzyme on basis of electrostatic preference for the oxidized (cationic nicotinamide or reduced (neutral nicotinamide coenzyme. Detailed comparisons of isozymes establish that the residues contributing in their redox specificity are scrambled in structure of the reductive enzyme.

  7. Redox Specificity of 2-Hydroxyacid-Coupled NAD+/NADH Dehydrogenases: A Study Exploiting “Reactive” Arginine as a Reporter of Protein Electrostatics

    Science.gov (United States)

    Durani, Susheel

    2013-01-01

    With “reactive” arginine as a kinetic reporter, 2-hydroxyacid dehydrogenases are assessed in basis of their specialization as NAD+-reducing or NADH-oxidizing enzymes. Specifically, M4 and H4 lactate dehydrogenases (LDHs) and cytoplasmic and mitochondrial malate dehydrogenases (MDHs) are compared to assess if their coenzyme specificity may involve electrostatics of cationic or neutral nicotinamide structure as the basis. The enzymes from diverse eukaryote and prokaryote sources thus are assessed in “reactivity” of functionally-critical arginine as a function of salt concentration and pH. Electrostatic calculations were performed on “reactive” arginines and found good correspondence with experiment. The reductive and oxidative LDHs and MDHs are assessed in their count over ionizable residues and in placement details of the residues in their structures as proteins. The variants found to be high or low in ΔpKa of “reactive” arginine are found to be also strong or weak cations that preferentially oxidize NADH (neutral nicotinamide structure) or reduce NAD+ (cationic nicotinamide structure). The ionized groups of protein structure may thus be important to redox specificity of the enzyme on basis of electrostatic preference for the oxidized (cationic nicotinamide) or reduced (neutral nicotinamide) coenzyme. Detailed comparisons of isozymes establish that the residues contributing in their redox specificity are scrambled in structure of the reductive enzyme. PMID:24391777

  8. Small Molecule Inhibitors of Protein Arginine Methyltransferases

    Science.gov (United States)

    Hu, Hao; Qian, Kun; Ho, Meng-Chiao; Zheng, Y. George

    2016-01-01

    Introduction Arginine methylation is an abundant posttranslational modification occurring in mammalian cells and catalyzed by protein arginine methyltransferases (PRMTs). Misregulation and aberrant expression of PRMTs are associated with various disease states, notably cancer. PRMTs are prominent therapeutic targets in drug discovery. Areas covered The authors provide an updated review of the research on the development of chemical modulators for PRMTs. Great efforts are seen in screening and designing potent and selective PRMT inhibitors, and a number of micromolar and submicromolar inhibitors have been obtained for key PRMT enzymes such as PRMT1, CARM1, and PRMT5. The authors provide a focus on their chemical structures, mechanism of action, and pharmacological activities. Pros and cons of each type of inhibitors are also discussed. Expert opinion Several key challenging issues exist in PRMT inhibitor discovery. Structural mechanisms of many PRMT inhibitors remain unclear. There lacks consistency in potency data due to divergence of assay methods and conditions. Physiologically relevant cellular assays are warranted. Substantial engagements are needed to investigate pharmacodynamics and pharmacokinetics of the new PRMT inhibitors in pertinent disease models. Discovery and evaluation of potent, isoform-selective, cell-permeable and in vivo-active PRMT modulators will continue to be an active arena of research in years ahead. PMID:26789238

  9. Arginine specific aminopeptidase from Lactobacillus brevis

    Directory of Open Access Journals (Sweden)

    Arya Nandan

    2010-12-01

    Full Text Available The proteolytic system of lactic acid bacteria contribute to the development of flavor during the ripening of cheese through the generation of short peptides and free amino acids, which directly or indirectly act as flavor precursors. Newly isolated lactic acid bacteria (LAB as well as those procured from culture collection centers were screened for the production of various substrate specific aminopeptidases. Among all the strains screened, L. brevis (NRRL B-1836 was found to produce quantifiable amount of intracellular arginine specific aminopeptidase (EC 3.4.11.6. The productivity of arginine aminopeptidase in 5 L fermentor was 36 IU/L/h. The Luedeking and Piret model was tested for intracellular production of aminopeptidase and the data seemed to fit well, as the correlation coefficient was 0.9964 for MRS. The αAP and βAP was 0.4865 and 0.0046, respectively in MRS medium indicating that the yield was predominantly depended on growth. The culture produced lactic acid and also tolerated pH 2.0-3.0 and 0.3-0.5% bile salts, the most important probiotic features.

  10. Purification of free arginine from chickpea (Cicer arietinum) seeds.

    Science.gov (United States)

    Cortés-Giraldo, Isabel; Megías, Cristina; Alaiz, Manuel; Girón-Calle, Julio; Vioque, Javier

    2016-02-01

    Chickpea is a grain legume widely consumed in the Mediterranean region and other parts of the world. Chickpea seeds are rich in proteins but they also contain a substantial amount of free amino acids, especially arginine. Hence chickpea may represent a useful source of free amino acids for nutritional or pharmaceutical purposes. Arginine is receiving great attention in recent years because it is the substrate for the synthesis of nitric oxide, an important signaling molecule involved in numerous physiological and pathological processes in mammals. In this work we describe a simple procedure for the purification of arginine from chickpea seeds, using nanofiltration technology and an ion-exchange resin, Amberlite IR-120. Arginine was finally purified by precipitation or crystallization, yielding preparations with purities of 91% and 100%, respectively. Chickpea may represent an affordable green source of arginine, and a useful alternative to production by fermentation or protein hydrolysis. Copyright © 2015 Elsevier Ltd. All rights reserved.

  11. Handling of Solid Residues

    International Nuclear Information System (INIS)

    Medina Bermudez, Clara Ines

    1999-01-01

    The topic of solid residues is specifically of great interest and concern for the authorities, institutions and community that identify in them a true threat against the human health and the atmosphere in the related with the aesthetic deterioration of the urban centers and of the natural landscape; in the proliferation of vectorial transmitters of illnesses and the effect on the biodiversity. Inside the wide spectrum of topics that they keep relationship with the environmental protection, the inadequate handling of solid residues and residues dangerous squatter an important line in the definition of political and practical environmentally sustainable. The industrial development and the population's growth have originated a continuous increase in the production of solid residues; of equal it forms, their composition day after day is more heterogeneous. The base for the good handling includes the appropriate intervention of the different stages of an integral administration of residues, which include the separation in the source, the gathering, the handling, the use, treatment, final disposition and the institutional organization of the administration. The topic of the dangerous residues generates more expectation. These residues understand from those of pathogen type that are generated in the establishments of health that of hospital attention, until those of combustible, inflammable type, explosive, radio-active, volatile, corrosive, reagent or toxic, associated to numerous industrial processes, common in our countries in development

  12. L-arginine and L-NMMA for Assessing Cerebral Endothelial Dysfunction in Ischemic Cerebrovascular Disease: A Systematic Review

    DEFF Research Database (Denmark)

    Karlsson, William Kristian; Sørensen, Caspar Godthaab; Kruuse, Christina

    2017-01-01

    Endothelial dysfunction (ED), in particular cerebral ED, may be an essential biomarker for ischaemic cerebrovascular disease. However, there is no consensus on methods to best estimate cerebral ED. In this systematic review, we evaluate the use of l-arginine and NG -monomethyl-l-arginine (l......-NMMA) for assessment of cerebral ED. A systematic search of PubMed, EMBASE and the Cochrane Library was done. We included studies investigating cerebrovascular response to l-arginine or l-NMMA in human subjects with vascular risk factors or ischaemic cerebrovascular disease. Seven studies (315 subjects) were eligible...... cerebrovascular disease. Inconsistencies in results were most likely due to variations in methods and included subject populations. In order to use cerebral ED as a prognostic marker, further studies are required to evaluate the association to cerebrovascular disease....

  13. Long term exposure to L-arginine accelerates endothelial cell senescence through arginase-II and S6K1 signaling.

    Science.gov (United States)

    Xiong, Yuyan; Fru, Michael Forbiteh; Yu, Yi; Montani, Jean-Pierre; Ming, Xiu-Fen; Yang, Zhihong

    2014-05-01

    L-arginine supplementation is proposed to improve health status or as adjunct therapy for diseases including cardiovascular diseases. However, controversial results and even detrimental effects of L-arginine supplementation are reported. We investigate potential mechanisms of L-arginine-induced detrimental effects on vascular endothelial cells. Human endothelial cells were exposed to a physiological (0.1 mmol/L) or pharmacological (0.5 mmol/L) concentration of L-arginine for 30 minutes (acute) or 7 days (chronic). The effects of L-arginine supplementation on endothelial senescence phenotype, i.e., levels of senescence-associated beta-galactosidase, expression of vascular cell adhesion molecule-1 and intercellular adhesion molecule-1, eNOS-uncoupling, arginase-II expression/activity, and mTORC1-S6K1 activity were analyzed. While acute L-arginine treatment enhances endothelial NO production accompanied with superoxide production and activation of S6K1 but no up-regulation of arginase-II, chronic L-arginine supplementation causes endothelial senescence, up-regulation of the adhesion molecule expression, and eNOS-uncoupling (decreased NO and enhanced superoxide production), which are associated with S6K1 activation and up-regulation of arginase-II. Silencing either S6K1 or arginase-II inhibits up-regulation/activation of each other, prevents endothelial dysfunction, adhesion molecule expression, and senescence under the chronic L-arginine supplementation condition. These results demonstrate that S6K1 and arginase-II form a positive circuit mediating the detrimental effects of chronic L-arginine supplementation on endothelial cells.

  14. Long term exposure to L-arginine accelerates endothelial cell senescence through arginase-II and S6K1 signaling

    Science.gov (United States)

    Xiong, Yuyani; Fru, Michael Forbiteh; Yu, Yi; Montani, Jean-Pierre; Ming, Xiu-Fen; Yang, Zhihong

    2014-01-01

    L-arginine supplementation is proposed to improve health status or as adjunct therapy for diseases including cardiovascular diseases. However, controversial results and even detrimental effects of L-arginine supplementation are reported. We investigate potential mechanisms of L-arginine-induced detrimental effects on vascular endothelial cells. Human endothelial cells were exposed to a physiological (0.1 mmol/L) or pharmacological (0.5 mmol/L) concentration of L-arginine for 30 minutes (acute) or 7 days (chronic). The effects of L-arginine supplementation on endothelial senescence phenotype, i.e., levels of senescence-associated beta-galactosidase, expression of vascular cell adhesion molecule-1 and intercellular adhesion molecule-1, eNOS-uncoupling, arginase-II expression/activity, and mTORC1-S6K1 activity were analyzed. While acute L-arginine treatment enhances endothelial NO production accompanied with superoxide production and activation of S6K1 but no up-regulation of arginase-II, chronic L-arginine supplementation causes endothelial senescence, up-regulation of the adhesion molecule expression, and eNOS-uncoupling (decreased NO and enhanced superoxide production), which are associated with S6K1 activation and up-regulation of arginase-II. Silencing either S6K1 or arginase-II inhibits up-regulation/activation of each other, prevents endothelial dysfunction, adhesion molecule expression, and senescence under the chronic L-arginine supplementation condition. These results demonstrate that S6K1 and arginase-II form a positive circuit mediating the detrimental effects of chronic L-arginine supplementation on endothelial cells. PMID:24860943

  15. Chemoproteomics Reveals Unexpected Lysine/Arginine-Specific Cleavage of Peptide Chains as a Potential Protein Degradation Machinery.

    Science.gov (United States)

    Tian, Caiping; Liu, Keke; Sun, Rui; Fu, Ling; Yang, Jing

    2018-01-02

    Proteins can undergo oxidative cleavage by in vitro metal-catalyzed oxidation (MCO) in either the α-amidation or the diamide pathway. However, whether oxidative cleavage of polypeptide-chain occurs in biological systems remains unexplored. We describe a chemoproteomic approach to globally and site-specifically profile electrophilic protein degradants formed from peptide backbone cleavages in human proteomes, including the known N-terminal α-ketoacyl products and >1000 unexpected N-terminal formyl products. Strikingly, such cleavages predominantly occur at the carboxyl side of lysine (K) and arginine (R) residues across native proteomes in situ, while MCO-induced oxidative cleavages randomly distribute on peptide/protein sequences in vitro. Furthermore, ionizing radiation-induced reactive oxygen species (ROS) also generate random oxidative cleavages in situ. These findings suggest that the endogenous formation of N-formyl and N-α-ketoacyl degradants in biological systems is more likely regulated by a previously unknown mechanism with a trypsin-like specificity, rather than the random oxidative damage as previously thought. More generally, our study highlights the utility of quantitative chemoproteomics in combination with unrestricted search tools as a viable strategy to discover unexpected chemical modifications of proteins labeled with active-based probes.

  16. Effect of Basic Residue on the Kinetics of Peptide Fragmentation Examined Using Surface-Induced Dissociation Combined with Resonant Ejection

    Energy Technology Data Exchange (ETDEWEB)

    Laskin, Julia

    2015-11-30

    In this work, resonant ejection coupled with surface-induced dissociation (SID) in a Fourier transform ion cyclotron resonance mass spectrometer is used to examine fragmentation kinetics of two singly protonated hexapeptides, RYGGFL and KYGGFL, containing the basic arginine residue and less basic lysine residue at the N-terminus. The kinetics of individual reaction channels at different collision energies are probed by applying a short ejection pulse (1 ms) in resonance with the cyclotron frequency of a selected fragment ion and varying the delay time between ion-surface collision and resonant ejection while keeping total reaction delay time constant. Rice-Ramsperger-Kassel-Marcus (RRKM) modeling of the experimental data provides accurate threshold energies and activation entropies of individual reaction channels. Substitution of arginine with less basic lysine has a pronounced effect on the observed fragmentation kinetics of several pathways, including the b2 ion formation, but has little or no effect on formation of the b5+H2O fragment ion. The combination of resonant ejection SID, time- and collision energy-resolved SID, and RRKM modeling of both types of experimental data provides a detailed mechanistic understanding of the primary dissociation pathways of complex gaseous ions.

  17. L-arginine supplementation and experimental airway hyperreactivity.

    Science.gov (United States)

    Antosova, M; Strapkova, A

    2013-01-01

    The interest in L-arginine metabolism was triggered primarily by the discovery of nitric oxide (NO) synthesis in mammals and its remarkable biological roles. The real role of L-arginine in the airway hyperreactivity (AHR) has not been established yet. Therefore, we studied whether supplementation of L-arginine can influence the experimental AHR evoked by two different triggers - allergen and exogenous irritant (toluene vapours). Male TRIK strain guinea pigs were used in the study. We used two patterns of pretreatment with L-arginine in vivo, short- and long-term, in a dose of 300 mg/kg administered i.p., after which we studied reactivity of airway smooth muscles in vitro. Pretreatment with L-arginine for 3 days decreased the airway smooth muscle reactivity induced by toluene vapour, whereas pretreatment for 17 days was without any additional effect on smooth muscle reactivity. The short-term pretreatment in ovalbumin-induced hyperreactivity caused an increase in airway smooth muscle reactivity to lower concentrations of both bronchoconstrictors. On the other side, this pretreatment significantly decreased smooth muscle reactivity to high concentrations of both bronchoconstrictors. Supplementation of L-arginine resulted in a modification of the airway smooth muscle response. The effect of supplementation was different depending on the AHR trigger, airway region and pretreatment duration. The results also underscore the importance of an optimal L-arginine level for the control of bronchial tone.

  18. Effects of L-Arginine Supplementation on Leukogram, Inflammatory Bowel Infiltrates and Immunoglobulins with 5-FU Use in Rats.

    Science.gov (United States)

    Balmant, Bianca D; Araújo, Eloisa O N; Yabuki, Denise; Novais, Amanda B; Genaro, Sandra C; Laposy, Cecilia B; Goiozo, Paulo F I; Chacur, Marcelo G M; Giuffrida, Rogério; Reis, Luis S L S

    2018-01-01

    This study evaluated the effects of L-arginine supplementation on blood parameters, kidney and liver function, immunoglobulins and noninflammatory infiltrates in the small intestines of rats subjected to chemotherapy with 5-fluorouracil (5-FU). Thirty-two Wistar rats were randomly distributed into 4 groups (8 rats/group): an untreated control group, and test groups receiving one dose of 5-FU (G 5-FU group), one dose of 5-FU and 295 mg L-arginine/day (G Arg295 group) or one dose of 5-FU and 458 mg L-arginine/day (G Arg458 group). Neutrophil count, platelet count, serum IgA, and fibrinogen levels in G Arg295 and G Arg458 remained within normal limits after chemotherapy. In addition, in G Arg458 the inflammatory bowel infiltrates improved in 57% of the rats, which showed mild inflammation. The results suggest that daily supplementation with 295 or 458 mg L-arginine attenuates the side effects of 5-FU, including thrombocytopenia and neutropenia, and modulates IgA production. Supplementation with 458 mg of L-arginine/day can also reduce mucositis levels in the small intestine after 5-FU chemotherapy.

  19. Characterisation of neuroprotective efficacy of modified poly-arginine-9 (R9) peptides using a neuronal glutamic acid excitotoxicity model.

    Science.gov (United States)

    Edwards, Adam B; Anderton, Ryan S; Knuckey, Neville W; Meloni, Bruno P

    2017-02-01

    In a recent study, we highlighted the importance of cationic charge and arginine residues for the neuroprotective properties of poly-arginine and arginine-rich peptides. In this study, using cortical neuronal cultures and an in vitro glutamic acid excitotoxicity model, we examined the neuroprotective efficacy of different modifications to the poly-arginine-9 peptide (R9). We compared an unmodified R9 peptide with R9 peptides containing the following modifications: (i) C-terminal amidation (R9-NH2); (ii) N-terminal acetylation (Ac-R9); (iii) C-terminal amidation with N-terminal acetylation (Ac-R9-NH2); and (iv) C-terminal amidation with D-amino acids (R9D-NH2). The three C-terminal amidated peptides (R9-NH2, Ac-R9-NH2, and R9D-NH2) displayed neuroprotective effects greater than the unmodified R9 peptide, while the N-terminal acetylated peptide (Ac-R9) had reduced efficacy. Using the R9-NH2 peptide, neuroprotection could be induced with a 10 min peptide pre-treatment, 1-6 h before glutamic acid insult, or when added to neuronal cultures up to 45 min post-insult. In addition, all peptides were capable of reducing glutamic acid-mediated neuronal intracellular calcium influx, in a manner that reflected their neuroprotective efficacy. This study further highlights the neuroprotective properties of poly-arginine peptides and provides insight into peptide modifications that affect efficacy.

  20. Asymmetric Dimethyl Arginine in Hypothyroid Patients

    International Nuclear Information System (INIS)

    Abdel-Messeih, P.L.

    2012-01-01

    Thyroid diseases may lead to endothelial dysfunction, however, the mechanism underlying the endothelial dysfunction in thyroid disease is still not clear. Asymmetric dimethyl arginine (ADMA), a novel inhibitor of endothelial nitric oxide synthetase (eNOS), was reported to inhibit nitric oxide (NO) synthesis from L-arginine. The present study was carried out to investigate ADMA levels together with effects of dislipidemia in sub-clinical and overt hypothyroid females. There were significant increase in the levels of total cholesterol, low density lipoprotein-cholesterol (LDL-c), high density lipoprotein-cholesterol (HDL-c), thyroid stimulating hormone (TSH) and ADMA in hypothyroid females as compared to controls while the levels of NO and free T 4 were significantly decreased than controls. Sub-clinical hypothyroid females had significant high TSH, LDL-c and non-significantly high ADMA levels and total cholesterol as compared to controls while they had significant decrease in NO, HDL-c and non-significant decrease in free T 4 as compared to controls. There were significant negative correlations between NO and both ADMA (r 2 = 0.84) and free T 4 (r 2 = 0.95) in overt hypothyroid group while significant positive correlation (r 2 = 0.85) was detected between TSH and HDL-c in the same group. These results are highly suggestive that the decrease of nitric oxide secondary to accumulation of ADMA represent an important pathogenic factor together with dyslipidemia in endothelial dysfunction and increased cardiovascular risk especially in hypothyroid females

  1. Reduced caloric intake during endotoxemia reduces arginine availability and metabolism.

    Science.gov (United States)

    Poeze, Martijn; Bruins, Maaike J; Luiking, Yvette C; Deutz, Nicolaas E

    2010-04-01

    Inadequate caloric intake increases the risk of sepsis-induced complications. Metabolic changes during sepsis indicate that the availability of the amino acid l-arginine decreases. Availability of arginine may further decrease during reduced caloric intake, which thereby limits the adaptive response of arginine-nitric oxide metabolism during sepsis. We tested the hypothesis that reduced caloric intake during endotoxemia, as an experimental model for sepsis, further reduces arginine availability. In a randomized trial, a 7-d reduced caloric intake feed regimen (RE; n = 9) was compared with a normal control feed regimen (CE; n = 9), before 24 h of endotoxemia, as a model for sepsis. Whole-body arginine-nitric oxide metabolism and protein metabolism were measured by using a stable-isotope infusion of [(15)N(2)]arginine, [(13)C-(2)H(2)]citrulline, [(2)H(5)]phenylalanine, and [(2)H(2)]tyrosine. Plasma pyruvate and lactate concentrations were determined by fully automated HPLC. Pre-endotoxin arginine appearance was significantly lower in the RE group than in the CE group (P = 0.002). During endotoxemia, arginine appearance increased in the CE animals but not in the RE animals (P = 0.04). In addition, nitric oxide production was significantly lower in the RE animals (P endotoxemia in the RE group than in the CE group (P endotoxemia but increased significantly during endotoxemia in the RE group (P = 0.04). A well-nourished condition before prolonged endotoxemia results in a better ability to adapt to endotoxin-induced metabolic deterioration of arginine-nitric oxide metabolism than does reduced caloric intake before endotoxemia.

  2. Residual risk

    African Journals Online (AJOL)

    ing the residual risk of transmission of HIV by blood transfusion. An epidemiological approach assumed that all HIV infections detected serologically in first-time donors were pre-existing or prevalent infections, and that all infections detected in repeat blood donors were new or incident infections. During 1986 - 1987,0,012%.

  3. Effects of L-arginine pretreatment on nitric oxide metabolism and hepatosplanchnic perfusion during porcine endotoxemia

    NARCIS (Netherlands)

    Poeze, Martijn; Bruins, Maaike J.; Kessels, Fons; Luiking, Yvette C.; Lamers, Wouter H.; Deutz, Nicolaas Ep

    2011-01-01

    Background: Sepsis is accompanied by an increased need for and a decreased supply of arginine, reflecting a condition of arginine deficiency. Objective: The objective was to evaluate the effects of L-arginine pretreatment on arginine-nitric oxide (NO) production and hepatosplanchnic perfusion during

  4. Pentadecapeptide BPC 157 Reduces Bleeding and Thrombocytopenia after Amputation in Rats Treated with Heparin, Warfarin, L-NAME and L-Arginine

    Science.gov (United States)

    Stupnisek, Mirjana; Kokot, Antonio; Drmic, Domagoj; Hrelec Patrlj, Masa; Zenko Sever, Anita; Kolenc, Danijela; Radic, Bozo; Suran, Jelena; Bojic, Davor; Vcev, Aleksandar; Seiwerth, Sven; Sikiric, Predrag

    2015-01-01

    Background BPC 157 is a stable gastric pentadecapeptide recently implicated with a role in hemostasis. While NO is largely implicated in hemostatic mechanisms, in tail-amputation-models under heparin- and warfarin-administration, both the NO-synthase (NOS)-blocker, L-NAME (prothrombotic) and the NOS-substrate L-arginine (antithrombotic), were little investigated. Objective. To investigate the effect of L-NAME and L-arginine on hemostatic parameters, and to reveal the effects of BPC 157 on the L-NAME- and L-arginine-induced hemostatic actions under different pathological condition: tail amputation without or with anticoagulants, heparin or warfarin. Methods Tail amputation, and/or i.v.-heparin (10 mg/kg), i.g.-warfarin (1.5 mg/kg/day for 3 days) were used in rats. Treatment includes BPC 157, L-NAME, L-arginine, per se and their combination. Results After (tail) amputation, with or without i.v.-heparin or i.g.-warfarin, BPC 157 (10 μg/kg, 10 ng/kg, i.p., i.v. (heparin), 10 μg/kg i.g. (warfarin)) always reduced bleeding time and/or haemorrhage and counteracted thrombocytopenia. As for L-NAME and/or L-arginine, we noted: L-arginine (100 mg/kg i.p.)–rats: more bleeding, less/no thrombocytopenia; L-NAME (5 mg/kg i.p.)-rats: less bleeding (amputation only), but present thrombocytopenia; L-NAME+L-arginine-rats also exhibited thrombocytopenia: L-NAME counteracted L-arginine-increased bleeding, L-arginine did not counteract L-NAME-thrombocytopenia. All animals receiving BPC 157 in addition (BPC 157μg+L-NAME; BPC 157μg+L-arginine, BPC 157μg+L-NAME+L-arginine), exhibited decreased haemorrhage and markedly counteracted thrombocytopenia. Conclusions L-NAME (thrombocytopenia), L-arginine (increased haemorrhage) counteraction and BPC 157 (decreased haemorrhage, counteracted thrombocytopenia) with rescue against two different anticoagulants, implicate a BPC 157 modulatory and balancing role with rescued NO-hemostatic mechanisms. PMID:25897838

  5. Unique contributions of an arginine side chain to ligand recognition in a glutamate-gated chloride channel

    DEFF Research Database (Denmark)

    Lynagh, Timothy; Komnatnyy, Vitaly V; Pless, Stephan A

    2017-01-01

    Glutamate recognition by neurotransmitter receptors often relies on arginine (Arg) residues in the binding site, leading to the assumption that charge-charge interactions underlie ligand recognition. However, assessing the precise chemical contribution of Arg side chains to protein function...... and pharmacology has proven to be exceedingly difficult in such large and complex proteins. Using the in vivo nonsense suppression approach, we report the first successful incorporation of the isosteric, titratable Arg analog, canavanine, into a neurotransmitter receptor in a living cell, utilizing a glutamate......-gated chloride channel from the nematode Haemonchus contortus. Our data unveil a surprisingly small contribution of charge at a conserved arginine side chain previously suggested to form a salt bridge with the ligand, glutamate. Instead, our data show that Arg contributes crucially to ligand sensitivity via...

  6. l-Lysine Catabolism Is Controlled by l-Arginine and ArgR in Pseudomonas aeruginosa PAO1▿

    Science.gov (United States)

    Chou, Han Ting; Hegazy, Mohamed; Lu, Chung-Dar

    2010-01-01

    In comparison to other pseudomonads, Pseudomonas aeruginosa grows poorly in l-lysine as a sole source of nutrient. In this study, the ldcA gene (lysine decarboxylase A; PA1818), previously identified as a member of the ArgR regulon of l-arginine metabolism, was found essential for l-lysine catabolism in this organism. LdcA was purified to homogeneity from a recombinant strain of Escherichia coli, and the results of enzyme characterization revealed that this pyridoxal-5-phosphate-dependent decarboxylase takes l-lysine, but not l-arginine, as a substrate. At an optimal pH of 8.5, cooperative substrate activation by l-lysine was depicted from kinetics studies, with calculated Km and Vmax values of 0.73 mM and 2.2 μmole/mg/min, respectively. Contrarily, the ldcA promoter was induced by exogenous l-arginine but not by l-lysine in the wild-type strain PAO1, and the binding of ArgR to this promoter region was demonstrated by electromobility shift assays. This peculiar arginine control on lysine utilization was also noted from uptake experiments in which incorporation of radioactively labeled l-lysine was enhanced in cells grown in the presence of l-arginine but not l-lysine. Rapid growth on l-lysine was detected in a mutant devoid of the main arginine catabolic pathway and with a higher basal level of the intracellular l-arginine pool and hence elevated ArgR-responsive regulons, including ldcA. Growth on l-lysine as a nitrogen source can also be enhanced when the aruH gene encoding an arginine/lysine:pyruvate transaminase was expressed constitutively from plasmids; however, no growth of the ldcA mutant on l-lysine suggests a minor role of this transaminase in l-lysine catabolism. In summary, this study reveals a tight connection of lysine catabolism to the arginine regulatory network, and the lack of lysine-responsive control on lysine uptake and decarboxylation provides an explanation of l-lysine as a poor nutrient for P. aeruginosa. PMID:20833801

  7. L-lysine catabolism is controlled by L-arginine and ArgR in Pseudomonas aeruginosa PAO1.

    Science.gov (United States)

    Chou, Han Ting; Hegazy, Mohamed; Lu, Chung-Dar

    2010-11-01

    In comparison to other pseudomonads, Pseudomonas aeruginosa grows poorly in L-lysine as a sole source of nutrient. In this study, the ldcA gene (lysine decarboxylase A; PA1818), previously identified as a member of the ArgR regulon of L-arginine metabolism, was found essential for L-lysine catabolism in this organism. LdcA was purified to homogeneity from a recombinant strain of Escherichia coli, and the results of enzyme characterization revealed that this pyridoxal-5-phosphate-dependent decarboxylase takes L-lysine, but not L-arginine, as a substrate. At an optimal pH of 8.5, cooperative substrate activation by L-lysine was depicted from kinetics studies, with calculated K(m) and V(max) values of 0.73 mM and 2.2 μmole/mg/min, respectively. Contrarily, the ldcA promoter was induced by exogenous L-arginine but not by L-lysine in the wild-type strain PAO1, and the binding of ArgR to this promoter region was demonstrated by electromobility shift assays. This peculiar arginine control on lysine utilization was also noted from uptake experiments in which incorporation of radioactively labeled L-lysine was enhanced in cells grown in the presence of L-arginine but not L-lysine. Rapid growth on L-lysine was detected in a mutant devoid of the main arginine catabolic pathway and with a higher basal level of the intracellular L-arginine pool and hence elevated ArgR-responsive regulons, including ldcA. Growth on L-lysine as a nitrogen source can also be enhanced when the aruH gene encoding an arginine/lysine:pyruvate transaminase was expressed constitutively from plasmids; however, no growth of the ldcA mutant on L-lysine suggests a minor role of this transaminase in L-lysine catabolism. In summary, this study reveals a tight connection of lysine catabolism to the arginine regulatory network, and the lack of lysine-responsive control on lysine uptake and decarboxylation provides an explanation of L-lysine as a poor nutrient for P. aeruginosa.

  8. l-arginine and l-NMMA for assessing cerebral endothelial dysfunction in ischaemic cerebrovascular disease: A systematic review.

    Science.gov (United States)

    Karlsson, William K; Sørensen, Caspar G; Kruuse, Christina

    2017-01-01

    Endothelial dysfunction (ED), in particular cerebral ED, may be an essential biomarker for ischaemic cerebrovascular disease. However, there is no consensus on methods to best estimate cerebral ED. In this systematic review, we evaluate the use of l-arginine and N G -monomethyl-l-arginine (l-NMMA) for assessment of cerebral ED. A systematic search of PubMed, EMBASE and the Cochrane Library was done. We included studies investigating cerebrovascular response to l-arginine or l-NMMA in human subjects with vascular risk factors or ischaemic cerebrovascular disease. Seven studies (315 subjects) were eligible according to inclusion and exclusion criteria. Studies investigated the effect of age (n=2), type 2 diabetes mellitus (DM) (n=1), cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) (n=1), leukoaraiosis (n=1), and prior ischaemic stroke or transient ischaemic attack (TIA) (n=2) on cerebral ED. Most studies applied transcranial Doppler to quantify cerebral ED. Endothelium-dependent vasodilatation (EDV) induced by l-arginine was impaired in elderly and subjects with leukoaraiosis, but enhanced in CADASIL patients. Studies including subjects with prior ischaemic stroke or TIA reported both enhanced and impaired EDV to l-arginine. Responses to l-NMMA deviated between subjects with type 2 DM and the elderly. We found only few studies investigating cerebral endothelial responses to l-arginine and l-NMMA in subjects with vascular risk factors or ischaemic cerebrovascular disease. Inconsistencies in results were most likely due to variations in methods and included subject populations. In order to use cerebral ED as a prognostic marker, further studies are required to evaluate the association to cerebrovascular disease. © 2016 John Wiley & Sons Australia, Ltd.

  9. Identification of hardly biodegradable residuals (sulfur- and nitrogen-containing substances) during waste water treatment, including the development of analytical methods; Identifizierung von schwer abbaubaren Reststoffen (stickstoff- und schwefelhaltigen Verbindungen) bei der Abwasserbehandlung, einschliesslich analytischer Methodenentwicklung

    Energy Technology Data Exchange (ETDEWEB)

    Moehle, E.; Huber, A.; Metzger, J.W.

    1999-07-01

    Organic residuals in sewage, which are not removed completely by waste water treatment may be relevant in environmental toxicology and may disturb drinking water treatment processes. The organic residuals must be identified before new techniques to eliminate these substances from waste water can be developed and steps can be taken to prevent them from polluting waste waters. In the research project sum parameters of sulfur- and nitrogen-containing substances in municipal waste water were determined. A new method was developed to determine the organic sulfur in compounds absorbed on activated carbon (AOS). The determination of dissolved organic nitrogen (DON) was calculated as the difference between total nitrogen and the sum of NH{sub 4}{sup +}-N, NO{sub 3}{sup -}-N and NO{sub 2}{sup -}N. The removal of organic substances from the inorganic matrix was only possible for standard solutions, but not for real samples. More than 60 substances contributing to the sum parameters could be identified with GC-MS and GC-AED, an most of them could be quantified. 30-70% of the sulfur-containing substances detected with GC-AED could be identified. With the GC-MS screening method 21 drugs or drug metabolites could be identified and partly quantified. Hydrophilic organic residuals were identified and quantified with high performance liquid chromatography coupled with UV- and fluorescence detectors and also with a mass detector (ESI-MS-MS). With the methods described only a small percentage of the sum of AOS and DON could be detected, although new materials for the solid phase enrichment and new analytical methods, such as HPLC-MS-MS were used. In order to get information about the degree of elimination (absorption or degradation) of different drugs in a municipal sewage plant, laboratory-scale tests under aerobic conditions were performed. A batch reactor containing drugs in environmentally relevant concentrations and a suspension of activated sludge was coupled online with HPLC

  10. A comparison of DNA compaction by arginine and lysine peptides: a physical basis for arginine rich protamines.

    Science.gov (United States)

    DeRouchey, Jason; Hoover, Brandon; Rau, Donald C

    2013-04-30

    Protamines are small, highly positively charged peptides used to package DNA at very high densities in sperm nuclei. Tight DNA packing is considered essential for the minimization of DNA damage by mutagens and reactive oxidizing species. A striking and general feature of protamines is the almost exclusive use of arginine over lysine for the positive charge to neutralize DNA. We have investigated whether this preference for arginine might arise from a difference in DNA condensation by arginine and lysine peptides. The forces underlying DNA compaction by arginine, lysine, and ornithine peptides are measured using the osmotic stress technique coupled with X-ray scattering. The equilibrium spacings between DNA helices condensed by lysine and ornithine peptides are significantly larger than the interhelical distances with comparable arginine peptides. The DNA surface-to-surface separation, for example, is some 50% larger with polylysine than with polyarginine. DNA packing by lysine rich peptides in sperm nuclei would allow much greater accessibility to small molecules that could damage DNA. The larger spacing with lysine peptides is caused by both a weaker attraction and a stronger short-range repulsion relative to that of the arginine peptides. A previously proposed model for binding of polyarginine and protamine to DNA provides a convenient framework for understanding the differences between the ability of lysine and arginine peptides to assemble DNA.

  11. Residual basins

    International Nuclear Information System (INIS)

    D'Elboux, C.V.; Paiva, I.B.

    1980-01-01

    Exploration for uranium carried out over a major portion of the Rio Grande do Sul Shield has revealed a number of small residual basins developed along glacially eroded channels of pre-Permian age. Mineralization of uranium occurs in two distinct sedimentary units. The lower unit consists of rhythmites overlain by a sequence of black shales, siltstones and coal seams, while the upper one is dominated by sandstones of probable fluvial origin. (Author) [pt

  12. L-Arginine Pathway in COPD Patients with Acute Exacerbation

    DEFF Research Database (Denmark)

    Ruzsics, Istvan; Nagy, Lajos; Keki, Sandor

    2016-01-01

    (ADMA, SDMA) is related to hypoxia. In COPD, a rise in ADMA results in a shift of L-arginine breakdown, contributing to airway obstruction. We aimed to compare serum levels of ADMA, SDMA and L-arginine in patients with and without AECOPD. METHODS: L-arginine metabolites quantified by high......-performance liquid chromatography in venous blood samples and partial capillary oxygen pressure were prospectively investigated in 32 patients with COPD, 12 with AECOPD and 30 healthy subjects. RESULTS: Both ADMA and SDMA were significantly higher in AECOPD compared to stable COPD (p = 0.004 and p ....001, respectively). Oxygen content in capillaries correlated with serum ADMA concentration. However, the concentration of L-arginine was not different between AECOPD and stable COPD. Both ADMA and SDMA separated AECOPD with high sensitivity and specificity (AUC: 0.81, p = 0.001; AUC: 0.91, p

  13. Monitoring the extraction of additives and additive degradation products from polymer packaging into solutions by multi-residue method including solid phase extraction and ultra-high performance liquid chromatography-tandem mass spectrometry analysis.

    Science.gov (United States)

    Pouech, Charlène; Lafay, Florent; Wiest, Laure; Baudot, Robert; Léonard, Didier; Cren-Olivé, Cécile

    2014-02-01

    The use of polymer materials in industry for product packaging is increasing. The presence of additives in the polymer matrix enables the modification or improvement of the properties and performance of the polymer, but these industries are concerned regarding the extractability of these additives. The quantification of these additives is particularly challenging because of the presence of these substances as contaminants in all the analytical equipment and the diversity of their physicochemical properties. In this context, a multi-residue analytical method was developed for the trace analysis of the twenty main additives (and their degradation products) authorized in plastic products such as pharmaceutical packaging (e.g., antioxidants, release agents, and light absorbers). This analytical method consisted of a solid phase extraction (SPE) followed by an analysis using ultra-high performance liquid chromatography coupled to a tandem mass spectrometer (UHPLC-MS/MS). A comparison of two ionization interfaces and the optimization of the extraction procedure were discussed. The influence of the quality of the solvent type (distilled versus not distilled) and the nature of the SPE cartridges (Polypropylene versus Teflon(®)) were demonstrated. The optimized method exhibited a quantification limit lower than 20 ng mL(-1) and recoveries between 70 % and 120 % for all compounds. Finally, the method was validated according to the ICH directive and was subsequently applied to the extraction of polymers under different pH conditions and storage temperatures. To the best of our knowledge, this study presents the first methodology allowing the simultaneous quantification of 24 additives at low ng mL(-1).

  14. Management of NORM Residues

    International Nuclear Information System (INIS)

    2013-06-01

    The IAEA attaches great importance to the dissemination of information that can assist Member States in the development, implementation, maintenance and continuous improvement of systems, programmes and activities that support the nuclear fuel cycle and nuclear applications, and that address the legacy of past practices and accidents. However, radioactive residues are found not only in nuclear fuel cycle activities, but also in a range of other industrial activities, including: - Mining and milling of metalliferous and non-metallic ores; - Production of non-nuclear fuels, including coal, oil and gas; - Extraction and purification of water (e.g. in the generation of geothermal energy, as drinking and industrial process water; in paper and pulp manufacturing processes); - Production of industrial minerals, including phosphate, clay and building materials; - Use of radionuclides, such as thorium, for properties other than their radioactivity. Naturally occurring radioactive material (NORM) may lead to exposures at some stage of these processes and in the use or reuse of products, residues or wastes. Several IAEA publications address NORM issues with a special focus on some of the more relevant industrial operations. This publication attempts to provide guidance on managing residues arising from different NORM type industries, and on pertinent residue management strategies and technologies, to help Member States gain perspectives on the management of NORM residues

  15. Selective small-chemical inhibitors of protein arginine methyltransferase 5 with anti-lung cancer activity.

    Directory of Open Access Journals (Sweden)

    Gui-Mei Kong

    Full Text Available Protein arginine methyltransferase 5 (PRMT5 plays critical roles in a wide variety of biological processes, including tumorigenesis. By screening a library of small chemical compounds, we identified eight compounds that selectively inhibit the PRMT5 enzymatic activity, with IC50 values ranging from 0.1 to 6 μM. Molecular docking simulation and site-directed mutagenesis indicated that identified compounds target the substrate-binding site in PRMT5. Treatment of lung cancer cells with identified inhibitors led to inhibition of the symmetrical arginine methylation of SmD3 and histones and the cellular proliferation. Oral administration of the inhibitor demonstrated antitumor activity in a lung tumor xenograft model. Thus, identified PRMT5-specific small-molecule inhibitors would help elucidate the biological roles of PRMT5 and serve as lead compounds for future drug development.

  16. Dietary L-arginine supplementation protects weanling pigs from deoxynivalenol-induced toxicity.

    Science.gov (United States)

    Wu, Li; Liao, Peng; He, Liuqin; Feng, Zemeng; Ren, Wenkai; Yin, Jie; Duan, Jielin; Li, Tiejun; Yin, Yulong

    2015-04-15

    This study was conducted to determine the positive effects of dietary supplementation with L-arginine (Arg) on piglets fed a deoxynivalenol (DON)-contaminated diet. A total of eighteen, 28-day-old healthy weanling pigs were randomly assigned into one of three groups: uncontaminated basal diet (control group), 6 mg/kg DON-contaminated diet (DON group) and 6 mg/kg DON + 1% L-arginine (DON + ARG group). After 21 days of Arg supplementation, piglets in the DON and DON + ARG groups were challenged by feeding 6 mg/kg DON-contaminated diet for seven days. The results showed that DON resulted in damage to piglets. However, clinical parameters, including jejunal morphology, amino acid concentrations in the serum, jejunum and ileum, were improved by Arg (p supplementation with Arg exerts a protective role in pigs fed DON-contaminated diets.

  17. Alternatives to crop residues for soil amendment

    OpenAIRE

    Powell, J.M.; Unger, P.W.

    1997-01-01

    Metadata only record In semiarid agroecosystems, crop residues can provide important benefits of soil and water conservation, nutrient cycling, and improved subsequent crop yields. However, there are frequently multiple competing uses for residues, including animal forage, fuel, and construction material. This chapter discusses the various uses of crop residues and examines alternative soil amendments when crop residues cannot be left on the soil.

  18. Hyperbranched lysine-arginine copolymer for gene delivery.

    Science.gov (United States)

    Peng, Qi; Zhu, Jianjun; Yu, Yongsheng; Hoffman, Lee; Yang, Xingkun

    2015-01-01

    Based on the reactivity of amine groups and carboxyl groups of L-lysine and L-arginine, thermal polymerization of these two natural amino acids results in hyperbranched lysine-arginine copolymers (P-lys-argX, where X refers to the relevant molar ratio of arginine to lysine). Hyperbranched polylysine (P-lys) and two derivatives (P-lys-arg0.10 and P-lys-arg0.20) have been prepared. The arginine-rich hyperbranched polymers can interact with plasmid DNA to form nano-sized particles. The polyplexes were physicochemically analyzed by agarose gel electrophoresis, dynamic light scattering, and zeta potential measurements. Furthermore, their transfection efficiency was assessed, employing COS-7, 293T, and HeLa cell lines. It was found that P-lys showed poorly in its ability of condensation with DNA and transfection efficiency. On the other hand, arginine-rich products resulted to significant enhancement of its transfection efficiency, which is dependent on the content of arginine in the polymers, and the cell line used. P-lys-arg0.20 exhibited better transfection efficiency under all the condition studied. Besides, P-lys-arg0.20 showed lower toxicity in COS-7 cells.

  19. Reference Intervals for Plasma l-Arginine and the l-Arginine:Asymmetric Dimethylarginine Ratio in the Framingham Offspring Cohort123

    OpenAIRE

    Lüneburg, Nicole; Xanthakis, Vanessa; Schwedhelm, Edzard; Sullivan, Lisa M.; Maas, Renke; Anderssohn, Maike; Riederer, Ulrich; Glazer, Nicole L.; Vasan, Ramachandran S.; Böger, Rainer H.

    2011-01-01

    l-Arginine, as a precursor of NO synthesis, has attracted much scientific attention in recent years. Experimental mouse models suggest that l-arginine supplementation can retard, halt, or even reverse atherogenesis. In human studies, supplementation with l-arginine improved endothelium-dependent vasodilation. However, l-arginine levels are best interpreted in the context of levels of asymmetric dimethylarginine (ADMA), a competitive inhibitor of NO synthase. Thus, reference limits for circula...

  20. The acute effects of L-arginine on hormonal and metabolic responses during submaximal exercise in trained cyclists.

    Science.gov (United States)

    Forbes, Scott C; Harber, Vicki; Bell, Gordon J

    2013-08-01

    L-arginine may enhance endurance performance mediated by two primary mechanisms including enhanced secretion of endogenous growth hormone (GH) and as a precursor of nitric oxide (NO); however, research in trained participants has been equivocal. The purpose was to investigate the effect of acute L-arginine ingestion on the hormonal and metabolic response during submaximal exercise in trained cyclists. Fifteen aerobically trained men (age: 28 ± 5 y; body mass: 77.4 ± 9.5 kg; height: 180.9 ± 7.9 cm; VO2max: 59.6 ± 5.9 ml·kg- 1·min-1) participated in a randomized, double-blind, crossover study. Subjects consumed L-arginine (ARG; 0. 075 g·kg-1 body mass) or a placebo (PLA) before performing an acute bout of submaximal exercise (60 min at 80% of power output achieved at ventilatory threshold). The ARG condition significantly increased plasma L-arginine concentrations (~146%), while no change was detected in the PLA condition. There were no differences between conditions for GH, nonesterified fatty acids (NEFA), lactate, glucose, VO2, VCO2, RER, CHO oxidation, and NOx. There was reduced fat oxidation at the start of exercise (ARG: 0.36 ± 0.25 vs. PLA: 0.42 ± 0.23 g·min-1, p L-arginine consumption. In conclusion, the acute ingestion of L-arginine did not alter any hormonal, metabolic, or cardio-respiratory responses during submaximal exercise except for a small but significant increase in glycerol at the 45-min time point and a reduction in fat oxidation at the start of exercise.

  1. Identification of a novel antimicrobial peptide from human hepatitis B virus core protein arginine-rich domain (ARD.

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    Heng-Li Chen

    Full Text Available The rise of multidrug-resistant (MDR pathogens causes an increasing challenge to public health. Antimicrobial peptides are considered a possible solution to this problem. HBV core protein (HBc contains an arginine-rich domain (ARD at its C-terminus, which consists of 16 arginine residues separated into four clusters (ARD I to IV. In this study, we demonstrated that the peptide containing the full-length ARD I-IV (HBc147-183 has a broad-spectrum antimicrobial activity at micro-molar concentrations, including some MDR and colistin (polymyxin E-resistant Acinetobacter baumannii. Furthermore, confocal fluorescence microscopy and SYTOX Green uptake assay indicated that this peptide killed Gram-negative and Gram-positive bacteria by membrane permeabilization or DNA binding. In addition, peptide ARD II-IV (HBc153-176 and ARD I-III (HBc147-167 were found to be necessary and sufficient for the activity against P. aeruginosa and K. peumoniae. The antimicrobial activity of HBc ARD peptides can be attenuated by the addition of LPS. HBc ARD peptide was shown to be capable of direct binding to the Lipid A of lipopolysaccharide (LPS in several in vitro binding assays. Peptide ARD I-IV (HBc147-183 had no detectable cytotoxicity in various tissue culture systems and a mouse animal model. In the mouse model by intraperitoneal (i.p. inoculation with Staphylococcus aureus, timely treatment by i.p. injection with ARD peptide resulted in 100-fold reduction of bacteria load in blood, liver and spleen, as well as 100% protection of inoculated animals from death. If peptide was injected when bacterial load in the blood reached its peak, the protection rate dropped to 40%. Similar results were observed in K. peumoniae using an IVIS imaging system. The finding of anti-microbial HBc ARD is discussed in the context of commensal gut microbiota, development of intrahepatic anti-viral immunity and establishment of chronic infection with HBV. Our current results suggested that

  2. Short-term arginine deprivation results in large-scale modulation of hepatic gene expression in both normal and tumor cells: microarray bioinformatic analysis

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    Sabo Edmond

    2006-09-01

    Full Text Available Abstract Background We have reported arginine-sensitive regulation of LAT1 amino acid transporter (SLC 7A5 in normal rodent hepatic cells with loss of arginine sensitivity and high level constitutive expression in tumor cells. We hypothesized that liver cell gene expression is highly sensitive to alterations in the amino acid microenvironment and that tumor cells may differ substantially in gene sets sensitive to amino acid availability. To assess the potential number and classes of hepatic genes sensitive to arginine availability at the RNA level and compare these between normal and tumor cells, we used an Affymetrix microarray approach, a paired in vitro model of normal rat hepatic cells and a tumorigenic derivative with triplicate independent replicates. Cells were exposed to arginine-deficient or control conditions for 18 hours in medium formulated to maintain differentiated function. Results Initial two-way analysis with a p-value of 0.05 identified 1419 genes in normal cells versus 2175 in tumor cells whose expression was altered in arginine-deficient conditions relative to controls, representing 9–14% of the rat genome. More stringent bioinformatic analysis with 9-way comparisons and a minimum of 2-fold variation narrowed this set to 56 arginine-responsive genes in normal liver cells and 162 in tumor cells. Approximately half the arginine-responsive genes in normal cells overlap with those in tumor cells. Of these, the majority was increased in expression and included multiple growth, survival, and stress-related genes. GADD45, TA1/LAT1, and caspases 11 and 12 were among this group. Previously known amino acid regulated genes were among the pool in both cell types. Available cDNA probes allowed independent validation of microarray data for multiple genes. Among genes downregulated under arginine-deficient conditions were multiple genes involved in cholesterol and fatty acid metabolism. Expression of low-density lipoprotein receptor was

  3. Prediction of twin-arginine signal peptides

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    Widdick David

    2005-07-01

    Full Text Available Abstract Background Proteins carrying twin-arginine (Tat signal peptides are exported into the periplasmic compartment or extracellular environment independently of the classical Sec-dependent translocation pathway. To complement other methods for classical signal peptide prediction we here present a publicly available method, TatP, for prediction of bacterial Tat signal peptides. Results We have retrieved sequence data for Tat substrates in order to train a computational method for discrimination of Sec and Tat signal peptides. The TatP method is able to positively classify 91% of 35 known Tat signal peptides and 84% of the annotated cleavage sites of these Tat signal peptides were correctly predicted. This method generates far less false positive predictions on various datasets than using simple pattern matching. Moreover, on the same datasets TatP generates less false positive predictions than a complementary rule based prediction method. Conclusion The method developed here is able to discriminate Tat signal peptides from cytoplasmic proteins carrying a similar motif, as well as from Sec signal peptides, with high accuracy. The method allows filtering of input sequences based on Perl syntax regular expressions, whereas hydrophobicity discrimination of Tat- and Sec-signal peptides is carried out by an artificial neural network. A potential cleavage site of the predicted Tat signal peptide is also reported. The TatP prediction server is available as a public web server at http://www.cbs.dtu.dk/services/TatP/.

  4. Fluorometric enzymatic assay of L-arginine

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    Stasyuk, Nataliya; Gayda, Galina; Yepremyan, Hasmik; Stepien, Agnieszka; Gonchar, Mykhailo

    2017-01-01

    The enzymes of L-arginine (further - Arg) metabolism are promising tools for elaboration of selective methods for quantitative Arg analysis. In our study we propose an enzymatic method for Arg assay based on fluorometric monitoring of ammonia, a final product of Arg splitting by human liver arginase I (further - arginase), isolated from the recombinant yeast strain, and commercial urease. The selective analysis of ammonia (at 415 nm under excitation at 360 nm) is based on reaction with o-phthalaldehyde (OPA) in the presence of sulfite in alkali medium: these conditions permit to avoid the reaction of OPA with any amino acid. A linearity range of the fluorometric arginase-urease-OPA method is from 100 nM to 6 μМ with a limit of detection of 34 nM Arg. The method was used for the quantitative determination of Arg in the pooled sample of blood serum. The obtained results proved to be in a good correlation with the reference enzymatic method and literature data. The proposed arginase-urease-OPA method being sensitive, economical, selective and suitable for both routine and micro-volume formats, can be used in clinical diagnostics for the simultaneous determination of Arg as well as urea and ammonia in serum samples.

  5. Arginine side chain interactions and the role of arginine as a gating charge carrier in voltage sensitive ion channels

    Science.gov (United States)

    Armstrong, Craig T.; Mason, Philip E.; Anderson, J. L. Ross; Dempsey, Christopher E.

    2016-02-01

    Gating charges in voltage-sensing domains (VSD) of voltage-sensitive ion channels and enzymes are carried on arginine side chains rather than lysine. This arginine preference may result from the unique hydration properties of the side chain guanidinium group which facilitates its movement through a hydrophobic plug that seals the center of the VSD, as suggested by molecular dynamics simulations. To test for side chain interactions implicit in this model we inspected interactions of the side chains of arginine and lysine with each of the 19 non-glycine amino acids in proteins in the protein data bank. The arginine guanidinium interacts with non-polar aromatic and aliphatic side chains above and below the guanidinium plane while hydrogen bonding with polar side chains is restricted to in-plane positions. In contrast, non-polar side chains interact largely with the aliphatic part of the lysine side chain. The hydration properties of arginine and lysine are strongly reflected in their respective interactions with non-polar and polar side chains as observed in protein structures and in molecular dynamics simulations, and likely underlie the preference for arginine as a mobile charge carrier in VSD.

  6. Effect of oral L-arginine supplementation on blood pressure: a meta-analysis of randomized, double-blind, placebo-controlled trials.

    Science.gov (United States)

    Dong, Jia-Yi; Qin, Li-Qiang; Zhang, Zengli; Zhao, Youyou; Wang, Junkuan; Arigoni, Fabrizio; Zhang, Weiguo

    2011-12-01

    Previous studies suggest that L-arginine, an amino acid and a substrate of nitric oxide synthase, may have blood pressure (BP)-lowering effect. Because some studies were performed with limited number of patients with hypertension and therefore limited statistical power with sometimes inconsistent results, we aimed to examine the effect of oral L-arginine supplementation on BP by conducting a meta-analysis of randomized, double-blind, placebo-controlled trials. PubMed, Cochrane Central Register of Controlled Trials, and the ClinicalTrials.gov databases were searched through June 2011 to identify randomized, double-blind, placebo-controlled trials of oral L-arginine supplementation on BP in humans. We also reviewed reference lists of obtained articles. Either a fixed-effects or, in the presence of heterogeneity, a random-effects model was used to calculate the combined treatment effect. We included 11 randomized, double-blind, placebo-controlled trials involving 387 participants with oral L-arginine intervention ranging from 4 to 24 g/d. Compared with placebo, L-arginine intervention significantly lowered systolic BP by 5.39 mm Hg (95% CI -8.54 to -2.25, P = .001) and diastolic BP by 2.66 mm Hg (95% CI -3.77 to -1.54, P L-arginine supplementation significantly lowers both systolic and diastolic BP. Copyright © 2011 Mosby, Inc. All rights reserved.

  7. Preoperative oral nutritional interventions in surgery, including arginine- and glutamine-enhanced supplements

    NARCIS (Netherlands)

    Brinkmann, S.J.H.; Buijs, N.; Luttikhold, J.; Mahdavian Delavary, B.; Niessen, F.B.; van Leeuwen, P.A.M.

    2013-01-01

    The patients' condition prior to surgery is of major importance for clinical outcome. It is believed nowadays that artificial nutrition in the form of a preoperative drink may improve postoperative outcome. Until now, a clear overview concerning the effects of preoperative supplementation on

  8. Arginine-phosphate salt bridges between histones and DNA: Intermolecular actuators that control nucleosome architecture

    Science.gov (United States)

    Yusufaly, Tahir I.; Li, Yun; Singh, Gautam; Olson, Wilma K.

    2014-10-01

    Structural bioinformatics and van der Waals density functional theory are combined to investigate the mechanochemical impact of a major class of histone-DNA interactions, namely, the formation of salt bridges between arginine residues in histones and phosphate groups on the DNA backbone. Principal component analysis reveals that the configurational fluctuations of the sugar-phosphate backbone display sequence-specific directionality and variability, and clustering of nucleosome crystal structures identifies two major salt-bridge configurations: a monodentate form in which the arginine end-group guanidinium only forms one hydrogen bond with the phosphate, and a bidentate form in which it forms two. Density functional theory calculations highlight that the combination of sequence, denticity, and salt-bridge positioning enables the histones to apply a tunable mechanochemical stress to the DNA via precise and specific activation of backbone deformations. The results suggest that selection for specific placements of van der Waals contacts, with high-precision control of the spatial distribution of intermolecular forces, may serve as an underlying evolutionary design principle for the structure and function of nucleosomes, a conjecture that is corroborated by previous experimental studies.

  9. Arginine dependence of tumor cells: targeting a chink in cancer's armor.

    Science.gov (United States)

    Patil, M D; Bhaumik, J; Babykutty, S; Banerjee, U C; Fukumura, D

    2016-09-22

    Arginine, one among the 20 most common natural amino acids, has a pivotal role in cellular physiology as it is being involved in numerous cellular metabolic and signaling pathways. Dependence on arginine is diverse for both tumor and normal cells. Because of decreased expression of argininosuccinate synthetase and/or ornithine transcarbamoylase, several types of tumor are auxotrophic for arginine. Deprivation of arginine exploits a significant vulnerability of these tumor cells and leads to their rapid demise. Hence, enzyme-mediated arginine depletion is a potential strategy for the selective destruction of tumor cells. Arginase, arginine deiminase and arginine decarboxylase are potential enzymes that may be used for arginine deprivation therapy. These arginine catabolizing enzymes not only reduce tumor growth but also make them susceptible to concomitantly administered anti-cancer therapeutics. Most of these enzymes are currently under clinical investigations and if successful will potentially be advanced as anti-cancer modalities.

  10. Chimpanzee Personality and the Arginine Vasopressin Receptor 1A Genotype.

    Science.gov (United States)

    Wilson, V A D; Weiss, A; Humle, T; Morimura, N; Udono, T; Idani, G; Matsuzawa, T; Hirata, S; Inoue-Murayama, M

    2017-03-01

    Polymorphisms of the arginine vasopressin receptor 1a (AVPR1a) gene have been linked to various measures related to human social behavior, including sibling conflict and agreeableness. In chimpanzees, AVPR1a polymorphisms have been associated with traits important for social interactions, including sociability, joint attention, dominance, conscientiousness, and hierarchical personality dimensions named low alpha/stability, disinhibition, and negative emotionality/low dominance. We examined associations between AVPR1a and six personality domains and hierarchical personality dimensions in 129 chimpanzees (Pan troglodytes) living in Japan or in a sanctuary in Guinea. We fit three linear and three animal models. The first model included genotype, the second included sex and genotype, and the third included genotype, sex, and sex × genotype. All personality phenotypes were heritable. Chimpanzees possessing the long form of the allele were higher in conscientiousness, but only in models that did not include the other predictors; however, additional analyses suggested that this may have been a consequence of study design. In animal models that included sex and sex × genotype, chimpanzees homozygous for the short form of the allele were higher in extraversion. Taken with the findings of previous studies of chimpanzees and humans, the findings related to conscientiousness suggest that AVPR1a may be related to lower levels of impulsive aggression. The direction of the association between AVPR1a genotype and extraversion ran counter to what one would expect if AVPR1a was related to social behaviors. These results help us further understand the genetic basis of personality in chimpanzees.

  11. Functional and Evolutionary Relationship between Arginine Biosynthesis and Prokaryotic Lysine Biosynthesis through α-Aminoadipate

    Science.gov (United States)

    Miyazaki, Junichi; Kobashi, Nobuyuki; Nishiyama, Makoto; Yamane, Hisakazu

    2001-01-01

    Our previous studies revealed that lysine is synthesized through α-aminoadipate in an extremely thermophilic bacterium, Thermus thermophilus HB27. Sequence analysis of a gene cluster involved in the lysine biosynthesis of this microorganism suggested that the conversion from α-aminoadipate to lysine proceeds in a way similar to that of arginine biosynthesis. In the present study, we cloned an argD homolog of T. thermophilus HB27 which was not included in the previously cloned lysine biosynthetic gene cluster and determined the nucleotide sequence. A knockout of the argD-like gene, now termed lysJ, in T. thermophilus HB27 showed that this gene is essential for lysine biosynthesis in this bacterium. The lysJ gene was cloned into a plasmid and overexpressed in Escherichia coli, and the LysJ protein was purified to homogeneity. When the catalytic activity of LysJ was analyzed in a reverse reaction in the putative pathway, LysJ was found to transfer the ɛ-amino group of N2-acetyllysine, a putative intermediate in lysine biosynthesis, to 2-oxoglutarate. When N2-acetylornithine, a substrate for arginine biosynthesis, was used as the substrate for the reaction, LysJ transferred the δ-amino group of N2-acetylornithine to 2-oxoglutarate 16 times more efficiently than when N2-acetyllysine was the amino donor. All these results suggest that lysine biosynthesis in T. thermophilus HB27 is functionally and evolutionarily related to arginine biosynthesis. PMID:11489859

  12. Hot Melt Extrusion and Spray Drying of Co-amorphous Indomethacin-Arginine With Polymers.

    Science.gov (United States)

    Lenz, Elisabeth; Löbmann, Korbinian; Rades, Thomas; Knop, Klaus; Kleinebudde, Peter

    2017-01-01

    Co-amorphous drug-amino acid systems have gained growing interest as an alternative to common amorphous formulations which contain polymers as stabilizers. Several preparation methods have recently been investigated, including vibrational ball milling on a laboratory scale or spray drying in a larger scale. In this study, the feasibility of hot melt extrusion for continuous manufacturing of co-amorphous drug-amino acid formulations was examined, challenging the fact that amino acids melt with degradation at high temperatures. Furthermore, the need for an addition of a polymer in this process was evaluated. After a polymer screening via the solvent evaporation method, co-amorphous indomethacin-arginine was prepared by a melting-solvent extrusion process without and with copovidone. The obtained products were characterized with respect to their solid-state properties, non-sink dissolution behavior, and stability. Results were compared to those of spray-dried formulations with the same compositions and to spray-dried indomethacin-copovidone. Overall, stable co-amorphous systems could be prepared by extrusion without or with copovidone, which exhibited comparable molecular interaction properties to the respective spray-dried products, while phase separation was detected by differential scanning calorimetry in several cases. The formulations containing indomethacin in combination with arginine and copovidone showed enhanced dissolution behavior over the formulations with only copovidone or arginine. Copyright © 2016 American Pharmacists Association®. Published by Elsevier Inc. All rights reserved.

  13. Combination of arginine deprivation with TRAIL treatment as a targeted-therapy for mesothelioma.

    Science.gov (United States)

    Wangpaichitr, Medhi; Wu, Chunjing; Bigford, Gregory; Theodoropoulos, George; You, Min; Li, Ying Ying; Verona-Santos, Javier; Feun, Lynn G; Nguyen, Dao M; Savaraj, Niramol

    2014-12-01

    In the present study we present data to show that certain tumor cells including malignant pleural mesothelioma (MPM) cells do not express argininosuccinate synthetase (ASS), and thus are unable to synthesize arginine from citrulline. Exposure of these ASS-negative cells to the arginine degrading enzyme, arginine deiminase (ADI-PEG20), for 72 h results in significant increases in cleaved caspase-3. Importantly, this apoptotic signal is further strengthened by the addition of TNF-related apoptosis-inducing ligand (TRAIL). Using flow cytometry, we showed that the combination treatment (ADI-PEG20 at 50 ng/ml and TRAIL at 10 ng/ml) for 24 h resulted in profound cell death with 67% of cells positive for caspase-3 activity, while ADI-PEG20 alone or TRAIL alone resulted in only 10-15% cell death. This positive amplification loop is mediated through the cleavage of proapototic protein "BID". Our work represents a new strategy for treating patients with malignant pleural mesothelioma using targeted molecular therapeutics based on selected tumor markers, thus avoiding the use of potentially cytotoxic chemotherapy. Copyright© 2014 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved.

  14. L-Arginine Supplementation and Metabolism in Asthma

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    Angela Linderholm

    2011-01-01

    Full Text Available L-Arginine, the amino acid substrate for nitric oxide synthase, has been tested as a therapeutic intervention in a variety of chronic diseases and is commonly used as a nutritional supplement. In this study, we hypothesized that a subset of moderate to severe persistent asthma patients would benefit from supplementation with L-arginine by transiently increasing nitric oxide levels, resulting in bronchodilation and a reduction in inflammation. The pilot study consisted of a 3 month randomized, double-blind, placebo-controlled trial of L-arginine (0.05 g/kg twice daily in patients with moderate to severe asthma. We measured spirometry, exhaled breath nitric oxide, serum arginine metabolites, questionnaire scores, daily medication use and PEFR with the primary endpoint being the number of minor exacerbations at three months. Interim analysis of the 20 subjects showed no difference in the number of exacerbations, exhaled nitric oxide levels or lung function between groups, though participants in the L-arginine group had higher serum L-arginine at day 60 (2.0 ± 0.6 × 10−3 vs. 1.1 ± 0.2 × 10−3 µmol/L, p < 0.05, ornithine at day 30 (2.4 ± 0.9 vs. 1.2 ± 0.3 µmol/L serum, p < 0.05 and ADMA at day 30 (6.0 ± 1.5 × 10−1 vs. 2.6 ± 0.6 × 10−1 µmol/L serum, p < 0.05 on average compared to the placebo group. The study was terminated prematurely. Supplementing asthma subjects with L-arginine increases plasma levels; whether subgroups might benefit from such supplementation requires further study.

  15. Cross-linking mechanisms of arginine and lysine with α,β-dicarbonyl compounds in aqueous solution.

    Science.gov (United States)

    Nasiri, Rasoul; Field, Martin J; Zahedi, Mansour; Moosavi-Movahedi, Ali Akbar

    2011-11-24

    Cross-linking in proteins by α,β-dicarbonyl compounds is one of the most damaging consequences of reactive carbonyl species in vivo and in foodstuffs. In this article we investigate computationally the cross-linking of glyoxal and methylglyoxal with lysine and arginine residues using density functional theory and the wB97XD dispersion-corrected functional. Five pathways, A-E, have been characterized. In pathways A and B, the reaction proceeds via formation of the Schiff base, aldimine, followed by addition of arginine. In contrast, in pathways C-E, direct addition of arginine to the dicarbonyl compounds occurs first, leading to a dihydroxyimidazolidine intermediate, which then reacts with lysine after dehydration and proton transfer reactions. The results reveal that pathways A, C, and E are competitive whereas reactions via pathways B and D are much less favorable. Inclusion of up to five explicit water molecules in the proton transfer and dehydration steps is found to lower the energy barriers in the feasible pathways by about 5-20 kcal/mol. Comparison of the mechanisms of methylglyoxal-derived imidazolium cross-linking (MODIC) and glyoxal-derived imidazolium cross-linking (GODIC) shows that the activation barriers are lower for GODIC than MODIC, in agreement with experimental observations.

  16. Expression of protein arginine methyltransferase-5 in oral squamous cell carcinoma and its significance in epithelial-to-mesenchymal transition.

    Science.gov (United States)

    Amano, Yusuke; Matsubara, Daisuke; Yoshimoto, Taichiro; Tamura, Tomoko; Nishino, Hiroshi; Mori, Yoshiyuki; Niki, Toshiro

    2018-03-30

    Protein arginine methyltransferases (PRMT) 5, a member of type II arginine methyltransferases, catalyzes the symmetrical dimethylation of arginine residues on histone and non-histone substrates. Although the overexpression of PRMT5 has been reported in various cancers, its role in oral squamous cell carcinoma (OSCC) has not been elucidated. In the present study, we immunohistochemically examined the expression of PRMT5 in surgically resected oral epithelial dysplasia (OED, n = 8), oral intraepithelial neoplasia (OIN)/carcinoma in situ (CIS) (n = 11) and OSCC (n = 52) with or without contiguous OED lesions. In the normal epithelium, PRMT5 was weakly expressed in the cytoplasm of basal layer cells. In OED, OIN/CIS, and OSCC, its expression consistently and uniformly increased in the cytoplasm of dysplastic and cancer cells. Moreover, nuclear and cytoplasmic localization was detected in the invasive front of cancer cells, particularly in cases showing poor differentiation or aggressive invasion patterns. The concomitant nuclear and cytoplasmic expression of PRMT5 correlated with the loss of E-cadherin and cytokeratin 17, and the upregulation of vimentin, features that are both indicative of epithelial-to-mesenchymal transition. PRMT5 may play a role from early oncogenesis through to the progression of OSCC, particularly in the aggressive mode of stromal invasion. © 2018 Japanese Society of Pathology and John Wiley & Sons Australia, Ltd.

  17. RESIDUAL RISK ASSESSMENTS - RESIDUAL RISK ...

    Science.gov (United States)

    This source category previously subjected to a technology-based standard will be examined to determine if health or ecological risks are significant enough to warrant further regulation for Coke Ovens. These assesments utilize existing models and data bases to examine the multi-media and multi-pollutant impacts of air toxics emissions on human health and the environment. Details on the assessment process and methodologies can be found in EPA's Residual Risk Report to Congress issued in March of 1999 (see web site). To assess the health risks imposed by air toxics emissions from Coke Ovens to determine if control technology standards previously established are adequately protecting public health.

  18. Determination of l-arginine and NG, NG - and NG, NG' -dimethyl-L-arginine in plasma by liquid chromatography as AccQ-Fluor fluorescent derivatives.

    Science.gov (United States)

    Heresztyn, Tamila; Worthley, Matthew I; Horowitz, John D

    2004-06-15

    A new HPLC assay for the detection of L-arginine, NG, NG-dimethyl-L-arginine (ADMA) and NG, NG' -dimethyl-L-arginine (SDMA) in plasma using the derivatisation reagent AccQ-Fluor (6-aminoquinolyl-N-hydroxysuccinimidyl carbamate) is described. The fluorescent derivatives produced are extremely stable enabling routine processing of large numbers of samples. Arginine and its metabolites are extracted from plasma on strong cation exchange (SCX) cartridges with NG-monomethyl-L-arginine (NMMA) as internal standard, derivatised and separated on a C18 column with acetonitrile in 0.1M sodium acetate buffer pH 6. Separation of the stereoisomers ADMA and SDMA was excellent and improvements to the solid phase extraction (SPE) procedure enabled good recovery (>80%) of arginine, ADMA and SDMA. The utility of the method is exemplified by comparison of plasma concentrations of ADMA, SDMA and arginine in healthy volunteers and diabetic/ischaemic patients.

  19. L-arginine:glycine amidinotransferase deficiency protects from metabolic syndrome.

    Science.gov (United States)

    Choe, Chi-un; Nabuurs, Christine; Stockebrand, Malte C; Neu, Axel; Nunes, Patricia; Morellini, Fabio; Sauter, Kathrin; Schillemeit, Stefan; Hermans-Borgmeyer, Irm; Marescau, Bart; Heerschap, Arend; Isbrandt, Dirk

    2013-01-01

    Phosphorylated creatine (Cr) serves as an energy buffer for ATP replenishment in organs with highly fluctuating energy demand. The central role of Cr in the brain and muscle is emphasized by severe neurometabolic disorders caused by Cr deficiency. Common symptoms of inborn errors of creatine synthesis or distribution include mental retardation and muscular weakness. Human mutations in l-arginine:glycine amidinotransferase (AGAT), the first enzyme of Cr synthesis, lead to severely reduced Cr and guanidinoacetate (GuA) levels. Here, we report the generation and metabolic characterization of AGAT-deficient mice that are devoid of Cr and its precursor GuA. AGAT-deficient mice exhibited decreased fat deposition, attenuated gluconeogenesis, reduced cholesterol levels and enhanced glucose tolerance. Furthermore, Cr deficiency completely protected from the development of metabolic syndrome caused by diet-induced obesity. Biochemical analyses revealed the chronic Cr-dependent activation of AMP-activated protein kinase (AMPK), which stimulates catabolic pathways in metabolically relevant tissues such as the brain, skeletal muscle, adipose tissue and liver, suggesting a mechanism underlying the metabolic phenotype. In summary, our results show marked metabolic effects of Cr deficiency via the chronic activation of AMPK in a first animal model of AGAT deficiency. In addition to insights into metabolic changes in Cr deficiency syndromes, our genetic model reveals a novel mechanism as a potential treatment option for obesity and type 2 diabetes mellitus.

  20. Arginine inhibits adsorption of proteins on polystyrene surface.

    Directory of Open Access Journals (Sweden)

    Yui Shikiya

    Full Text Available Nonspecific adsorption of protein on solid surfaces causes a reduction of concentration as well as enzyme inactivation during purification and storage. However, there are no versatile inhibitors of the adsorption between proteins and solid surfaces at low concentrations. Therefore, we examined additives for the prevention of protein adsorption on polystyrene particles (PS particles as a commonly-used material for vessels such as disposable test tubes and microtubes. A protein solution was mixed with PS particles, and then adsorption of protein was monitored by the concentration and activity of protein in the supernatant after centrifugation. Five different proteins bound to PS particles through electrostatic, hydrophobic, and aromatic interactions, causing a decrease in protein concentration and loss of enzyme activity in the supernatant. Among the additives, including arginine hydrochloride (Arg, lysine hydrochloride, guanidine hydrochloride, NaCl, glycine, and glucose, Arg was most effective in preventing the binding of proteins to PS particles as well as activity loss. Moreover, even after the mixing of protein and PS particles, the addition of Arg caused desorption of the bound protein from PS particles. This study demonstrated a new function of Arg, which expands the potential for application of Arg to proteins.

  1. Urinary and metabolic clearances of arginine vasopressin in normal subjects

    International Nuclear Information System (INIS)

    Moses, A.M.; Steciak, E.

    1986-01-01

    Synthetic arginine vasopressin (AVP) was infused into 11 hydrated normal subjects at five different infusion rates ranging from 10 to 350 μU kg -1 min -1 . Each infusion rate was continued for 1 h, and urinary determinations were made on the 30- to 60-min specimens during which time there was no further rise in plasma AVP. Urinary AVP concentrations (μU/ml) and excretion rates (μU/min) increased linearly with increasing infusion rates, and the concentration of AVP in urine increased 120 times more rapid than plasma. Urinary and metabolic clearances of AVP also increased linearly with the maximum urinary clearance being 60.6% of the creatinine clearance. The total metabolic clearance of AVP (including urinary clearance) was 17.8 times that of the urinary clearance of AVP alone. These data clarify the relationships between plasma and urinary AVP in normal hydrated subjects during AVP infusion under steady-state conditions and emphasize the potential advantage of measuring urinary AVP as a monitor of endogenous AVP secretion. AVP was measured by radioimmunoassay

  2. Mutational and structural analyses of Caldanaerobius polysaccharolyticus Man5B reveal novel active site residues for family 5 glycoside hydrolases.

    Directory of Open Access Journals (Sweden)

    Takuji Oyama

    Full Text Available CpMan5B is a glycoside hydrolase (GH family 5 enzyme exhibiting both β-1,4-mannosidic and β-1,4-glucosidic cleavage activities. To provide insight into the amino acid residues that contribute to catalysis and substrate specificity, we solved the structure of CpMan5B at 1.6 Å resolution. The structure revealed several active site residues (Y12, N92 and R196 in CpMan5B that are not present in the active sites of other structurally resolved GH5 enzymes. Residue R196 in GH5 enzymes is thought to be strictly conserved as a histidine that participates in an electron relay network with the catalytic glutamates, but we show that an arginine fulfills a functionally equivalent role and is found at this position in every enzyme in subfamily GH5_36, which includes CpMan5B. Residue N92 is required for full enzymatic activity and forms a novel bridge over the active site that is absent in other family 5 structures. Our data also reveal a role of Y12 in establishing the substrate preference for CpMan5B. Using these molecular determinants as a probe allowed us to identify Man5D from Caldicellulosiruptor bescii as a mannanase with minor endo-glucanase activity.

  3. Mutational and structural analyses of Caldanaerobius polysaccharolyticus Man5B reveal novel active site residues for family 5 glycoside hydrolases.

    Science.gov (United States)

    Oyama, Takuji; Schmitz, George E; Dodd, Dylan; Han, Yejun; Burnett, Alanna; Nagasawa, Naoko; Mackie, Roderick I; Nakamura, Haruki; Morikawa, Kosuke; Cann, Isaac

    2013-01-01

    CpMan5B is a glycoside hydrolase (GH) family 5 enzyme exhibiting both β-1,4-mannosidic and β-1,4-glucosidic cleavage activities. To provide insight into the amino acid residues that contribute to catalysis and substrate specificity, we solved the structure of CpMan5B at 1.6 Å resolution. The structure revealed several active site residues (Y12, N92 and R196) in CpMan5B that are not present in the active sites of other structurally resolved GH5 enzymes. Residue R196 in GH5 enzymes is thought to be strictly conserved as a histidine that participates in an electron relay network with the catalytic glutamates, but we show that an arginine fulfills a functionally equivalent role and is found at this position in every enzyme in subfamily GH5_36, which includes CpMan5B. Residue N92 is required for full enzymatic activity and forms a novel bridge over the active site that is absent in other family 5 structures. Our data also reveal a role of Y12 in establishing the substrate preference for CpMan5B. Using these molecular determinants as a probe allowed us to identify Man5D from Caldicellulosiruptor bescii as a mannanase with minor endo-glucanase activity.

  4. L-arginine as dietary supplement for improving microvascular function.

    Science.gov (United States)

    Melik, Ziva; Zaletel, Polona; Virtic, Tina; Cankar, Ksenija

    2017-01-01

    Reduced availability of nitric oxide leads to dysfunction of endothelium which plays an important role in the development of cardiovascular diseases. The aim of the present study was to determine whether the dietary supplement L-arginine improves the endothelial function of microvessels by increasing nitric oxide production. We undertook experiments on 51 healthy male volunteers, divided into 4 groups based on their age and physical activity since regular physical activity itself increases endothelium-dependent vasodilation. The skin laser Doppler flux was measured in the microvessels before and after the ingestion of L-arginine (0.9 g). The endothelium-dependent vasodilation was assessed by acetylcholine iontophoresis and the endothelium-independent vasodilation by sodium nitroprusside iontophoresis. In addition, we measured endothelium-dependent and endothelium-independent vasodilation in 81 healthy subjects divided into four age groups. After the ingestion of L-arginine, the endothelium-dependent vasodilation in the young trained subjects increased (paired t-test, p L-arginine. With aging endothelium-independent vasodilation decreased while endothelium-dependent vasodilation remained mainly unchanged. Obtained results demonstrated that a single dose of L-arginine influences endothelium-dependent vasodilation predominantly in young, trained individuals.

  5. Arginine and citrulline supplementation in sports and exercise: ergogenic nutrients?

    Science.gov (United States)

    Sureda, Antoni; Pons, Antoni

    2012-01-01

    Dietary L-citrulline malate supplements may increase levels of nitric oxide (NO) metabolites, although this response has not been related to an improvement in athletic performance. NO plays an important role in many functions in the body regulating vasodilatation, blood flow, mitochondrial respiration and platelet function. L-Arginine is the main precursor of NO via nitric oxide synthase (NOS) activity. Additionally, L-citrulline has been indicated to be a second NO donor in the NOS-dependent pathway, since it can be converted to L-arginine. The importance of L-citrulline as an ergogenic support derives from the fact that L-citrulline is not subject to pre-systemic elimination and, consequently, could be a more efficient way to elevate extracellular levels of L-arginine by itself. L-Citrulline malate can develop beneficial effects on the elimination of NH(3) in the course of recovery from exhaustive muscular exercise and also as an effective precursor of L-arginine and creatine. Dietary supplementation with L-citrulline alone does not improve exercise performance. The ergogenic response of L-citrulline or L-arginine supplements depends on the training status of the subjects. Studies involving untrained or moderately healthy subjects showed that NO donors could improve tolerance to aerobic and anaerobic exercise. However, when highly-trained subjects were supplemented, no positive effect on performance was indicated. Copyright © 2012 S. Karger AG, Basel.

  6. Guanidinium Group Remains Protonated in a Strongly Basic Arginine Solution.

    Science.gov (United States)

    Xu, Bo; Jacobs, Michael I; Kostko, Oleg; Ahmed, Musahid

    2017-06-20

    Knowledge of the acid dissociation constant of an amino acid has very important ramifications in the biochemistry of proteins and lipid bilayers in aqueous environments because charge and proton transfer depend on its value. The acid dissociation constant for the guanidinium group in arginine has historically been posited as 12.5, but there is substantial variation in published values over the years. Recent experiments suggest that the dissociation constant for arginine is much higher than 12.5, which explains why the arginine guanidinium group retains its positive charge under all physiological conditions. In this work, we use X-ray photoelectron spectroscopy to study unsupported, aqueous arginine nanoparticles. By varying the pH of the constituent solution, we provide evidence that the guanidinium group is protonated even in a very basic solution. By analyzing the energy shifts in the C and N X-ray photoelectron spectra, we establish a molecular level picture of how charge and proton transport in aqueous solutions of arginine occur. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. Landfilling of waste incineration residues

    DEFF Research Database (Denmark)

    Christensen, Thomas Højlund; Astrup, Thomas; Cai, Zuansi

    2002-01-01

    Residues from waste incineration are bottom ashes and air-pollution-control (APC) residues including fly ashes. The leaching of heavy metals and salts from the ashes is substantial and a wide spectrum of leaching tests and corresponding criteria have been introduced to regulate the landfilling...

  8. Influence of two insecticides, chlorpyrifos and quinalphos, on arginine ammonification and mineralizable nitrogen in two tropical soil types.

    Science.gov (United States)

    Menon, Pramila; Gopal, Madhuban; Prasad, Rajender

    2004-12-01

    Effects of seed treatments with chlorpyrifos [5 g of active ingredient (ai) kg(-1) of seed] and quinalphos (6.25 g of ai kg(-1) of seed) and standing crop treatments with chlorpyrifos (800 g of ai ha(-1)) and quinalphos (1000 g of ai ha(-1)) on arginine deamination and mineralizable nitrogen were monitored, in the sandy loam and loamy sand soils of two tropical semiarid fields, for three consecutive crop seasons. The arginine ammonification activity of rhizospheric microbes was inhibited after seed treatment with chlorpyrifos and quinalphos and their principal metabolites, 3,5,6-trichloro-2-pyridinol (TCP) and 3,5,6-trichloro-2-methoxypyridine (TMP) and 2-hydroxyquinoxaline and quinoxaline-2-thiol, respectively. Quinalphos produced transient inhibitions, whereas chlorpyrifos and its metabolites (TCP and TMP) exerted a greater inhibition in both loamy sand and sandy loam soils. Arginine ammonification by nonrhizospheric microbes was stimulated by standing crop treatments with both pesticides. In the loamy sand soil, the parent compounds stimulated rhizospheric N-mineralization, whereas the metabolites were inhibitory. However, nonrhizospheric N-mineralization was inhibited by both chlorpyrifos and quinalphos and stimulated by their metabolites. A higher magnitude of inhibition of arginine deamination in the loamy sand than in the sandy loam soil could be due to greater bioavailability of the pesticides in the former, resulting from lesser sorption of the pesticides due to alkalinity of the soil and its low content of clay and organic carbon. Although both pesticides affected mineralizable nitrogen, seed treatment with quinalphos and standing crop treatment with quinalphos and chlorpyrifos produced the most significant effects. The recommended doses of the pesticides not only efficiently controlled whitegrubs, which increased pod yields, but also left no residues in harvested kernels. They also caused no long-term inhibition of ammonification, which could have been

  9. Current Understanding of Physicochemical Mechanisms for Cell Membrane Penetration of Arginine-rich Cell Penetrating Peptides: Role of Glycosaminoglycan Interactions.

    Science.gov (United States)

    Takechi-Haraya, Yuki; Saito, Hiroyuki

    2018-01-01

    Arginine-rich cell penetrating peptides (CPPs) are very promising drug carriers to deliver membrane-impermeable pharmaceuticals, such as siRNA, bioactive peptides and proteins. CPPs directly penetrate into cells across cell membranes via a spontaneous energy-independent process, in which CPPs appear to interact with acidic lipids in the outer leaflet of the cell membrane. However, acidic lipids represent only 10 to 20% of the total membrane lipid content and in mammalian cell membranes they are predominantly located in the inner leaflet. Alternatively, CPPs favorably bind in a charge density- dependent manner to negatively charged, sulfated glycosaminoglycans (GAGs), such as heparan sulfate and chondroitin sulfate, which are abundant on the cell surface and are involved in many biological functions. We have recently demonstrated that the interaction of CPPs with sulfated GAGs plays a critical role in their direct cell membrane penetration: the favorable enthalpy contribution drives the high-affinity binding of arginine-rich CPPs to sulfated GAGs, initiating an efficient cell membrane penetration. The favorable enthalpy gain is presumably mainly derived from a unique property of the guanidino group of arginine residues forming multidentate hydrogen bonding with sulfate and carboxylate groups in GAGs. Such interactions can be accompanied with charge neutralization of arginine-rich CPPs, promoting their partition into cell membranes. This review summarizes the current understanding of the physicochemical mechanism for lipid membrane penetration of CPPs, and discusses the role of the GAG interactions on the cell membrane penetration of CPPs. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  10. Residual nilpotence and residual solubility of groups

    International Nuclear Information System (INIS)

    Mikhailov, R V

    2005-01-01

    The properties of the residual nilpotence and the residual solubility of groups are studied. The main objects under investigation are the class of residually nilpotent groups such that each central extension of these groups is also residually nilpotent and the class of residually soluble groups such that each Abelian extension of these groups is residually soluble. Various examples of groups not belonging to these classes are constructed by homological methods and methods of the theory of modules over group rings. Several applications of the theory under consideration are presented and problems concerning the residual nilpotence of one-relator groups are considered.

  11. Safety of long-term dietary supplementation with L-arginine in rats.

    Science.gov (United States)

    Yang, Ying; Wu, Zhenlong; Jia, Sichao; Dahanayaka, Sudath; Feng, Shuo; Meininger, Cynthia J; McNeal, Catherine J; Wu, Guoyao

    2015-09-01

    This study was conducted with rats to determine the safety of long-term dietary supplementation with L-arginine. Beginning at 6 weeks of age, male and female rats were fed a casein-based semi-purified diet containing 0.61 % L-arginine and received drinking water containing L-arginine-HCl (0, 1.8, or 3.6 g L-arginine/kg body-weight/day; n = 10/group). These supplemental doses of L-arginine were equivalent to 0, 286, and 573 mg L-arginine/kg body-weight/day, respectively, in humans. After a 13-week supplementation period, blood samples were obtained from rats for biochemical analyses. Supplementation with L-arginine increased plasma concentrations of arginine, ornithine, proline, homoarginine, urea, and nitric oxide metabolites without affecting those for lysine, histidine, or methylarginines, while reducing plasma concentrations of ammonia, glutamine, free fatty acids, and triglycerides. L-Arginine supplementation enhanced protein gain and reduced white-fat deposition in the body. Based on general appearance, feeding behavior, and physiological parameters, all animals showed good health during the entire experimental period; Plasma concentrations of all measured hormones (except leptin) did not differ between control and arginine-supplemented rats. L-Arginine supplementation reduced plasma levels of leptin. Additionally, L-arginine supplementation increased L-arginine:glycine amidinotransferase activity in kidneys but not in the liver or small intestine, suggesting tissue-specific regulation of enzyme expression by L-arginine. Collectively, these results indicate that dietary supplementation with L-arginine (e.g., 3.6 g/kg body-weight/day) is safe in rats for at least 91 days. This dose is equivalent to 40 g L-arginine/kg body-weight/day for a 70-kg person. Our findings help guide clinical studies to determine the safety of long-term oral administration of L-arginine to humans.

  12. Effect of dietary taurine and arginine supplementation on bone mineral density in growing female rats.

    Science.gov (United States)

    Choi, Mi-Ja; Chang, Kyung Ja

    2013-01-01

    The purpose of this study was to determine the effect of arginine or -taurine alone and taurine plus arginine on bone mineral density (BMD) and markers of bone formation and bone resorption in growing female rats. Forty female SD rats (75 ± 5 g) were randomly divided into four groups (control, taurine, arginine, taurine + arginine group) and treatment lasted for 9 weeks. All rats were fed on a diet and deionized water. BMD and bone mineral content (BMC) were measured using PIXImus (GE Lunar Co, Wisconsin, USA) in spine and femur. The serum and urine concentrations of calcium and phosphorus were determined. Bone formation was measured by serum osteocalcin and alkaline phosphatase concentrations, and the bone resorption rate was measured by deoxypyridinoline cross-links. Femur BMD was significantly increased in the group with taurine supplementation and femur BMC/weight was significantly increased in the group with arginine + taurine supplementation. Rats fed an arginine or taurine supplemental diet increased femur BMD or femur BMC, but a taurine + arginine-supplemented diet does not have a better effect than arginine or taurine alone in the spine BMD. The femur BMC, expressed per body weight, was higher in arginine + taurine group than in the taurine or arginine group. The results of this study suggest that taurine + arginine supplementation may be beneficial on femur BMC in growing female rats. Additional work is needed to clarify the interactive effects between the taurine and arginine to determine whether dietary intakes of arginine and taurine affect bone quality in growing rats.

  13. Citrulline Supplementation Improves Organ Perfusion and Arginine Availability under Conditions with Enhanced Arginase Activity.

    Science.gov (United States)

    Wijnands, Karolina A P; Meesters, Dennis M; van Barneveld, Kevin W Y; Visschers, Ruben G J; Briedé, Jacob J; Vandendriessche, Benjamin; van Eijk, Hans M H; Bessems, Babs A F M; van den Hoven, Nadine; von Wintersdorff, Christian J H; Brouckaert, Peter; Bouvy, Nicole D; Lamers, Wouter H; Cauwels, Anje; Poeze, Martijn

    2015-06-29

    Enhanced arginase-induced arginine consumption is believed to play a key role in the pathogenesis of sickle cell disease-induced end organ failure. Enhancement of arginine availability with L-arginine supplementation exhibited less consistent results; however, L-citrulline, the precursor of L-arginine, may be a promising alternative. In this study, we determined the effects of L-citrulline compared to L-arginine supplementation on arginine-nitric oxide (NO) metabolism, arginine availability and microcirculation in a murine model with acutely-enhanced arginase activity. The effects were measured in six groups of mice (n = 8 each) injected intraperitoneally with sterile saline or arginase (1000 IE/mouse) with or without being separately injected with L-citrulline or L-arginine 1 h prior to assessment of the microcirculation with side stream dark-field (SDF)-imaging or in vivo NO-production with electron spin resonance (ESR) spectroscopy. Arginase injection caused a decrease in plasma and tissue arginine concentrations. L-arginine and L-citrulline supplementation both enhanced plasma and tissue arginine concentrations in arginase-injected mice. However, only the citrulline supplementation increased NO production and improved microcirculatory flow in arginase-injected mice. In conclusion, the present study provides for the first time in vivo experimental evidence that L-citrulline, and not L-arginine supplementation, improves the end organ microcirculation during conditions with acute arginase-induced arginine deficiency by increasing the NO concentration in tissues.

  14. The Effect of l-Arginine on Dural Healing After Experimentally Induced Dural Defect in a Rat Model.

    Science.gov (United States)

    Ahmadi, Sayed Ali; Jafari, Mostafa; Darabi, Mohammad Reza; Chehrei, Ali; Rezaei, Masoud; Mirsalehi, Marjan

    2017-01-01

    Incomplete repair of the dura mater may result in numerous complications such as cerebrospinal fluid leakage and meningitis. For this reason, accurate repair of the dura mater is essential. In this study, the effect of systemic and local supplementation of l-arginine on dural healing was evaluated. Thirty male Wistar rats were used and divided into control, local, and systemic l-arginine groups, with 10 rats in each. In each group, a 5-mm experimental incision was made at the lumbar segment of the dura mater and cerebrospinal fluid leakage was induced. Each group was divided into 2 subgroups and at the end of the first and sixth weeks, the rats were killed and the damaged segments of the dura were separated, histologically evaluated and the dural healing indicators including cell types, granulation tissue formation, collagen deposit, and vascularization were compared between groups. The systematic supplementation of l-arginine showed a significant effect in dural healing compared with the control group. After the first week, granulation formation increased considerably (P supplementation of l-arginine may accelerate dural healing by increasing the level of granulation tissue formation, collagen deposition, and vascularization. Copyright © 2016 Elsevier Inc. All rights reserved.

  15. One-Pot Green Synthesis and Bioapplication ofl-Arginine-Capped Superparamagnetic Fe3O4 Nanoparticles

    Directory of Open Access Journals (Sweden)

    Lai Yongchao

    2009-01-01

    Full Text Available Abstract Water-solublel-arginine-capped Fe3O4 nanoparticles were synthesized using a one-pot and green method. Nontoxic, renewable and inexpensive reagents including FeCl3,l-arginine, glycerol and water were chosen as raw materials. Fe3O4 nanoparticles show different dispersive states in acidic and alkaline solutions for the two distinct forms of surface bindingl-arginine. Powder X-ray diffraction and X-ray photoelectron spectroscopy were used to identify the structure of Fe3O4 nanocrystals. The products behave like superparamagnetism at room temperature with saturation magnetization of 49.9 emu g−1 and negligible remanence or coercivity. In the presence of 1-ethyl-3-(dimethylaminopropyl carbodiimide hydrochloride, the anti-chloramphenicol monoclonal antibodies were connected to thel-arginine-capped magnetite nanoparticles. The as-prepared conjugates could be used in immunomagnetic assay. (See supplementary material 1 Electronic supplementary material The online version of this article (doi:10.1007/s11671-009-9480-x contains supplementary material, which is available to authorized users. Click here for file

  16. Contents of corticotropin-releasing hormone and arginine vasopressin immunoreativity in the spleen and thymus during a chronic inflammatory stress

    DEFF Research Database (Denmark)

    Chowdrey, H.S.; Lightman, S.L.; Harbuz, M.S.

    1994-01-01

    Corticotropin-releasing hormone, spleen, thymus, immune system, stress, arthritis, arginine vasopressin......Corticotropin-releasing hormone, spleen, thymus, immune system, stress, arthritis, arginine vasopressin...

  17. L-arginine supplementation and risk factors of cardiovascular diseases in healthy men: a double-blind randomized clinical trial [version 2; referees: 2 approved

    Directory of Open Access Journals (Sweden)

    Naseh Pahlavani

    2017-06-01

    Full Text Available Context: The effect of L-arginine on risk factors of cardiovascular diseases (CVD has mostly focused on western countries. Since cardiovascular diseases is the second cause of death in Iran and, as far as we are aware, there have been no studies about the effect of L-arginine on CVD risk factors, the aim of this trial was to assess the effects of L-arginine supplementation on CVD risk factors in healthy men. Objective: The purpose of this study was to evaluate the effect of low-dose L-arginine supplementation on CVD risk factors (lipid profile, blood sugar and blood pressure in Iranian healthy men. Design, setting, participants: We conducted a double-blind randomized controlled trial in 56 patients selected from sport clubs at the Isfahan University of Medical Science between November 2013 and December 2013. Interventions: Healthy men received L-arginine supplementation (2000 mg daily in the intervention group or placebo (2000 mg maltodextrin daily in the control group for 45 days. Main outcome measure: The primary outcome measures were we measured the levels of fasting blood sugar, blood pressure and lipid profile including triglyceride (TG, cholesterol, LDL and HDL in healthy subjects. It was hypothesized that these measures would be significantly improved in those receiving L–arginine supplementation. at the beginning and end of the study. Results: In this trial, we had complete data for 52 healthy participants with mean age of 20.85±4.29 years. At the end of study, fasting blood sugar (P=0.001 and lipid profile (triglycerideTG (P<0.001, cholesterol (P<0.001, LDL (P=0.04, HDL (P=0.015 decreased in the L-arginine group but we found no significant change in the placebo group. In addition, the reduction of fasting blood sugar and lipid profile in L-arginine was significant compared with placebo group. No significant changes were found about systolic (P=0.81 and diastolic blood pressure either in L-arginine or placebo group. (P=0

  18. Arginine restores cholinergic relaxation of hypercholesterolemic rabbit thoracic aorta.

    Science.gov (United States)

    Cooke, J P; Andon, N A; Girerd, X J; Hirsch, A T; Creager, M A

    1991-03-01

    Reduced synthesis of endothelium-derived relaxing factor (EDRF) may explain impaired endothelium-dependent vasodilation in hypercholesterolemia. Accordingly, we designed studies to determine if endothelium-dependent relaxation in hypercholesterolemic rabbits may be restored by supplying L-arginine, the precursor of EDRF. Normal or hypercholesterolemic rabbits received intravenous L-arginine (10 mg/kg/min) or vehicle for 70 minutes. Subsequently, animals were killed, thoracic aortas were harvested, and vascular rings were studied in vitro. Rings were contracted by norepinephrine and relaxed by acetylcholine chloride or sodium nitroprusside. Vasorelaxation was quantified by determining the maximal response (expressed as percent relaxation of the contraction) and the ED50 (dose of drug inducing 50% relaxation; expressed as -log M). In vessels from hypercholesterolemic animals receiving vehicle, there was a fivefold rightward shift in sensitivity to acetylcholine compared with normal animals (p = 0.05, n = 5 in each group). In vessels from hypercholesterolemic animals, L-arginine augmented the maximal response to acetylcholine (83 +/- 16% versus 60 +/- 15%, p = 0.04 versus vehicle) and increased the sensitivity to acetylcholine (ED50 value: 6.7 +/- 0.2 versus 6.2 +/- 0.2, p less than 0.05 versus vehicle). Arginine did not affect maximal and EC50 responses to acetylcholine in vessels from normal animals. Arginine did not potentiate endothelium-independent responses in either group. We conclude that the endothelium-dependent relaxation is normalized in hypercholesterolemic rabbit thoracic aorta by in vivo exposure to L-arginine, the precursor for EDRF.

  19. Plasma glucagon responses to L-arginine in various diseases

    International Nuclear Information System (INIS)

    Morita, Nobuto; Hayakawa, Hiroyuki; Kawai, Kohzo; Noto, Yutaka; Ohno, Taro

    1978-01-01

    To clarify the mechanism of abnormal glucose metabolism in the secondary diabetes, we examined the dynamics of plasma glucagon levels in various diseases which may accompany glucose intolerance. Plasma glucagon responses to L-arginine were observed in 20 liver cirrhotics, 8 patients with chronic renal failure, 6 patients with chronic pancreatitis, 4 patients, with hyperthyroidism, 22 diabetics and 9 normal controls. Plasma glucagon levels were determined by the radioimmunoassay method of Unger using 125 I-glucagon and antiserum 30K which is specific for pancreatic glucagon. In the cirrhotics, the plasma glucagon responses to L-arginine were significantly higher than in normal controls. The patients whose BSP retention at 45 minutes were above 30% showed higher plasma glucagon responses than in the patients whose BSP retention at 45 minutes were below 30%, suggesting that the more severely the liver was damaged, the more the plasma glucagon levels were elevated. In the patients with chronic renal failure, the plasma glucagon responses to L-arginine were also significantly higher than in normal controls. These abnormal levels were not improved by a hemodialysis, although serum creatinine levels were fairly decreased. In the patients with chronic pancreatitis, the plasma glucagon responses to L-arginine were the same as those in normal controls. In the patients with hyperthyroidism the plasma glucagon responses to L-arginine seemed to be lower than normal controls. In the diabetics, the plasma glucagon responses to L-arginine were almost the same as in normal controls. However their glucagon levels seemed to be relatively high, considering the fact that diabetics had high blood glucose levels. (auth.)

  20. Statistical inference on residual life

    CERN Document Server

    Jeong, Jong-Hyeon

    2014-01-01

    This is a monograph on the concept of residual life, which is an alternative summary measure of time-to-event data, or survival data. The mean residual life has been used for many years under the name of life expectancy, so it is a natural concept for summarizing survival or reliability data. It is also more interpretable than the popular hazard function, especially for communications between patients and physicians regarding the efficacy of a new drug in the medical field. This book reviews existing statistical methods to infer the residual life distribution. The review and comparison includes existing inference methods for mean and median, or quantile, residual life analysis through medical data examples. The concept of the residual life is also extended to competing risks analysis. The targeted audience includes biostatisticians, graduate students, and PhD (bio)statisticians. Knowledge in survival analysis at an introductory graduate level is advisable prior to reading this book.

  1. The effect of aspartate-lysine-isoleucine and aspartate-arginine-tyrosine mutations on the expression and activity of vasopressin V2 receptor gene.

    Science.gov (United States)

    Najafzadeh, Hossein; Safaeian, Leila; Mirmohammad Sadeghi, Hamid; Rabbani, Mohammad; Jafarian, Abbas

    2010-01-01

    Vasopressin type 2 receptor (V2R) plays an important role in the water reabsorption in the kidney collecting ducts. V2R is a G protein coupled receptor (GPCR) and the triplet of amino acids aspartate-arginine-histidine (DRH) in this receptor might significantly influence its activity similar to other GPCR. However, the role of this motif has not been fully confirmed. Therefore, the present study attempted to shed some more light on the role of DRH motif in G protein coupling and V2R function with the use of site-directed mutagenesis. Nested PCR using specific primers was used to produce DNA fragments containing aspartate-lysine-isoleucine and aspartate-arginine-tyrosine mutations with replacements of the arginine to lysine and histidine to tyrosine, respectively. After digestion, these inserts were ligated into the pcDNA3 vector and transformation into E. coli HB101 was performed using heat shock method. The obtained colonies were analyzed for the presence and orientation of the inserts using proper restriction enzymes. After transient transfection of COS-7 cells using diethylaminoethyl-dextran method, the adenylyl cyclase activity assay was performed for functional study. The cell surface expression was analyzed by indirect ELISA method. The functional assay indicated that none of these mutations significantly altered cAMP production and cell surface expression of V2R in these cells. Since some substitutions in arginine residue have shown to lead to the inactive V2 receptor, further studies are required to define the role of this residue more precisely. However, it seems that the role of the histidine residue is not critical in the V2 receptor function.

  2. Relation of arginine-lysine antagonism to herpes simplex growth in tissue culture.

    Science.gov (United States)

    Griffith, R S; DeLong, D C; Nelson, J D

    1981-01-01

    In the studies conducted, arginine deficiency suppressed herpes simplex virus replication in tissue culture. Lysine, an analog of arginine, as an antimetabolite, antagonized the viral growth-promoting action of arginine. The in vitro data may be the basis for the observation that patients prone to herpetic lesions and other related viral infections, particularly during periods of stress, should abstain from arginine excess and may also require supplemental lysine in their diet.

  3. X-linked familial exudative vitreoretinopathy caused by an arginine to leucine substitution in exon 3 of the Norrie gene

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, K.; Perry, Y.M.; Ferrell, R.E. [Univ. of Pittsburg, PA (United States)] [and others

    1994-09-01

    Familial exudative vitreoretinopathy (FEVR) is a disorder characterized by abnormal vascularization of the peripheral retina affecting both the retina and the vitreous body. This is a bilateral disorder and leads to a clinical phenotype resembling retinopathy of prematurity, but affected individuals experience a normal gestational period, and they do not have a history of oxygen therapy. Manifestations of the disorder may include retinal folds, retinal traction, sub- or intraretinal exudates, and in severe cases enophthalmos or phthisis ultimately leading to blindness. Autosomal dominant and X-linked patterns of segregation have been reported. We studied a large three-generation family in which FEVR segregated as an X-linked recessive trait. The Norrie gene was examined because of a prior report of mutation in this gene in a small X-linked FEVR family. Exons 1-3 of the Norrie gene were amplified and screened for mutations by single stranded conformational analysis. A variant conformer of exon 3 was observed in an affected male and in combination with the normal conformer in an obligate carrier female. Sequence analysis revealed a G{r_arrow}T transversion destroying an MspI restriction site. The mutation was present in all affected males, and all obligate carrier females were heterozygous for the mutation. The mutation was not present in unaffected males or in 108 randomly selected normal females. The G{r_arrow}T mutation leads to the substitution of a hydrophobic leucine residue for the positively charged arginine normally present at position 121 of the Norrie gene product. This study confirms that mutation in the Norrie gene can lead to the FEVR phenotype and the existence of allelic heterogeneity.

  4. Intravenous glutamine supplementation enhances renal de novo arginine synthesis in humans: a stable isotope study

    NARCIS (Netherlands)

    Buijs, Nikki; Brinkmann, Saskia J. H.; Oosterink, J. Efraim; Luttikhold, Joanna; Schierbeek, Henk; Wisselink, Willem; Beishuizen, Albertus; van Goudoever, Johannes B.; Houdijk, Alexander P. J.; van Leeuwen, Paul A. M.; Vermeulen, Mechteld A. R.

    2014-01-01

    Arginine plays a role in many different pathways in multiple cell types. Consequently, a shortage of arginine, caused by pathologic conditions such as cancer or injury, has the potential to disturb many cellular and organ functions. Glutamine is the ultimate source for de novo synthesis of arginine

  5. L-arginine increases nitric oxide and attenuates pressor and heart ...

    African Journals Online (AJOL)

    L-Arginine supplementation increased plasma L-Arginine concentration ([R]) in both groups of subjects (p<0.001 in each group) and serum nitric oxide metabolites concentration ([NOx]) (p<0.01 in each group). Change (Δ) [R] correlated positively with Δ [NOx] in both groups (+ 0.7 in each group). L-Arginine supplementation ...

  6. Composition of carbonization residues

    Energy Technology Data Exchange (ETDEWEB)

    Hupfer; Leonhardt

    1943-11-27

    This report compared the composition of samples from Wesseling and Leuna. In each case the sample was a residue from carbonization of the residues from hydrogenation of the brown coal processed at the plant. The composition was given in terms of volatile components, fixed carbon, ash, water, carbon, hydrogen, oxygen, nitrogen, volatile sulfur, and total sulfur. The result of carbonization was given in terms of (ash and) coke, tar, water, gas and losses, and bitumen. The composition of the ash was given in terms of silicon dioxide, ferric oxide, aluminum oxide, calcium oxide, magnesium oxide, potassium and sodium oxides, sulfur trioxide, phosphorus pentoxide, chlorine, and titanium oxide. The most important difference between the properties of the two samples was that the residue from Wesseling only contained 4% oil, whereas that from Leuna had about 26% oil. Taking into account the total amount of residue processed yearly, the report noted that better carbonization at Leuna could save 20,000 metric tons/year of oil. Some other comparisons of data included about 33% volatiles at Leuna vs. about 22% at Wesseling, about 5 1/2% sulfur at Leuna vs. about 6 1/2% at Leuna, but about 57% ash for both. Composition of the ash differed quite a bit between the two. 1 table.

  7. Lysine, Arginine, and Histidine Residues in Peptide-Catalyzed Hydrogen Evolution at Mercury Electrodes

    Czech Academy of Sciences Publication Activity Database

    Dorčák, Vlastimil; Vargová, Veronika; Ostatná, Veronika; Paleček, Emil

    2015-01-01

    Roč. 27, č. 4 (2015), s. 910-916 ISSN 1040-0397 R&D Projects: GA ČR(CZ) GA15-15479S; GA ČR(CZ) GA13-00956S Institutional support: RVO:68081707 Keywords : AMALGAM ELECTRODES * STRIPPING CHRONOPOTENTIOMETRY * CARBON ELECTRODES Subject RIV: BO - Biophysics Impact factor: 2.471, year: 2015

  8. Residual stress analysis: a review

    International Nuclear Information System (INIS)

    Finlayson, T.R.

    1983-01-01

    The techniques which are or could be employed to measure residual stresses are outlined. They include X-ray and neutron diffraction. Comments are made on the reliability and accuracy to be expected from particular techniques

  9. Amphipathicity Determines Different Cytotoxic Mechanisms of Lysine- or Arginine-Rich Cationic Hydrophobic Peptides in Cancer Cells.

    Science.gov (United States)

    Liu, Xiaoli; Cao, Rui; Wang, Sha; Jia, Junli; Fei, Hao

    2016-06-09

    Cationic amphipathic peptides (CAPs) are known to be able to cause membrane destabilization and induce cell death, yet how the hydrophobicity, amphipathicity, and lysine (K)/arginine (R) composition synergistically affect the peptide activity remains incompletely understood. Here, we designed a panel of peptides based on the well-known anticancer peptide KLA. Increasing hydrophobicity enhanced the cytotoxicities of both the K- and R-rich peptides. Peptides with an intact amphipathic helical interface can cause instant cell death through a membrane lysis mechanism. Interestingly, rearranging the residue positions to minimize amphipathicity caused a great decrease of cytotoxicity to the K-rich peptides but not to the R-rich peptides. The amphipathicity-minimized R-rich peptide 6 (RL2) (RLLRLLRLRRLLRL-NH2) penetrated the cell membrane and induced caspase-3-dependent apoptotic cell death. We found that the modulation of hydrophobicity, amphipathicity, and K/R residues leads to distinct mechanisms of action of cationic hydrophobic peptides. Amphipathicity-reduced, arginine-rich cationic hydrophobic peptides (CHPs) may represent a new class of peptide therapeutics.

  10. L-Arginine treatment for severe vascular fetal intrauterine growth restriction: a randomized double-bind controlled trial.

    Science.gov (United States)

    Winer, Norbert; Branger, Bernard; Azria, Elie; Tsatsaris, Vassilis; Philippe, Henri-Jean; Rozé, Jean Christophe; Descamps, Philippe; Boog, Georges; Cynober, Luc; Darmaun, Dominique

    2009-06-01

    Infants born with severe IUGR are exposed to higher neonatal mortality and morbidity rates, as compared with appropriate-for-gestational-age. They are exposed to a higher risk of developing chronic disease such as hypertension, coronary artery disease, obesity, and type 2 diabetes in adulthood. L-Arginine is a precursor of nitric oxide (NO) and may play a role in placental vascular mediation or local vasodilatation. The current study was designed to determine whether oral supplementation of gravid patients suffering from severe intrauterine growth restriction (IUGR) with L-arginine, would enhance birth weight and/or decrease neonatal morbidity. Forty-four patients with a singleton pregnancy who had been referred for IUGR detected by ultrasonic examination were included. Vascular IUGR was defined by fetal abdominal circumference less than or equal to the 3rd percentile, associated with abnormal uterine Doppler. After double-blind randomization, patients received either 14 g/day of L-arginine, or a placebo. The characteristics of the two groups of patients (IUGR with L-arginine vs IUGR with placebo) were similar upon randomization. There was no significant difference between the two groups concerning birth weight (1042+/-476 vs. 1068+/-452 g). At delivery, maternal and neonatal characteristics were similar in the two groups. There was no difference in the Clinical Risk Index for Babies (CRIB) score, the duration of ventilatory assistance, nor the delay between birth and full enteral feeding between the two groups. In this study which is, at the best of our knowledge, the first double-bind, multicenter, randomized trial in this condition, L-arginine is not an effective treatment for severe vascular growth restriction.

  11. Whole-body synthesis of L-homoarginine in pigs and rats supplemented with L-arginine.

    Science.gov (United States)

    Hou, Yongqing; Hu, Shengdi; Jia, Sichao; Nawaratna, Gayan; Che, Dongsheng; Wang, Fenglai; Bazer, Fuller W; Wu, Guoyao

    2016-04-01

    Recent studies suggest an important role for L-homoarginine in cardiovascular, hepatic and neurological functions, as well as the regulation of glucose metabolism. However, little is known about whole-body L-homoarginine synthesis or its response to dietary L-arginine intake in animals. Four series of experiments were conducted to determine L-homoarginine synthesis and catabolism in pigs and rats. In Experiment 1, male and female pigs were fed a corn- and soybean meal-based diet supplemented with 0.0-2.42 % L-arginine-HCl. In Experiment 2, male and female rats were fed a casein-based diet, while receiving drinking water containing supplemental L-arginine-HCl to provide 0.0-3.6 g L-arginine/kg body-weight/day. In both experiments, urine collected from the animals for 24 h was analyzed for L-homoarginine and related metabolites. In Experiment 3, pigs and rats received a single oral dose of 1 or 10 mg L-homoarginine/kg body-weight, respectively, and their urine was collected for 24 h for analyses of L-homoarginine and related substances. In Experiment 4, slices of pig and rat tissues (including liver, brain, kidney, heart, and skeletal-muscle) were incubated for 1 h in Krebs-bicarbonate buffer containing 5 or 50 µM L-homoarginine. Our results indicated that: (a) animal tissues did not degrade L-homoarginine in the presence of physiological concentrations of other amino-acids; (b) 95-96 % of orally administered L-homoarginine was recovered in urine; (c) L-homoarginine was quantitatively a minor product of L-arginineg catabolism in the body; and (d) dietary L-arginine supplementation dose-dependently increased whole-body L-homoarginine synthesis. These novel findings provide a new framework for future studies of L-homoarginine metabolism and physiology in animals and humans.

  12. An Association between l-Arginine/Asymmetric Dimethyl Arginine Balance, Obesity, and the Age of Asthma Onset Phenotype

    Science.gov (United States)

    Comhair, Suzy A. A.; Hazen, Stanley L.; Powers, Robert W.; Khatri, Sumita S.; Bleecker, Eugene R.; Busse, William W.; Calhoun, William J.; Castro, Mario; Fitzpatrick, Anne M.; Gaston, Benjamin; Israel, Elliot; Jarjour, Nizar N.; Moore, Wendy C.; Peters, Stephen P.; Teague, W. Gerald; Chung, Kian Fan; Erzurum, Serpil C.; Wenzel, Sally E.

    2013-01-01

    Rationale: Increasing body mass index (BMI) has been associated with less fractional exhaled nitric oxide (FeNO). This may be explained by an increase in the concentration of asymmetric dimethyl arginine (ADMA) relative to l-arginine, which can lead to greater nitric oxide synthase uncoupling. Objectives: To compare this mechanism across age of asthma onset groups and determine its association with asthma morbidity and lung function. Methods: Cross-sectional study of participants from the Severe Asthma Research Program, across early- (12 yr) onset asthma phenotypes. Measurements and Main Results: Subjects with late-onset asthma had a higher median plasma ADMA level (0.48 μM, [interquartile range (IQR), 0.35–0.7] compared with early onset, 0.37 μM [IQR, 0.29–0.59], P = 0.01) and lower median plasma l-arginine (late onset, 52.3 [IQR, 43–61] compared with early onset, 51 μM [IQR 39–66]; P = 0.02). The log of plasma l-arginine/ADMA was inversely correlated with BMI in the late- (r = −0.4, P = 0.0006) in contrast to the early-onset phenotype (r = −0.2, P = 0.07). Although FeNO was inversely associated with BMI in the late-onset phenotype (P = 0.02), the relationship was lost after adjusting for l-arginine/ADMA. Also in this phenotype, a reduced l-arginine/ADMA was associated with less IgE, increased respiratory symptoms, lower lung volumes, and worse asthma quality of life. Conclusions: In late-onset asthma phenotype, plasma ratios of l-arginine to ADMA may explain the inverse relationship of BMI to FeNO. In addition, these lower l-arginine/ADMA ratios are associated with reduced lung function and increased respiratory symptom frequency, suggesting a role in the pathobiology of the late-onset phenotype. PMID:23204252

  13. Reference Intervals for Plasma l-Arginine and the l-Arginine:Asymmetric Dimethylarginine Ratio in the Framingham Offspring Cohort123

    Science.gov (United States)

    Lüneburg, Nicole; Xanthakis, Vanessa; Schwedhelm, Edzard; Sullivan, Lisa M.; Maas, Renke; Anderssohn, Maike; Riederer, Ulrich; Glazer, Nicole L.; Vasan, Ramachandran S.; Böger, Rainer H.

    2011-01-01

    l-Arginine, as a precursor of NO synthesis, has attracted much scientific attention in recent years. Experimental mouse models suggest that l-arginine supplementation can retard, halt, or even reverse atherogenesis. In human studies, supplementation with l-arginine improved endothelium-dependent vasodilation. However, l-arginine levels are best interpreted in the context of levels of asymmetric dimethylarginine (ADMA), a competitive inhibitor of NO synthase. Thus, reference limits for circulating l-arginine and the l-arginine:ADMA ratio may help to determine the nutritional state of individuals at high cardiovascular risk in light of increased ADMA levels. We defined reference limits for plasma l-arginine in 1141 people and for the l-arginine:ADMA ratio in 1138 relatively healthy individuals from the Framingham Offspring Cohort. Plasma l-arginine and ADMA concentrations were determined by using a stable isotope-based LC-MS/MS method. The reference limits (2.5th and 97.5th percentiles) for plasma l-arginine were 41.0 μmol/L (95% CI = 39.5–42.5 μmol/L) and 114 μmol/L (95% CI = 112–115 μmol/L), whereas corresponding reference limits (2.5th and 97.5th percentiles) for the l-arginine:ADMA ratio were 74.3 μmol/L (95% CI = 71.1–77.3 μmol/L) and 225 μmol/L (95% CI = 222–228 μmol/L). Plasma l-arginine was positively associated with the estimated glomerular filtration rate (eGFR) and blood glucose levels, whereas the l-arginine:ADMA ratio was positively associated with eGFR and diastolic blood pressure but inversely associated with homocysteine and (log)C-reactive protein. We report reference levels for plasma l-arginine and for the l-arginine:ADMA ratio that may be helpful for evaluation of the effects of l-arginine supplementation in participants with an impaired l-arginine/NO pathway. PMID:22031661

  14. An evolutionarily conserved arginine is essential for Tre1 G protein-coupled receptor function during germ cell migration in Drosophila melanogaster.

    Directory of Open Access Journals (Sweden)

    Angela R Kamps

    Full Text Available BACKGROUND: G protein-coupled receptors (GPCRs play central roles in mediating cellular responses to environmental signals leading to changes in cell physiology and behaviors, including cell migration. Numerous clinical pathologies including metastasis, an invasive form of cell migration, have been linked to abnormal GPCR signaling. While the structures of some GPCRs have been defined, the in vivo roles of conserved amino acid residues and their relationships to receptor function are not fully understood. Trapped in endoderm 1 (Tre1 is an orphan receptor of the rhodopsin class that is necessary for primordial germ cell migration in Drosophila melanogaster embryos. In this study, we employ molecular genetic approaches to identify residues in Tre1 that are critical to its functions in germ cell migration. METHODOLOGY/PRINCIPAL FINDINGS: First, we show that the previously reported scattershot mutation is an allele of tre1. The scattershot allele results in an in-frame deletion of 8 amino acids at the junction of the third transmembrane domain and the second intracellular loop of Tre1 that dramatically impairs the function of this GPCR in germ cell migration. To further refine the molecular basis for this phenotype, we assayed the effects of single amino acid substitutions in transgenic animals and determined that the arginine within the evolutionarily conserved E/N/DRY motif is critical for receptor function in mediating germ cell migration within an intact developing embryo. CONCLUSIONS/SIGNIFICANCE: These structure-function studies of GPCR signaling in native contexts will inform future studies into the basic biology of this large and clinically important family of receptors.

  15. Effect of iron, taurine and arginine on rat hepatic fibrosis

    International Nuclear Information System (INIS)

    Song Liangwen; Wang Dewen; Cui Xuemei

    1997-01-01

    Objective: The promotion role of iron on pathogenesis of hepatic fibrosis and the protective role of taurine and L-arginine against hepatic fibrosis were studied. Method: The model of rat radiation hepatic fibrosis was used. Experimental rats were divided into 0 Gy, 30 Gy, 30 Gy + iron, 30 Gy + taurine and 30 Gy + L-arginine groups. Serum iron, liver tissue hydroxyproline (Hyp) and malondialdehyde (MDA) were measured one and three months respectively after irradiation of hepatic tissue, production and distribution characteristics of hepatic tissue type I and III collagen were observed with a polarizing microscope. Results: Administration of iron agent could significantly increase hepatic tissue MDA content and serum iron concentration, one month after irradiation, hepatic tissue Hyp in 30 Gy + iron group began to increase, and collagen in hepatic tissue obviously increased. Taurine and L-arginine could reduce serum iron concentration and decrease production of hepatic fissure Hyp. Conclusion: Exogenous iron agent could promote early development of radiation hepatic fibrosis; taurine and arginine could diminish pathologic alteration of hepatic fibrosis to a certain extent

  16. Theoretical insights into catalytic mechanism of protein arginine methyltransferase 1.

    Directory of Open Access Journals (Sweden)

    Ruihan Zhang

    Full Text Available Protein arginine methyltransferase 1 (PRMT1, the major arginine asymmetric dimethylation enzyme in mammals, is emerging as a potential drug target for cancer and cardiovascular disease. Understanding the catalytic mechanism of PRMT1 will facilitate inhibitor design. However, detailed mechanisms of the methyl transfer process and substrate deprotonation of PRMT1 remain unclear. In this study, we present a theoretical study on PRMT1 catalyzed arginine dimethylation by employing molecular dynamics (MD simulation and quantum mechanics/molecular mechanics (QM/MM calculation. Ternary complex models, composed of PRMT1, peptide substrate, and S-adenosyl-methionine (AdoMet as cofactor, were constructed and verified by 30-ns MD simulation. The snapshots selected from the MD trajectory were applied for the QM/MM calculation. The typical SN2-favored transition states of the first and second methyl transfers were identified from the potential energy profile. Deprotonation of substrate arginine occurs immediately after methyl transfer, and the carboxylate group of E144 acts as proton acceptor. Furthermore, natural bond orbital analysis and electrostatic potential calculation showed that E144 facilitates the charge redistribution during the reaction and reduces the energy barrier. In this study, we propose the detailed mechanism of PRMT1-catalyzed asymmetric dimethylation, which increases insight on the small-molecule effectors design, and enables further investigations into the physiological function of this family.

  17. Arginine-dependent acid resistance in Salmonella enterica serovar Typhimurium

    NARCIS (Netherlands)

    Kieboom, J.; Abee, T.

    2006-01-01

    Salmonella enterica serovar Typhimurium does not survive a pH 2.5 acid challenge under conditions similar to those used for Escherichia coli (J. W. Foster, Nat. Rev. Microbiol. 2:898-907, 2004). Here, we provide evidence that S. enterica serovar Typhimurium can display arginine-dependent acid

  18. l-Arginine is a Radioprotector for Hematopoietic Progenitor Cells

    Science.gov (United States)

    Pearce, Linda L.; Zheng, Xichen; Martinez-Bosch, Sandra; Kerr, Patrick P.; Khlangwiset, Pornsri; Epperly, Michael W.; Fink, Mitchell P.; Greenberger, Joel S.; Peterson, Jim

    2012-01-01

    l-Arginine is shown to protect hematopoietic progenitor (32D cl 3) cells from death due to exposure to γ radiation (137Cs). Some of the other intermediates in the urea cycle, namely ornithine and citrulline, plus urea itself, were not found to have any significant impact on cell survival after irradiation. Intriguingly, supplementation of irradiated cells with l-arginine results in decreased production of peroxynitrite, suggesting that suppression of superoxide generation by nitric oxide synthase in one or more microenvironments is an important factor in the observed radioprotection. The absence of any radioprotective effect of l-arginine in cells at 3% oxygen also confirms the involvement of one or more oxygen-derived species. Knockdown experiments with nitric oxide synthase (NOS) siRNAs in cells and NOS knockout animals confirm that the observed radioprotection is associated with nNOS (NOS-1). l-Arginine also ameliorates the transient inhibition of the electron-transport chain complex I that occurs within 30 min of completing the dose (10 Gy) and that appears to be a functional marker for postirradiation mitochondrial oxidant production. PMID:22175298

  19. Twin-arginine-dependent translocation of folded proteins

    Science.gov (United States)

    Fröbel, Julia; Rose, Patrick; Müller, Matthias

    2012-01-01

    Twin-arginine translocation (Tat) denotes a protein transport pathway in bacteria, archaea and plant chloroplasts, which is specific for precursor proteins harbouring a characteristic twin-arginine pair in their signal sequences. Many Tat substrates receive cofactors and fold prior to translocation. For a subset of them, proofreading chaperones coordinate maturation and membrane-targeting. Tat translocases comprise two kinds of membrane proteins, a hexahelical TatC-type protein and one or two members of the single-spanning TatA protein family, called TatA and TatB. TatC- and TatA-type proteins form homo- and hetero-oligomeric complexes. The subunits of TatABC translocases are predominantly recovered from two separate complexes, a TatBC complex that might contain some TatA, and a homomeric TatA complex. TatB and TatC coordinately recognize twin-arginine signal peptides and accommodate them in membrane-embedded binding pockets. Advanced binding of the signal sequence to the Tat translocase requires the proton-motive force (PMF) across the membranes and might involve a first recruitment of TatA. When targeted in this manner, folded twin-arginine precursors induce homo-oligomerization of TatB and TatA. Ultimately, this leads to the formation of a transmembrane protein conduit that possibly consists of a pore-like TatA structure. The translocation step again is dependent on the PMF. PMID:22411976

  20. Optimizing aerosolization of a high-dose L-arginine powder for pulmonary delivery

    Directory of Open Access Journals (Sweden)

    Satu Lakio

    2015-12-01

    Full Text Available In this study a carrier-free dry powder inhalation (DPI containing L-arginine (ARG was developed. As such, it is proposed that ARG could be used for adjunctive treatment of cystic fibrosis and/or tuberculosis. Various processing methods were used to manufacture high-dose formulation batches consisting various amounts of ARG and excipients. The formulations were evaluated using several analytical methods to assess suitability for further investigation. Several batches had enhanced in vitro aerolization properties. Significant future challenges include the highly hygroscopic nature of unformulated ARG powder and identifying the scale of dose of ARG required to achieve the response in lungs.

  1. Transsulfuration pathway thiols and methylated arginines: the Hunter Community Study.

    Directory of Open Access Journals (Sweden)

    Arduino A Mangoni

    Full Text Available Serum homocysteine, when studied singly, has been reported to be positively associated both with the endogenous nitric oxide synthase inhibitor asymmetric dimethylarginine [ADMA, via inhibition of dimethylarginine dimethylaminohydrolase (DDAH activity] and with symmetric dimethylarginine (SDMA. We investigated combined associations between transsulfuration pathway thiols, including homocysteine, and serum ADMA and SDMA concentrations at population level.Data on clinical and demographic characteristics, medication exposure, C-reactive protein, serum ADMA and SDMA (LC-MS/MS, and thiols (homocysteine, cysteine, taurine, glutamylcysteine, total glutathione, and cysteinylglycine; capillary electrophoresis were collected from a sample of the Hunter Community Study on human ageing [n = 498, median age (IQR = 64 (60-70 years].REGRESSION ANALYSIS SHOWED THAT: a age (P = 0.001, gender (P = 0.03, lower estimated glomerular filtration rate (eGFR, P = 0.08, body mass index (P = 0.008, treatment with beta-blockers (P = 0.03, homocysteine (P = 0.02, and glutamylcysteine (P = 0.003 were independently associated with higher ADMA concentrations; and b age (P = 0.001, absence of diabetes (P = 0.001, lower body mass index (P = 0.01, lower eGFR (P<0.001, cysteine (P = 0.007, and glutamylcysteine (P < 0.001 were independently associated with higher SDMA concentrations. No significant associations were observed between methylated arginines and either glutathione or taurine concentrations.After adjusting for clinical, demographic, biochemical, and pharmacological confounders the combined assessment of transsulfuration pathway thiols shows that glutamylcysteine has the strongest and positive independent associations with ADMA and SDMA. Whether this reflects a direct effect of glutamylcysteine on DDAH activity (for ADMA and/or cationic amino acid transport requires further investigations.

  2. 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.

  3. Characterisation and management of concrete grinding residuals.

    Science.gov (United States)

    Kluge, Matt; Gupta, Nautasha; Watts, Ben; Chadik, Paul A; Ferraro, Christopher; Townsend, Timothy G

    2018-02-01

    Concrete grinding residue is the waste product resulting from the grinding, cutting, and resurfacing of concrete pavement. Potential beneficial applications for concrete grinding residue include use as a soil amendment and as a construction material, including as an additive to Portland cement concrete. Concrete grinding residue exhibits a high pH, and though not hazardous, it is sufficiently elevated that precautions need to be taken around aquatic ecosystems. Best management practices and state regulations focus on reducing the impact on such aquatic environment. Heavy metals are present in concrete grinding residue, but concentrations are of the same magnitude as typically recycled concrete residuals. The chemical composition of concrete grinding residue makes it a useful product for some soil amendment purposes at appropriate land application rates. The presence of unreacted concrete in concrete grinding residue was examined for potential use as partial replacement of cement in new concrete. Testing of Florida concrete grinding residue revealed no dramatic reactivity or improvement in mortar strength.

  4. L-Arginine supplementation prevents allodynia and hyperalgesia in painful diabetic neuropathic rats by normalizing plasma nitric oxide concentration and increasing plasma agmatine concentration.

    Science.gov (United States)

    Rondón, Lusliany J; Farges, M C; Davin, N; Sion, B; Privat, A M; Vasson, M P; Eschalier, A; Courteix, C

    2017-07-19

    Neuropathic pain is a common diabetic complication. It is characterized by symptoms of spontaneous and stimulus-evoked pain including hyperalgesia and allodynia. L-Arginine is a common precursor of many metabolites of biological interest, in particular, nitric oxide (NO), ornithine, and hence polyamines. In central nervous system, NO, glutamate, and polyamines share an N-methyl-D-aspartate (NMDA) receptor-mediated effect. We hypothesized that a variation in arginine metabolism caused by diabetes may contribute to development and maintenance of neuropathic pain and to the worsening of clinical and biological signs of diabetes. We examined whether oral L-arginine supplementation (2.58 ± 0.13 g/l in drinking water for 3 weeks) could improve the development of neuropathic pain and the clinical, biological, and metabolic complications of diabetes in streptozocin (STZ)-induced diabetic (D) rats. STZ administration induced classical symptoms of type 1 diabetes. Diabetic rats also displayed mechanical hypersensitivity, tactile, and thermal allodynia. Plasma citrulline and NO levels were increased in diabetic hyperalgesic/allodynic rats. L-Arginine supplementation failed to reduce hyperglycaemia, polyphagia, and weight loss. Moreover, it abolished hyperalgesia and allodynia by normalizing NO plasma concentration and increasing plasma agmatine concentration. L-Arginine supplementation prevented the development of mechanical hyperalgesia, tactile, and thermal allodynia in painful diabetic neuropathy with concomitant reduction of NO and increased agmatine production, offering new therapeutic opportunities for the management of diabetic neuropathic pain.

  5. Composition of carbonization residues

    Energy Technology Data Exchange (ETDEWEB)

    Hupfer; Leonhardt

    1943-11-30

    This report gave a record of the composition of several samples of residues from carbonization of various hydrogenation residue from processing some type of coal or tar in the Bergius process. These included Silesian bituminous coal processed at 600 atm. with iron catalyst, in one case to produce gasoline and middle oil and in another case to produce heavy oil excess, Scholven coal processed at 250 atm. with tin oxalate and chlorine catalyst, Bruex tar processed in a 10-liter oven using iron catalyst, and a pitch mixture from Welheim processed in a 10-liter over using iron catalyst. The values gathered were compared with a few corresponding values estimated for Boehlen tar and Gelsenberg coal based on several assumptions outlined in the report. The data recorded included percentage of ash in the dry residue and percentage of carbon, hydrogen, oxygen, nitrogen, chlorine, total sulfur, and volatile sulfur. The percentage of ash varied from 21.43% in the case of Bruex tar to 53.15% in the case of one of the Silesian coals. Percentage of carbon varied from 44.0% in the case of Scholven coal to 78.03% in the case of Bruex tar. Percentage of total sulfur varied from 2.28% for Bruex tar to a recorded 5.65% for one of the Silesian coals and an estimated 6% for Boehlen tar. 1 table.

  6. Enzymatic production of l-citrulline by hydrolysis of the guanidinium group of l-arginine with recombinant arginine deiminase.

    Science.gov (United States)

    Song, Wei; Sun, Xia; Chen, Xiulai; Liu, Dongxu; Liu, Liming

    2015-08-20

    In this study, a simple, efficient enzymatic production process for the environmentally friendly synthesis of l-citrulline from l-arginine was developed using arginine deiminase (ADI) from Lactococcus lactis. Following overexpression of L. lactis ADI in Escherichia. coli BL21 (DE3) and experimental evolution using error-prone PCR, mutant FMME106 was obtained with a Km for l-arginine of 3.5mM and a specific activity of 195.7U/mg. This mutant exhibited a maximal conversion of 92.6% and achieved a final l-citrulline concentration of 176.9g/L under optimal conditions (190g/L l-arginine, 15g/L whole-cell biocatalyst treated with 2% isopropanol for 30min, 50°C, pH 7.2, 8h). The average l-citrulline synthesis rate of 22.1g/L/h is considerably higher than that reported for other similar biocatalytic approaches, therefore the process developed in the present work has great potential for large-scale production of l-citrulline. Copyright © 2015. Published by Elsevier B.V.

  7. Role of arginine and its methylated derivatives in cancer biology and treatment

    Directory of Open Access Journals (Sweden)

    Tyihák Erno

    2001-12-01

    Full Text Available Abstract Both L-arginine supplementation and deprivation influence cell proliferation. The effect of high doses on tumours is determined by the optical configuration: L-arginine is stimulatory, D-arginine inhibitory. Arginine-rich hexapeptides inhibited tumour growth. Deprivation of L-arginine from cell cultures enhanced apoptosis. The pro-apoptotic action of NO synthase inhibitors, like NG-monomethyl-L-arginine, is manifested through inhibition of the arginase pathway. NG-hydroxymethyl-L-arginines caused apoptosis in cell cultures and inhibited the growth of various transplantable mouse tumours. These diverse biological activities become manifest through formaldehyde (HCHO because guanidine group of L-arginine in free and bound form can react rapidly with endogenous HCHO, forming NG-hydroxymethylated derivatives. L-arginine is a HCHO capturer, carrier and donor molecule in biological systems. The role of formaldehyde generated during metabolism of NG-methylated and hydroxymethylated arginines in cell proliferation and death can be shown. The supposedly anti-apoptotic homozygous Arg 72-p53 genotype may increase susceptibility of some cancers. The diverse biological effects of L-arginine and its methylated derivatives call for further careful studies on their possible application in chemoprevention and cancer therapy.

  8. Adaptation to a long term (4 weeks) arginine- and precursor (glutamate, proline and aspartate)-free diet

    Science.gov (United States)

    It is not known whether arginine homeostasis is negatively affected by a "long-term" dietary restriction of arginine and its major precursors in healthy adults. To assess the effects of a 4-week arginine- and precursor-free dietary intake on the regulatory mechanisms of arginine homeostasis in healt...

  9. Arginine consumption by the intestinal parasite Giardia intestinalis reduces proliferation of intestinal epithelial cells.

    Science.gov (United States)

    Stadelmann, Britta; Merino, María C; Persson, Lo; Svärd, Staffan G

    2012-01-01

    In the field of infectious diseases the multifaceted amino acid arginine has reached special attention as substrate for the hosts production of the antimicrobial agent nitric oxide (NO). A variety of infectious organisms interfere with this part of the host immune response by reducing the availability of arginine. This prompted us to further investigate additional roles of arginine during pathogen infections. As a model we used the intestinal parasite Giardia intestinalis that actively consumes arginine as main energy source and secretes an arginine-consuming enzyme, arginine deiminase (ADI). Reduced intestinal epithelial cell (IEC) proliferation is a common theme during bacterial and viral intestinal infections, but it has never been connected to arginine-consumption. Our specific question was thereby, whether the arginine-consumption by Giardia leads to reduced IEC proliferation, in addition to NO reduction. In vitro cultivation of human IEC lines in arginine-free or arginine/citrulline-complemented medium, as well as in interaction with different G. intestinalis isolates, were used to study effects on host cell replication by MTT assay. IEC proliferation was further analyzed by DNA content analysis, polyamine measurements and expressional analysis of cell cycle regulatory genes. IEC proliferation was reduced upon arginine-withdrawal and also in an arginine-dependent manner upon interaction with G. intestinalis or addition of Giardia ADI. We show that arginine-withdrawal by intestinal pathogens leads to a halt in the cell cycle in IECs through reduced polyamine levels and upregulated cell cycle inhibitory genes. This is of importance with regards to intestinal tissue homeostasis that is affected through reduced cell proliferation. Thus, the slower epithelial cell turnover helps the pathogen to maintain a more stable niche for colonization. This study also shows why supplementation therapy of diarrhea patients with arginine/citrulline is helpful and that

  10. Effect of L-arginine supplementation on blood pressure in pregnant women: a meta-analysis of placebo-controlled trials.

    Science.gov (United States)

    Zhu, Qing; Yue, Xin; Tian, Qing-Yin; Saren, Gaowa; Wu, Ming-Hui; Zhang, Yun; Liu, Tong-Tao

    2013-01-01

    A meta-analysis of placebo-controlled trials was conducted to evaluate the effect of L-arginine supplementation on blood pressure (BP) in pregnancy. Trials were searched in PubMed, Embase, and Cochrane Library. A total of five trials were included in the meta-analysis. L-arginine supplementation exhibited a mean decrease of 3.07 mmHg (p = 0.004) for diastolic blood pressure and a mean increase of 1.23 weeks (p = 0.002) for gestation age at delivery in pregnancy, but did not reduce systolic BP (p = 0.19) as compared to placebo. L-arginine supplementation had a significant effect of lowering diastolic blood pressure and prolonging gestation age in pregnancy.

  11. Exercise training reverses the negative effects of chronic L-arginine supplementation on insulin sensitivity.

    Science.gov (United States)

    Salgueiro, Rafael Barrera; Gerlinger-Romero, Frederico; Guimarães-Ferreira, Lucas; de Castro Barbosa, Thais; Nunes, Maria Tereza

    2017-12-15

    L-Arginine has emerged as an important supplement for athletes and non-athletes in order to improve performance. Arginine has been extensively used as substrate for nitric oxide synthesis, leading to increased vasodilatation and hormonal secretion. However, the chronic consumption of arginine has been shown to impair insulin sensitivity. In the present study, we aimed to evaluate whether chronic arginine supplementation associated with exercise training would have a beneficial impact on insulin sensitivity. We, therefore, treated Wistar rats for 4weeks with arginine, associated or not with exercise training (treadmill). We assessed the somatotropic activation, by evaluating growth hormone (GH) gene expression and protein content in the pituitary, as well is GH concentration in the serum. Additionally, we evaluate whole-body insulin sensitivity, by performing an insulin tolerance test. Skeletal muscle morpho-physiological parameters were also assessed. Insulin sensitivity was impaired in the arginine-treated rats. However, exercise training reversed the negative effects of arginine. Arginine and exercise training increased somatotropic axis function, muscle mass and body weight gain. The combination arginine and exercise training further decreased total fat mass. Our results confirm that chronic arginine supplementation leads to insulin resistance, which can be reversed in the association with exercise training. We provide further evidence that exercise training is an important tool to improve whole-body metabolism. Copyright © 2017 Elsevier Inc. All rights reserved.

  12. Arginine decarboxylase as the source of putrescine for tobacco alkaloids

    Science.gov (United States)

    Tiburcio, A. F.; Galston, A. W.

    1986-01-01

    The putrescine which forms a part of nicotine and other pyrrolidine alkaloids is generally assumed to arise through the action of ornithine decarboxylase (ODC). However, we have previously noted that changes in the activity of arginine decarboxylase (ADC), an alternate source of putrescine, parallel changes in tissue alkaloids, while changes in ODC activity do not. This led us to undertake experiments to permit discrimination between ADC and ODC as enzymatic sources of putrescine destined for alkaloids. Two kinds of evidence presented here support a major role for ADC in the generation of putrescine going into alkaloids: (a) A specific 'suicide inhibitor' of ADC effectively inhibits the biosynthesis of nicotine and nornicotine in tobacco callus, while the analogous inhibitor of ODC is less effective, and (b) the flow of 14C from uniformly labelled arginine into nicotine is much more efficient than that from ornithine.

  13. Triple therapy with pyridoxine, arginine supplementation and dietary lysine restriction in pyridoxine-dependent epilepsy: Neurodevelopmental outcome.

    Science.gov (United States)

    Coughlin, Curtis R; van Karnebeek, Clara D M; Al-Hertani, Walla; Shuen, Andrew Y; Jaggumantri, Sravan; Jack, Rhona M; Gaughan, Sommer; Burns, Casey; Mirsky, David M; Gallagher, Renata C; Van Hove, Johan L K

    2015-01-01

    Pyridoxine-dependent epilepsy (PDE) is an epileptic encephalopathy characterized by response to pharmacologic doses of pyridoxine. PDE is caused by deficiency of α-aminoadipic semialdehyde dehydrogenase resulting in impaired lysine degradation and subsequent accumulation of α-aminoadipic semialdehyde. Despite adequate seizure control with pyridoxine monotherapy, 75% of individuals with PDE have significant developmental delay and intellectual disability. We describe a new combined therapeutic approach to reduce putative toxic metabolites from impaired lysine metabolism. This approach utilizes pyridoxine, a lysine-restricted diet to limit the substrate that leads to neurotoxic metabolite accumulation and L-arginine to compete for brain lysine influx and liver mitochondrial import. We report the developmental and biochemical outcome of six subjects who were treated with this triple therapy. Triple therapy reduced CSF, plasma, and urine biomarkers associated with neurotoxicity in PDE. The addition of arginine supplementation to children already treated with dietary lysine restriction and pyridoxine further reduced toxic metabolites, and in some subjects appeared to improve neurodevelopmental outcome. Dietary lysine restriction was associated with improved seizure control in one subject, and the addition of arginine supplementation increased the objective motor outcome scale in two twin siblings, illustrating the contribution of each component of this treatment combination. Optimal results were noted in the individual treated with triple therapy early in the course of the disease. Residual disease symptoms could be related to early injury suggested by initial MR imaging prior to initiation of treatment or from severe epilepsy prior to diagnosis. This observational study reports the use of triple therapy, which combines three effective components in this rare condition, and suggests that early diagnosis and treatment with this new triple therapy may ameliorate the

  14. The free energy barrier for arginine gating charge translation is altered by mutations in the voltage sensor domain.

    Directory of Open Access Journals (Sweden)

    Christine S Schwaiger

    Full Text Available The gating of voltage-gated ion channels is controlled by the arginine-rich S4 helix of the voltage-sensor domain moving in response to an external potential. Recent studies have suggested that S4 moves in three to four steps to open the conducting pore, thus visiting several intermediate conformations during gating. However, the exact conformational changes are not known in detail. For instance, it has been suggested that there is a local rotation in the helix corresponding to short segments of a 3(10-helix moving along S4 during opening and closing. Here, we have explored the energetics of the transition between the fully open state (based on the X-ray structure and the first intermediate state towards channel closing (C1, modeled from experimental constraints. We show that conformations within 3 Å of the X-ray structure are obtained in simulations starting from the C1 model, and directly observe the previously suggested sliding 3(10-helix region in S4. Through systematic free energy calculations, we show that the C1 state is a stable intermediate conformation and determine free energy profiles for moving between the states without constraints. Mutations indicate several residues in a narrow hydrophobic band in the voltage sensor contribute to the barrier between the open and C1 states, with F233 in the S2 helix having the largest influence. Substitution for smaller amino acids reduces the transition cost, while introduction of a larger ring increases it, largely confirming experimental activation shift results. There is a systematic correlation between the local aromatic ring rotation, the arginine barrier crossing, and the corresponding relative free energy. In particular, it appears to be more advantageous for the F233 side chain to rotate towards the extracellular side when arginines cross the hydrophobic region.

  15. l-Arginine Supplementation Alleviates Postprandial Endothelial Dysfunction When Baseline Fasting Plasma Arginine Concentration Is Low: A Randomized Controlled Trial in Healthy Overweight Adults with Cardiometabolic Risk Factors.

    Science.gov (United States)

    Deveaux, Ambre; Pham, Isabelle; West, Sheila G; André, Etienne; Lantoine-Adam, Frédérique; Bunouf, Pierre; Sadi, Samira; Hermier, Dominique; Mathé, Véronique; Fouillet, Hélène; Huneau, Jean-François; Benamouzig, Robert; Mariotti, François

    2016-07-01

    Vascular endothelial dysfunction, the hallmark of early atherosclerosis, is induced transiently by a high-fat meal. High doses of free l-arginine supplements reduce fasting endothelial dysfunction. We sought to determine the effects of a low dose of a sustained-release (SR) l-arginine supplement on postprandial endothelial function in healthy overweight adults with cardiometabolic risk factors and to investigate whether this effect may vary by baseline arginine status. In a randomized, double-blind, 2-period crossover, placebo-controlled trial (4-wk treatment, 4-wk washout), we compared the effects of 1.5 g SR-l-arginine 3 times/d (4.5 g/d) with placebo in 33 healthy overweight adults [body mass index (BMI, in kg/m(2)): 25 to >30] with the hypertriglyceridemic waist (HTW) phenotype [plasma triglycerides > 150 mg/dL; waist circumference > 94 cm (men) or > 80 cm (women)]. The main outcome variable tested was postprandial endothelial function after a high-fat meal (900 kcal), as evaluated by use of flow-mediated dilation (FMD) and Framingham reactive hyperemia index (fRHI), after each treatment. By use of subgroup analysis, we determined whether the effect was related to the baseline plasma arginine concentration. In the total population, the effects of SR-arginine supplementation on postprandial endothelial function were mixed and largely varied with baseline fasting arginine concentration (P-interaction supplementation attenuated the postprandial decrease in both FMD (29% decrease with SR-arginine compared with 50% decrease with placebo) and fRHI (5% increase with SR-arginine compared with 49% decrease with placebo), resulting in significantly higher mean ± SEM values with SR-arginine (FMD: 4.0% ± 0.40%; fRHI: 0.41 ± 0.069) than placebo (FMD: 2.9% ± 0.31%; fRHI: 0.21 ± 0.060) at the end of the postprandial period (P Supplementation with low-dose SR-arginine alleviates postprandial endothelial dysfunction in healthy HTW adults when the baseline plasma arginine

  16. Protective effect of quercetin and/or l-arginine against nano-zinc oxide-induced cardiotoxicity in rats

    Energy Technology Data Exchange (ETDEWEB)

    Faddah, L. M.; Baky, Nayira A. Abdel [King Saud University, Pharmacology Department, Faculty of Pharmacy (Saudi Arabia); Mohamed, Azza M., E-mail: azzamohamed99@yahoo.com [King Abdulaziz University, Biochemistry Department, Faculty of Science for Girls (Saudi Arabia); Al-Rasheed, Nouf M.; Al-Rasheed, Nawal M. [King Saud University, Pharmacology Department, Faculty of Pharmacy (Saudi Arabia)

    2013-04-15

    The aim of this study was to investigate the protective role of quercetin and/or l-arginine against the cardiotoxic potency of zinc oxide nanoparticle (ZnO-NP)-induced cardiac infarction. ZnO-NPs (50 nm) were administered orally at either 600 mg or 1 g/kg body weight for 5 consecutive days. The results revealed that co-administration of quercetin and/or l-arginine (each 200 mg/kg body weight) daily for 3 weeks to rats intoxicated by either of the two doses markedly ameliorated increases in serum markers of cardiac infarction, including troponin T, creatine kinase-MB, and myoglobin, as well as increases in proinflammatory biomarkers, including tumor necrosis factor-{alpha}, interleukin-6, and C-reactive protein, compared with intoxicated, untreated rats. Each agent alone or in combination also successfully modulated the alterations in serum vascular endothelial growth factor, cardiac calcium concentration, and oxidative DNA damage as well as the increase in the apoptosis marker caspase 3 of cardiac tissue in response to ZnO-NP toxicity. In conclusion, early treatment with quercetin and l-arginine may protect cardiac tissue from infarction induced by the toxic effects of ZnO-NPs.

  17. Protective effect of quercetin and/or l-arginine against nano-zinc oxide-induced cardiotoxicity in rats

    Science.gov (United States)

    Faddah, L. M.; Baky, Nayira A. Abdel; Mohamed, Azza M.; Al-Rasheed, Nouf M.; Al-Rasheed, Nawal M.

    2013-04-01

    The aim of this study was to investigate the protective role of quercetin and/or l-arginine against the cardiotoxic potency of zinc oxide nanoparticle (ZnO-NP)-induced cardiac infarction. ZnO-NPs (50 nm) were administered orally at either 600 mg or 1 g/kg body weight for 5 consecutive days. The results revealed that co-administration of quercetin and/or l-arginine (each 200 mg/kg body weight) daily for 3 weeks to rats intoxicated by either of the two doses markedly ameliorated increases in serum markers of cardiac infarction, including troponin T, creatine kinase-MB, and myoglobin, as well as increases in proinflammatory biomarkers, including tumor necrosis factor-α, interleukin-6, and C-reactive protein, compared with intoxicated, untreated rats. Each agent alone or in combination also successfully modulated the alterations in serum vascular endothelial growth factor, cardiac calcium concentration, and oxidative DNA damage as well as the increase in the apoptosis marker caspase 3 of cardiac tissue in response to ZnO-NP toxicity. In conclusion, early treatment with quercetin and l-arginine may protect cardiac tissue from infarction induced by the toxic effects of ZnO-NPs.

  18. Effects of Citrate and Arginine on Sorption of Nickel to Yazd Sepiolite and Calcite

    Directory of Open Access Journals (Sweden)

    Ahmadreza Sheikhhosseini

    2017-03-01

    Full Text Available Introduction: Pollution of soil and water environment by release of heavy metals is of great concerns of the last decades. Sorption of heavy metals by low cost materials is considered as an inexpensive and efficient method used for removal of heavy metals from soil-water systems. The presence of different ligands with various complexing abilities can change the sorption properties of heavy metals and their fate in the environment as well. In order to assess the effect of citrate and arginine as natural organic ligands in soil environment, in a batch study we investigated the effects of these ligands on equilibrium sorption of nickel to sepiolite and calcite minerals and also kinetics of Ni sorption by these minerals. Materials and Methods: Minerals used in this study included sepiolite from Yazd (Iran and pure calcite (Analytical grade, Merck, Germany. Sepiolite was purified, saturated with Ca using 0.5 M CaCl2, powdered in a mortar and sieved by non-metal 230 mesh standard wire sieve. For equilibrium sorption study, in a 50-mL polyethylene centrifuge tube,0.3 g sample of each mineral was suspended in 30 mL of a 0.01 M CaCl2 solution containing 0, 5, 10, 20, 40, 60, 80 and 100 mg L-1 Ni (NiCl2 and containing zero (as control or 0.1mmol L-1 citrate or arginine ligands. The applied concentrationsfor each ligand can naturally occur in soils. Preparedtubes were shaken (180±2 rpm, 25±1oC for 24 h using an orbital shaker and centrifuged (4000×g for 10 min and the supernatants were analyzed for Ni concentration using an atomic absorption spectrophotometer (AAnalyst 200 Perkin-Elmer at a wavelength of 232 nm and a detection limit of 0.05 mg L-1. The quantity of Ni retained by each mineral at equilibrium was calculated using equation qe = (Ci - CeV/W where qe was the amount of nickel retained by mineral surface at equilibrium. Ci and Ce were the initial and the equilibrium concentrations (mg L-1 of Ni, respectively, V was the volume (L of the solution

  19. The effect of l-arginine supplementation on body composition and performance in male athletes: a double-blinded randomized clinical trial.

    Science.gov (United States)

    Pahlavani, N; Entezari, M H; Nasiri, M; Miri, A; Rezaie, M; Bagheri-Bidakhavidi, M; Sadeghi, O

    2017-04-01

    Athletes used a lot of dietary supplements to achieve the more muscle mass and improve their athletic performance. The objective of this study was to investigate the effect of l-arginine supplementation on sport performance and body composition in male soccer players. This double-blinded, randomized and placebo-controlled trial was conducted on 56 male soccer players, with age range of 16-35, who referred to sport clubs in Isfahan, Iran. Subjects were randomly assigned to either l-arginine or placebo groups. Athletes received daily either 2 g per day l-arginine supplement or the same amount of placebo (maltodextrin) for 45 days. Sport performance and also body mass index (BMI), body fat mass (BFM) and lean body mass (LBM) were measured at the beginning and end of the study. Also, 3-day dietary records were collected at three different time points (before, in the middle of, and at the end of the study). The mean age of subjects was 20.85±4.29 years. Sport performance (VO 2 max) significantly increased in l-arginine supplementation group (4.12±6.07) compared with placebo group (1.23±3.36) (P=0.03). This increase remained significant even after adjustment of baseline values, physical activity and usual dietary intake of subjects throughout the study. No significant effect of l-arginine supplementation was found on weight, BMI, BFM and LBM. l-arginine supplementation (2 g per day) could increase the sport performance in male athletes, but had no effect on anthropometric measurements, including BMI, BFM and LBM. So, further studies are needed to shed light our findings.

  20. A diverse array of creatine kinase and arginine kinase isoform genes is present in the starlet sea anemone Nematostella vectensis, a cnidarian model system for studying developmental evolution.

    Science.gov (United States)

    Uda, Kouji; Ellington, W Ross; Suzuki, Tomohiko

    2012-04-15

    Phosphagen (guanidino) kinases (PK) constitute a family of homologous phosphotransferases catalyzing the reversible transfer of the high-energy phosphoryl group of ATP to naturally occurring guanidine compounds. Prior work has shown that PKs can be phylogenetically separated into two distinct groups- an arginine kinase (AK) subfamily and a creatine kinase (CK) subfamily. The latter includes three CK isoforms- cytoplasmic CK (CyCK), mitochondrial CK (MiCK) and three-domain flagellar CK (fCK). In the present study we identified six unique PK genes from the draft genome sequence of the starlet sea anemone Nematostella vectensis, a well-known model organism for understanding metazoan developmental evolution. Using reverse transcription polymerase chain reaction (RTPCR) methods, full length cDNAs were amplified for all of these PKs. These cDNAs were cloned and expressed in Escherichia coli as 6x His-tagged fusion proteins. The six PKs were identified as the three typical CK isoforms (CyCK, MiCK and fCK), two unusual AKs (a two-domain AK (2DAK) and a three-domain AK (3DAK)) and a PK which phosphorylated arginine. The latter enzyme had a very low AK activity (its apparent V(max) value being less than 0.2% that of 3DAK), lacks several key residues necessary for AK enzyme activity, and was tentatively designated as AK1. As far as we know, this constitutes the first report of an AK with the three fused AK domains. The Bayesian tree suggested that the third domain of 3DAK likely evolved from the gene for domain 2 of typical two-domain AK found widely in cnidarians. Construction of phylogenetic trees and comparison of exon-intron organizations of their respective genes indicated that the N. vectensis three-domain fCK and 3DAK evolved independently, and both enzymes are likely to be targeted to cell membranes since they have a myristoylation signal at their respective N-termini. These results complement prior work on other basal invertebrates showing that multiple CK and AK

  1. PRMT1-mediated arginine methylation controls ATXN2L localization

    Energy Technology Data Exchange (ETDEWEB)

    Kaehler, Christian; Guenther, Anika; Uhlich, Anja; Krobitsch, Sylvia, E-mail: krobitsc@molgen.mpg.de

    2015-05-15

    Arginine methylation is a posttranslational modification that is of importance in diverse cellular processes. Recent proteomic mass spectrometry studies reported arginine methylation of ataxin-2-like (ATXN2L), the paralog of ataxin-2, a protein that is implicated in the neurodegenerative disorder spinocerebellar ataxia type 2. Here, we investigated the methylation state of ATXN2L and its significance for ATXN2L localization. We first confirmed that ATXN2L is asymmetrically dimethylated in vivo, and observed that the nuclear localization of ATXN2L is altered under methylation inhibition. We further discovered that ATXN2L associates with the protein arginine-N-methyltransferase 1 (PRMT1). Finally, we showed that neither mutation of the arginine–glycine-rich motifs of ATXN2L nor methylation inhibition alters ATXN2L localization to stress granules, suggesting that methylation of ATXN2L is probably not mandatory. - Highlights: • ATXN2L is asymmetrically dimethylated in vivo. • ATXN2L interacts with PRMT1 under normal and stress conditions. • PRMT1-mediated dimethylation of ATXN2L controls its nuclear localization. • ATXN2L localization to stress granules appears independent of its methylation state.

  2. Structures of the N47A and E109Q mutant proteins of pyruvoyl-dependent arginine decarboxylase from Methanococcus jannaschii.

    Science.gov (United States)

    Soriano, Erika V; McCloskey, Diane E; Kinsland, Cynthia; Pegg, Anthony E; Ealick, Steven E

    2008-04-01

    Pyruvoyl-dependent arginine decarboxylase (PvlArgDC) catalyzes the first step of the polyamine-biosynthetic pathway in plants and some archaebacteria. The pyruvoyl group of PvlArgDC is generated by an internal autoserinolysis reaction at an absolutely conserved serine residue in the proenzyme, resulting in two polypeptide chains. Based on the native structure of PvlArgDC from Methanococcus jannaschii, the conserved residues Asn47 and Glu109 were proposed to be involved in the decarboxylation and autoprocessing reactions. N47A and E109Q mutant proteins were prepared and the three-dimensional structure of each protein was determined at 2.0 A resolution. The N47A and E109Q mutant proteins showed reduced decarboxylation activity compared with the wild-type PvlArgDC. These residues may also be important for the autoprocessing reaction, which utilizes a mechanism similar to that of the decarboxylation reaction.

  3. Antifungal properties of peptidomimetics with an arginine-[β-(2,5,7-tri-tert-butylindol-3-yl)alanine]-arginine motif against Saccharomyces cerevisiae and Zygosaccharomyces bailii.

    Science.gov (United States)

    Larsen, Camilla Eggert; Larsen, Camilla Josephine; Franzyk, Henrik; Regenberg, Birgitte

    2015-05-01

    Due to increased occurrence of infections and food spoilage caused by yeast, there is an unmet need for new antifungal agents. The arginine-β-(2,5,7-tri-tert-butylindol-3-yl) alanine-arginine (R-Tbt-R) motif was previously proved useful in the design of an antifungal tripeptide. Here, an array of peptidomimetics based on this motif was investigated for antifungal and hemolytic activity. The five most promising modified tetrapeptide analogues ( 6: and 9-12: contain an additional C-terminal hydrophobic residue, and these were found to exhibit antifungal activity against Saccharomyces cerevisiae (MIC 6 and 12 μg mL(-1)) and Zygosaccharomyces bailii (MIC 6-25 μg mL(-1)). Four compounds ( 6: and 9-11: , had limited hemolytic activity (<10% hemolysis at 8 × MIC). Determination of their killing kinetics revealed that compound 9: displayed fungicidal effect. Testing against cells from an S. cerevisiae deletion mutant library indicated that interaction with yeast-specific fungal sphingolipids, most likely constitutes a crucial step in the mode of action. Interestingly, a lack of activity of peptidomimetics 6: and 9-11: towards Candida spp. was shown to be due to degradation or sequestering by the yeast. Due to their ultrashort nature, antifungal activity and low toxicity, the four compounds may have potential as leads for novel preservatives. © FEMS 2015. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  4. PRMT1 promotes mitosis of cancer cells through arginine methylation of INCENP.

    Science.gov (United States)

    Deng, Xiaolan; Von Keudell, Gottfried; Suzuki, Takehiro; Dohmae, Naoshi; Nakakido, Makoto; Piao, Lianhua; Yoshioka, Yuichiro; Nakamura, Yusuke; Hamamoto, Ryuji

    2015-11-03

    Inner centromere protein (INCENP) is a part of a protein complex known as the chromosomal passenger complex (CPC) that is essential for correcting non-bipolar chromosome attachments and for cytokinesis. We here demonstrate that a protein arginine methyltransferase PRMT1, which are overexpressed in various types of cancer including lung and bladder cancer, methylates arginine 887 in an Aurora Kinase B (AURKB)-binding region of INCENP both in vitro and in vivo. R887-substituted INCENP revealed lower binding-affinity to AURKB than wild-type INCENP in the presence of PRMT1. Knockdown of PRMT1 as well as overexpression of methylation-inactive INCENP attenuated the AURKB activity in cancer cells, and resulted in abnormal chromosomal alignment and segregation. Furthermore, introduction of methylation-inactive INCENP into cancer cells reduced the growth rate, compared with those introduced wild-type INCENP or Mock. Our data unveils a novel mechanism of PRMT1-mediated CPC regulation through methylation of INCENP.

  5. Stress, sex, and addiction: potential roles of corticotropin-releasing factor, oxytocin, and arginine-vasopressin.

    Science.gov (United States)

    Bisagno, Verónica; Cadet, Jean Lud

    2014-09-01

    Stress sensitivity and sex are predictive factors for the development of neuropsychiatric disorders. Life stresses are not only risk factors for the development of addiction but also are triggers for relapse to drug use. Therefore, it is imperative to elucidate the molecular mechanisms underlying the interactions between stress and drug abuse, as an understanding of this may help in the development of novel and more effective therapeutic approaches to block the clinical manifestations of drug addiction. The development and clinical course of addiction-related disorders do appear to involve neuroadaptations within neurocircuitries that modulate stress responses and are influenced by several neuropeptides. These include corticotropin-releasing factor, the prototypic member of this class, as well as oxytocin and arginine-vasopressin that play important roles in affiliative behaviors. Interestingly, these peptides function to balance emotional behavior, with sexual dimorphism in the oxytocin/arginine-vasopressin systems, a fact that might play an important role in the differential responses of women and men to stressful stimuli and the specific sex-based prevalence of certain addictive disorders. Thus, this review aims to summarize (i) the contribution of sex differences to the function of dopamine systems, and (ii) the behavioral, neurochemical, and anatomical changes in brain stress systems.

  6. Dietary l-Arginine Supplementation Protects Weanling Pigs from Deoxynivalenol-Induced Toxicity

    Directory of Open Access Journals (Sweden)

    Li Wu

    2015-04-01

    Full Text Available This study was conducted to determine the positive effects of dietary supplementation with l-arginine (Arg on piglets fed a deoxynivalenol (DON-contaminated diet. A total of eighteen, 28-day-old healthy weanling pigs were randomly assigned into one of three groups: uncontaminated basal diet (control group, 6 mg/kg DON-contaminated diet (DON group and 6 mg/kg DON + 1% l-arginine (DON + ARG group. After 21 days of Arg supplementation, piglets in the DON and DON + ARG groups were challenged by feeding 6 mg/kg DON-contaminated diet for seven days. The results showed that DON resulted in damage to piglets. However, clinical parameters, including jejunal morphology, amino acid concentrations in the serum, jejunum and ileum, were improved by Arg (p < 0.05. Furthermore, the mRNA levels for sodium-glucose transporter-1 (SGLT-1, glucose transporter type-2 (GLUT-2 and y+l-type amino acid transporter-1 (y+LAT-1 were downregulated in the DON group, but the values were increased in the DON + ARG group (p < 0.05. Collectively, these results indicate that dietary supplementation with Arg exerts a protective role in pigs fed DON-contaminated diets.

  7. Cerebral Endothelial Function Determined by Cerebrovascular Reactivity to L-Arginine

    Science.gov (United States)

    Pretnar-Oblak, Janja

    2014-01-01

    Endothelium forms the inner cellular lining of blood vessels and plays an important role in many physiological functions including the control of vasomotor tone. Cerebral endothelium is probably one of the most specific types but until recently it was impossible to determine its function. In this review, the role of cerebrovascular reactivity to L-arginine (CVR-L-Arg) for assessment of cerebral endothelial function is discussed. L-Arginine induces vasodilatation through enhanced production of nitric oxide (NO) in the cerebral endothelium. Transcranial Doppler sonography is used for evaluation of cerebral blood flow changes. The method is noninvasive, inexpensive, and enables reproducible measurements. CVR-L-Arg has been compared to flow-mediated dilatation as a gold standard for systemic endothelial function and intima-media thickness as a marker for morphological changes. However, it seems to show specific cerebral endothelial function. So far CVR-L-Arg has been used to study cerebral endothelial function in many pathological conditions such as stroke, migraine, etc. In addition CVR-L-Arg has also proven its usefulness in order to show potential improvement after pharmacological interventions. In conclusion CVR-L-Arg is a promising noninvasive research method that could provide means for evaluation of cerebral endothelial function in physiological and pathological conditions. PMID:24860826

  8. Oral L-Arginine Stimulates GLP-1 Secretion to Improve Glucose Tolerance in Male Mice

    DEFF Research Database (Denmark)

    Clemmensen, Christoffer; Smajilovic, Sanela; Smith, Eric P

    2013-01-01

    -induced obesity, may provide an alternative therapeutic approach. Importantly, recent evidence suggests the amino acid l-arginine, a well-known insulin secretagogue, can also stimulate release of GLP-1 from isolated rat intestine. Here we tested the hypothesis that oral l-arginine acts as a GLP-1 secretagogue...... in vivo, to augment postprandial insulin secretion and improve glucose tolerance. To test this, we administered l-arginine or vehicle by oral gavage, immediately prior to an oral glucose tolerance test in lean and diet-induced obese mice. In both lean and obese mice oral l-arginine increased plasma GLP-1...... and insulin and substantially improved glucose clearance. To directly assess the contribution of GLP-1 receptor (GLP-1R)-signaling to these improvements, l-arginine was given to Glp1r knockout mice and their wild-type littermates. In this experiment oral l-arginine significantly augmented insulin secretion...

  9. Does an ‘L-arginine doped orthophosphoric acid’ crystal exist?

    Energy Technology Data Exchange (ETDEWEB)

    Srinivasan, Bikshandarkoil R., E-mail: srini@unigoa.ac.in

    2014-04-15

    The reactive nature of aqueous orthophosphoric acid (H{sub 3}PO{sub 4}) towards L-arginine (L-Arg), to form a phosphate salt namely L-arginine phosphate monohydrate (LAP), rules out the doping of any L-arginine into H{sub 3}PO{sub 4}. Hence, the reported claim of growth of ‘L-arginine doped orthophosphoric acid’ crystals by Saradha et al. J. Lumin (2013) is untenable. -- Highlights: • Orthophosphoric acid (H{sub 3}PO{sub 4}) is a tetrahedral molecule. • Aqueous H{sub 3}PO{sub 4} reacts with L-arginine to form mono- or bis-dihydrogenphosphate salt. • L-arginine doped orthophosphoric acid crystal does not exist.

  10. A novel L-arginine salt nonlinear optical crystal: L-arginine p-nitrobenzoate monohydrate (LANB)

    Science.gov (United States)

    Wang, L.; Zhang, G. H.; Liu, X. T.; Wang, L. N.; Wang, X. Q.; Zhu, L. Y.; Xu, D.

    2014-01-01

    A novel L-arginine salt nonlinear optical single crystal, L-arginine p-nitrobenzoate monohydrate (LANB) has been grown by slow cooling method from aqueous solution. Its solubility at different temperatures in water was measured. The grown crystal was characterized by the elemental analyses, X-ray single crystal and powder diffractions, Fourier transform infrared and Raman spectra. The structure analysis revealed that LANB belongs to the monoclinic crystallographic system, space group P21, with unit cell parameters: a = 8.566(3), b = 5.817(2), c = 17.131(7) Å, β = 101.223(5)°, Z = 2 and V = 837.2(6) Å3. The proton and carbon configurations of L-arginine were confirmed through 1H NMR and 13C NMR spectra analyses. The linear and nonlinear optical properties of LANB crystal were studied by the use of transmission spectrum and second harmonic generation (SHG). The thermal properties were investigated by using thermo gravimetric (TG) and differential thermal analysis (DTA).

  11. Structures of the N47A and E109Q mutant proteins of pyruvoyl-dependent arginine decarboxylase from Methanococcus jannaschii

    Energy Technology Data Exchange (ETDEWEB)

    Soriano, Erika V. [Department of Chemistry and Chemical Biology, Cornell University, Ithaca, NY 14850-1301 (United States); McCloskey, Diane E. [Department of Cellular and Molecular Physiology, Pennsylvania State University, College of Medicine, Hershey, PA 17033 (United States); Kinsland, Cynthia [Department of Chemistry and Chemical Biology, Cornell University, Ithaca, NY 14850-1301 (United States); Pegg, Anthony E. [Department of Cellular and Molecular Physiology, Pennsylvania State University, College of Medicine, Hershey, PA 17033 (United States); Ealick, Steven E., E-mail: see3@cornell.edu [Department of Chemistry and Chemical Biology, Cornell University, Ithaca, NY 14850-1301 (United States)

    2008-04-01

    The crystal structures of two arginine decarboxylase mutant proteins provide insights into the mechanisms of pyruvoyl-group formation and the decarboxylation reaction. Pyruvoyl-dependent arginine decarboxylase (PvlArgDC) catalyzes the first step of the polyamine-biosynthetic pathway in plants and some archaebacteria. The pyruvoyl group of PvlArgDC is generated by an internal autoserinolysis reaction at an absolutely conserved serine residue in the proenzyme, resulting in two polypeptide chains. Based on the native structure of PvlArgDC from Methanococcus jannaschii, the conserved residues Asn47 and Glu109 were proposed to be involved in the decarboxylation and autoprocessing reactions. N47A and E109Q mutant proteins were prepared and the three-dimensional structure of each protein was determined at 2.0 Å resolution. The N47A and E109Q mutant proteins showed reduced decarboxylation activity compared with the wild-type PvlArgDC. These residues may also be important for the autoprocessing reaction, which utilizes a mechanism similar to that of the decarboxylation reaction.

  12. Safety of long-term dietary supplementation with L-arginine in pigs.

    Science.gov (United States)

    Hu, Shengdi; Li, Xilong; Rezaei, Reza; Meininger, Cynthia J; McNeal, Catherine J; Wu, Guoyao

    2015-05-01

    This study was conducted with a swine model to determine the safety of long-term dietary supplementation with L-arginine-HCl or L-arginine free base. Beginning at 30 days of age, pigs were fed a corn- and soybean meal-based diet (31.5 g/kg body weight/day) supplemented with 0, 1.21, 1.81 or 2.42 % L-arginine-HCl (Experiment 1) or with 0, 1, 1.5 or 2 % L-arginine (Experiment 2). The supplemental doses of 0, 1, 1.5, and 2 % L-arginine provided pigs with 0, 315, 473, and 630 mg L-arginine/kg body weight/day, respectively, which were equivalent to 0, 286, 430, and 573 mg L-arginine/kg body weight/day, respectively, in humans. At 121 days of age (91 days after initiation of supplementation), blood samples were obtained from the jugular vein of pigs at 1 and 4 h after feeding for hematological and clinical chemistry tests. Dietary supplementation with L-arginine increased plasma concentrations of arginine, ornithine, proline, albumin and reticulocytes, while reducing plasma concentrations of ammonia, free fatty acids, triglyceride, cholesterol, and neutrophils. L-Arginine supplementation enhanced protein gain and reduced white-fat deposition in the body. Other variables in standard hematology and clinical chemistry tests, serum concentrations of insulin, growth hormone and insulin-like growth factor-I did not differ among all the groups of pigs. These results indicate that dietary supplementation with L-arginine (up to 630 mg/kg body weight/day) is safe in pigs for at least 91 days. Our findings help guide clinical studies to determine the safety of long-term oral administration of L-arginine to humans.

  13. Oral L-arginine supplementation impacts several reproductive parameters during the postpartum period in mares.

    Science.gov (United States)

    Kelley, Dale E; Warren, Lori K; Mortensen, Christopher J

    2013-05-01

    L-arginine is an amino acid which can alter pituitary function and increase blood flow to the reproductive tract. The objective was to determine the effect of supplementing 100g of L-arginine on plasma arginine concentrations, follicular dynamics and ovarian and uterine artery blood flow during the estrus that occurs subsequent to foaling. In Experiment 1, mares were fed 100g L-arginine for 1 day during the last 3 weeks of pregnancy and plasma samples taken for every hour for the first 4h and every other hour until 12h.L-arginine supplementation elevated plasma arginine concentrations from 1 to 8h post feeding; arginine peaked at 6h (arginine: 515±33μmol/L; control: 80±33μmol/L). In Experiment 2, mares received either 100g L-arginine or control diets beginning 21 d before the expected foaling date and continued for 30 d postpartum. The reproductive tract was evaluated by transrectal Doppler ultrasonography from Day 1 postpartum through Day 30. There were no differences in ovarian follicular dynamics, ovarian or uterine resistance indices between groups. Vascular perfusion of the F1 follicular wall was greater in L-arginine supplemented mares (37.3±2.6%) than controls (25.4±2.7%; PL-arginine supplemented mares had a smaller uterine body and horns and accumulated less uterine fluid than controls (PL-arginine supplementation as a breeding management tool during the postpartum period to increase reproductive success. Copyright © 2013 Elsevier B.V. All rights reserved.

  14. l-Arginine Availability Modulates Local Nitric Oxide Production and Parasite Killing in Experimental Trypanosomiasis

    OpenAIRE

    Gobert, Alain P.; Daulouede, Sylvie; Lepoivre, Michel; Boucher, Jean Luc; Bouteille, Bernard; Buguet, Alain; Cespuglio, Raymond; Veyret, Bernard; Vincendeau, Philippe

    2000-01-01

    Nitric oxide (NO) is an important effector molecule of the immune system in eliminating numerous pathogens. Peritoneal macrophages from Trypanosoma brucei brucei-infected mice express type II NO synthase (NOS-II), produce NO, and kill parasites in the presence of l-arginine in vitro. Nevertheless, parasites proliferate in the vicinity of these macrophages in vivo. The present study shows that l-arginine availability modulates NO production. Trypanosomes use l-arginine for polyamine synthesis,...

  15. Arginine Improves pH Homeostasis via Metabolism and Microbiome Modulation.

    Science.gov (United States)

    Agnello, M; Cen, L; Tran, N C; Shi, W; McLean, J S; He, X

    2017-07-01

    Dental caries can be described as a dysbiosis of the oral microbial community, in which acidogenic, aciduric, and acid-adapted bacterial species promote a pathogenic environment, leading to demineralization. Alkali generation by oral microbes, specifically via arginine catabolic pathways, is an essential factor in maintaining plaque pH homeostasis. There is evidence that the use of arginine in dentifrices helps protect against caries. The aim of the current study was to investigate the mechanistic and ecological effect of arginine treatment on the oral microbiome and its regulation of pH dynamics, using an in vitro multispecies oral biofilm model that was previously shown to be highly reflective of the in vivo oral microbiome. Pooled saliva from 6 healthy subjects was used to generate overnight biofilms, reflecting early stages of biofilm maturation. First, we investigated the uptake of arginine by the cells of the biofilm as well as the metabolites generated. We next explored the effect of arginine on pH dynamics by pretreating biofilms with 75 mM arginine, followed by the addition of sucrose (15 mM) after 0, 6, 20, or 48 h. pH was measured at each time point and biofilms were collected for 16S sequencing and targeted arginine quantification, and supernatants were prepared for metabolomic analysis. Treatment with only sucrose led to a sustained pH drop from 7 to 4.5, while biofilms treated with sucrose after 6, 20, or 48 h of preincubation with arginine exhibited a recovery to higher pH. Arginine was detected within the cells of the biofilms, indicating active uptake, and arginine catabolites citrulline, ornithine, and putrescine were detected in supernatants, indicating active metabolism. Sequencing analysis revealed a shift in the microbial community structure in arginine-treated biofilms as well as increased species diversity. Overall, we show that arginine improved pH homeostasis through a remodeling of the oral microbial community.

  16. Bioinformatic evaluation of L-arginine catabolic pathways in 24 cyanobacteria and transcriptional analysis of genes encoding enzymes of L-arginine catabolism in the cyanobacterium Synechocystis sp. PCC 6803

    Directory of Open Access Journals (Sweden)

    Pistorius Elfriede K

    2007-11-01

    Full Text Available Abstract Background So far very limited knowledge exists on L-arginine catabolism in cyanobacteria, although six major L-arginine-degrading pathways have been described for prokaryotes. Thus, we have performed a bioinformatic analysis of possible L-arginine-degrading pathways in cyanobacteria. Further, we chose Synechocystis sp. PCC 6803 for a more detailed bioinformatic analysis and for validation of the bioinformatic predictions on L-arginine catabolism with a transcript analysis. Results We have evaluated 24 cyanobacterial genomes of freshwater or marine strains for the presence of putative L-arginine-degrading enzymes. We identified an L-arginine decarboxylase pathway in all 24 strains. In addition, cyanobacteria have one or two further pathways representing either an arginase pathway or L-arginine deiminase pathway or an L-arginine oxidase/dehydrogenase pathway. An L-arginine amidinotransferase pathway as a major L-arginine-degrading pathway is not likely but can not be entirely excluded. A rather unusual finding was that the cyanobacterial L-arginine deiminases are substantially larger than the enzymes in non-photosynthetic bacteria and that they are membrane-bound. A more detailed bioinformatic analysis of Synechocystis sp. PCC 6803 revealed that three different L-arginine-degrading pathways may in principle be functional in this cyanobacterium. These are (i an L-arginine decarboxylase pathway, (ii an L-arginine deiminase pathway, and (iii an L-arginine oxidase/dehydrogenase pathway. A transcript analysis of cells grown either with nitrate or L-arginine as sole N-source and with an illumination of 50 μmol photons m-2 s-1 showed that the transcripts for the first enzyme(s of all three pathways were present, but that the transcript levels for the L-arginine deiminase and the L-arginine oxidase/dehydrogenase were substantially higher than that of the three isoenzymes of L-arginine decarboxylase. Conclusion The evaluation of 24

  17. Heat Shock Proteins, L-Arginine, and Asymmetric Dimethylarginine Levels in Patients With Obstructive Sleep Apnea Syndrome.

    Science.gov (United States)

    İn, Erdal; Özdemir, Cengiz; Kaman, Dilara; Sökücü, Sinem Nedime

    2015-11-01

    Vascular endothelial inflammation and enhanced oxidative stress are important factors in the pathogenesis of obstructive sleep apnea syndrome (OSAS). The aim of this study was to determine the levels of heat shock protein (HSP) 27, HSP70, HSP90, L-arginine, and asymmetric dimethylarginine (ADMA) in patients with OSAS and determine their relationship with cardiovascular (CV) risk factors. Forty patients with OSAS, comprising 26 with and 14 without traditional CV risk factors (obesity, hypercholesterolemia, diabetes, hypertension, and smoking), and 20 control subjects without OSAS were included. All patients underwent a full polysomnographic evaluation, and blood samples were obtained in the morning after the night the diagnostic study was performed. No significant differences were found in serum HSP27 and HSP70 levels between the groups. HSP90 and ADMA levels increased significantly, whereas L-arginine levels decreased significantly in patients with OSAS, both with and without CV risk factors, compared with controls, but were not different among the subgroups. In all patients with OSAS, serum HSP70 levels were positively correlated with a percent time with saturationL-arginine levels were negatively correlated with desaturation number (r=-.360, P=.022) and apnea-hypopnea index (r=-.354, P=.025) and positively correlated with mean oxygen saturation (r=.328, P=.039). Serum levels of HSP90 and ADMA increased, whereas those of L-arginine decreased in patients with OSAS regardless of CV risk factors. These findings indicate the presence of oxidative stress and endothelial dysfunction in patients with OSAS. Copyright © 2014 SEPAR. Published by Elsevier Espana. All rights reserved.

  18. Graphene Functionalized with Arginine Decreases the Development of Glioblastoma Multiforme Tumor in a Gene-Dependent Manner

    Directory of Open Access Journals (Sweden)

    Ewa Sawosz

    2015-10-01

    Full Text Available Our previous studies revealed that graphene had anticancer properties in experiments in vitro with glioblastoma multiforme (GBM cells and in tumors cultured in vivo. We hypothesized that the addition of arginine or proline to graphene solutions might counteract graphene agglomeration and increase the activity of graphene. Experiments were performed in vitro with GBM U87 cells and in vivo with GBM tumors cultured on chicken embryo chorioallantoic membranes. The measurements included cell morphology, mortality, viability, tumor morphology, histology, and gene expression. The cells and tumors were treated with reduced graphene oxide (rGO and rGO functionalized with arginine (rGO + Arg or proline (rGO + Pro. The results confirmed the anticancer effect of graphene on GBM cells and tumor tissue. After functionalization with amino acids, nanoparticles were distributed more specifically, and the flakes of graphene were less agglomerated. The molecule of rGO + Arg did not increase the expression of TP53 in comparison to rGO, but did not increase the expression of MDM2 or the MDM2/TP53 ratio in the tumor, suggesting that arginine may block MDM2 expression. The expression of NQO1, known to be a strong protector of p53 protein in tumor tissue, was greatly increased. The results indicate that the complex of rGO + Arg has potential in GBM therapy.

  19. Graphene Functionalized with Arginine Decreases the Development of Glioblastoma Multiforme Tumor in a Gene-Dependent Manner

    Science.gov (United States)

    Sawosz, Ewa; Jaworski, Sławomir; Kutwin, Marta; Vadalasetty, Krishna Prasad; Grodzik, Marta; Wierzbicki, Mateusz; Kurantowicz, Natalia; Strojny, Barbara; Hotowy, Anna; Lipińska, Ludwika; Jagiełło, Joanna; Chwalibog, André

    2015-01-01

    Our previous studies revealed that graphene had anticancer properties in experiments in vitro with glioblastoma multiforme (GBM) cells and in tumors cultured in vivo. We hypothesized that the addition of arginine or proline to graphene solutions might counteract graphene agglomeration and increase the activity of graphene. Experiments were performed in vitro with GBM U87 cells and in vivo with GBM tumors cultured on chicken embryo chorioallantoic membranes. The measurements included cell morphology, mortality, viability, tumor morphology, histology, and gene expression. The cells and tumors were treated with reduced graphene oxide (rGO) and rGO functionalized with arginine (rGO + Arg) or proline (rGO + Pro). The results confirmed the anticancer effect of graphene on GBM cells and tumor tissue. After functionalization with amino acids, nanoparticles were distributed more specifically, and the flakes of graphene were less agglomerated. The molecule of rGO + Arg did not increase the expression of TP53 in comparison to rGO, but did not increase the expression of MDM2 or the MDM2/TP53 ratio in the tumor, suggesting that arginine may block MDM2 expression. The expression of NQO1, known to be a strong protector of p53 protein in tumor tissue, was greatly increased. The results indicate that the complex of rGO + Arg has potential in GBM therapy. PMID:26512645

  20. Dimethyl Fumarate Protects Pancreatic Islet Cells and Non-Endocrine Tissue in L-Arginine-Induced Chronic Pancreatitis

    Science.gov (United States)

    Robles, Lourdes; Vaziri, Nosratola D.; Li, Shiri; Masuda, Yuichi; Takasu, Chie; Takasu, Mizuki; Vo, Kelly; Farzaneh, Seyed H.; Stamos, Michael J.; Ichii, Hirohito

    2014-01-01

    Background Chronic pancreatitis (CP) is a progressive disorder resulting in the destruction and fibrosis of the pancreatic parenchyma which ultimately leads to impairment of the endocrine and exocrine functions. Dimethyl Fumarate (DMF) was recently approved by FDA for treatment of patients with multiple sclerosis. DMF's unique anti-oxidant and anti-inflammatory properties make it an interesting drug to test on other inflammatory conditions. This study was undertaken to determine the effects of DMF on islet cells and non-endocrine tissue in a rodent model of L-Arginine-induced CP. Methods Male Wistar rats fed daily DMF (25 mg/kg) or vehicle by oral gavage were given 5 IP injections of L-Arginine (250 mg/100 g×2, 1 hr apart). Rats were assessed with weights and intra-peritoneal glucose tolerance tests (IPGTT, 2 g/kg). Islets were isolated and assessed for islet mass and viability with flow cytometry. Non-endocrine tissue was assessed for histology, myeloperoxidase (MPO), and lipid peroxidation level (MDA). In vitro assessments included determination of heme oxygenase (HO-1) protein expression by Western blot. Results Weight gain was significantly reduced in untreated CP group at 6 weeks. IPGTT revealed significant impairment in untreated CP group and its restoration with DMF therapy (P L-Arginine-induced CP and islet function in rats. DMF treatment could be a possible strategy to improve clinical outcome in patients with CP. PMID:25198679

  1. Oligomerization and chaperone-like activity of Drosophila melanogaster small heat shock protein DmHsp27 and three arginine mutants in the alpha-crystallin domain.

    Science.gov (United States)

    Moutaoufik, Mohamed Taha; Morrow, Geneviève; Maaroufi, Halim; Férard, Céline; Finet, Stéphanie; Tanguay, Robert M

    2017-07-01

    The small Hsp DmHsp27 from Drosophila melanogaster is one of the few small heat shock proteins (sHsps) found within the nucleus. We report that its dimerization is independent of disulfide bond formation and seems to rely on salt bridges. Unlike metazoan sHsps, DmHsp27 forms two populations of oligomers not in equilibrium. Mutations at highly conserved arginine residues in mammalian sHsps have been reported to be associated with protein conformational defects and intracellular aggregation. Independent mutation of three highly conserved arginines (R122, R131, and R135) to glycine in DmHsp27 results in only one population of higher molecular weight form. In vitro, the chaperone-like activity of wild-type DmHsp27 was comparable with that of its two isolated populations and to the single population of the R122G, R131G, and R135G using luciferase as substrate. However, using insulin, the chaperone-like activity of wild-type DmHsp27 was lower than that of R122G and R131G mutants. Altogether, the results characterize wild-type DmHsp27 and its alpha-crystallin domain (ACD) arginine mutants and may give insight into protection mechanism of sHsps.

  2. l-Arginine modulates neonatal lymphocyte proliferation through an interleukin-2 independent pathway

    Science.gov (United States)

    Yu, Hong-Ren; Kuo, Ho-Chang; Huang, Li-Tung; Chen, Chih-Cheng; Tain, You-Lin; Sheen, Jiunn-Ming; Tiao, Mao-Meng; Huang, Hsin-Chun; Yang, Kuender D; Ou, Chia-Yo; Hsu, Te-Yao

    2014-01-01

    In cases of arginine depletion, lymphocyte proliferation, cytokine production and CD3ζ chain expression are all diminished. In addition to myeloid suppressor cells, polymorphonuclear cells (PMN) also exert T-cell immune suppressive effects through arginase-induced l-arginine depletion, especially during pregnancy. In this study, we investigated how arginase/l-arginine modulates neonatal lymphocyte proliferation. Results showed that the neonatal plasma l-arginine level was lower than in adults (48·1 ± 11·3 versus 86·5 ± 14·6 μm; P = 0·003). Neonatal PMN had a greater abundance of arginase I protein than adult PMN. Both transcriptional regulation and post-transcriptional regulation were responsible for the higher arginase I expression of neonatal PMN. Exogenous l-arginine enhanced neonate lymphocyte proliferation but not that of adult cells. The RNA-binding protein HuR was important but was not the only modulation factor in l-arginine-regulated neonatal T-cell proliferation. l-Arginine-mediated neonatal lymphocyte proliferation could not be blocked by interleukin-2 receptor blocking antibodies. These results suggest that the altered arginase/l-arginine cascade may be one of the mechanisms that contribute to altered neonatal immune responses. Exogenous l-arginine could enhance neonate lymphocyte proliferation through an interleukin-2-independent pathway. PMID:24697328

  3. Supplementation with l-arginine stabilizes plasma arginine and nitric oxide metabolites, suppresses elevated liver enzymes and peroxidation in sickle cell anaemia.

    Science.gov (United States)

    Jaja, S I; Ogungbemi, S O; Kehinde, M O; Anigbogu, C N

    2016-06-01

    The effect of l-arginine on liver function in SCD has received little or no attention. The effect of a chronic, oral, low-dose supplementation with l-arginine (1gm/day for 6 weeks) on some liver enzymes, lipid peroxidation and nitric oxide metabolites was studied in 20 normal (non-sickle cell anaemia; NSCA) subjects and 20 sickle cell anaemia (SCA) subjects. Ten milliliters of blood was withdrawn from an ante-cubital vein for the estimation of plasma arginine concentration ([R]), alanine aminotransaminase (ALT), aspartate aminotransaminase (AST) and alkaline phosphatase (ALP), plasma total bilirubin concentration [TB], malondialdehyde concentration [MDA] and nitric oxide metabolites concentration [NOx]. Before supplementation, ALT, AST, ALP (pSupplementation caused greater percent increases in [R], and [NOX] in SCA than in NSCA subjects (pl-Arginine caused greater percent reductions in ALT and AST in SCA subjects but greater percent reduction in ALP in NSCA subjects (psupplementation with l-arginine improved liver function, oxidative stress, plasma arginine concentration and nitric oxide metabolites levels in NSCA and SCA subjects. Responses in SCA subjects to l-arginine were more sensitive than in NSCA subjects. Copyright © 2016 Elsevier B.V. All rights reserved.

  4. L-Arginine oxidase from Pseudomonas sp. TPU 7192: Characterization, gene cloning, heterologous expression, and application to L-arginine determination.

    Science.gov (United States)

    Matsui, Daisuke; Terai, Anna; Asano, Yasuhisa

    2016-01-01

    L-Arginine oxidase (AROD, EC 1.4.3.-) was discovered in newly discovered Pseudomonas sp. TPU 7192 and its characteristics were described. The molecular mass (MS) of the enzyme was estimated to be 528 kDa, which was accounted for by eight identical subunits with MS of 66 kDa each. AROD was identified as a flavin adenine dinucleotide (FAD)-dependent enzyme with 1 mol of FAD being contained in each subunit. It catalyzed the oxidative deamination of L-arginine and converted L-arginine to 2-ketoarginine, which was non-enzymatically converted into 4-guanidinobutyric acid when the hydrogen peroxide (H2O2) formed by L-arginine oxidation was not removed. In contrast, 2-ketoarginine was present when H2O2was decomposed. AROD was specific to L-arginine with a Km value of 149 μM. It exhibited maximal activity at 55 °C and pH 5.5. AROD was stable in the pH range 5.5-7.5 and >95% of its original activity was below 60 °C at pH 7.0. Since these enzymatic properties are considered suitable for the determination of L-arginine, the gene was cloned and expressed in a heterologous expression system. We herein successfully developed a new simple enzymatic method for the determination of L-arginine using Pseudomonas AROD. Copyright © 2015 Elsevier Inc. All rights reserved.

  5. Oral L-arginine supplementation in patients with mild arterial hypertension and its effect on plasma level of asymmetric dimethylarginine, L-citruline, L-arginine and antioxidant status.

    Science.gov (United States)

    Jabecka, A; Ast, J; Bogdaski, P; Drozdowski, M; Pawlak-Lemaska, K; Cielewicz, A R; Pupek-Musialik, D

    2012-11-01

    Potential role of L-arginine supplementation as a new effective strategy of improving endothelial function in patients with hypertension is recently under consideration. To evaluate influence of 28-day oral supplementation of L-arginine on plasma level of asymmetric dimethylarginine (ADMA), L-citrulline, L-arginine and total antioxidant status (TAS), in patients with mild arterial hypertension. 54 participants (24 women and 30 men) were studied. Ambulatory blood pressure monitoring (ABPM) was used for allotting patients to either healthy control group (19 subjects) or hypertensive treatment group (35 patients). Patients were later randomized to either L-arginine (2 g tid or 4 g tid) or placebo. During 28 days of study on 5 consecutive visits TAS, plasma level of ADMA, L-citrulline, and L-arginine were measured. In patients with mild hypertension treated with L-arginine significant increase in TAS and plasma level of arginine and citrulline was observed. Additionally plasma ADMA concentrations after 28 days of L-arginine supplementation significantly exceeded initial concentrations. L-arginine supplementation increases plasma arginine, citrulline and TAS in patients with mild arterial hypertension. It confirms the thesis that augmented concentrations of L-arginine stimulate NO biosynthesis which leads to reduction of oxidative stress. Increase of ADMA plasma level after L-arginine supplementation confirms correlation between ADMA and L-arginine.

  6. The orthologue of the "acatalytic" mammalian ART4 in chicken is an arginine-specific mono-ADP-ribosyltransferase

    Directory of Open Access Journals (Sweden)

    Berndt Angela

    2008-10-01

    Full Text Available Abstract Background Human ART4, carrier of the GPI-(glycosyl-phosphatidylinositol anchored Dombrock blood group antigens, is an apparently inactive member of the mammalian mono-ADP-ribosyltransferase (ART family named after the enzymatic transfer of a single ADP-ribose moiety from NAD+ to arginine residues of extracellular target proteins. All known mammalian ART4 orthologues are predicted to lack ART activity because of one or more changes in essential active site residues that make up the R-S-EXE motif. So far, no other function has been detected. Results Here we report the identification and characterisation of ART4 in chicken, which to our knowledge is the first true non-mammalian orthologue of a mammalian ART family member. The chicken ART4 gene has the same physical structure as its mammalian counterparts (three coding exons separated by two introns in phase 0 and phase 1, respectively and maps to a region of conserved linkage synteny on chromosome 1. Its mRNA encodes a 289 amino acid protein with predicted N-terminal signal peptide and C-terminal GPI-anchor sequences and 47% sequence identity to human ART4. However, in striking contrast to its mammalian orthologues, the chicken protein contains an intact R-S-EXE motif. Upon ectopic expression in C-33A cells, recombinant chicken ART4 localized at the cell surface as a GPI-anchored, highly glycosylated protein, which displayed arginine-specific ART activity (apparent Km of the recombinant protein for etheno-NAD+ 1.0 ± 0.18 μM. Conclusion The avian orthologue of the "acatalytic" mammalian ART4 is a mono-ADP-ribosyltransferase with enzymatic activity comparable to that of other, catalytically active and GPI-anchored members of the mammalian ART family.

  7. Neutral loss fragmentation pattern based screening for arginine-rich natural products in Xenorhabdus and Photorhabdus.

    Science.gov (United States)

    Fuchs, Sebastian W; Sachs, Christian C; Kegler, Carsten; Nollmann, Friederike I; Karas, Michael; Bode, Helge B

    2012-08-21

    Although sharing a certain degree of structural uniformity, natural product classes exhibit variable functionalities such as different amino acid or acyl residues. During collision induced dissociation, some natural products exhibit a conserved fragmentation pattern close to the precursor ion. The observed fragments result from a shared set of neutral losses, creating a unique fragmentation pattern, which can be used as a fingerprint for members of these natural product classes. The culture supernatants of 69 strains of the entomopathogenic bacteria Photorhabdus and Xenorhabdus were analyzed by MALDI-MS(2), and a database comprising MS(2) data from each strain was established. This database was scanned for concordant fragmentation patterns of different compounds using a customized software, focusing on relative mass differences of the fragment ions to their precursor ion. A novel group of related natural products comprising 25 different arginine-rich peptides from 16 different strains was identified due to its characteristic neutral loss fragmentation pattern, and the structures of eight compounds were elucidated. Two biosynthesis gene clusters encoding nonribosomal peptide synthetases were identified, emphasizing the possibility to identify a group of structurally and biosynthetically related natural products based on their neutral loss fragmentation pattern.

  8. Purification, cloning, and immunological characterization of arginine kinase, a novel allergen of Octopus fangsiao.

    Science.gov (United States)

    Shen, Hai-Wang; Cao, Min-Jie; Cai, Qiu-Feng; Ruan, Mi-Mi; Mao, Hai-Yan; Su, Wen-Jin; Liu, Guang-Ming

    2012-03-07

    Arginine kinase (AK) is an important enzyme participating in energy metabolism in invertebrates, but, to date, there have been no reports that AK from octopus is an allergen. In this study, octopus AK was purified, and its molecular biological, immunological, and physicochemical characterizations were analyzed. The results showed that octopus AK was purified and confirmed by mass spectrometry for the first time, and its molecular mass was 38 kDa. The full-length gene sequence of octopus AK encompassed 1209 bp and was predicted to encode a protein with 348 amino acid residues. The homology of octopus AK and crustacean AK was about 54%, but the similarity between their three-dimensional structures was high. Octopus AK could react with mouse anti-shrimp AK and rabbit anti-crab AK polyclonal antibody singly. Octopus AK could also react with specific IgE of the sera from octopus-allergic patients effectively, whereas crab AK could inhibit the reaction between them. Finally, the IgE-binding activity of octopus AK could be reduced in the processes of thermal or acid-alkali treatment. In summary, AK was identified as a novel allergen in octopus, which had a sensitizing ability similar to that of crustacean AK. This is significant in allergy diagnosis and the treatment of octopus-allergic disorders.

  9. Exercise-induced Protein Arginine Methyltransferase Expression in Skeletal Muscle.

    Science.gov (United States)

    Vanlieshout, Tiffany L; Stouth, Derek W; Tajik, Tania; Ljubicic, Vladimir

    2018-03-01

    This study aimed to determine protein arginine methyltransferase 1 (PRMT1), -4 (also known as coactivator-associated arginine methyltransferase 1 [CARM1]), and -5 expression and function during acute, exercise-induced skeletal muscle remodeling in vivo. C57BL/6 mice were assigned to one of three experimental groups: sedentary, acute bout of exercise, or acute exercise followed by 3 h of recovery. Mice in the exercise groups performed a single bout of treadmill running at 15 m·min for 90 min. Hindlimb muscles were collected, and quantitative real-time polymerase chain reaction and Western blotting were used to examine exercise-induced gene expression. The PRMT gene expression and global enzyme activity were muscle-specific, generally being higher (P < 0.05) in slow, oxidative muscle, as compared with faster, more glycolytic tissue. Despite the significant activation of canonical exercise-induced signaling involving AMP-activated protein kinase and peroxisome proliferator-activated receptor γ coactivator-1α (PGC-1α), PRMT expression and activity at the whole muscle level were unchanged. However, subcellular analyses revealed a significant exercise-evoked myonuclear translocation of PRMT1 before the nuclear accumulation of PGC-1α. Acute physical activity also augmented (P < 0.05) the targeted methyltransferase activities of the PRMT in the myonuclear compartment, suggesting that PRMT-mediated histone arginine methylation is part of the early signals that drive muscle plasticity. Finally, basal PGC-1α asymmetric dimethylarginine status, as well as constitutive interactions between PGC-1α and PRMT1 or CARM1 may contribute to the exercise-induced muscle remodeling process. The present study provides the first evidence that PRMT activity is selectively augmented during the initial activation of exercise-induced skeletal muscle remodeling in vivo. These data support the emergence of PRMTs as important players in the regulation of skeletal muscle plasticity.

  10. A new arginine-based dental adhesive system: formulation, mechanical and anti-caries properties.

    Science.gov (United States)

    Geraldeli, Saulo; Soares, Eveline F; Alvarez, Andres J; Farivar, Tanaz; Shields, Robert C; Sinhoreti, Mario A C; Nascimento, Marcelle M

    2017-08-01

    Secondary caries at the margins of composite restorations has been attributed to adhesive failure and consequent accumulation of cariogenic biofilms. To develop and evaluate an etch-and-rinse adhesive system containing arginine for sustainable release and recharge without affecting its mechanical properties. Arginine metabolism by oral bacteria generates ammonia, which neutralizes glycolytic acids and creates a neutral environmental pH that is less favorable to the growth of caries pathogens, thus reducing the caries risk at the tooth-composite interface. Experimental adhesives were formulated with methacrylate monomers and arginine at 5%, 7%, and 10% or no arginine (control). Adhesives were tested for: (i) mechanical properties of true stress (FS and UTS), modulus of elasticity (E), degree of conversion (DC), Knoop hardness number (KHN) and dentin microtensile bond strength (μ-TBS), (ii) arginine release and recharge, and (iii) antibacterial activities. Data was analyzed by t-test, one-way ANOVA and Tukey's tests. FS and UTS results showed no statistically significant differences between the 7% arginine-adhesive and control, while the results for E, DC, KHN and μ-TBS showed no difference among all groups. The 7% arginine-adhesive showed a high release rate of arginine (75.0μmol/cm 2 ) at 2h, and a more sustainable, controlled release rate (up to 0.2μmol/cm 2 ) at 30days. Incorporation of 7% arginine did not affect the physical and mechanical properties of the adhesive. Arginine was released from the adhesive at a rate and concentration that exhibited antibacterial effects, regardless of shifts in biofilm conditions such as sugar availability and pH. Secondary caries is recognized as the main reason for failure of dental restorations. The development of an arginine-based adhesive system has the potential to dramatically reduce the incidence and severity of secondary caries in adhesive restorations in a very economical fashion. Copyright © 2017 Elsevier Ltd

  11. Effects of arginine and phytogenic additive supplementation on performance and health of brown-egg layers

    Directory of Open Access Journals (Sweden)

    Vitor Barbosa Fascina

    Full Text Available ABSTRACT This study was performed to evaluate the effects of the association of different digestible arginine and phytogenic additive dietary levels on performance and health status of brown-egg layers. In this study, a total of 504 33-week-old Hisex Brown layers were distributed into a completely randomized experimental design to a 4 × 3 factorial arrangement (dietary digestible arginine levels: 880, 968, 1056, or 1144 mg/kg of feed × phytogenic additive levels: 0, 100, and 200 mg/kg of feed with six replicate cages of seven birds per cage. The phytogenic additive was composed of extracts of Baccharis dracunculifolia (40%, Astragalus membranaceus lipopolysaccharides (20%, cinnamon, and grape seed (20%. Feed intake was reduced when diets containing 1056 mg of arginine were supplemented with 100 or 200 mg phytogenic additive per kg. Feed conversion ratio was improved when diets were supplemented with 100 mg of phytogenic additive or with 1056 mg of arginine per kg of feed. Egg mass was increased when diets were supplemented with 1056 mg arginine per kg of feed. Arginine supplementation quadratically increased albumen percentage and reduced yolk percentage. Higher arginine and phytogenic additive levels reduced heterophyl:lymphocyte ratio and blood uric acid, total cholesterol, very-low density lipoprotein, and triglyceride levels. Dietary supplementation of 100 mg of phytogenic additive associated with high arginine levels increased nitric oxide production by peritoneal macrophages and 1056 mg of arginine increased antibodies titers against Newcastle disease virus. Blood and intestinal malonaldehyde levels were reduced when 200 mg of the phytogenic additive was added. Dietary supplementation of 968 mg of arginine or 100 mg of a phytogenic additive (40% Baccharis dracunculifolia, 20% Astragalus membranaceus, 20% cinnamon, and 20% grape seed extracts per kilogram of diet improves the feed conversion ratio and associated inclusion of 1144 mg of

  12. L-arginine prevents hypoxia-induced vasoconstriction in dual-perfused human placental cotyledons.

    Science.gov (United States)

    Bednov, Andrey; Espinoza, Jimmy; Betancourt, Ancizar; Vedernikov, Yuri; Belfort, Michael; Yallampalli, Chandrasekhar

    2015-11-01

    Chronic hypoxia in the uteroplacental unit is associated with increased resistance to blood flow in the fetal-placental circulation. These changes can lead to adverse cardiovascular events in adulthood. This study investigates whether L-arginine (substrate for nitric oxide synthase (NOS) or endothelin-A receptor antagonist BQ123 administration reverses hypoxia-induced changes in perfusion pressure in the fetal compartment in dual-perfused placental cotyledons. Human placental cotyledons (n = 15) from term deliveries (n = 15) were perfused with Krebs solution from maternal and fetal sides. Normal and reduced oxygen tension conditions were sequentially created in the perfused maternal compartment. Fetal perfusion pressure was continuously monitored. 1 mM L-arginine, D-arginine (an enantiomer of L-arginine and not a substrate for NOS), and BQ123 or normal saline were administered to the fetal compartment; L-arginine was also administered to the maternal compartment prior to maternal side hypoxia. Changes in perfusion pressure were compared between groups. Maternal hypoxia increased (19 ± 6%) perfusion pressure and this was blunted by L-arginine injection (3 ± 5%; p = 0.006) into the fetal compartment. L-arginine in the maternal compartment had no significant effect (22 ± 4% with L-arginine vs.14 ± 3% at control) on perfusion pressure. Similarly, D-arginine (23 ± 11% vs.19 ± 8% at control) or BQ123 (12 ± 3% vs.13 ± 3% at control) in the fetal compartment did not blunt the hypoxia-induced increase in perfusion pressure. Fetal vasoconstriction induced by maternal hypoxia is blunted by NO synthase substrate L-arginine, but not by D-arginine, in the fetal compartment, suggesting the involvement of NO synthesis in regulating the hypoxia-induced fetal vasoconstriction. Endothelin A receptor-related mechanisms does not appear to play a role in the maternal hypoxia-induced fetal vasoconstriction. Copyright © 2015 Elsevier Ltd. All rights reserved.

  13. Effect of l-arginine therapy on plasma NO/sub 2/ and NO/sub 3/ levels, and blood pressure in uremic rabbits

    International Nuclear Information System (INIS)

    Hanif, M.; Khemomal, A.

    2011-01-01

    Background: Normal kidney function is regulated by Nitric oxide (NO) and Superoxide (O/sub 2/-) in the body, and consequently controls blood pressure. Nitric Oxide promotes natriuresis and diuresis, and therefore results in reduction of blood pressure. The objective of this study was to determine the effect of L-arginine supplementation on blood pressure, urinary protein, nitrite and nitrate in addition to blood urea, serum creatinine and creatinine clearance in uremic rabbits. Methods: This study was carried out in the Department of Biochemistry Basic Medical Sciences Institute, Jinnah Postgraduate Medical Centre, Karachi. A total of 48 rabbits were included in the study. Twenty-four of the rabbits on surgical intervention were prepared as uremic and so became hypertensive as well. Two groups were uremic, one group was given L-arginine and the other was remained untreated. Systolic and diastolic blood pressure was measured on week 0, week 2, week 4, and week 6, while blood and urine was collected on week 0 and week 6. Results: On supplementation with L-arginine to uremic rabbits systolic and diastolic blood pressures were decreased significantly. Nitrite/nitrate and urinary protein were corrected to some extent while blood urea and serum creatinine were unaffected. Conclusion: L-arginine has a beneficial role as blood pressure lowering agent in uremic rabbits. It corrects NO/sub 2/NO/sub 3/ plasma level and proteinuria which is indicator of renal failure. (author)

  14. Nitric oxide donors (nitrates), L-arginine, or nitric oxide synthase inhibitors for acute stroke.

    Science.gov (United States)

    Bath, Philip Mw; Krishnan, Kailash; Appleton, Jason P

    2017-04-21

    Nitric oxide (NO) has multiple effects that may be beneficial in acute stroke, including lowering blood pressure, and promoting reperfusion and cytoprotection. Some forms of nitric oxide synthase inhibition (NOS-I) may also be beneficial. However, high concentrations of NO are likely to be toxic to brain tissue. This is an update of a Cochrane review first published in 1998, and last updated in 2002. To assess the safety and efficacy of NO donors, L-arginine, and NOS-I in people with acute stroke. We searched the Cochrane Stroke Group Trials Register (last searched 6 February 2017), MEDLINE (1966 to June 2016), Embase (1980 to June 2016), ISI Science Citation Indexes (1981 to June 2016), Stroke Trials Registry (searched June 2016), International Standard Randomised Controlled Trial Number (ISRCTN) (searched June 2016), Clinical Trials registry (searched June 2016), and International Clinical Trials Registry Platform (ICTRP) (searched June 2016). Previously, we had contacted drug companies and researchers in the field. Randomised controlled trials comparing nitric oxide donors, L-arginine, or NOS-I versus placebo or open control in people within one week of onset of confirmed stroke. Two review authors independently applied the inclusion criteria, assessed trial quality and risk of bias, and extracted data. The review authors cross-checked data and resolved issues through discussion. We obtained published and unpublished data, as available. Data were reported as mean difference (MD) or odds ratio (OR) with 95% confidence intervals (CI). We included five completed trials, involving 4197 participants; all tested transdermal glyceryl trinitrate (GTN), an NO donor. The assessed risk of bias was low across the included studies; one study was double-blind, one open-label and three were single-blind. All included studies had blinded outcome assessment. Overall, GTN did not improve the primary outcome of death or dependency at the end of trial (modified Rankin Scale (m

  15. Bioinformatic evaluation of L-arginine catabolic pathways in 24 cyanobacteria and transcriptional analysis of genes encoding enzymes of L-arginine catabolism in the cyanobacterium Synechocystis sp. PCC 6803

    OpenAIRE

    Schriek, Sarah; R?ckert, Christian; Staiger, Dorothee; Pistorius, Elfriede K; Michel, Klaus-Peter

    2007-01-01

    Abstract Background So far very limited knowledge exists on L-arginine catabolism in cyanobacteria, although six major L-arginine-degrading pathways have been described for prokaryotes. Thus, we have performed a bioinformatic analysis of possible L-arginine-degrading pathways in cyanobacteria. Further, we chose Synechocystis sp. PCC 6803 for a more detailed bioinformatic analysis and for validation of the bioinformatic predictions on L-arginine catabolism with a transcript analysis. Results W...

  16. Solidification process for sludge residue

    International Nuclear Information System (INIS)

    Pearce, K.L.

    1998-01-01

    This report investigates the solidification process used at 100-N Basin to solidify the N Basin sediment and assesses the N Basin process for application to the K Basin sludge residue material. This report also includes a discussion of a solidification process for stabilizing filters. The solidified matrix must be compatible with the Environmental Remediation Disposal Facility acceptance criteria

  17. Interactions between L-arginine/L-arginine derivatives and lysozyme and implications to their inhibition effects on protein aggregation.

    Science.gov (United States)

    Gao, Ming-Tao; Dong, Xiao-Yan; Sun, Yan

    2013-01-01

    L-arginine (Arg), L-homoarginine (HArg), L-arginine ethylester (ArgEE), and L-arginine methylester (ArgME) were found effective in inhibiting protein aggregation, but the molecular mechanisms are not clear. Herein, stopped-flow fluorescence spectroscopy, isothermal titration calorimetry, and mass spectroscopy were used to investigate the folding kinetics of lysozyme and the interactions of the additives with lysozyme. It was found that the interactions of ArgME and ArgEE with lysozyme were similar to that of guanidine hydrochloride and were much stronger than those of Arg and HArg. The binding forces were all mainly hydrogen bonding and cation-π interaction from the guanidinium group, but their differences in molecular states led to the significantly different binding strengths. The additives formed molecular clusters in an increasing order of ArgEE, ArgME, HArg, and Arg. Arg and HArg mainly formed annular clusters with head-to-tail bonding, while ArgME and ArgEE formed linear clusters with guanidinium groups stacking. The interactions between the additives and lysozyme were positively related to the monomer contents. That is, the monomers were the primary species that participated in the direct interactions due to their intact guanidinium groups and small sizes, while the clusters performed as barriers to crowd out the protein-protein interactions for aggregation. Thus, it is concluded that the effects of Arg and its derivatives on protein aggregation stemmed from the direct interactions by the monomers and the crowding effects by the clusters. Interplay of the two effects led to the differences in their inhibition effects on protein aggregation. © 2013 American Institute of Chemical Engineers.

  18. Synthesis, characterization and behaviour of trans-bis (argininate) copper (II) to gamma radiation

    International Nuclear Information System (INIS)

    Pereira, A.B.

    1984-01-01

    The synthesis, the characterization and the behaviour to gamma radiation of trans-bis (argininate) copper (II) are presented. The synthesis is made from copper sulfate, sodium hydroxide and hydrochloride of L (+) arginine, in aqueous medium, and the characterization by infrared spectroscopy, visible and ultraviolet spectroscopy and elementary analysis. (C.G.C.)

  19. Enteral L-Arginine and Glutamine Supplementation for Prevention of NEC in Preterm Neonates

    Directory of Open Access Journals (Sweden)

    M. S. El-Shimi

    2015-01-01

    Full Text Available Objective. Evaluating the efficacy and safety of arginine and glutamine supplementation in decreasing the incidence of NEC among preterm neonates. Methods. Prospective case-control study done on 75 preterm neonates ≤34 weeks, divided equally into L-arginine group receiving enteral L-arginine, glutamine group receiving enteral glutamine, and control group. Serum L-arginine and glutamine levels were measured at time of enrollment (sample 1, after 14 days of enrollment (sample 2, and at time of diagnosis of NEC (sample 3. Results. The incidence of NEC was 9.3%. There was no difference in the frequency of NEC between L-arginine and control groups (P>0.05. NEC was not detected in glutamine group; L-arginine concentrations were significantly lower in arginine group than control group in both samples while glutamine concentrations were comparable in glutamine and control groups in both samples. No significant difference was found between groups as regards number of septic episodes, duration to reach full oral intake, or duration of hospital stay. Conclusion. Enteral L-arginine supplementation did not seem to reduce the incidence of NEC. Enteral glutamine may have a preventive role against NEC if supplied early to preterm neonates. However, larger studies are needed to confirm these findings. This work is registered in ClinicalTrials.gov (ClinicalTrials.gov Identifier: NCT01263041.

  20. Arginine supplementation in four patients with X-linked creatine transporter defect

    NARCIS (Netherlands)

    Fons, C.; Sempere, A.; Arias, A.; Lopez-Sala, A.; Poo, P.; Pineda, M.; Mas, A.; Vilaseca, M.A.; Salomons, G.S.; Ribes, A.; Artuch, R.; Campistol, J.

    2008-01-01

    Background: Treatment with oral creatine monohydrate has not shown efficacy in patients with creatine transporter deficiency (CRTR-D). Another therapeutic option proposed is L-arginine, the substrate for the enzyme L-arginine:glycine amidinotransferase (AGAT). We evaluate clinical characteristics

  1. Abnormal Mitochondrial L-Arginine Transport Contributes to the Pathogenesis of Heart Failure and Rexoygenation Injury

    Science.gov (United States)

    Byrne, Melissa; Joshi, Mandar; Horlock, Duncan; Lam, Nicholas T.; Gregorevic, Paul; McGee, Sean L.; Kaye, David M.

    2014-01-01

    Background Impaired mitochondrial function is fundamental feature of heart failure (HF) and myocardial ischemia. In addition to the effects of heightened oxidative stress, altered nitric oxide (NO) metabolism, generated by a mitochondrial NO synthase, has also been proposed to impact upon mitochondrial function. However, the mechanism responsible for arginine transport into mitochondria and the effect of HF on such a process is unknown. We therefore aimed to characterize mitochondrial L-arginine transport and to investigate the hypothesis that impaired mitochondrial L-arginine transport plays a key role in the pathogenesis of heart failure and myocardial injury. Methods and Results In mitochondria isolated from failing hearts (sheep rapid pacing model and mouse Mst1 transgenic model) we demonstrated a marked reduction in L-arginine uptake (pL-arginine transporter, CAT-1 (pL-arginine transport in modulating cardiac stress responses was examined in cardiomyocytes with mitochondrial specific overexpression of CAT-1 (mtCAT1) exposed to hypoxia-reoxygenation stress. mtCAT1 cardiomyocytes had significantly improved mitochondrial membrane potential, respiration and ATP turnover together with significantly decreased reactive oxygen species production and cell death following mitochondrial stress. Conclusion These data provide new insights into the role of L-arginine transport in mitochondrial biology and cardiovascular disease. Augmentation of mitochondrial L-arginine availability may be a novel therapeutic strategy for myocardial disorders involving mitochondrial stress such as heart failure and reperfusion injury. PMID:25111602

  2. The do's and don'ts of arginine supplementation | Chetty | South ...

    African Journals Online (AJOL)

    In the last three decades the nutritional and pharmacologic effects of arginine have been the subject of intense investigation. Taking into consideration the many benefits that have been demonstrated from arginine supplementation, the question remains: “Can we afford not to supplement with this immuno-nutrient”.

  3. The ArcD1 and ArcD2 arginine/ornithine exchangers encoded in the arginine deiminase (ADI) pathway gene cluster of Lactococcus lactis

    NARCIS (Netherlands)

    Noens, Elke E E; Kaczmarek, Michał B; Żygo, Monika; Lolkema, Juke S

    2015-01-01

    The arginine deiminase pathway (ADI) gene cluster in Lactococcus lactis contains two copies of a gene encoding an L-arginine/L-ornithine exchanger, the arcD1 and arcD2 genes. The physiological function of ArcD1 and ArcD2 was studied by deleting the two genes. Deletion of arcD1 resulted in loss of

  4. Global proteomic analysis in trypanosomes reveals unique proteins and conserved cellular processes impacted by arginine methylation.

    Science.gov (United States)

    Lott, Kaylen; Li, Jun; Fisk, John C; Wang, Hao; Aletta, John M; Qu, Jun; Read, Laurie K

    2013-10-08

    Arginine methylation is a common posttranslational modification with reported functions in transcription, RNA processing and translation, and DNA repair. Trypanosomes encode five protein arginine methyltransferases, suggesting that arginine methylation exerts widespread impacts on the biology of these organisms. Here, we performed a global proteomic analysis of Trypanosoma brucei to identify arginine methylated proteins and their sites of modification. Using an approach entailing two-dimensional chromatographic separation and alternating electron transfer dissociation and collision induced dissociation, we identified 1332 methylarginines in 676 proteins. The resulting data set represents the largest compilation of arginine methylated proteins in any organism to date. Functional classification revealed numerous arginine methylated proteins involved in flagellar function, RNA metabolism, DNA replication and repair, and intracellular protein trafficking. Thus, arginine methylation has the potential to impact aspects of T. brucei gene expression, cell biology, and pathogenesis. Interestingly, pathways with known methylated proteins in higher eukaryotes were identified in this study, but often different components of the pathway were methylated in trypanosomes. Methylarginines were often identified in glycine rich contexts, although exceptions to this rule were detected. Collectively, these data inform on a multitude of aspects of trypanosome biology and serve as a guide for the identification of homologous arginine methylated proteins in higher eukaryotes. T. brucei is a protozoan parasite that causes lethal African sleeping sickness in humans and nagana in livestock, thereby imposing a significant medical and economic burden on sub-Saharan Africa. The parasite encounters very different environments as it cycles between mammalian and insect hosts, and must exert cellular responses to these varying milieus. One mechanism by which all cells respond to changing

  5. Effects of a chronic l-arginine supplementation on the arginase pathway in aged rats.

    Science.gov (United States)

    Moretto, Johnny; Guglielmetti, Anne-Sophie; Tournier-Nappey, Maude; Martin, Hélène; Prigent-Tessier, Anne; Marie, Christine; Demougeot, Céline

    2017-04-01

    While ageing is frequently associated with l-arginine deficiency, clinical and experimental studies provided controversial data on the interest of a chronic l-arginine supplementation with beneficial, no or even deleterious effects. It was hypothesized that these discrepancies might relate to a deviation of l-arginine metabolism towards production of l-ornithine rather than nitric oxide as a result of age-induced increase in arginase activity. This study investigated the effect of ageing on arginase activity/expression in target tissues and determined whether l-arginine supplementation modulated the effect of ageing on arginase activity. Arginase activity and expression were measured in the heart, vessel, brain, lung, kidney and liver in young rats (3-months old) and aged Wistar rats (22-24-months-old) with or without l-arginine supplementation (2.25% in drinking water for 6weeks). Plasma levels of l-arginine and l-ornithine were quantified in order to calculate the plasma l-arginine/l-ornithine ratio, considered as a reflection of arginase activity. Cardiovascular parameters (blood pressure, heart rate) and aortic vascular reactivity were also studied. Ageing dramatically reduced plasma l-arginine and l-arginine/l-ornithine ratio, decreased liver and kidney arginase activities but did not change activities in other tissues. l-Arginine supplementation normalized plasma l-arginine and l-arginine/l-ornithine ratio, improved endothelial function and decreased systolic blood pressure. These effects were associated with decreased arginase activity in aorta along with no change in the other tissues except in the lung in which activity was increased. A strong mismatch was therefore observed between arginase activity and expression in analyzed tissues. The present study reveals that ageing selectively changes arginase activity in clearance tissues, but does not support a role of the arginase pathway in the potential deleterious effect of the l-arginine supplementation in

  6. Agmatine: multifunctional arginine metabolite and magic bullet in clinical neuroscience?

    Science.gov (United States)

    Laube, Gregor; Bernstein, Hans-Gert

    2017-07-26

    Agmatine, the decarboxylation product of arginine, was largely neglected as an important player in mammalian metabolism until the mid-1990s, when it was re-discovered as an endogenous ligand of imidazoline and α 2 -adrenergic receptors. Since then, a wide variety of agmatine-mediated effects have been observed, and consequently agmatine has moved from a wallflower existence into the limelight of clinical neuroscience research. Despite this quantum jump in scientific interest, the understanding of the anabolism and catabolism of this amine is still vague. The purification and biochemical characterization of natural mammalian arginine decarboxylase and agmatinase still are open issues. Nevertheless, the agmatinergic system is currently one of the most promising candidates in order to pharmacologically interfere with some major diseases of the central nervous system, which are summarized in the present review. Particularly with respect to major depression, agmatine, its derivatives, and metabolizing enzymes show great promise for the development of an improved treatment of this common disease. © 2017 The Author(s); published by Portland Press Limited on behalf of the Biochemical Society.

  7. Protein Arginine Methyltransferase 5 as a Driver of Lymphomagenesis

    Science.gov (United States)

    Smith, Porsha Latrice

    Over the past decade, it has become clear that oncogenesis is a process driven by a wide variety of triggers including gene mutations, gene amplifications, inflammation, and immune deficiency. The growing pool of data collected from whole genome and epigenome studies of both solid and blood cancers has pointed toward dysregulation of chromatin remodelers as a unique class of cancer drivers. Next generation sequencing studies of lymphomas have identified a wide array of somatic mutations affecting enzymes that regulate epigenetic control of gene expression. Lymphoma is a type of cancer that originates in secondary lymphoid organs and manifests as an outgrowth of transformed lymphocytes, or white blood cells (WBCs) in the blood. The majority of lymphoma cases can be grouped into the Non-Hodgkins lymphoma (NHL) subset and mainly occurs in B-cells. B-cell NHL is a heterogeneous set of cancers that would benefit from new therapies to improve patient progression-free survival. Cancers such as NHL typically present with a combination of genetic and epigenetic aberrations that contribute to the malignancy program. The epigenetic modifier protein arginine methyltransferase 5 (PRMT5) is required for B-cell transformation following Epstein-Barr virus (EBV) infection, and is overexpressed in various subsets of B-cell NHL. Based on these data we hypothesized that PRMT5 is a major driver of B-cell lymphomagenesis. To explore the role of PRMT5 in the development and progression of B-cell NHL we created a small molecule inhibitors targeted to PRMT5. Using the NHL subset mantle cell lymphoma (MCL) as a model we tested the efficacy of the drug. We discovered that PRMT5 was overexpressed in MCL primary samples and cell lines as compared to normal resting B cells. Furthermore, use of the small molecule inhibitor decreased the proliferation and viability in these cells without affecting the normal B-cells. Additionally, use of inhibitors caused G2/M cell cycle and decreased the

  8. Arginine does not exacerbate markers of inflammation in cocultures of human enterocytes and leukocytes

    DEFF Research Database (Denmark)

    Parlesak, Alexandr; Negrier, I.; Neveux, N.

    2007-01-01

    the catabolism of serine, asparagine, and lysine, and reduced glutamine catabolism. Addition of arginine increased ornithine formation and moderately reduced transepithelial transport of methionine and other amino acids. Hence, arginine supplementation does not interfere with inflammation-associated cross......Enteral arginine supplementation in the critically ill has become a matter of controversy. In this study, we investigated effects of the addition of 0.4 and 1.2 mmol/L arginine in a coculture model on markers of inflammation, enterocyte layer integrity, and amino acid transport. In this model...... with arginine did not affect epithelial integrity, production of any of the cytokines investigated, or the amount of nitric oxide. The amino acid used primarily by nonstimulated intestinal epithelial cells cocultured with leukocytes was glutamine. Activation of IEC with bacteria significantly enhanced...

  9. Potentiality of application of the conductometric L-arginine biosensors for the real sample analysis

    Directory of Open Access Journals (Sweden)

    Jaffrezic-Renault N.

    2012-12-01

    Full Text Available Aim. To determine an influence of serum components on the L-arginine biosensor sensitivity and to formulate practical recommendations for its reliable analysis. Methods. The L-arginine biosensor comprised arginase and urease co-immobilized by cross-linking. Results. The biosensor specificity was investigated based on a series of representative studies (namely, through urea determination in the serum; inhibitory effect studies of mercury ions; high temperature treatment of sensors; studying the biosensor sensitivity to the serum treated by enzymes, and selectivity studies. It was found that the response of the biosensor to the serum injections was determined by high sensitivity of the L-arginine biosensor toward not only to L-arginine but also toward two other basic amino acids (L-lysine and L-histidine. Conclusions. A detailed procedure of optimization of the conductometric biosensor for L-arginine determination in blood serum has been proposed.

  10. Effects of Aging and Tocotrienol-Rich Fraction Supplementation on Brain Arginine Metabolism in Rats

    Directory of Open Access Journals (Sweden)

    Musalmah Mazlan

    2017-01-01

    Full Text Available Accumulating evidence suggests that altered arginine metabolism is involved in the aging and neurodegenerative processes. This study sought to determine the effects of age and vitamin E supplementation in the form of tocotrienol-rich fraction (TRF on brain arginine metabolism. Male Wistar rats at ages of 3 and 21 months were supplemented with TRF orally for 3 months prior to the dissection of tissue from five brain regions. The tissue concentrations of L-arginine and its nine downstream metabolites were quantified using high-performance liquid chromatography and liquid chromatography tandem mass spectrometry. We found age-related alterations in L-arginine metabolites in the chemical- and region-specific manners. Moreover, TRF supplementation reversed age-associated changes in arginine metabolites in the entorhinal cortex and cerebellum. Multiple regression analysis revealed a number of significant neurochemical-behavioral correlations, indicating the beneficial effects of TRF supplementation on memory and motor function.

  11. Preharvest L-arginine treatment induced postharvest disease resistance to Botrysis cinerea in tomato fruits.

    Science.gov (United States)

    Zheng, Yang; Sheng, Jiping; Zhao, Ruirui; Zhang, Jian; Lv, Shengnan; Liu, Lingyi; Shen, Lin

    2011-06-22

    L-arginine is the precursor of nitric oxide (NO). In order to examine the influence of L-arginine on tomato fruit resistance, preharvest green mature tomato fruits (Solanum lycopersicum cv. No. 4 Zhongshu) were treated with 0.5, 1, and 5 mM L-arginine. The reduced lesion size (in diameter) on fruit caused by Botrytis cinerea, as well as activities of phenylalanine ammonia-lyase (PAL), Chitinase (CHI), β-1,3-glucanase (GLU), and polyphenoloxidase (PPO), was compared between L-arginine treated fruits and untreated fruits. We found that induced resistance increased and reached the highest level at 3-6 days after treatment. Endogenous NO concentrations were positively correlated with PAL, PPO, CHI, and GLU activities after treatment with Pearson coefficients of 0.71, 0.94, 0.97, and 0.87, respectively. These results indicate that arginine induces disease resistance via its effects on NO biosynthesis and defensive enzyme activity.

  12. Proteome-wide analysis of arginine monomethylation reveals widespread occurrence in human cells

    DEFF Research Database (Denmark)

    Larsen, Sara C; Sylvestersen, Kathrine B; Mund, Andreas

    2016-01-01

    The posttranslational modification of proteins by arginine methylation is functionally important, yet the breadth of this modification is not well characterized. Using high-resolution mass spectrometry, we identified 8030 arginine methylation sites within 3300 human proteins in human embryonic...... kidney 293 cells, indicating that the occurrence of this modification is comparable to phosphorylation and ubiquitylation. A site-level conservation analysis revealed that arginine methylation sites are less evolutionarily conserved compared to arginines that were not identified as modified...... as coactivator-associated arginine methyltransferase 1 (CARM1)] or PRMT1 increased the RNA binding function of HNRNPUL1. High-content single-cell imaging additionally revealed that knocking down CARM1 promoted the nuclear accumulation of SRSF2, independent of cell cycle phase. Collectively, the presented human...

  13. Nucleation studies of ZTC doped with L-arginine in supersaturated aqueous solutions

    Energy Technology Data Exchange (ETDEWEB)

    Balu, T. [Department of Physics, Aditanar College of Arts and Science, Tiruchendur 628 216 (India); Rajasekaran, T.R., E-mail: trrajasekaran@yahoo.co [Department of Physics, Manonmaniam Sundaranar University, Tirunelveli 627 012 (India); Murugakoothan, P. [Post Graduate and Research Department of Physics, Pachaiyappa' s College, Chennai 600 030 (India)

    2009-06-01

    The metastable zonewidth studies are carried out for various temperatures for supersaturated aqueous solutions of zinc thiourea chloride added with 1 mole % of L-arginine. The metastable zonewidth is increased with the addition of L-arginine. The induction period is experimentally determined and various critical nucleation parameters such as radius of critical nucleus, number of molecules in the critical nucleus, critical free energy of nucleus and interfacial tension are also calculated based on the classical theory for homogeneous crystal nucleation. The induction period is increased with the increase of L-arginine addition. The critical nucleation parameters vary with increase in doping concentration. It is also observed that the nucleation rate increases with the increase of supersaturation. The second harmonic generation (SHG) efficiency measurements are carried out with different doping concentration of L-arginine reveal that nonlinear optical (NLO) property is enhanced by L-arginine dopant.

  14. Efficient ammonium uptake and mobilization of vacuolar arginine by Saccharomyces cerevisiae wine strains during wine fermentation.

    Science.gov (United States)

    Crépin, Lucie; Sanchez, Isabelle; Nidelet, Thibault; Dequin, Sylvie; Camarasa, Carole

    2014-08-19

    Under N-limiting conditions, Saccharomyces cerevisiae strains display a substantial variability in their biomass yield from consumed nitrogen -in particular wine yeasts exhibit high growth abilities- that is correlated with their capacity to complete alcoholic fermentation, a trait of interest for fermented beverages industries. The aim of the present work was to assess the contribution of nitrogen availability to the strain-specific differences in the ability to efficiently use N-resource for growth and to identify the underlying mechanisms. We compared the profiles of assimilation of several nitrogen sources (mostly ammonium, glutamine, and arginine) for high and low biomass-producing strains in various conditions of nitrogen availability. We also analyzed the intracellular fate of nitrogen compounds. Strains clustered into two groups at initial nitrogen concentrations between 85 and 385 mg N.L(-1): high biomass producers that included wine strains, were able to complete fermentation of 240 g.L(-1) glucose and quickly consume nitrogen, in contrast to low biomass producers. The two classes of strains exhibited distinctive characteristics that contributed to their differential capacity to produce biomass. The contribution of each characteristic varied according to nitrogen availability. In high biomass producers, the high rate of ammonium uptake resulted in an important consumption of this preferred nitrogen source that promoted the growth of these yeasts when nitrogen was provided in excess. Both classes of yeast accumulated poor nitrogen sources, mostly arginine, in vacuoles during the first stages of growth. However, at end of the growth phase when nitrogen had become limiting, high biomass producers more efficiently used this vacuolar nitrogen fraction for protein synthesis and further biomass formation than low biomass producers. Overall, we demonstrate that the efficient management of the nitrogen resource, including efficient ammonium uptake and efficient

  15. Altered Nitrogen Balance and Decreased Urea Excretion in Male Rats Fed Cafeteria Diet Are Related to Arginine Availability

    Directory of Open Access Journals (Sweden)

    David Sabater

    2014-01-01

    rats, but low arginine levels point to a block in the urea cycle between ornithine and arginine, thereby preventing the elimination of excess nitrogen as urea. The ultimate consequence of this paradoxical block in the urea cycle seems to be the limitation of arginine production and/or availability.

  16. Stationary phase expression of the arginine biosynthetic operon argCBH in Escherichia coli

    Directory of Open Access Journals (Sweden)

    Sun Yuan

    2006-02-01

    Full Text Available Abstract Background Arginine biosynthesis in Escherichia coli is elevated in response to nutrient limitation, stress or arginine restriction. Though control of the pathway in response to arginine limitation is largely modulated by the ArgR repressor, other factors may be involved in increased stationary phase and stress expression. Results In this study, we report that expression of the argCBH operon is induced in stationary phase cultures and is reduced in strains possessing a mutation in rpoS, which encodes an alternative sigma factor. Using strains carrying defined argR, and rpoS mutations, we evaluated the relative contributions of these two regulators to the expression of argH using operon-lacZ fusions. While ArgR was the main factor responsible for modulating expression of argCBH, RpoS was also required for full expression of this biosynthetic operon at low arginine concentrations (below 60 μM L-arginine, a level at which growth of an arginine auxotroph was limited by arginine. When the argCBH operon was fully de-repressed (arginine limited, levels of expression were only one third of those observed in ΔargR mutants, indicating that the argCBH operon is partially repressed by ArgR even in the absence of arginine. In addition, argCBH expression was 30-fold higher in ΔargR mutants relative to levels found in wild type, fully-repressed strains, and this expression was independent of RpoS. Conclusion The results of this study indicate that both derepression and positive control by RpoS are required for full control of arginine biosynthesis in stationary phase cultures of E. coli.

  17. Dietary silicon and arginine affect mineral element composition of rat femur and vertebra.

    Science.gov (United States)

    Seaborn, C D; Nielsen, F H

    2002-12-01

    Both arginine and silicon affect collagen formation and bone mineralization. Thus, an experiment was designed to determine if dietary arginine would alter the effect of dietary silicon on bone mineralization and vice versa. Male weanling Sprague-Dawley rats were assigned to groups of 12 in a 2 x 2 factorially arranged experiment. Supplemented to a ground corn/casein basal diet containing 2.3 microg Si/g and adequate arginine were silicon as sodium metasilicate at 0 or 35 microg/g diet and arginine at 0 or 5 mg/g diet. The rats were fed ad libitum deionized water and their respective diets for 8 wk. Body weight, liver weight/body weight ratio, and plasma silicon were decreased, and plasma alkaline phosphatase activity was increased by silicon deprivation. Silicon deprivation also decreased femoral calcium, copper, potassium, and zinc concentrations, but increased the femoral manganese concentration. Arginine supplementation decreased femoral molybdenum concentration but increased the femoral manganese concentration. Vertebral concentrations of phosphorus, sodium, potassium, copper, manganese, and zinc were decreased by silicon deprivation. Arginine supplementation increased vertebral concentrations of sodium, potassium, manganese, zinc, and iron. The arginine effects were more marked in the silicon-deprived animals, especially in the vertebra. Germanium concentrations of the femur and vertebra were affected by an interaction between silicon and arginine; the concentrations were decreased by silicon deprivation in those animals not fed supplemental arginine. The change in germanium is consistent with a previous finding by us suggesting that this element may be physiologically important, especially as related to bone DNA concentrations. The femoral and vertebral mineral findings support the contention that silicon has a physiological role in bone formation and that arginine intake can affect that role.

  18. Nitrate reductase, arginine deaminase, urease and dehydrogenase activities in natural soil (ridges with forest) and in cotton soil after acetamiprid treatments.

    Science.gov (United States)

    Singh, Dileep K; Kumar, Sunil

    2008-03-01

    Soil enzymes are indicators of microbial activities in soil and are often considered as an indicator of soil health and fertility. They are very sensitive to the agricultural practices, pH of the soil, nutrients, inhibitors and weather conditions. To understand the effect of an insecticide, acetamiprid (IUPAC Name: (E)-N1-[(6-chloro-3-pyridyl) methyl]-N2-cyano-N1-methyl acetamidine) on different soil enzyme activities, the experiments were conducted for three consecutive years (2003--2005) at control and cotton experimental fields of Indian Agricultural Research Institute (IARI) and natural area (ridges with forest) in Delhi. The combined results for all three years were presented here to understand the impact of acetamiprid on soil enzyme activities. Acetamiprid was applied three times in one crop season after 41, 48 and 73 days of sowing, to control the pest. Soil of treated fields was analyzed for insecticide residues immediately after first insecticide treatment and thereafter at definite period. The residues of acetamiprid in experimental soil was varied from 0.30+/-0.13 to 22.67+/-0.2 microg g(-1)d.wt. soil, during the crop period of 2003. The insecticide residues for 2004 ranged between 0.59+/-0.38 and 13.42+/-0.71 microg g(-1)d.wt. soil and for 2005 it ranged between 0.48+/-0.22 and 19.81+/-0.33 microg g(-1)d.wt. soil. An average half life of acetamiprid in our treated field was 11.2+/-1.7 days for all three years. Similarly, the soil from natural area and control were also tested for insecticide residues. No detectable insecticide residues had been found. Soil from three localities i.e. natural, control and experimental fields were tested for different enzyme activities. Nitrate reductase, arginine deaminase, urease and dehydrogenase activities were high in natural soil in comparison to control soil and insecticide treated soil in all three experimental years. At the same time, nitrate reductase activity was all time low in acetamiprid treated soil

  19. Residual gas analysis

    International Nuclear Information System (INIS)

    Berecz, I.

    1982-01-01

    Determination of the residual gas composition in vacuum systems by a special mass spectrometric method was presented. The quadrupole mass spectrometer (QMS) and its application in thin film technology was discussed. Results, partial pressure versus time curves as well as the line spectra of the residual gases in case of the vaporization of a Ti-Pd-Au alloy were demonstrated together with the possible construction schemes of QMS residual gas analysers. (Sz.J.)

  20. Antibodies against the mono-methylated arginine-glycine repeat (MMA-RG) of the Epstein-Barr virus nuclear antigen 2 (EBNA2) identify potential cellular proteins targeted in viral transformation.

    Science.gov (United States)

    Ayoubian, Hiresh; Fröhlich, Thomas; Pogodski, Dagmar; Flatley, Andrew; Kremmer, Elisabeth; Schepers, Aloys; Feederle, Regina; Arnold, Georg J; Grässer, Friedrich A

    2017-08-01

    The Epstein-Barr virus is a human herpes virus with oncogenic potential. The virus-encoded nuclear antigen 2 (EBNA2) is a key mediator of viral tumorigenesis. EBNA2 features an arginine-glycine (RG) repeat at amino acids (aa)339-354 that is essential for the transformation of lymphocytes and contains symmetrically (SDMA) and asymmetrically (ADMA) di-methylated arginine residues. The SDMA-modified EBNA2 binds the survival motor neuron protein (SMN), thus mimicking SMD3, a cellular SDMA-containing protein that interacts with SMN. Accordingly, a monoclonal antibody (mAb) specific for the SDMA-modified RG repeat of EBNA2 also binds to SMD3. With the novel mAb 19D4 we now show that EBNA2 contains mono-methylated arginine (MMA) residues within the RG repeat. Using 19D4, we immune-precipitated and analysed by mass spectrometry cellular proteins in EBV-transformed B-cells that feature MMA motifs that are similar to the one in EBNA2. Among the cellular proteins identified, we confirmed by immunoprecipitation and/or Western blot analyses Aly/REF, Coilin, DDX5, FXR1, HNRNPK, LSM4, MRE11, NRIP, nucleolin, PRPF8, RBM26, SMD1 (SNRDP1) and THRAP3 proteins that are either known to contain MMA residues or feature RG repeat sequences that probably serve as methylation substrates. The identified proteins are involved in splicing, tumorigenesis, transcriptional activation, DNA stability and RNA processing or export. Furthermore, we found that several proteins involved in energy metabolism are associated with MMA-modified proteins. Interestingly, the viral EBNA1 protein that features methylated RG repeat motifs also reacted with the antibodies. Our results indicate that the region between aa 34-52 of EBNA1 contains ADMA or SDMA residues, while the region between aa 328-377 mainly contains MMA residues.

  1. Semantic Tagging with Deep Residual Networks

    NARCIS (Netherlands)

    Bjerva, Johannes; Plank, Barbara; Bos, Johan

    2016-01-01

    We propose a novel semantic tagging task, semtagging, tailored for the purpose of multilingual semantic parsing, and present the first tagger using deep residual networks (ResNets). Our tagger uses both word and character representations and includes a novel residual bypass architecture. We evaluate

  2. Functional and molecular effects of arginine butyrate and prednisone on muscle and heart in the mdx mouse model of Duchenne Muscular Dystrophy.

    Directory of Open Access Journals (Sweden)

    Alfredo D Guerron

    2010-06-01

    Full Text Available The number of promising therapeutic interventions for Duchenne Muscular Dystrophy (DMD is increasing rapidly. One of the proposed strategies is to use drugs that are known to act by multiple different mechanisms including inducing of homologous fetal form of adult genes, for example utrophin in place of dystrophin.In this study, we have treated mdx mice with arginine butyrate, prednisone, or a combination of arginine butyrate and prednisone for 6 months, beginning at 3 months of age, and have comprehensively evaluated the functional, biochemical, histological, and molecular effects of the treatments in this DMD model. Arginine butyrate treatment improved grip strength and decreased fibrosis in the gastrocnemius muscle, but did not produce significant improvement in muscle and cardiac histology, heart function, behavioral measurements, or serum creatine kinase levels. In contrast, 6 months of chronic continuous prednisone treatment resulted in deterioration in functional, histological, and biochemical measures. Arginine butyrate-treated mice gene expression profiling experiments revealed that several genes that control cell proliferation, growth and differentiation are differentially expressed consistent with its histone deacetylase inhibitory activity when compared to control (saline-treated mdx mice. Prednisone and combination treated groups showed alterations in the expression of genes that control fibrosis, inflammation, myogenesis and atrophy.These data indicate that 6 months treatment with arginine butyrate can produce modest beneficial effects on dystrophic pathology in mdx mice by reducing fibrosis and promoting muscle function while chronic continuous treatment with prednisone showed deleterious effects to skeletal and cardiac muscle. Our results clearly indicate the usefulness of multiple assays systems to monitor both beneficial and toxic effects of drugs with broad range of in vivo activity.

  3. /sup 13/C NMR studies of bacterial dihydrofolate reductase containing (methyl-/sup 13/C)methionine and (guanido-/sup 13/C)arginine. [Streptococcus

    Energy Technology Data Exchange (ETDEWEB)

    Matwiyoff, N.A.; London, R.E.; Walker, T.E.; Blakley, R.L.; Cocco, L.

    1978-01-01

    (Methyl-/sup 13/C)methionine and (guanido-/sup 13/C)arginine have been incorporated with high efficiency by Streptococcus faecium var. Durans strain A into dihydrofolate reductase isoenzyme 2 and /sup 13/C NMR spectra have been obtained for the labeled enzymes and their complexes with substrates, co-factors, and inhibitors. The /sup 13/C NMR spectra exhibit a high degree of discrimination--up to six guanido-/sup 13/C resonances spanning a 1.2 ppM range have been resolved for the eight arginine residues and, under certain conditions, seven methyl-/sup 13/C resonances spanning a 3 ppM chemical shift range have been resolved for the seven methionine residues of the enzyme. The /sup 13/C chemical shifts and spin lattice relaxation times of these distinct, relatively narrow resonances can be interpreted in terms of the conformational states of the enzyme and the interactions of the /sup 13/C-labeled residues with bound ligands. In a larger context, the results reported here provide experimental data which bear on a central question in the use of /sup 13/C NMR spectroscopy to probe the structure of labeled macromolecules, vis.: Where should the /sup 13/C label be incorporated to ensure a relatively narrow resonance whose chemical shift is nonetheless sensitive to perturbations of the macromolecule. Contrary to one accepted view, this study demonstrates that a significant degree of internal motion for a class of amino acid residues is not necessarily incompatible with a large chemical shift dispersion within the class.

  4. Citrulline a More Suitable Substrate than Arginine to Restore NO Production and the Microcirculation during Endotoxemia

    Science.gov (United States)

    Wijnands, Karolina A. P.; Vink, Hans; Briedé, Jacob J.; van Faassen, Ernst E.; Lamers, Wouter H.; Buurman, Wim A.; Poeze, Martijn

    2012-01-01

    Background Impaired microcirculation during endotoxemia correlates with a disturbed arginine-nitric oxide (NO) metabolism and is associated with deteriorating organ function. Improving the organ perfusion in endotoxemia, as often seen in patients with severe infection or systemic inflammatory response syndrome (SIRS) is, therefore, an important therapeutic target. We hypothesized that supplementation of the arginine precursor citrulline rather than arginine would specifically increase eNOS-induced intracellular NO production and thereby improve the microcirculation during endotoxemia. Methodology/Principal Findings To study the effects of L-Citrulline and L-Arginine supplementation on jejunal microcirculation, intracellular arginine availability and NO production in a non-lethal prolonged endotoxemia model in mice. C57/Bl6 mice received an 18 hrs intravenous infusion of endotoxin (LPS, 0.4 µg•g bodyweight−1•h−1), combined with either L-Citrulline (6.25 mg•h-1), L-Arginine (6.25 mg•h−1), or L-Alanine (isonitrogenous control; 12.5 mg•h−1) during the last 6 hrs. The control group received an 18 hrs sterile saline infusion combined with L-Alanine or L-Citrulline during the last 6 hrs. The microcirculation was evaluated at the end of the infusion period using sidestream dark-field imaging of jejunal villi. Plasma and jejunal tissue amino-acid concentrations were measured by HPLC, NO tissue concentrations by electron-spin resonance spectroscopy and NOS protein concentrations using Western blot. Conclusion/Significance L-Citrulline supplementation during endotoxemia positively influenced the intestinal microvascular perfusion compared to L-Arginine-supplemented and control endotoxemic mice. L-Citrulline supplementation increased plasma and tissue concentrations of arginine and citrulline, and restored intracellular NO production in the intestine. L-Arginine supplementation did not increase the intracellular arginine availability. Jejunal tissues in the

  5. Citrulline a more suitable substrate than arginine to restore NO production and the microcirculation during endotoxemia.

    Directory of Open Access Journals (Sweden)

    Karolina A P Wijnands

    Full Text Available BACKGROUND: Impaired microcirculation during endotoxemia correlates with a disturbed arginine-nitric oxide (NO metabolism and is associated with deteriorating organ function. Improving the organ perfusion in endotoxemia, as often seen in patients with severe infection or systemic inflammatory response syndrome (SIRS is, therefore, an important therapeutic target. We hypothesized that supplementation of the arginine precursor citrulline rather than arginine would specifically increase eNOS-induced intracellular NO production and thereby improve the microcirculation during endotoxemia. METHODOLOGY/PRINCIPAL FINDINGS: To study the effects of L-Citrulline and L-Arginine supplementation on jejunal microcirculation, intracellular arginine availability and NO production in a non-lethal prolonged endotoxemia model in mice. C57/Bl6 mice received an 18 hrs intravenous infusion of endotoxin (LPS, 0.4 µg • g bodyweight(-1 • h(-1, combined with either L-Citrulline (6.25 mg • h-1, L-Arginine (6.25 mg • h(-1, or L-Alanine (isonitrogenous control; 12.5 mg • h(-1 during the last 6 hrs. The control group received an 18 hrs sterile saline infusion combined with L-Alanine or L-Citrulline during the last 6 hrs. The microcirculation was evaluated at the end of the infusion period using sidestream dark-field imaging of jejunal villi. Plasma and jejunal tissue amino-acid concentrations were measured by HPLC, NO tissue concentrations by electron-spin resonance spectroscopy and NOS protein concentrations using Western blot. CONCLUSION/SIGNIFICANCE: L-Citrulline supplementation during endotoxemia positively influenced the intestinal microvascular perfusion compared to L-Arginine-supplemented and control endotoxemic mice. L-Citrulline supplementation increased plasma and tissue concentrations of arginine and citrulline, and restored intracellular NO production in the intestine. L-Arginine supplementation did not increase the intracellular arginine availability

  6. Arginine Vasotocin Preprohormone Is Expressed in Surprising Regions of the Teleost Forebrain

    Directory of Open Access Journals (Sweden)

    Mariana Rodriguez-Santiago

    2017-08-01

    Full Text Available Nonapeptides play a fundamental role in the regulation of social behavior, among numerous other functions. In particular, arginine vasopressin and its non-mammalian homolog, arginine vasotocin (AVT, have been implicated in regulating affiliative, reproductive, and aggressive behavior in many vertebrate species. Where these nonapeptides are synthesized in the brain has been studied extensively in most vertebrate lineages. While several hypothalamic and forebrain populations of vasopressinergic neurons have been described in amniotes, the consensus suggests that the expression of AVT in the brain of teleost fish is limited to the hypothalamus, specifically the preoptic area (POA and the anterior tuberal nucleus (putative homolog of the mammalian ventromedial hypothalamus. However, as most studies in teleosts have focused on the POA, there may be an ascertainment bias. Here, we revisit the distribution of AVT preprohormone mRNA across the dorsal and ventral telencephalon of a highly social African cichlid fish. We first use in situ hybridization to map the distribution of AVT preprohormone mRNA across the telencephalon. We then use quantitative real-time polymerase chain reaction to assay AVT expression in the dorsomedial telencephalon, the putative homolog of the mammalian basolateral amygdala. We find evidence for AVT preprohormone mRNA in regions previously not associated with the expression of this nonapeptide, including the putative homologs of the mammalian extended amygdala, hippocampus, striatum, and septum. In addition, AVT preprohormone mRNA expression within the basolateral amygdala homolog differs across social contexts, suggesting a possible role in behavioral regulation. We conclude that the surprising presence of AVT preprohormone mRNA within dorsal and medial telencephalic regions warrants a closer examination of possible AVT synthesis locations in teleost fish, and that these may be more similar to what is observed in mammals and

  7. Improving the thermostability by introduction of arginines on the surface of α-L-rhamnosidase (r-Rha1) from Aspergillus niger.

    Science.gov (United States)

    Li, Lijun; Liao, Hui; Yang, Yan; Gong, Jianye; Liu, Jianan; Jiang, Zedong; Zhu, Yanbing; Xiao, Anfeng; Ni, Hui

    2018-06-01

    To improve the thermostability of α-L-rhamnosidase (r-Rha1), an enzyme previously identified from Aspergillus niger JMU-TS528, multiple arginine (Arg) residues were introduced into the r-Rha1 sequence to replace several lysine (Lys) residues that located on the surface of the folded r-Rha1. Hinted by in silico analysis, five surface Lys residues (K134, K228, K406, K440, K573) were targeted to produce a list of 5 single-residue mutants and 4 multiple-residue mutants using site-directed mutagenesis. Among these mutants, a double Lys to Arg mutant, i.e. K406R/K573R, showed the best thermostability improvement. The half-life of this mutant's enzyme activity increased 3 h at 60 °C, 23 min at 65 °C, and 3.5 min at 70 °C, when compared with the wild type. The simulated protein structure based interaction analysis and molecular dynamics calculation indicate that the thermostability improvement of the mutant K406R-K573R was possibly due to the extra hydrogen bonds, the additional cation-π interactions, and the relatively compact conformation. With the enhanced thermostability, the α-L-rhamnosidase mutant, K406R-K573R, has potentially broadened the r-Rha1 applications in food processing industry. Copyright © 2018 Elsevier B.V. All rights reserved.

  8. Agricultural pesticide residues

    International Nuclear Information System (INIS)

    Fuehr, F.

    1984-01-01

    The utilization of tracer techniques in the study of agricultural pesticide residues is reviewed under the following headings: lysimeter experiments, micro-ecosystems, translocation in soil, degradation of pesticides in soil, biological availability of soil-applied substances, bound residues in the soil, use of macro- and microautography, double and triple labelling, use of tracer labelling in animal experiments. (U.K.)

  9. The role of myeloid cell activation and arginine metabolism in the pathogenesis of virus-induced diseases

    Directory of Open Access Journals (Sweden)

    Kristina S. Burrack

    2014-09-01

    Full Text Available When an antiviral immune response is generated, a balance must be reached between two opposing pathways: the production of proinflammatory and cytotoxic effectors that drive a robust antiviral immune response to control the infection and regulators that function to limit or blunt an excessive immune response to minimize immune-mediated pathology and repair tissue damage. Myeloid cells, including monocytes and macrophages, play an important role in this balance, particularly through the activities of the arginine-hydrolyzing enzymes nitric oxide synthase 2 (Nos2; iNOS and arginase 1 (Arg1. Nitric oxide (NO production by iNOS is an important proinflammatory mediator, whereas Arg1-expressing macrophages contribute to the resolution of inflammation and wound repair. In the context of viral infections, expression of these enzymes can result in a variety of outcomes for the host. NO has direct antiviral properties against some viruses, whereas during other virus infections NO can mediate immunopathology and/or inhibit the antiviral immune response to promote chronic infection. Arg1 activity has important wound healing functions but can also inhibit the antiviral immune response during some viral infections. Thus, depending on the specific virus and the tissue(s involved, the activity of both of these arginine-hydrolyzing enzymes can either exacerbate or limit the severity of virus-induced disease. In this review, we will discuss a variety of viral infections, including HIV, SARS-CoV, LCMV, HCV, RSV, and others, where myeloid cells influence the control and clearance of the virus from the host, as well as the severity and resolution of tissue damage, via the activities of iNOS and/or Arg1. Clearly, monocyte/macrophage activation and arginine metabolism will continue to be important areas of investigation in the context of viral infections.

  10. Depletion of arginine in yeast cells decreases the resistance to hydrostatic pressure

    Science.gov (United States)

    Nomura, Kazuki; Iwahashi, Hitoshi; Iguchi, Akinori; Shigematsu, Toru

    2015-07-01

    High hydrostatic pressure (HP) inhibits growth and inactivates microorganisms by destabilizing non-covalent molecular interactions. Arginine contributes to stress resistance because it has a guanidine side chain, which assists in the refolding of aggregated proteins. We attempted to analyze the contribution of arginine to high HP stress using a pressure-sensitive mutant strain of Saccharomyces cerevisiae and a metabolomics approach. Our results showed that the content of 136 out of 250 detected metabolites differed in the mutant and parent strains. Decreased metabolites were involved in the tricarboxylic acid cycle and arginine biosynthesis. The expression of genes contributing to arginine biosynthesis was significantly lower in the mutant strain than in the parent strain. When arginine was supplemented to the medium, the mutant strain showed more tolerance to pressure. These results suggest that yeast cells survived due to the contribution of arginine to high pressure resistance. This indicates that depletion of arginine caused by decreased activity of the biosynthesis pathway confers sensitivity to HP.

  11. L-arginine supplementation reduces mortality and improves disease outcome in mice infected with Trypanosoma cruzi.

    Science.gov (United States)

    Carbajosa, Sofía; Rodríguez-Angulo, Héctor O; Gea, Susana; Chillón-Marinas, Carlos; Poveda, Cristina; Maza, María C; Colombet, Diana; Fresno, Manuel; Gironès, Núria

    2018-01-01

    Chagas disease caused by Trypanosoma cruzi is a neglected disease that affects about 7 million people in Latin America, recently emerging on other continents due to migration. As infection in mice is characterized by depletion of plasma L-arginine, the effect on infection outcome was tested in mice with or without L-arginine supplementation and treatment with 1400W, a specific inhibitor of inducible nitric oxide synthase (iNOS). We found that levels of L-arginine and citrulline were reduced in the heart and plasma of infected mice, whereas levels of asymmetric dimethylarginine, an endogenous iNOS inhibitor, were higher. Moreover, L-arginine supplementation decreased parasitemia and heart parasite burden, improving clinical score and survival. Nitric oxide production in heart tissue and plasma was increased by L-arginine supplementation, while pharmacological inhibition of iNOS yielded an increase in parasitemia and worse clinical score. Interestingly, electrocardiograms improved in mice supplemented with L-arginine, suggesting that it modulates infection and heart function and is thus a potential biomarker of pathology. More importantly, L-arginine may be useful for treating T. cruzi infection, either alone or in combination with other antiparasitic drugs.

  12. L-arginine supplementation reduces mortality and improves disease outcome in mice infected with Trypanosoma cruzi.

    Directory of Open Access Journals (Sweden)

    Sofía Carbajosa

    2018-01-01

    Full Text Available Chagas disease caused by Trypanosoma cruzi is a neglected disease that affects about 7 million people in Latin America, recently emerging on other continents due to migration. As infection in mice is characterized by depletion of plasma L-arginine, the effect on infection outcome was tested in mice with or without L-arginine supplementation and treatment with 1400W, a specific inhibitor of inducible nitric oxide synthase (iNOS. We found that levels of L-arginine and citrulline were reduced in the heart and plasma of infected mice, whereas levels of asymmetric dimethylarginine, an endogenous iNOS inhibitor, were higher. Moreover, L-arginine supplementation decreased parasitemia and heart parasite burden, improving clinical score and survival. Nitric oxide production in heart tissue and plasma was increased by L-arginine supplementation, while pharmacological inhibition of iNOS yielded an increase in parasitemia and worse clinical score. Interestingly, electrocardiograms improved in mice supplemented with L-arginine, suggesting that it modulates infection and heart function and is thus a potential biomarker of pathology. More importantly, L-arginine may be useful for treating T. cruzi infection, either alone or in combination with other antiparasitic drugs.

  13. L-arginine supplementation reduces mortality and improves disease outcome in mice infected with Trypanosoma cruzi

    Science.gov (United States)

    Gea, Susana; Chillón-Marinas, Carlos; Poveda, Cristina; Maza, María C.; Colombet, Diana; Fresno, Manuel

    2018-01-01

    Chagas disease caused by Trypanosoma cruzi is a neglected disease that affects about 7 million people in Latin America, recently emerging on other continents due to migration. As infection in mice is characterized by depletion of plasma L-arginine, the effect on infection outcome was tested in mice with or without L-arginine supplementation and treatment with 1400W, a specific inhibitor of inducible nitric oxide synthase (iNOS). We found that levels of L-arginine and citrulline were reduced in the heart and plasma of infected mice, whereas levels of asymmetric dimethylarginine, an endogenous iNOS inhibitor, were higher. Moreover, L-arginine supplementation decreased parasitemia and heart parasite burden, improving clinical score and survival. Nitric oxide production in heart tissue and plasma was increased by L-arginine supplementation, while pharmacological inhibition of iNOS yielded an increase in parasitemia and worse clinical score. Interestingly, electrocardiograms improved in mice supplemented with L-arginine, suggesting that it modulates infection and heart function and is thus a potential biomarker of pathology. More importantly, L-arginine may be useful for treating T. cruzi infection, either alone or in combination with other antiparasitic drugs. PMID:29337988

  14. Microwave heating of arginine yields highly fluorescent nanoparticles

    International Nuclear Information System (INIS)

    Philippidis, Aggelos; Stefanakis, Dimitrios; Anglos, Demetrios; Ghanotakis, Demetrios

    2013-01-01

    Brightly fluorescent nanoparticles were produced via a single-step, single-precursor procedure based on microwave heating of an aqueous solution of the amino acid arginine. Key structural and optical properties of the resulting Arg nanoparticles, Arg-dots, are reported and discussed with emphasis on the pH dependence of their fluorescence emission. The surface of the Arg-dots was functionalised through coupling to folic acid, opening up ways for connecting fluorescent nanoparticles to cancer cells. The generality and versatility of the microwave heating procedure was further demonstrated by the synthesis of different types of carbon nanoparticles, such as CE-dots, that were produced by use of citric acid and ethanolamine as precursors and compared to the Arg-dots.

  15. Haloarchaeal Protein Translocation via the Twin Arginine Translocation Pathway

    Energy Technology Data Exchange (ETDEWEB)

    Pohlschroder Mechthild

    2009-02-03

    Protein transport across hydrophobic membranes that partition cellular compartments is essential in all cells. The twin arginine translocation (Tat) pathway transports proteins across the prokaryotic cytoplasmic membranes. Distinct from the universally conserved Sec pathway, which secretes unfolded proteins, the Tat machinery is unique in that it secretes proteins in a folded conformation, making it an attractive pathway for the transport and secretion of heterologously expressed proteins that are Sec-incompatible. During the past 7 years, the DOE-supported project has focused on the characterization of the diversity of bacterial and archaeal Tat substrates as well as on the characterization of the Tat pathway of a model archaeon, Haloferax volcanii, a member of the haloarchaea. We have demonstrated that H. volcanii uses this pathway to transport most of its secretome.

  16. Arginine Vasotocin, the Social Neuropeptide of Amphibians and Reptiles

    Directory of Open Access Journals (Sweden)

    Walter Wilczynski

    2017-08-01

    Full Text Available Arginine vasotocin (AVT is the non-mammalian homolog of arginine vasopressin (AVP and, like vasopressin, serves as an important modulator of social behavior in addition to its peripheral functions related to osmoregulation, reproductive physiology, and stress hormone release. In amphibians and reptiles, the neuroanatomical organization of brain AVT cells and fibers broadly resembles that seen in mammals and other taxa. Both parvocellular and magnocellular AVT-containing neurons are present in multiple populations located mainly in the basal forebrain from the accumbens–amygdala area to the preoptic area and hypothalamus, from which originate widespread fiber connections spanning the brain with a particularly heavy innervation of areas associated with social behavior and decision-making. As for mammalian AVP, AVT is present in greater amounts in males in many brain areas, and its presence varies seasonally, with hormonal state, and in males with differing social status. AVT’s social influence is also conserved across herpetological taxa, with significant effects on social signaling and aggression, and, based on the very small number of studies investigating more complex social behaviors in amphibians and reptiles, AVT may also modulate parental care and social bonding when it is present in these vertebrates. Within this conserved pattern, however, both AVT anatomy and social behavior effects vary significantly across species. Accounting for this diversity represents a challenge to understanding the mechanisms by which AVT exerts its behavioral effects, as well are a potential tool for discerning the structure-function relationships underlying AVT’s many effects on behavior.

  17. Arginine Vasotocin, the Social Neuropeptide of Amphibians and Reptiles

    Science.gov (United States)

    Wilczynski, Walter; Quispe, Maricel; Muñoz, Matías I.; Penna, Mario

    2017-01-01

    Arginine vasotocin (AVT) is the non-mammalian homolog of arginine vasopressin (AVP) and, like vasopressin, serves as an important modulator of social behavior in addition to its peripheral functions related to osmoregulation, reproductive physiology, and stress hormone release. In amphibians and reptiles, the neuroanatomical organization of brain AVT cells and fibers broadly resembles that seen in mammals and other taxa. Both parvocellular and magnocellular AVT-containing neurons are present in multiple populations located mainly in the basal forebrain from the accumbens–amygdala area to the preoptic area and hypothalamus, from which originate widespread fiber connections spanning the brain with a particularly heavy innervation of areas associated with social behavior and decision-making. As for mammalian AVP, AVT is present in greater amounts in males in many brain areas, and its presence varies seasonally, with hormonal state, and in males with differing social status. AVT’s social influence is also conserved across herpetological taxa, with significant effects on social signaling and aggression, and, based on the very small number of studies investigating more complex social behaviors in amphibians and reptiles, AVT may also modulate parental care and social bonding when it is present in these vertebrates. Within this conserved pattern, however, both AVT anatomy and social behavior effects vary significantly across species. Accounting for this diversity represents a challenge to understanding the mechanisms by which AVT exerts its behavioral effects, as well are a potential tool for discerning the structure-function relationships underlying AVT’s many effects on behavior. PMID:28824546

  18. Arginine Silicate Inositol Complex Accelerates Cutaneous Wound Healing.

    Science.gov (United States)

    Durmus, Ali Said; Tuzcu, Mehmet; Ozdemir, Oguzhan; Orhan, Cemal; Sahin, Nurhan; Ozercan, Ibrahim Hanifi; Komorowski, James Richard; Ali, Shakir; Sahin, Kazim

    2017-05-01

    Arginine silicate inositol (ASI) complex is a composition of arginine, silicon, and inositol that has been shown to have beneficial effects on vascular health. This study reports the effects of an ASI ointment on wound healing in rats. A full-thickness excision wound was created by using a disposable 5 mm diameter skin punch biopsy tool. In this placebo-controlled study, the treatment group's wound areas were covered by 4 or 10 % ASI ointments twice a day for 5, 10, or 15 days. The rats were sacrificed either 5, 10, or 15 days after the wounds were created, and biopsy samples were taken for biochemical and histopathological analysis. Granulation tissue appeared significantly faster in the ASI-treated groups than in the control groups (P < 0.05). The mean unhealed wound area was significantly smaller, and the mean percentage of total wound healing was significantly higher in ASI-treated wounds than in the control wounds. Hydroxyproline, collagen, and matrix metalloproteinases were measured in the granulated tissue and found to be affected. Inducible nitric oxide synthase (iNOS), endothelial nitric oxide synthase (eNOS), collagen, matrix metalloproteinase-2 (MMP-2), matrix metalloproteinase-9 (MMP-9), vascular endothelial growth factor (VEGF), fibroblast growth factor (FGF), epidermal growth factor (EGF), nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB), and various cytokines (TNF-α and IL-1β) measured in this study showed a significant fall in expression level in ASI-treated wounds. The results suggest that topical application of ASI ointment (especially 4 % concentration) has beneficial effects on the healing response of an excisional wound.

  19. European Sea Bass (Dicentrarchus labrax) Immune Status and Disease Resistance Are Impaired by Arginine Dietary Supplementation.

    Science.gov (United States)

    Azeredo, Rita; Pérez-Sánchez, Jaume; Sitjà-Bobadilla, Ariadna; Fouz, Belén; Tort, Lluis; Aragão, Cláudia; Oliva-Teles, Aires; Costas, Benjamín

    2015-01-01

    Infectious diseases and fish feeds management are probably the major expenses in the aquaculture business. Hence, it is a priority to define sustainable strategies which simultaneously avoid therapeutic procedures and reinforce fish immunity. Currently, one preferred approach is the use of immunostimulants which can be supplemented to the fish diets. Arginine is a versatile amino acid with important mechanisms closely related to the immune response. Aiming at finding out how arginine affects the innate immune status or improve disease resistance of European seabass (Dicentrarchus labrax) against vibriosis, fish were fed two arginine-supplemented diets (1% and 2% arginine supplementation). A third diet meeting arginine requirement level for seabass served as control diet. Following 15 or 29 days of feeding, fish were sampled for blood, spleen and gut to assess cell-mediated immune parameters and immune-related gene expression. At the same time, fish from each dietary group were challenged against Vibrio anguillarum and survival was monitored. Cell-mediated immune parameters such as the extracellular superoxide and nitric oxide decreased in fish fed arginine-supplemented diets. Interleukins and immune-cell marker transcripts were down-regulated by the highest supplementation level. Disease resistance data were in accordance with a generally depressed immune status, with increased susceptibility to vibriosis in fish fed arginine supplemented diets. Altogether, these results suggest a general inhibitory effect of arginine on the immune defences and disease resistance of European seabass. Still, further research will certainly clarify arginine immunomodulation pathways thereby allowing the validation of its potential as a prophylactic strategy.

  20. Acute supplementation of L-arginine affects neither strength performance nor nitric oxide production.

    Science.gov (United States)

    Meirelles, Claudia M; Matsuura, Cristiane

    2018-03-01

    L-arginine is a semi-essential amino acid involved in nitric oxide production. As nitric oxide is an important vasodilator, L-arginine supplementation would increase blood perfusion and, subsequently, muscle performance during exercises. The aim of this study was to determine the acute effect of L-arginine supplementation on strength performance and nitric oxide levels in healthy trained individuals. In a double-blind, placebo-controlled, cross-over study, 12 men were randomly assigned to L-arginine or placebo supplementation. Subjects received 6 g of L-arginine or placebo 60 minutes before strength test (maximum number of repetitions, 3 sets at 70% of one repetition maximum on bench press and at 80% of one repetition maximum on knee extensions, 2 minutes of rest between sets and exercises). Blood samples were collected before supplementation and 6 min after exercise. Plasma nitrite levels did not significantly change after L-arginine or placebo supplementation and strength-training exercise (placebo, from 13.01±1.18 to 11.83±2.81 mM; L-arginine, from 10.95±4.09 to 11.99±2.5 mM). There was a significant reduction in the number of repetitions performed from set 1 to set 3 in each set of both bench press and knee extension, but no significant interactions were observed between placebo and L-arginine. These results do not support the use of L-arginine as an ergogenic aid for strength performance, at least in context of acute use immediately before resistance exercise performance.

  1. PRE-EXERCISE ARGININE SUPPLEMENTATION INCREASES TIME TO EXHAUSTION IN ELITE MALE WRESTLERS

    Directory of Open Access Journals (Sweden)

    H.U. Yavuz

    2014-08-01

    Full Text Available Dietary supplements containing arginine are among the most popular ergogenics intended to enhance strength, power and muscle recovery associated with both anaerobic and aerobic exercise. The aim of the present study was to evaluate the possible effect of pre-exercise acute intake of arginine on performance and exercise metabolism during incremental exhaustive exercise in elite male wrestlers. Nine volunteer elite male wrestlers (24.7±3.8 years participated in this study. The test-retest protocol was used on the same subjects. The study was conducted using a cross-over design. A single dose of arginine (1.5 g · 10 kg-1 body weight or placebo was given to the subjects after 12 hours fasting (during the night for both test and retest. Subjects were allowed to drink water but not allowed to eat anything between arginine or placebo ingestion and the exercise protocol. An incremental exercise protocol was applied and oxygen consumption was measured during the exercise. Heart rate and plasma lactate levels were measured during the exercise and recovery. Results showed that in the same working loads there was no significant difference for the mean lactate levels and no difference in maximum oxygen consumption (arginine 52.47±4.01 mL · kg-1 · min-1, placebo 52.07±5.21 mL · kg-1 · min-1 or in maximum heart rates (arginine 181.09±13.57 bpm, placebo 185.89±7.38 bpm between arginine and placebo trials. Time to exhaustion was longer with arginine supplementation (1386.8±69.8 s compared to placebo (1313±90.8 s (p<0.05. These results suggest that L-arginine supplementation can have beneficial effects on exercise performance in elite male wrestlers but cannot explain the metabolic pathways which are responsible from these effects.

  2. Oral l-Arginine Stimulates GLP-1 Secretion to Improve Glucose Tolerance in Male Mice

    Science.gov (United States)

    Clemmensen, Christoffer; Smajilovic, Sanela; Smith, Eric P.; Woods, Stephen C.; Bräuner-Osborne, Hans; Seeley, Randy J.; D'Alessio, David A.

    2013-01-01

    Pharmacological and surgical interventions that increase glucagon-like peptide 1 (GLP-1) action are effective to improve glucose homeostasis in type 2 diabetes mellitus. In light of this, nutritional strategies to enhance postprandial GLP-1 secretion, particularly in the context of diet-induced obesity, may provide an alternative therapeutic approach. Importantly, recent evidence suggests the amino acid l-arginine, a well-known insulin secretagogue, can also stimulate release of GLP-1 from isolated rat intestine. Here we tested the hypothesis that oral l-arginine acts as a GLP-1 secretagogue in vivo, to augment postprandial insulin secretion and improve glucose tolerance. To test this, we administered l-arginine or vehicle by oral gavage, immediately prior to an oral glucose tolerance test in lean and diet-induced obese mice. In both lean and obese mice oral l-arginine increased plasma GLP-1 and insulin and substantially improved glucose clearance. To directly assess the contribution of GLP-1 receptor (GLP-1R)-signaling to these improvements, l-arginine was given to Glp1r knockout mice and their wild-type littermates. In this experiment oral l-arginine significantly augmented insulin secretion and improved glucose clearance in WT mice, but not in Glp1r knockout littermates. Taken together these findings identify l-arginine as a GLP-1 secretagogue in vivo and demonstrate that improvement of glucose tolerance by oral l-arginine depends on GLP-1R-signaling. These findings raise the intriguing possibility that l-arginine-based nutritional and/or pharmaceutical therapies may benefit glucose tolerance by improving the postprandial GLP-1 response in obese individuals. PMID:23959939

  3. L-Arginine in the treatment of valproate overdose - five clinical cases.

    Science.gov (United States)

    Schrettl, Verena; Felgenhauer, Norbert; Rabe, Christian; Fernando, Malkanthi; Eyer, Florian

    2017-04-01

    Valproic acid and its metabolites - particularly valproyl-CoA - are inhibitors of the enzyme N-acetylglutamate synthetase. The amino acid l-arginine can stimulate N-acetylglutamate synthetase activity and could be potentially used therapeutically to correct hyperammonemia caused by valproate therapy or overdose. Severely valproic-acid-poisoned patients are usually treated with l-carnitine or hemodialysis in order to decrease hyperammonemia. We herein report of five cases, in which l-arginine was administered. Observational study on five cases. Patients with hyperammonemia (i.e., ammonia 80 > μg/dL) and symptoms consistent with valproate overdose (i.e., drowsiness, coma) were selected for treatment with l-arginine. Data was collected retrospectively. l-Arginine decreased ammonia levels in a close temporal relation (case I ammonia in EDTA-plasma [μg/dL] decreased from 381 to 39; case II from 281 to 50; case III from 669 to 74; case IV from 447 to 56; case V from 202 to 60). In cases I and II, hemodialysis was performed and l-carnitine was given before the administration of l-arginine. In case III, hemodialysis was performed after the administration of l-arginine was already started. In cases IV and V, treatment with l-arginine was the sole measure to decrease ammonia levels in plasma. The results suggest that l-arginine may be beneficial in selected cases of valproate overdose complicated by hyperammonemia. l-Arginine could extend our conventional treatment options for valproic acid overdose.

  4. Pre-exercise arginine supplementation increases time to exhaustion in elite male wrestlers.

    Science.gov (United States)

    Yavuz, H U; Turnagol, H; Demirel, A H

    2014-08-01

    Dietary supplements containing arginine are among the most popular ergogenics intended to enhance strength, power and muscle recovery associated with both anaerobic and aerobic exercise. The aim of the present study was to evaluate the possible effect of pre-exercise acute intake of arginine on performance and exercise metabolism during incremental exhaustive exercise in elite male wrestlers. Nine volunteer elite male wrestlers (24.7±3.8 years) participated in this study. The test-retest protocol was used on the same subjects. The study was conducted using a cross-over design. A single dose of arginine (1.5 g · 10 kg(-1) body weight) or placebo was given to the subjects after 12 hours fasting (during the night) for both test and retest. Subjects were allowed to drink water but not allowed to eat anything between arginine or placebo ingestion and the exercise protocol. An incremental exercise protocol was applied and oxygen consumption was measured during the exercise. Heart rate and plasma lactate levels were measured during the exercise and recovery. Results showed that in the same working loads there was no significant difference for the mean lactate levels and no difference in maximum oxygen consumption (arginine 52.47±4.01 mL · kg(-1) · min(-1), placebo 52.07±5.21 mL · kg(-1) · min(-1)) or in maximum heart rates (arginine 181.09±13.57 bpm, placebo 185.89±7.38 bpm) between arginine and placebo trials. Time to exhaustion was longer with arginine supplementation (1386.8±69.8 s) compared to placebo (1313±90.8 s) (p L-arginine supplementation can have beneficial effects on exercise performance in elite male wrestlers but cannot explain the metabolic pathways which are responsible from these effects.

  5. Dietary l-arginine inhibits intestinal Clostridium perfringens colonisation and attenuates intestinal mucosal injury in broiler chickens.

    Science.gov (United States)

    Zhang, Beibei; Lv, Zengpeng; Li, Huixian; Guo, Shuangshuang; Liu, Dan; Guo, Yuming

    2017-09-01

    We investigated the effects of dietary l-arginine level and feeding duration on the intestinal damage of broilers induced by Clostridium perfringens (CP) in vivo, and the antimicrobial effect of its metabolite nitric oxide (NO) in vitro. The in vivo experiment was designed as a factorial arrangement of three dietary treatments×two challenge statuses. Broilers were fed a basal diet (CON) or a high-arginine diet (ARG) containing 1·87 % l-arginine, or CON for the first 8 d and ARG from days 9 to 28 (CON/ARG). Birds were co-infected with or without Eimeria and CP (EM/CP). EM/CP challenge led to intestinal injury, as evidenced by lower plasma d-xylose concentration (Pl-arginine supplementation (Pl-arginine supplementation (Pl-arginine supplementation elevated (Pl-arginine supplementation could inhibit CP overgrowth and alleviate intestinal mucosal injury by modulating innate immune responses, enhancing barrier function and producing NO.

  6. l-arginine supplementation reduces cardiac noradrenergic neurotransmission in spontaneously hypertensive rats

    OpenAIRE

    Lee, Chee-Wan; Li, Dan; Channon, Keith M.; Paterson, David J.

    2009-01-01

    Spontaneously hypertensive rats (SHR) are known to have cardiac noradrenergic hyperactivity due to an impaired nitric oxide (NO)?cGMP pathway. We hypothesized that dietary l-arginine supplementation may correct this autonomic phenotype. Male SHR and Wistar Kyoto rats (WKY) aged 16?18?weeks were given l-arginine (10?g/L in drinking water) for 1?week. Separate control groups received no supplementation. The SHR control had a significantly lower plasma l-arginine than WKY control, but this was i...

  7. L-arginine supplementation reduces mortality and improves disease outcome in mice infected with Trypanosoma cruzi

    OpenAIRE

    Carbajosa, Sofía; Rodríguez-Angulo, Héctor O.; Gea, Susana; Chillón-Marinas, Carlos; Poveda, Cristina; Maza, María C.; Colombet, Diana; Fresno, Manuel; Gironès, Núria

    2018-01-01

    Chagas disease caused by Trypanosoma cruzi is a neglected disease that affects about 7 million people in Latin America, recently emerging on other continents due to migration. As infection in mice is characterized by depletion of plasma L-arginine, the effect on infection outcome was tested in mice with or without L-arginine supplementation and treatment with 1400W, a specific inhibitor of inducible nitric oxide synthase (iNOS). We found that levels of L-arginine and citrulline were reduced i...

  8. Dietary l-arginine supplementation improves semen quality and libido of boars under high ambient temperature.

    Science.gov (United States)

    Chen, J Q; Li, Y S; Li, Z J; Lu, H X; Zhu, P Q; Li, C M

    2017-12-04

    l-Arginine is a nutritionally essential amino acid for spermatogenesis and plays versatile roles in animal health and can be utilized as a potential agent to improve reproductive performance of boars under high ambient temperature. The present study aimed to determine whether dietary l-arginine could alleviate heat stress-induced infertility in boars. In all, 20 boars (PIC 1040; 248.59±3.84 kg BW and 407.65±6.40 days of age) were selected and randomly assigned to four groups (group 0.0%, basal diet; group 0.6%, 0.8% or 1.0%, basal diet added with 0.6%, 0.8% or 1.0% l-arginine (wt:wt), respectively.) The four diets were made isonitrogenous by addition of appropriate amounts of l-alanine. Boars were pre-fed the corresponding experimental diet for 42 days. Then, the semen characteristics and libido were accessed for 6 weeks during the hot summer period (25.5° to 33.0°C). Results show that dietary l-arginine remarkably improved sperm motility, normality, total sperm number and effective total sperm number. Also, dietary l-arginine improved semen antioxidant capacity, such as decrease of malondialdehyde and 8-Hydroxy-2'-deoxyguanosine content in sperm (Pl-arginine-supplemented group which also accompany with higher ATP content than the 0.0% group. The boars fed 0.8% l-arginine show increased levels of estradiol-17β and testosterone and exhibit improved libido performance than boars in the 0.0% group. Adding dietary l-arginine linearly increased (P=0.002) nitric oxide content (as l-arginine increased). The scrotal surface temperature in the 0.6%, 0.8% and 1.0% group were decreased by 0.9°C, 0.9°C and 0.4°C, respectively, compared with the 0.0% group. l-Arginine levels caused linear effect on semen quality and antioxidant capacity, also caused quadratic effect on libido performance. During the hot summer months, the predicted optimal l-arginine levels for best semen quality and antioxidant capacity was 0.8% to 1.0% and for best libido performance was 0.8%. It can

  9. Endothelial arginine resynthesis contributes to the maintenance of vasomotor function in male diabetic mice

    DEFF Research Database (Denmark)

    Chennupati, Ramesh; Meens, Merlijn J P M T; Marion, Vincent

    2014-01-01

    AIM: Argininosuccinate synthetase (ASS) is essential for recycling L-citrulline, the by-product of NO synthase (NOS), to the NOS substrate L-arginine. Here, we assessed whether disturbed arginine resynthesis modulates endothelium-dependent vasodilatation in normal and diabetic male mice. METHODS...... in control and Ass-KOTie2 mice. Depletion of circulating L-arginine by arginase 1 infusion or inhibition of NOS activity with L-NAME resulted in an increased MAP (10 and 30 mmHg, respectively) in control and Ass-KOTie2 mice. Optimal arterial diameter, contractile responses to phenylephrine, and relaxing...

  10. Asymmetric dimethyl-L-arginine (ADMA): a possible link between homocyst(e)ine and endothelial dysfunction.

    Science.gov (United States)

    Stühlinger, Markus C; Stanger, Olaf

    2005-02-01

    Hyperhomocyst(e)inemia is associated with an increased risk for atherosclerotic disease and venous thromboembolism. The impact of elevated plasma homocysteine levels seems to be clinically relevant, since the total cardiovascular risk of hyperhomocyst(e)inemia is comparable to the risk associated with hyperlipidemia or smoking. There is substantial evidence for impairment of endothelial function in human and animal models of atherosclerosis, occurring even before development of overt plaques. Interestingly endothelial dysfunction appears to be a sensitive indicator of the process of atherosclerotic lesion development and predicts future vascular events. NO is the most potent endogenous vasodilator known. It is released by the endothelium, and reduced NO bioavailability is responsible for impaired endothelium-dependent vasorelaxation in hyperhomocyst(e)inemia and other metabolic disorders associated with vascular disease. Substances leading to impaired endothelial function as a consequence of reduced NO generation are endogenous NO synthase inhibitors such as ADMA. Indeed there is accumulating evidence from animal and human studies that ADMA, endothelial function and homocyst(e)ine might be closely interrelated. Specifically elevations of ADMA associated with impaired endothelium-dependent relaxation were found in chronic hyperhomocyst(e)inemia, as well as after acute elevation of plasma homocyst(e)ine following oral methionine intake. The postulated mechanisms for ADMA accumulation are increased methylation of arginine residues within proteins, as well as reduced metabolism of ADMA by the enzyme DDAH, but they still need to be confirmed to be operative in vivo. Hyperhomocyst(e)inemia, as well as subsequent endothelial dysfunction can be successfully treated by application of folate and B vitamins. Since ADMA seems to play a central role in homocyst(e)ine-induced endothelial dysfunction, another way of preventing vascular disease in patients with elevated homocyst

  11. The Conserved Arginine Cluster in the Insert of the Third Cytoplasmic Loop of the Long Form of the D2 Dopamine Receptor (D2L-R Acts as an Intracellular Retention Signal

    Directory of Open Access Journals (Sweden)

    Valentina Kubale

    2016-07-01

    Full Text Available This study examined whether the conserved arginine cluster present within the 29-amino acid insert of the long form of the D2 dopamine receptor (D2L-R confers its predominant intracellular localization. We hypothesized that the conserved arginine cluster (RRR located within the insert could act as an RXR-type endoplasmic reticulum (ER retention signal. Arginine residues (R within the cluster at positions 267, 268, and 269 were charge-reserved to glutamic acids (E, either individually or in clusters, thus generating single, double, and triple D2L-R mutants. Through analyses of cellular localization by confocal microscopy and enzyme-linked immunosorbent assay (ELISA, radioligand binding assay, bioluminescence resonance energy transfer (BRET2 β-arrestin 2 (βarr2 recruitment assay, and cAMP signaling, it was revealed that charge reversal of the R residues at all three positions within the motif impaired their colocalization with ER marker calnexin and led to significantly improved cell surface expression. Additionally, these data demonstrate that an R to glutamic acid (E substitution at position 2 within the RXR motif is not functionally permissible. Furthermore, all generated D2L-R mutants preserved their functional integrity regarding ligand binding, agonist-induced βarr2 recruitment and Gαi-mediated signaling. In summary, our results show that the conserved arginine cluster within the 29-amino acid insert of third cytoplasmic loop (IC3 of the D2L-R appears to be the ER retention signal.

  12. Dimethyl fumarate protects pancreatic islet cells and non-endocrine tissue in L-arginine-induced chronic pancreatitis.

    Directory of Open Access Journals (Sweden)

    Lourdes Robles

    Full Text Available Chronic pancreatitis (CP is a progressive disorder resulting in the destruction and fibrosis of the pancreatic parenchyma which ultimately leads to impairment of the endocrine and exocrine functions. Dimethyl Fumarate (DMF was recently approved by FDA for treatment of patients with multiple sclerosis. DMF's unique anti-oxidant and anti-inflammatory properties make it an interesting drug to test on other inflammatory conditions. This study was undertaken to determine the effects of DMF on islet cells and non-endocrine tissue in a rodent model of L-Arginine-induced CP.Male Wistar rats fed daily DMF (25 mg/kg or vehicle by oral gavage were given 5 IP injections of L-Arginine (250 mg/100 g × 2, 1 hr apart. Rats were assessed with weights and intra-peritoneal glucose tolerance tests (IPGTT, 2 g/kg. Islets were isolated and assessed for islet mass and viability with flow cytometry. Non-endocrine tissue was assessed for histology, myeloperoxidase (MPO, and lipid peroxidation level (MDA. In vitro assessments included determination of heme oxygenase (HO-1 protein expression by Western blot.Weight gain was significantly reduced in untreated CP group at 6 weeks. IPGTT revealed significant impairment in untreated CP group and its restoration with DMF therapy (P <0.05. Untreated CP rats had pancreatic atrophy, severe acinar architectural damage, edema, and fatty infiltration as well as elevated MDA and MPO levels, which were significantly improved by DMF treatment. After islet isolation, the volume of non-endocrine tissue was significantly smaller in untreated CP group. Although islet counts were similar in the two groups, islet viability was significantly reduced in untreated CP group and improved with DMF treatment. In vitro incubation of human pancreatic tissue with DMF significantly increased HO-1 expression.Administration of DMF attenuated L-Arginine-induced CP and islet function in rats. DMF treatment could be a possible strategy to improve clinical

  13. The effect of oral supplementation with a combination of beta-hydroxy-beta-methylbutyrate, arginine and glutamine on wound healing: a retrospective analysis of diabetic haemodialysis patients

    OpenAIRE

    Sipahi, Savas; Gungor, Ozkan; Gunduz, Mehmet; Cilci, Mehmet; Demirci, Mustafa Cahit; Tamer, Ali

    2013-01-01

    Background Diabetes is an important reason for end-stage renal failure and diabetic foot wounds worsen the life qualities of these patients. Protein and amino acid support accelerates the wound healing. The purpose of this retrospective study is to examine the effect of beta-hydroxy-beta-methylbutyrate, arginine and glutamine (Abound?) supplementation on the wound healing. Methods A total of 11 diabetic dialysis patients were included in this retrospective study aiming to evaluate the effect ...

  14. [Residual neuromuscular blockade].

    Science.gov (United States)

    Fuchs-Buder, T; Schmartz, D

    2017-06-01

    Even small degrees of residual neuromuscular blockade, i. e. a train-of-four (TOF) ratio >0.6, may lead to clinically relevant consequences for the patient. Especially upper airway integrity and the ability to swallow may still be markedly impaired. Moreover, increasing evidence suggests that residual neuromuscular blockade may affect postoperative outcome of patients. The incidence of these small degrees of residual blockade is relatively high and may persist for more than 90 min after a single intubating dose of an intermediately acting neuromuscular blocking agent, such as rocuronium and atracurium. Both neuromuscular monitoring and pharmacological reversal are key elements for the prevention of postoperative residual blockade.

  15. TENORM: Wastewater Treatment Residuals

    Science.gov (United States)

    Water and wastes which have been discharged into municipal sewers are treated at wastewater treatment plants. These may contain trace amounts of both man-made and naturally occurring radionuclides which can accumulate in the treatment plant and residuals.

  16. Residuation in orthomodular lattices

    Directory of Open Access Journals (Sweden)

    Chajda Ivan

    2017-04-01

    Full Text Available We show that every idempotent weakly divisible residuated lattice satisfying the double negation law can be transformed into an orthomodular lattice. The converse holds if adjointness is replaced by conditional adjointness. Moreover, we show that every positive right residuated lattice satisfying the double negation law and two further simple identities can be converted into an orthomodular lattice. In this case, also the converse statement is true and the corresponence is nearly one-to-one.

  17. Corticotropin-releasing hormone and arginine vasopressin in depression focus on the human postmortem hypothalamus

    NARCIS (Netherlands)

    Bao, Ai-Min; Swaab, Dick F.

    2010-01-01

    The neuropeptides corticotropin-releasing hormone (CRH) and arginine vasopressin (AVP) are crucially involved in the pathogenesis of depression. The close correlation between the etiology of depression and dysregulation of the stress responses is based upon a hyperactivity of the

  18. LAAT-1 is the lysosomal lysine/arginine transporter that maintains amino acid homeostasis.

    Science.gov (United States)

    Liu, Bin; Du, Hongwei; Rutkowski, Rachael; Gartner, Anton; Wang, Xiaochen

    2012-07-20

    Defective catabolite export from lysosomes results in lysosomal storage diseases in humans. Mutations in the cystine transporter gene CTNS cause cystinosis, but other lysosomal amino acid transporters are poorly characterized at the molecular level. Here, we identified the Caenorhabditis elegans lysosomal lysine/arginine transporter LAAT-1. Loss of laat-1 caused accumulation of lysine and arginine in enlarged, degradation-defective lysosomes. In mutants of ctns-1 (C. elegans homolog of CTNS), LAAT-1 was required to reduce lysosomal cystine levels and suppress lysosome enlargement by cysteamine, a drug that alleviates cystinosis by converting cystine to a lysine analog. LAAT-1 also maintained availability of cytosolic lysine/arginine during embryogenesis. Thus, LAAT-1 is the lysosomal lysine/arginine transporter, which suggests a molecular explanation for how cysteamine alleviates a lysosomal storage disease.

  19. Utilization of arginine as an energy source for the growth of Streptococcus faecalis.

    Science.gov (United States)

    Deibel, R H

    1964-05-01

    Deibel, R. H. (American Meat Institute Foundation, Chicago, Ill.). Utilization of arginine as an energy source for the growth of Streptococcus faecalis. J. Bacteriol. 87:988-992. 1964.-Although both Streptococcus faecalis and S. faecium (and its variety durans) hydrolyze arginine, the utilization of this amino acid as an energy source appears to have taxonomic utility, as only S. faecalis and its varieties can couple the resultant energy with growth processes. Utilization of arginine by S. faecalis in a semisynthetic, casein-hydrolysate medium requires small concentrations of a fermentable carbohydrate (0.05%), presumably for synthetic reactions. The arginine analogue, agmatine, is utilized as an energy source by S. faecalis but not by S. faecium, and only approxinately 50% of the latter strains hydrolyzed this compound. Other ureido- and guanido-containing compounds tested were neither utilized as an energy source nor deaminated.

  20. Evidence that the presence of arginine can lead to overestimation of glucagon levels measured by radioimmunoassay

    International Nuclear Information System (INIS)

    Lacey, R.J.; Morgan, N.G.; Scarpello, J.H.B.

    1992-01-01

    Accurate measurement of glucagon levels by radioimmunoassay (RIA) has proved more difficult than with certain other hormones and wide variations in the concentration of this hormone in plasma have been reported. During recent studies glucagon secretion from isolated rat pancreatic islets incubated in vitro was measured using L-arginine as stimulus. In view of the reported difficulties associated with measurement of glucagon by RIA, it was considered important to examine whether L-arginine might affect the accuracy of glucagon measurement. In the present work, it is reported that L-arginine can interfere with measurement of glucagon by RIA, leading to overestimation of glucagon levels. It is suggested that possible artifactual effects of the amino acid should be considered when arginine is employed as a stimulus for glucagon secretion. (author). 15 refs., 4 figs

  1. Performance and nitrogen balance of laying hens fed increasing levels of digestible lysine and arginine

    Directory of Open Access Journals (Sweden)

    Fabyola Barros de Carvalho

    2012-10-01

    Full Text Available The objective of this experiment was to evaluate the effect of two digestible lysine levels and four digestible arginine levels on laying hens from 24 to 48 weeks of age. Three hundred and twenty Lohmann LSL laying hens were allotted in a completely randomized design in a 2 × 4 factorial arrangement, with two levels of digestible lysine (700 and 900 mg/kg of diet and four digestible arginine levels (700, 800, 900 and 1000 mg/kg of diet. Results indicated requirement of 884 and 830 mg of digestible arginine/kg of diet, considering an average feed intake of 95 g/hen/day and an average hen weight of 1.5 kg, aiming at lesser feed intake and better nutritional balance of nitrogen, respectively. High digestible lysine levels in the diet require higher digestible arginine supplementation for a better performance of hens.

  2. Synthesis, characterization and properties of L-arginine-passivated silver nanocolloids

    International Nuclear Information System (INIS)

    Sunatkari, A. L.; Talwatkar, S. S.; Tamgadge, Y. S.; Muley, G. G.

    2016-01-01

    We investigate the effect of L-arginine-surface passivation on localised surface plasmon resonance (LSPR), size and stability of colloidal Silver Nanoparticles (AgNPs) synthesized by chemical reduction method. The surface Plasmon resonance absorption peak of AgNPs shows blue shift with the increase in L-arginine concentration. Transmission electron microscopy (TEM) analysis confirmed that the average size of AgNPs reduces from 10 nm to 6 nm as the concentration of L-Arginine increased from 1 to 5 mM. The X-ray diffraction study (XRD) confirmed the formation face-centred cubic (fcc) structured AgNPs. FT-IR studies revealed strong bonding between L-arginine functional groups and AgNPs.

  3. Tyrosine binding and promiscuity in the arginine repressor from the pathogenic bacterium Corynebacterium pseudotuberculosis.

    Science.gov (United States)

    Mariutti, Ricardo Barros; Ullah, Anwar; Araujo, Gabriela Campos; Murakami, Mario Tyago; Arni, Raghuvir Krishnaswamy

    2016-07-08

    The arginine repressor (ArgR) regulates arginine biosynthesis in a number of microorganisms and consists of two domains interlinked by a short peptide; the N-terminal domain is involved in DNA binding and the C-terminal domain binds arginine and forms a hexamer made-up of a dimer of trimers. The crystal structure of the C-terminal domain of ArgR from the pathogenic Corynebacterium pseudotuberculosis determined at 1.9 Å resolution contains a tightly bound tyrosine at the arginine-binding site indicating hitherto unobserved promiscuity. Structural analysis of the binding pocket displays clear molecular adaptations to accommodate tyrosine binding suggesting the possible existence of an alternative regulatory process in this pathogenic bacterium. Copyright © 2016 Elsevier Inc. All rights reserved.

  4. Enteral Glutamine Administration in Critically Ill Nonseptic Patients Does Not Trigger Arginine Synthesis

    NARCIS (Netherlands)

    Vermeulen, Mechteld A. R.; Brinkmann, Saskia J. H.; Buijs, Nikki; Beishuizen, Albertus; Bet, Pierre M.; Houdijk, Alexander P. J.; van Goudoever, Johannes B.; van Leeuwen, Paul A. M.

    2016-01-01

    Glutamine supplementation in specific groups of critically ill patients results in favourable clinical outcome. Enhancement of citrulline and arginine synthesis by glutamine could serve as a potential mechanism. However, while receiving optimal enteral nutrition, uptake and enteral metabolism of

  5. Citrulline a more suitable substrate than arginine to restore NO production and the microcirculation during endotoxemia

    NARCIS (Netherlands)

    Wijnands, Karolina A. P.; Vink, Hans; Briedé, Jacob J.; van Faassen, Ernst E.; Lamers, Wouter H.; Buurman, Wim A.; Poeze, Martijn

    2012-01-01

    Impaired microcirculation during endotoxemia correlates with a disturbed arginine-nitric oxide (NO) metabolism and is associated with deteriorating organ function. Improving the organ perfusion in endotoxemia, as often seen in patients with severe infection or systemic inflammatory response syndrome

  6. Dietary L-arginine supplementation enhances placental growth and reproductive performance in sows.

    Science.gov (United States)

    Gao, Kaiguo; Jiang, Zongyong; Lin, Yingcai; Zheng, Chuntian; Zhou, Guilian; Chen, Fang; Yang, Lin; Wu, Guoyao

    2012-06-01

    Suboptimal embryonic/fetal survival and growth remains a significant problem in mammals. Using a swine model, we tested the hypothesis that dietary L-arginine supplementation during gestation may improve pregnancy outcomes through enhancing placental growth and modulating hormonal secretions. Gestating pigs (Yorkshire×Landrace, n=108) were assigned randomly into two groups based on parity and body weight, representing dietary supplementation with 1.0% L-arginine-HCl or 1.7% L-alanine (isonitrogenous control) between days 22 and 114 of gestation. Blood samples were obtained from the ear vein on days 22, 40, 70 and 90 of gestation. On days 40, 70 and 90 of gestation, concentrations of estradiol in plasma were higher (Psupplemented than in control sows. Moreover, arginine supplementation increased (Psupplementation increased (Psupplementation enhanced (Psupplementation during gestation. These results indicate that dietary arginine supplementation beneficially enhances placental growth and the reproductive performance of sows.

  7. Microcirculatory effects of L-arginine during acute anaerobic exercise in healthy men: A pilot study

    Directory of Open Access Journals (Sweden)

    Andrius Pranskunas

    2015-12-01

    Conclusion: Our findings show that supplementation with L-arginine may cause additional effects on the acute anaerobic exercise-induced transient increase in capillary density in the sublingual mucosa of untrained men.

  8. Synthesis, characterization and properties of L-arginine-passivated silver nanocolloids

    Energy Technology Data Exchange (ETDEWEB)

    Sunatkari, A. L., E-mail: ashok.sunatkari@rediffmail.com [Department of Physics, Siddhartha College of Arts, Science and Commerce, Fort, Mumbai-400001, India. Email: ashok.sunatkari@rediffmail.com (India); Talwatkar, S. S. [Department of Physics, N.G. Aacharya and D.K. Maratha College of Arts, Science and Commerce, Chembur, Mumbai-400071, India. Email: swarna-81@rediffmail.com (India); Tamgadge, Y. S. [Department of Physics, Mahatma Phule Arts, Commerce & S.R.C. Science College, Warud-444906, India. Email: ystamgadge@gmail.com (India); Muley, G. G., E-mail: gajananggm@yahoo.co.in [Department of Physics, Sant Gadge Baba Amravati University, Amravati-444602 India. Email: gajananggm@yahoo.co.in (India)

    2016-05-06

    We investigate the effect of L-arginine-surface passivation on localised surface plasmon resonance (LSPR), size and stability of colloidal Silver Nanoparticles (AgNPs) synthesized by chemical reduction method. The surface Plasmon resonance absorption peak of AgNPs shows blue shift with the increase in L-arginine concentration. Transmission electron microscopy (TEM) analysis confirmed that the average size of AgNPs reduces from 10 nm to 6 nm as the concentration of L-Arginine increased from 1 to 5 mM. The X-ray diffraction study (XRD) confirmed the formation face-centred cubic (fcc) structured AgNPs. FT-IR studies revealed strong bonding between L-arginine functional groups and AgNPs.

  9. Arginine methylation analysis of the splicing-associated SR protein SFRS9/SRP30C.

    Science.gov (United States)

    Bressan, Gustavo C; Moraes, Eduardo C; Manfiolli, Adriana O; Kuniyoshi, Tais M; Passos, Dario O; Gomes, Marcelo D; Kobarg, Jörg

    2009-01-01

    The human SFRS9/SRp30c belongs to the SR family of splicing regulators. Despite evidence that members of this protein family may be targeted by arginine methylation, this has yet to be experimentally addressed. In this study, we found that SFRS9 is a target for PRMT1-mediated arginine methylation in vitro, and that it is immunoprecipitated from HEK-293 lysates by antibodies that recognize both mono- and dimethylated arginines. We further observed that upon treatment with the methylation inhibitor Adox, the fluorescent EGFP-SFRS9 re-localizes to dot-like structures in the cell nucleus. In subsequent confocal analyses, we found that EGFP-SFRS9 localizes to nucleoli in Adox-treated cells. Our findings indicate the importance of arginine methylation for the subnuclear localization of SFRS9.

  10. Clinical effectiveness of exogenous L-arginine in patients with coronary heart disease after community-acquired pneumonia

    Directory of Open Access Journals (Sweden)

    T. O. Kulynych

    2017-02-01

    Full Text Available Coronary heart disease and community acquired pneumonia associated with a higher risk for morbidity and mortality. The optimization of treatment of comorbid pathology by medicines which modify endothelium functional state is important. Aim: to study effect of exogenous L-arginine on clinical course of disease, markers of systemic inflammation and endothelial dysfunction in patients with coronary heart disease (CHD and community-acquired pneumonia (CAP. Materials and methods. 60 patients with CHD and CAP (the median 72.50 years, range 66.00; 75.00 were included into the study. Patients were randomized in 2 groups: first – 30 patients with basic therapy combined with L-arginine; and second – 30 patients with basic therapy. hs-CRP, neopterin, РАРР-А, NT-proBNP were measured by ELISA-TEST before treatment and 1 month after. Clinical course was assessed during 1 year of follow-up. Results. In the first group the hospitalization rate due to CHD and heart failure decompensation was significantly rare. Biomarkers changes in the 1st group were significant: hs-CRP was significantly decreased by 57.14 % (in the 2nd group – by 28.57 %; neopterin – by 36.57 % (in the 2nd group – by 20.91 %; РАРР-А – by 35.71 % (in the 2nd group – by 4.76 %. There was revealed a significant decreasing of NT-proBNP levels in patients receiving L-arginine by comparing with basic therapy: with the I stage of heart failure (HF – by 50.97 % vs 21.82 %, with the II-A stage of HF – by 43.82 % vs 5.61 % (p < 0.05. After 1 month of therapy patients from the 1st group had significantly lower rates of neopterin – by 16.46 %, and NT-proBNP – by 40.92 % in the subgroup of patients with II-A stage of HF (p < 0.05 compared with patients who received only the basic therapy. Conclusions. Combination of exogenous L-arginine and basic therapy in patients with CHD and CAP was associated with benign clinical course and positive changes of endothelium functional

  11. L-Glutamine and L-arginine protect against enterotoxigenic Escherichia coli infection via intestinal innate immunity in mice.

    Science.gov (United States)

    Liu, Gang; Ren, Wenkai; Fang, Jun; Hu, Chien-An Andy; Guan, Guiping; Al-Dhabi, Naif Abdullah; Yin, Jie; Duraipandiyan, Veeramuthu; Chen, Shuai; Peng, Yuanyi; Yin, Yulong

    2017-12-01

    Dietary glutamine (Gln) or arginine (Arg) supplementation is beneficial for intestinal health; however, whether Gln or Arg may confer protection against Enterotoxigenic Escherichia coli (ETEC) infection is not known. To address this, we used an ETEC-infected murine model to investigate the protective effects of Gln and Arg. Experimentally, we pre-treated mice with designed diet of Gln or Arg supplementation prior to the oral ETEC infection and then assessed mouse mortality and intestinal bacterial burden. We also determined the markers of intestinal innate immunity in treated mice, including secretory IgA response (SIgA), mucins from goblet cells, as well as antimicrobial peptides from Paneth cells. ETEC colonized in mouse small intestine, including duodenum, jejunum, and ileum, and inhibited the mRNA expression of intestinal immune factors, such as polymeric immunoglobulin receptor (pIgR), cryptdin-related sequence 1C (CRS1C), and Reg3γ. We found that dietary Gln or Arg supplementation decreased bacterial colonization and promoted the activation of innate immunity (e.g., the mRNA expression of pIgR, CRS1C, and Reg3γ) in the intestine of ETEC-infected mice. Our results suggest that dietary arginine or glutamine supplementation may inhibit intestinal ETEC infection through intestinal innate immunity.

  12. Characterization of Hospital Residuals

    International Nuclear Information System (INIS)

    Blanco Meza, A.; Bonilla Jimenez, S.

    1997-01-01

    The main objective of this investigation is the characterization of the solid residuals. A description of the handling of the liquid and gassy waste generated in hospitals is also given, identifying the source where they originate. To achieve the proposed objective the work was divided in three stages: The first one was the planning and the coordination with each hospital center, in this way, to determine the schedule of gathering of the waste can be possible. In the second stage a fieldwork was made; it consisted in gathering the quantitative and qualitative information of the general state of the handling of residuals. In the third and last stage, the information previously obtained was organized to express the results as the production rate per day by bed, generation of solid residuals for sampled services, type of solid residuals and density of the same ones. With the obtained results, approaches are settled down to either determine design parameters for final disposition whether for incineration, trituration, sanitary filler or recycling of some materials, and storage politics of the solid residuals that allow to determine the gathering frequency. The study concludes that it is necessary to improve the conditions of the residuals handling in some aspects, to provide the cleaning personnel of the equipment for gathering disposition and of security, minimum to carry out this work efficiently, and to maintain a control of all the dangerous waste, like sharp or polluted materials. In this way, an appreciable reduction is guaranteed in the impact on the atmosphere. (Author) [es

  13. Plasma l-citrulline concentrations in l-arginine-supplemented healthy dogs.

    Science.gov (United States)

    Flynn, K M; Kellihan, H B; Trepanier, L A

    2017-08-01

    To determine whether oral l-arginine increases plasma [l-citrulline] in dogs. Eleven healthy staff-owned dogs were used in this study. Dogs (n = 3) were given l-arginine (50mg/kg PO q8h) for 7 days, and plasma [l-arginine] and [l-citrulline] were analyzed by high performance liquid chromatography at baseline (BL), steady state trough, and 0.5, 1, 1.5, 2, 4, 6, and 8 h after final dosing on day 7. Eleven dogs were then treated with 100mg/kg l-arginine PO q8h for 7 days, and [l-arginine] and [l-citrulline] were measured at BL, steady state trough, and at peak 4 hrs after dosing (T4 hrs). - Plasma [l-arginine] and [l-citrulline] peaked at T4 hrs on the 50mg/kg dosage. Target outcome, modeled after human study results, of a doubling of [l-arginine] and a 25-30% increase in [l-citrulline] from BL were not reached. After the 100mg/kg dosage, plasma [l-arginine] increased from a BL median of 160.1 μM (range, 100.2-231.4 μM) to a peak of 417.4 μM (206.5-807.3 μM) at T4 hrs, and plasma [l-citrulline] increased from a BL median of 87.8 μM (59.1-117.1 μM) to peak of 102.2 μM (47.4-192.6 μM) at T4 hrs. Ten of eleven dogs showed a doubling of plasma [l-arginine] and 4/11 dogs achieved 25-30% or greater increases in plasma [l-citrulline]. No adverse effects on heart rate or blood pressure were noted. - Oral l-arginine dosage of 100mg/kg q8h doubles plasma [l-arginine] in healthy dogs, but conversion to l-citrulline is quite variable. Further evaluation of this dosage regimen in dogs with pulmonary hypertension is warranted. Copyright © 2017 Elsevier B.V. All rights reserved.

  14. New Insights into the Methodology of L-Arginine-Induced Acute Pancreatitis

    Science.gov (United States)

    Kui, Balázs; Balla, Zsolt; Vasas, Béla; Végh, Eszter T.; Pallagi, Petra; Kormányos, Eszter S.; Venglovecz, Viktória; Iványi, Béla; Takács, Tamás; Hegyi, Péter; Rakonczay, Zoltán

    2015-01-01

    Animal models are ideal to study the pathomechanism and therapy of acute pancreatitis (AP). The use of L-arginine-induced AP model is nowadays becoming increasingly popular in mice. However, carefully looking through the literature, marked differences in disease severity could be observed. In fact, while setting up the L-arginine (2×4 g/kg i.p.)-induced AP model in BALB/c mice, we found a relatively low rate (around 15%) of pancreatic necrosis, whereas others have detected much higher rates (up to 55%). We suspected that this may be due to differences between mouse strains. We administered various concentrations (5–30%, pH = 7.4) and doses (2×4, 3×3, or 4×2.5 g/kg) of L-arginine-HCl in BALB/c, FVB/n and C57BL/6 mice. The potential gender-specific effect of L-arginine was investigated in C57BL/6 mice. The fate of mice in response to the i.p. injections of L arginine followed one of three courses. Some mice (1) developed severe AP or (2) remained AP-free by 72 h, whereas others (3) had to be euthanized (to avoid their death, which was caused by the high dose of L-arginine and not AP) within 12 h., In FVB/n and C57BL/6 mice, the pancreatic necrosis rate (about 50%) was significantly higher than that observed in BALB/c mice using 2×4 g/kg 10% L–arginine, but euthanasia was necessary in a large proportion of animals, The i.p. injection of lower L-arginine concentrations (e.g. 5–8%) in case of the 2×4 g/kg dose, or other L-arginine doses (3×3 or 4×2.5 g/kg, 10%) were better for inducing AP. We could not detect any significant differences between the AP severity of male and female mice. Taken together, when setting up the L-arginine-induced AP model, there are several important factors that are worth consideration such as the dose and concentration of the administered L arginine-HCl solution and also the strain of mice. PMID:25688985

  15. Arginine metabolism by macrophages promotes cardiac and muscle fibrosis in mdx muscular dystrophy.

    Directory of Open Access Journals (Sweden)

    Michelle Wehling-Henricks

    2010-05-01

    Full Text Available Duchenne muscular dystrophy (DMD is the most common, lethal disease of childhood. One of 3500 new-born males suffers from this universally-lethal disease. Other than the use of corticosteroids, little is available to affect the relentless progress of the disease, leading many families to use dietary supplements in hopes of reducing the progression or severity of muscle wasting. Arginine is commonly used as a dietary supplement and its use has been reported to have beneficial effects following short-term administration to mdx mice, a genetic model of DMD. However, the long-term effects of arginine supplementation are unknown. This lack of knowledge about the long-term effects of increased arginine metabolism is important because elevated arginine metabolism can increase tissue fibrosis, and increased fibrosis of skeletal muscles and the heart is an important and potentially life-threatening feature of DMD.We use both genetic and nutritional manipulations to test whether changes in arginase metabolism promote fibrosis and increase pathology in mdx mice. Our findings show that fibrotic lesions in mdx muscle are enriched with arginase-2-expressing macrophages and that muscle macrophages stimulated with cytokines that activate the M2 phenotype show elevated arginase activity and expression. We generated a line of arginase-2-null mutant mdx mice and found that the mutation reduced fibrosis in muscles of 18-month-old mdx mice, and reduced kyphosis that is attributable to muscle fibrosis. We also observed that dietary supplementation with arginine for 17-months increased mdx muscle fibrosis. In contrast, arginine-2 mutation did not reduce cardiac fibrosis or affect cardiac function assessed by echocardiography, although 17-months of dietary supplementation with arginine increased cardiac fibrosis. Long-term arginine treatments did not decrease matrix metalloproteinase-2 or -9 or increase the expression of utrophin, which have been reported as beneficial

  16. 40 CFR 180.586 - Clothianidin; tolerances for residues.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Clothianidin; tolerances for residues... § 180.586 Clothianidin; tolerances for residues. (a) General. Tolerances are established for residues of the insecticide clothianidin, including its metabolites and degradates. Compliance with the tolerance...

  17. Logging residues under different stand and harvesting conditions, Rocky Mountains

    Science.gov (United States)

    Robert E. Benson; Cameron M. Johnston

    1976-01-01

    Volume and characteristics of logging residues from 34 harvest areas are presented. Clearcuts and partial cuts logged to conventional utilization levels and to close utilization levels are included. Residue volumes ranged from almost 3, 600 ft3 /acre of wood 3-inches-plus down to about 550 ft3 /acre, depending on treatment. More than 60 percent of the residues were...

  18. LAAT-1 is the Lysosomal Lysine/Arginine Transporter that Maintains Amino Acid Homeostasis

    OpenAIRE

    Liu, Bin; Du, Hongwei; Rutkowski, Rachael; Gartner, Anton; Wang, Xiaochen

    2012-01-01

    Defective catabolite export from lysosomes results in lysosomal storage diseases in humans. Mutations in the cystine transporter gene CTNS cause cystinosis, but other lysosomal amino acid transporters are poorly characterized at the molecular level. Here we identified the C. elegans lysosomal lysine/arginine transporter, LAAT-1. Loss of laat-1 caused accumulation of lysine and arginine in enlarged, degradation-defective lysosomes. In mutants of ctns-1 (C. elegans homolog of CTNS), LAAT-1 was ...

  19. Insulin rapidly stimulates L-arginine transport in human aortic endothelial cells via Akt.

    Science.gov (United States)

    Kohlhaas, Christine F; Morrow, Valerie A; Jhakra, Neelam; Patil, Vrushali; Connell, John M C; Petrie, John R; Salt, Ian P

    2011-09-09

    Insulin stimulates endothelial NO synthesis, at least in part mediated by phosphorylation and activation of endothelial NO synthase at Ser1177 and Ser615 by Akt. We have previously demonstrated that insulin-stimulated NO synthesis is inhibited under high culture glucose conditions, without altering Ca(2+)-stimulated NO synthesis or insulin-stimulated phosphorylation of eNOS. This indicates that stimulation of endothelial NO synthase phosphorylation may be required, yet not sufficient, for insulin-stimulated nitric oxide synthesis. In the current study we investigated the role of supply of the eNOS substrate, L-arginine as a candidate parallel mechanism underlying insulin-stimulated NO synthesis in cultured human aortic endothelial cells. Insulin rapidly stimulated L-arginine transport, an effect abrogated by incubation with inhibitors of phosphatidylinositol-3'-kinase or infection with adenoviruses expressing a dominant negative mutant Akt. Furthermore, supplementation of endothelial cells with extracellular L-arginine enhanced insulin-stimulated NO synthesis, an effect reversed by co-incubation with the L-arginine transport inhibitor, L-lysine. Basal L-arginine transport was significantly increased under high glucose culture conditions, yet insulin-stimulated L-arginine transport remained unaltered. The increase in L-arginine transport elicited by high glucose was independent of the expression of the cationic amino acid transporters, hCAT1 and hCAT2 and not associated with any changes in the activity of ERK1/2, Akt or protein kinase C (PKC). We propose that rapid stimulation of L-arginine transport contributes to insulin-stimulated NO synthesis in human endothelial cells, yet attenuation of this is unlikely to underlie the inhibition of insulin-stimulated NO synthesis under high glucose conditions. Copyright © 2011 Elsevier Inc. All rights reserved.

  20. Insulin rapidly stimulates l-arginine transport in human aortic endothelial cells via Akt

    Science.gov (United States)

    Kohlhaas, Christine F.; Morrow, Valerie A.; Jhakra, Neelam; Patil, Vrushali; Connell, John M.C.; Petrie, John R.; Salt, Ian P.

    2011-01-01

    Insulin stimulates endothelial NO synthesis, at least in part mediated by phosphorylation and activation of endothelial NO synthase at Ser1177 and Ser615 by Akt. We have previously demonstrated that insulin-stimulated NO synthesis is inhibited under high culture glucose conditions, without altering Ca2+-stimulated NO synthesis or insulin-stimulated phosphorylation of eNOS. This indicates that stimulation of endothelial NO synthase phosphorylation may be required, yet not sufficient, for insulin-stimulated nitric oxide synthesis. In the current study we investigated the role of supply of the eNOS substrate, l-arginine as a candidate parallel mechanism underlying insulin-stimulated NO synthesis in cultured human aortic endothelial cells. Insulin rapidly stimulated l-arginine transport, an effect abrogated by incubation with inhibitors of phosphatidylinositol-3′-kinase or infection with adenoviruses expressing a dominant negative mutant Akt. Furthermore, supplementation of endothelial cells with extracellular l-arginine enhanced insulin-stimulated NO synthesis, an effect reversed by co-incubation with the l-arginine transport inhibitor, l-lysine. Basal l-arginine transport was significantly increased under high glucose culture conditions, yet insulin-stimulated l-arginine transport remained unaltered. The increase in l-arginine transport elicited by high glucose was independent of the expression of the cationic amino acid transporters, hCAT1 and hCAT2 and not associated with any changes in the activity of ERK1/2, Akt or protein kinase C (PKC). We propose that rapid stimulation of L-arginine transport contributes to insulin-stimulated NO synthesis in human endothelial cells, yet attenuation of this is unlikely to underlie the inhibition of insulin-stimulated NO synthesis under high glucose conditions. PMID:21871446

  1. Acute hypothalamic administration of L-arginine increases feed intake in rats

    Directory of Open Access Journals (Sweden)

    Carlos Ricardo Maneck Malfatti

    2015-02-01

    Full Text Available Objective: This study investigated the chronic (oral and acute (hypothalamic infusion effects of L-arginine supplementation on feed intake, body composition, and behavioral changes in rats. Methods: Twenty rats were divided into two groups treated orally for 60 days; one group received L-arginine (1 g/kg body weight and one group received saline (1 mL/NaCl 0.9%. Daily consumption of water and food were evaluated, and weight monitored. After the oral treatment, the rats underwent stereotactic biopsy and a group was injected with 2 µL of L-arginine (0.5 mM and another received an injection of saline (0.9% NaCl, in the hypothalamic route, through micro infusion. Immediately after micro infusion, the animal behavior was evaluated through tests in the open field. Food and water consumption were evaluated at 12 and 24 hours after the micro infusion. Daily water consumption and weight gain evolution were evaluated. At the end of treatments, rats were euthanized and blood was collected for glucose, glycerol, and cholesterol evaluation, and histological analysis of vital organs. Results: Oral supplementation with L-arginine increased water intake (11%, p<0.05 and promoted weight gain (3%, p<0.05. However, hypothalamic infusion promoted a significant increase in chow intake (30%, p<0.05 after 24 hours of L-arginine administration. Conclusion: Chronic oral treatment with L-arginine was not effective on appetite modulation; however, an effect was observed when L-arginine was administered directly into the hypothalamus, suggesting a central regulation on appetite through nNOS sensitization. Chronic use of L-arginine did not cause substantial changes in anthropometric, biochemical, behavioral, or histological variables.

  2. Influence of L-arginine supplementation on reproductive blood flow and embryo recovery rates in mares.

    Science.gov (United States)

    Kelley, Dale; LeBlanc, Michelle M; Warren, Lori K; Mortensen, Christopher J

    2014-03-15

    Supplementation with L-arginine can increase uterine arterial blood flow and vascular perfusion of the preovulatory follicle in mares. Increased vascular perfusion of the preovulatory follicle has been correlated with successful pregnancy in mares. The objective of this study was to determine if supplemental L-arginine would increase ovarian arterial blood flow, vascular perfusion of the preovulatory follicle, and embryo recovery rates in mares. Mares were blocked by age and breed and assigned at random within block to L-arginine supplementation or control groups. Mares were fed L-arginine beginning 17 days before and through the duration of the study. Transrectal Doppler ultrasonography was used to measure ovarian arterial blood flow and vascular perfusion of the preovulatory follicle daily when it reached 35 mm and subsequent CL on Days 2, 4, and 6. Mares, on achieving a follicle of 35 mm or more were bred via artificial insemination and an embryo collection was attempted 7 days after ovulation. Treatment did not affect interovulatory interval (arginine-treated, 18.1 ± 2.6 days; control, 20.7 ± 2.3 days) or embryo recovery rate (arginine-treated, 54%; control, 48%). Mares treated with l-arginine had a larger follicle for the 10 days preceding ovulation than control mares (30.4 ± 1.2 and 26.3 ± 1.3 mm, respectively; P l-arginine supplementation increased the size and tended to increase perfusion of the follicle 1, but had no effect on luteal perfusion or embryo recovery rates in mares. Copyright © 2014 Elsevier Inc. All rights reserved.

  3. Effect of L-arginine supplement on liver regeneration after partial hepatectomy in rats

    Directory of Open Access Journals (Sweden)

    Kurokawa Tsuyoshi

    2012-05-01

    Full Text Available Abstract Background Nitric oxide (NO has been reported to be a key mediator in hepatocyte proliferation during liver regeneration. NO is the oxidative metabolite of L-arginine, and is produced by a family of enzymes, collective termed nitric oxide synthase (NOS. Thus, administration of L-arginine might enhance liver regeneration after a hepatectomy. Another amino acid, L-glutamine, which plays an important role in catabolic states and is a crucial factor in various cellular and organ functions, is widely known to enhance liver regeneration experimentally. Thus, the present study was undertaken to evaluate the effects of an L-arginine supplement on liver regeneration, and to compared this with supplementation with L-glutamine and L-alanine (the latter as a negative control, using a rat partial hepatectomy model. Methods Before and after a 70% hepatectomy, rats received one of three amino acid solutions (L-arginine, L-glutamine, or L-alanine. The effects on liver regeneration of the administered solutions were examined by assessment of restituted liver mass, staining for proliferating cell nuclear antigen (PCNA, and total RNA and DNA content 24 and 72 hours after the operation. Results At 72 hours after the hepatectomy, the restituted liver mass, the PCNA labeling index and the DNA quantity were all significantly higher in the L-arginine and L-glutamine groups than in the control. There were no significant differences in those parameters between the L-arginine and L-glutamine groups, nor were any significant differences found between the L-alanine group and the control. Conclusion Oral supplements of L-arginine and L-glutamine enhanced liver regeneration after hepatectomy in rats, suggesting that an oral arginine supplement can clinically improve recovery after a major liver resection.

  4. Cleansing effect of acidic L-arginine on human oral biofilm.

    Science.gov (United States)

    Tada, Ayano; Nakayama-Imaohji, Haruyuki; Yamasaki, Hisashi; Hasibul, Khaleque; Yoneda, Saori; Uchida, Keiko; Nariya, Hirofumi; Suzuki, Motoo; Miyake, Minoru; Kuwahara, Tomomi

    2016-03-22

    Dental plaque formed on tooth surfaces is a complex ecosystem composed of diverse oral bacteria and salivary components. Accumulation of dental plaque is a risk factor for dental caries and periodontal diseases. L-arginine has been reported to decrease the risk for dental caries by elevating plaque pH through the activity of arginine deiminase in oral bacteria. Here we evaluated the potential of L-arginine to remove established oral biofilms. Biofilms were formed using human saliva mixed with Brain Heart Infusion broth supplemented with 1 % sucrose in multi-well plates or on plastic discs. After washing the biofilms with saline, citrate (10 mM, pH3.5), or L-arginine (0.5 M, pH3.5), the retained biofilms were analyzed by crystal violet staining, scanning electron microscopy, and Illumina-based 16S rDNA sequencing. Washing with acidic L-arginine detached oral biofilms more efficiently than saline and significantly reduced biofilm mass retained in multi-well plates or on plastic discs. Illumina-based microbiota analysis showed that citrate (pH3.5) preferentially washed out Streptococcus from mature oral biofilm, whereas acidic L-arginine prepared with 10 mM citrate buffer (pH3.5) non-specifically removed microbial components of the oral biofilm. Acidic L-arginine prepared with citrate buffer (pH3.5) effectively destabilized and removed mature oral biofilms. The acidic L-arginine solution described here could be used as an additive that enhances the efficacy of mouth rinses used in oral hygiene.

  5. Specific amino acid (L-arginine) requirement for the microbiostatic activity of murine macrophages.

    OpenAIRE

    Granger, D L; Hibbs, J B; Perfect, J R; Durack, D T

    1988-01-01

    The microbiostatic action of macrophages was studied in vitro employing peritoneal cytotoxic macrophages (CM) from mice acting against Cryptococcus neoformans cultured in Dulbecco's medium with 10% dialyzed fetal bovine serum. Fungistasis was measured using electronic particle counting after lysis of macrophages with detergent. Macrophage fungistasis failed in medium lacking only L-arginine. Complete fungistasis was restored by L-arginine; restoration was concentration dependent, maximal at 2...

  6. Effects of exercise and L-arginine on ventricular remodeling and oxidative stress.

    Science.gov (United States)

    Xu, Xiaohua; Zhao, Weiyan; Lao, Shunhua; Wilson, Bryan S; Erikson, John M; Zhang, John Q

    2010-02-01

    Our aim was to characterize the changes in messenger RNA (mRNA) abundance, protein, and activity levels of the enzymatic antioxidants, superoxide dismutase (SOD), glutathione peroxidase, and catalase by exercise training combined with L-arginine after myocardial infarction (MI). L-Arginine (1 g x kg(-1) x d(-1)) and N(G)-nitro-L-arginine methyl ester (L-NAME; 10 mg x kg(-1) x d(-1)) were administered in drinking water for 8 wk. Sprague-Dawley rats were randomized to the following groups: sham-operated control (Sham); MI sedentary (Sed); MI exercise (Ex); MI sedentary + L-arginine (Sed + LA); MI exercise + L-arginine (Ex + LA); MI sedentary + L-NAME (Sed + L-NAME); and MI exercise + L-NAME (Ex + L-NAME). The glutathione peroxidase, catalase, and gp91(phox) mRNA levels were comparable among all the groups. The SOD mRNA level was significantly increased in the Ex group (5.43 +/- 0.87) compared with the Sed group (1.74 +/- 0.29), whereas this effect was pronouncedly down-regulated by the L-NAME intervention (2.51 +/- 1.17, P L-arginine treatment when compared with the Sed group. Fractional shortening was significantly preserved in the trained groups compared with their corresponding sedentary groups with or without drug treatments. However, the beneficial effect was not further improved by L-arginine treatment. Our results suggest that exercise training exerts antioxidative effects and attenuates myocardial fibrosis in the MI rats. These improvements, in turn, alleviate cardiac stiffness and preserve post-MI cardiac function. In addition, L-arginine appears to have no additive effect on cardiac function or expression of enzymatic antioxidants.

  7. Oral L-arginine before resistance exercise blunts growth hormone in strength trained males.

    Science.gov (United States)

    Forbes, Scott C; Harber, Vicki; Bell, Gordon J

    2014-04-01

    Acute resistance exercise and L-arginine have both been shown to independently elevate plasma growth hormone (GH) concentrations; however, their combined effect is controversial. The purpose was to investigate the combined effects of resistance exercise and L-arginine supplementation on plasma L-arginine, GH, GH secretagogues, and IGF-1 in strength trained participants. Fourteen strength trained males (age: 25 ± 4 y; body mass: 81.4 ± 9.0 kg; height: 179.4 ± 6.9 cm; and training experience: 6.3 ± 3.4 y) participated in a randomized double-blind crossover design (separated by ~7 days). Subjects reported to the laboratory at 08:00 in a fasted state, consumed L-arginine (ARG; 0.075 g·kg-1 body mass) or a placebo (PLA) before performing an acute bout of resistance exercise (3 sets of 8 exercises, 10 repetitions at ~75% 1RM). Blood samples were collected at rest, before exercise, and at 0, 15, 30, and 60 min of rest-recovery. The ARG condition significantly increased plasma L-arginine concentrations (~120%) while no change was detected in the PLA condition. There were no differences between conditions for GH, GH-releasing hormone, ghrelin, or IGF-1 at any time point. GH-inhibiting hormone was significantly lower in the ARG condition. However, integrated area under the curve for GH was blunted in the ARG condition (L-arginine = 288.4 ± 368.7 vs. placebo = 487.9± 482.0 min·ng·mL1, p L-arginine ingested before resistance exercise significantly elevated plasma L-arginine concentration but attenuated plasma GH in strength trained individuals despite a lower GHIH. Furthermore our data shows that the GH suppression was not due to a GH or IGF-1 induced autonegative feedback loop.

  8. Biocatalytic synthesis, antimicrobial properties and toxicity studies of arginine derivative surfactants.

    Science.gov (United States)

    Fait, M Elisa; Garrote, Graciela L; Clapés, Pere; Tanco, Sebastian; Lorenzo, Julia; Morcelle, Susana R

    2015-07-01

    Two novel arginine-based cationic surfactants were synthesized using as biocatalyst papain, an endopeptidase from Carica papaya latex, adsorbed onto polyamide. The classical substrate N (α)-benzoyl-arginine ethyl ester hydrochloride for the determination of cysteine and serine proteases activity was used as the arginine donor, whereas decyl- and dodecylamine were used as nucleophiles for the condensation reaction. Yields higher than 90 and 80 % were achieved for the synthesis of N (α)-benzoyl-arginine decyl amide (Bz-Arg-NHC10) and N (α)-benzoyl-arginine dodecyl amide (Bz-Arg-NHC12), respectively. The purification process was developed in order to make it more sustainable, by using water and ethanol as the main separation solvents in a single cationic exchange chromatographic separation step. Bz-Arg-NHC10 and Bz-Arg-NHC12 proved antimicrobial activity against both Gram-positive and Gram-negative bacteria, revealing their potential use as effective disinfectants as they reduced 99 % the initial bacterial population after only 1 h of contact. The cytotoxic effect towards different cell types of both arginine derivatives was also measured. Bz-Arg-NHCn demonstrated lower haemolytic activity and were less eye-irritating than the commercial cationic surfactant cetrimide. A similar trend could also be observed when cytotoxicity was tested on hepatocytes and fibroblast cell lines: both arginine derivatives were less toxic than cetrimide. All these properties would make the two novel arginine compounds a promising alternative to commercial cationic surfactants, especially for their use as additives in topical formulations.

  9. The Effects of L-arginine on the Hippocampus of Male Rat Fetuses under Maternal Stress

    Directory of Open Access Journals (Sweden)

    Reza Mahmoudi

    2016-01-01

    arginine (1.7±0.15 mm and nonstress (1.6±0.13 mm groups. Discussion: Results indicated that prenatal stress could lead to neurodegeneration of hippocampus and prefrontal cortex of rat fetuses. L-arginine as a precursor of NO synthesis had neuroprotective effect during prenatal stress and could be used an effective treatment for stress.

  10. The effect of L-arginine on guinea-pig and rabbit airway smooth muscle function in vitro

    Directory of Open Access Journals (Sweden)

    A.C. Perez

    1998-06-01

    Full Text Available We have investigated the effects of L-arginine, D-arginine and L-lysine on airway smooth muscle responsiveness to spasmogens in vitro. Both L-arginine and D-arginine (100 mM significantly reduced the contractile potency and maximal contractile response to histamine but not to methacholine or potassium chloride in guinea-pig epithelium-denuded isolated trachea. Similarly, the contractile response to histamine was significantly reduced by L-arginine (100 mM in rabbit epithelium-denuded isolated bronchus. The amino acid L-lysine (100 mM failed to significantly alter the contractile potency of histamine in guinea-pig isolated trachea (P>0.05. In guinea-pig isolated trachea precontracted with histamine, both L-arginine and D-arginine produced a concentration-dependent relaxation which was not significantly altered by epithelium removal or by the presence of the nitric oxide synthase inhibitor, NG-nitro L-arginine methyl ester (L-NAME; 50 µM. Thus, at very high concentrations, arginine exhibit a non-competitive antagonism of histamine-induced contraction of isolated airway preparations that was independent of the generation of nitric oxide and was not dependent on charge. These observations confirm previous studies of cutaneous permeability responses and of contractile responses of guinea-pig isolated ileal smooth muscle. Taken together, the data suggest that high concentrations of arginine can exert an anti-histamine effect.

  11. The role of arginine metabolic pathway during embryogenesis and germination in maritime pine (Pinus pinaster Ait.).

    Science.gov (United States)

    Llebrés, María-Teresa; Pascual, María-Belén; Debille, Sandrine; Trontin, Jean-François; Harvengt, Luc; Avila, Concepción; Cánovas, Francisco M

    2018-03-01

    Vegetative propagation through somatic embryogenesis is critical in conifer biotechnology towards multivarietal forestry that uses elite varieties to cope with environmental and socio-economic issues. An important and still sub-optimal process during in vitro maturation of somatic embryos (SE) is the biosynthesis and deposition of storage proteins, which are rich in amino acids with high nitrogen (N) content, such as arginine. Mobilization of these N-rich proteins is essential for the germination and production of vigorous somatic seedlings. Somatic embryos accumulate lower levels of N reserves than zygotic embryos (ZE) at a similar stage of development. To understand the molecular basis for this difference, the arginine metabolic pathway has been characterized in maritime pine (Pinus pinaster Ait.). The genes involved in arginine metabolism have been identified and GFP-fusion constructs were used to locate the enzymes in different cellular compartments and clarify their metabolic roles during embryogenesis and germination. Analysis of gene expression during somatic embryo maturation revealed high levels of transcripts for genes involved in the biosynthesis and metabolic utilization of arginine. By contrast, enhanced expression levels were only observed during the last stages of maturation and germination of ZE, consistent with the adequate accumulation and mobilization of protein reserves. These results suggest that arginine metabolism is unbalanced in SE (simultaneous biosynthesis and degradation of arginine) and could explain the lower accumulation of storage proteins observed during the late stages of somatic embryogenesis.

  12. Synthesis and characterization of ZnS quantum dots and application for development of arginine biosensor

    Directory of Open Access Journals (Sweden)

    Neelam Verma

    2017-09-01

    Full Text Available Arginine deiminase co-immobilized with ZnS QDs coupled micro-disk was applied for the sensing of arginine in real and spiked fruit samples. Intracellular arginine deiminase from Lactococcus lactis MTCC 460 was partially purified by ammonium sulphate precipitation and co-immobilized on hydrosol gel disk with ZnS quantum dots. Surface study and topology of immobilized ZnS QDs were characterized by SEM. The size of MPA capped ZnS quantum dots was achieved up to 200 nm. Excitation and emission wavelength of synthesized ZnS QDs was observed to be 259 and 580 nm respectively. Linear range of detection of arginine was found to be 1.0 to 10−4 M and developed biosensor was used to monitor arginine in water melon and pomegranate fruit juices. Main advantage of the developed system is there is no need of pretreatment of sample for the estimation of arginine content.

  13. Effects of various dietary arginine and lysine concentrations on plasma and liver cholesterol concentrations in rats.

    Science.gov (United States)

    Spielmann, Julia; Noatsch, Anne; Brandsch, Corinna; Stangl, Gabriele I; Eder, Klaus

    2008-01-01

    It has been hypothesized that the arginine:lysine ratio of dietary proteins influences cholesterol concentrations in plasma and liver of men and animals. This study was performed to test this hypothesis in rats by using diets with various concentrations of arginine and lysine, differing in their arginine:lysine ratios. Two experiments with growing rats were performed, some of which received diets containing 4.5, 9 or 18 g arginine/kg and 9 or 18 g lysine/kg, respectively, for a period of 21 days. In the first experiment, a cholesterol-free diet was used; in the second experiment, a diet supplemented with cholesterol and sodium cholate as hypercholesterolaemic compounds was used. In experiment 1, increasing the arginine concentration lowered HDL and plasma cholesterol concentration; however, cholesterol concentrations in liver, LDL and VLDL remained unchanged. In experiment 2, increasing the arginine concentration lowered HDL cholesterol and increased liver cholesterol (plysine concentration concerned the effect on VLDL and liver cholesterol concentration, which were both lower in rats fed the diets with 18 g lysine/kg than in those fed the diets with 9 g lysine/kg (parginine:lysine ratio between 0.25 and 2.0 had no influence on cholesterol concentration in LDL and VLDL in both experiments; HDL cholesterol concentration was lowered by increasing this ratio (parginine:lysine ratio causes hypocholesterolaemic effects in rats. Copyright 2008 S. Karger AG, Basel.

  14. tlpA gene expression is required for arginine and bicarbonate chemotaxis in Helicobacter pylori.

    Science.gov (United States)

    Cerda, Oscar A; Núñez-Villena, Felipe; Soto, Sarita E; Ugalde, José Manuel; López-Solís, Remigio; Toledo, Héctor

    2011-01-01

    About half of the human population is infected with Helicobacter pylori, a bacterium causing gastritis, peptic ulcer and progression to gastric cancer. Chemotaxis and flagellar motility are required for colonization and persistence of H. pylori in the gastric mucus layer. It is not completely clear which chemical gradients are used by H. pylori to maintain its position. TlpA, a chemotaxis receptor for arginine/ bicarbonate, has been identified. This study aimed to find out whether tlpA gene expression is required for the chemotactic response to arginine/bicarbonate. Wild-type motile H. pylori ATCC 700392 and H. pylori ATCC 43504, a strain having an interrupted tlpA gene, were used. Also, a tlpA-knockout mutant of H. pylori 700392 (H. pylori 700-tlpA::cat) was produced by homologous recombination. Expression of tlpA was assessed by a Reverse Transcriptase-Polymerase Chain Reaction (RT-PCR) assay. Chemotaxis was measured as a Relative Chemotaxis Response (RCR) by a modified capillary assay. H. pylori 700392 presented chemotaxis to arginine and sodium bicarbonate. H. pylori 700-tlpA::cat showed neither tlpA gene expression nor chemotaxis towards arginine and bicarbonate. Besides confirming that TlpA is a chemotactic receptor for arginine/bicarbonate in H. pylori, this study showed that tlpA gene expression is required for arginine/bicarbonate chemotaxis.

  15. Streptococcus pyogenes Arginine and Citrulline Catabolism Promotes Infection and Modulates Innate Immunity

    Science.gov (United States)

    Cusumano, Zachary T.; Watson, Michael E.

    2014-01-01

    A bacterium's ability to acquire nutrients from its host during infection is an essential component of pathogenesis. For the Gram-positive pathogen Streptococcus pyogenes, catabolism of the amino acid arginine via the arginine deiminase (ADI) pathway supplements energy production and provides protection against acid stress in vitro. Its expression is enhanced in murine models of infection, suggesting an important role in vivo. To gain insight into the function of the ADI pathway in pathogenesis, the virulence of mutants defective in each of its enzymes was examined. Mutants unable to use arginine (ΔArcA) or citrulline (ΔArcB) were attenuated for carriage in a murine model of asymptomatic mucosal colonization. However, in a murine model of inflammatory infection of cutaneous tissue, the ΔArcA mutant was attenuated but the ΔArcB mutant was hyperattenuated, revealing an unexpected tissue-specific role for citrulline metabolism in pathogenesis. When mice defective for the arginine-dependent production of nitric oxide (iNOS−/−) were infected with the ΔArcA mutant, cutaneous virulence was rescued, demonstrating that the ability of S. pyogenes to utilize arginine was dispensable in the absence of nitric oxide-mediated innate immunity. This work demonstrates the importance of arginine and citrulline catabolism and suggests a novel mechanism of virulence by which S. pyogenes uses its metabolism to modulate innate immunity through depletion of an essential host nutrient. PMID:24144727

  16. Egg quality of hens fed different digestible lysine and arginine levels

    Directory of Open Access Journals (Sweden)

    FB de Carvalho

    2015-03-01

    Full Text Available This experiment aimed at evaluating the influence of the supplementation of digestible lysine and digestible arginine at different ratios in the diet fed to layers between 24 to 44 weeks of age on egg quality. In total,320 Lohmann LSL laying hens were allotted according to a completely randomized design in a 2 x 4factorial arrangement, consisting of two digestible lysine levels (700 or 900 mg/kg of diet and four digestible arginine levels (700, 800, 900,or 1000 mg/kg of diet. Diets contained, therefore, digestible Lys:Arg ratios of 100, 114, 128, and 142 when the diet contained 700 mg digestible lysine per kg of diet, and 78, 89, 100, and 111 when 900 mg digestible lysine per kg was supplemented. The data obtained with digestible arginine levels were fitted to polynomial regression equations, and with digestible lysine, the F test (5% probability was used to compare the means. The following variables were evaluated: egg weight; internal egg quality (yolk percentage and index, albumen percentage, Haugh units, eggshell quality (specific gravity andeggshell percentage; and whole egg, albumen, and yolk solids content. Digestible lysine and arginine interaction did not affect egg quality. Increasing levels of digestible lysine and arginine reduced eggshell quality and albumen solids, respectively. The levels of these amino acids suggested to improveegg quality are 700 mg digestible lysine and 700 mg digestible arginine/kg of feed at a Dig Lys: Dig Arg ratio of 100.

  17. tlpA gene expression is required for arginine and bicarbonate chemotaxis in Helicobacter pylori

    Directory of Open Access Journals (Sweden)

    Oscar A Cerda

    2011-01-01

    Full Text Available About half of the human population is infected with Helicobacter pylori, a bacterium causing gastritis, peptic ulcer and progression to gastric cancer. Chemotaxis and flagellar motility are required for colonization and persistence of H. pylori in the gastric mucus layer. It is not completely clear which chemical gradients are used by H. pylori to maintain its position. TlpA, a chemotaxis receptor for arginine/ bicarbonate, has been identified. This study aimed to find out whether tlpA gene expression is required for the chemotactic response to arginine/bicarbonate. Wild-type motile H. pylori ATCC 700392 and H. pylori ATCC 43504, a strain having an interrupted tlpA gene, were used. Also, a tlpA-knockout mutant of H. pylori 700392 (H. pylori 700-tlpA::cat was produced by homologous recombination. Expression of tlpA was assessed by a Reverse Transcriptase-Polymerase Chain Reaction (RT-PCR assay. Chemotaxis was measured as a Relative Chemotaxis Response (RCR by a modified capillary assay. H. pylori 700392 presented chemotaxis to arginine and sodium bicarbonate. H. pylori 700-tlpA::cat showed neither tlpA gene expression nor chemotaxis towards arginine and bicarbonate. Besides confirming that TlpA is a chemotactic receptor for arginine/bicarbonate in H. pylori, this study showed that tlpA gene expression is required for arginine/bicarbonate chemotaxis.

  18. Regulatory roles for L-arginine in reducing white adipose tissue

    Science.gov (United States)

    Tan, Bi’e; Li, Xinguo; Yin, Yulong; Wu, Zhenlong; Liu, Chuang; Tekwe, Carmen D.; Wu, Guoyao

    2012-01-01

    As the nitrogenous precursor of nitric oxide, L-arginine regulates multiple metabolic pathways involved in the metabolism of fatty acids, glucose, amino acids, and proteins through cell signaling and gene expression. Specifically, arginine stimulates lipolysis and the expression of key genes responsible for activation of fatty acid oxidation to CO2 and water. The underlying mechanisms involve increases in the expression of peroxisome proliferator-activated receptor-gamma coactivator-1 alpha (PGC-1 alpha), mitochondrial biogenesis, and the growth of brown adipose tissue growth. Furthermore, arginine regulates adipocyte-muscle crosstalk and energy partitioning via the secretion of cytokines and hormones. In addition, arginine enhances AMP-activated protein kinase (AMPK) expression and activity, thereby modulating lipid metabolism and energy balance toward the loss of triacylglycerols. Growing evidence shows that dietary supplementation with arginine effectively reduces white adipose tissue in Zucker diabetic fatty rats, diet-induced obese rats, growing-finishing pigs, and obese patients with type II diabetes. Thus, arginine can be used to prevent and treat adiposity and the associated metabolic syndrome. PMID:22652774

  19. Dietary L-arginine supplementation affects the skeletal longissimus muscle proteome in finishing pigs.

    Science.gov (United States)

    Ma, Xianyong; Zheng, Chuntian; Hu, Youjun; Wang, Li; Yang, Xuefen; Jiang, Zongyong

    2015-01-01

    Forty-eight Duroc x Landrace x Large White gilts were used to determine the relationship between proteome changes of longissimus muscle and intramuscular fat (IMF) content in arginine-supplemented pigs. Beginning at 60 kg BW, pigs were fed a corn- and soybean meal-based diet supplemented or not with 1% L-arginine until they reached a BW of 100 kg. Supplementation with 1% L-arginine did not affect the growth performance or carcass traits, while it increased IMF content by 32% (P supplementation with 1% dietary L-arginine did not change the proportion of SFA and MUFA in muscle lipids. The proteome changes in longissimus muscle between the control and supplemented pigs showed that L-arginine significantly influenced the abundance of proteins related to energy metabolism, fiber type and structure. The increase in IMF content was positively correlated with the increased abundance of slow twitch troponin I (TNNI1) protein and negatively correlated with myosin heavy chain IIb (MyHC IIb) protein content. It is suggested that the proteome changes in longissimus muscle contributed to the greater IMF content in L-arginine supplemented pigs.

  20. Dietary L-arginine supplementation affects the skeletal longissimus muscle proteome in finishing pigs.

    Directory of Open Access Journals (Sweden)

    Xianyong Ma

    Full Text Available Forty-eight Duroc x Landrace x Large White gilts were used to determine the relationship between proteome changes of longissimus muscle and intramuscular fat (IMF content in arginine-supplemented pigs. Beginning at 60 kg BW, pigs were fed a corn- and soybean meal-based diet supplemented or not with 1% L-arginine until they reached a BW of 100 kg. Supplementation with 1% L-arginine did not affect the growth performance or carcass traits, while it increased IMF content by 32% (P < 0.01, it also decreased the drip loss at 48 h post-mortem and the b* meat color value at 24 h post-mortem; supplementation with 1% dietary L-arginine did not change the proportion of SFA and MUFA in muscle lipids. The proteome changes in longissimus muscle between the control and supplemented pigs showed that L-arginine significantly influenced the abundance of proteins related to energy metabolism, fiber type and structure. The increase in IMF content was positively correlated with the increased abundance of slow twitch troponin I (TNNI1 protein and negatively correlated with myosin heavy chain IIb (MyHC IIb protein content. It is suggested that the proteome changes in longissimus muscle contributed to the greater IMF content in L-arginine supplemented pigs.

  1. Serum L-arginine and dimethylarginine levels in migraine patients with brain white matter lesions.

    Science.gov (United States)

    Erdélyi-Bótor, Szilvia; Komáromy, Hedvig; Kamson, David Olayinka; Kovács, Norbert; Perlaki, Gábor; Orsi, Gergely; Molnár, Tihamér; Illes, Zsolt; Nagy, Lajos; Kéki, Sándor; Deli, Gabriella; Bosnyák, Edit; Trauninger, Anita; Pfund, Zoltán

    2017-05-01

    Background/Aim Migraine is a risk factor for the formation of silent brain white matter lesions (WMLs) that are possibly ischemic in nature. Although dysfunction of the L-arginine/nitric oxide (NO) pathway has been associated with oxidative stress and endothelial dysfunction in migraine, its role in WML development has not been specifically investigated. Thus, this prospective study aimed to measure the serum concentrations of the NO substrate L-arginine, the NO synthase inhibitor asymmetric dimethylarginine (ADMA), and the L-arginine transport regulator symmetric dimethylarginine (SDMA) in migraine patients in a headache-free period. Methods All participants underwent MR imaging to assess for the presence of WMLs on fluid-attenuated inversion recovery imaging. Altogether 109 migraine patients (43 with lesions, 66 without lesions) and 46 control individuals were studied. High-performance liquid chromatography was used to quantify L-arginine, ADMA and SDMA serum concentrations. Migraine characteristics were investigated, and participants were screened for risk factors that can lead to elevated serum ADMA levels independent of migraine. Results Migraine patients and controls did not differ in regard to vascular risk factors. Migraineurs with WMLs had a longer disease duration ( p L-arginine serum levels were found in both migraine subgroups compared to controls ( p L-arginine serum levels might reflect an increased demand for NO synthesis.

  2. Dietary L-Arginine Supplementation Affects the Skeletal Longissimus Muscle Proteome in Finishing Pigs

    Science.gov (United States)

    Ma, Xianyong; Zheng, Chuntian; Hu, Youjun; Wang, Li; Yang, Xuefen; Jiang, Zongyong

    2015-01-01

    Forty-eight Duroc x Landrace x Large White gilts were used to determine the relationship between proteome changes of longissimus muscle and intramuscular fat (IMF) content in arginine-supplemented pigs. Beginning at 60 kg BW, pigs were fed a corn- and soybean meal-based diet supplemented or not with 1% L-arginine until they reached a BW of 100 kg. Supplementation with 1% L-arginine did not affect the growth performance or carcass traits, while it increased IMF content by 32% (P L-arginine did not change the proportion of SFA and MUFA in muscle lipids. The proteome changes in longissimus muscle between the control and supplemented pigs showed that L-arginine significantly influenced the abundance of proteins related to energy metabolism, fiber type and structure. The increase in IMF content was positively correlated with the increased abundance of slow twitch troponin I (TNNI1) protein and negatively correlated with myosin heavy chain IIb (MyHC IIb) protein content. It is suggested that the proteome changes in longissimus muscle contributed to the greater IMF content in L-arginine supplemented pigs. PMID:25635834

  3. L-Arginine metabolism in cardiovascular and renal tissue from hyper- and hypothyroid rats.

    Science.gov (United States)

    Rodríguez-Gómez, Isabel; Moliz, Juan N; Quesada, Andrés; Montoro-Molina, Sebastian; Vargas-Tendero, Pablo; Osuna, Antonio; Wangensteen, Rosemary; Vargas, Félix

    2016-03-01

    This study assessed the effects of thyroid hormones on the enzymes involved in l-arginine metabolism and the metabolites generated by the different metabolic pathways. Compounds of l-arginine metabolism were measured in the kidney, heart, aorta, and liver of euthyroid, hyperthyroid, and hypothyroid rats after 6 weeks of treatment. Enzymes studied were NOS isoforms (neuronal [nNOS], inducible [iNOS], and endothelial [eNOS]), arginases I and II, ornithine decarboxylase (ODC), ornithine aminotransferase (OAT), and l-arginine decarboxylase (ADC). Metabolites studied were l-arginine, l-citrulline, spermidine, spermine, and l-proline. Kidney heart and aorta levels of eNOS and iNOS were augmented and reduced (P l-arginine, was reduced (P l-arginine metabolic pathways. The changes recorded in the abundance of eNOS, arginases I and II, and ADC protein in renal and cardiovascular tissues may play a role in the hemodynamic and renal manifestations observed in thyroid disorders. Furthermore, the changes in ODC and spermidine might contribute to the changes in cardiac and renal mass observed in thyroid disorders. © 2015 by the Society for Experimental Biology and Medicine.

  4. L-Arginine Pathway in COPD Patients with Acute Exacerbation: A New Potential Biomarker.

    Science.gov (United States)

    Ruzsics, Istvan; Nagy, Lajos; Keki, Sandor; Sarosi, Veronika; Illes, Balazs; Illes, Zsolt; Horvath, Ildiko; Bogar, Lajos; Molnar, Tihamer

    2016-01-01

    Acute exacerbation of chronic obstructive pulmonary disease (AECOPD) remains a major cause of mortality. Clinical criteria of AECOPD are subjective. Biomarkers for AECOPD may aid in the initiation of early treatment. Increased production of asymmetric and symmetric dimethylarginine (ADMA, SDMA) is related to hypoxia. In COPD, a rise in ADMA results in a shift of L-arginine breakdown, contributing to airway obstruction. We aimed to compare serum levels of ADMA, SDMA and L-arginine in patients with and without AECOPD. L-arginine metabolites quantified by high-performance liquid chromatography in venous blood samples and partial capillary oxygen pressure were prospectively investigated in 32 patients with COPD, 12 with AECOPD and 30 healthy subjects. Both ADMA and SDMA were significantly higher in AECOPD compared to stable COPD (p = 0.004 and p L-arginine was not different between AECOPD and stable COPD. Both ADMA and SDMA separated AECOPD with high sensitivity and specificity (AUC: 0.81, p = 0.001; AUC: 0.91, p L-arginine, ADMA and SDMA serum levels. In patients with AECOPD, production of ADMA and SDMA are more pronounced presumably due to more severe hypoxic insult. Methylated arginine derivatives in the sera may help early recognition of AECOPD.

  5. L-arginine ingestion after rest and exercise: effects on glucose disposal.

    Science.gov (United States)

    Robinson, Tristan M; Sewell, Dean A; Greenhaff, Paul L

    2003-08-01

    There is considerable interest, both in health and disease, in enhancing postexercise glucose uptake and glycogen resynthesis in skeletal muscle. The amino acid, arginine, is known to stimulate insulin release and enhance glucose-stimulated insulin release. The present investigation examined whether an oral dose of L-arginine (10 g), when given with 70 g carbohydrate (CHO, in the form of simple sugars) improved factors associated with glucose disposal in previously exercised and nonexercised healthy males. The effects of different modes of activity (resistance or cycling exercise) upon these factors were also examined. Whole-blood glucose and serum insulin concentrations after L-arginine + CHO ingestion were not significantly different from the placebo condition (glycine + CHO ingestion) in all experimental treatments (nonexercised, resistance exercise, and cycling exercise). Similarly, CHO oxidation, forearm blood flow, blood pressure, and heart rate during the postingestion period were unaffected by L-arginine + CHO consumption in all three experimental treatments. A 10-g oral dose of L-arginine was found to have no effect on blood glucose disposal in human subjects after oral CHO ingestion, either when rested or after different modes of exercise known to differentially affect glucose disposal. These results suggest that the addition of L-arginine to a CHO beverage would not augment postexercise CHO replenishment in healthy human subjects.

  6. Growth hormone response to insulin and to arginine in patients with familial hypercholesterolaemia.

    Science.gov (United States)

    Muggeo, M; Tiengo, A; Fedele, D; Crepaldi, G

    1975-01-01

    Human growth hormone (HGH) response to i.v. insulin (0.1 U/kg body weight) and arginine infusion (25 g of L-arginine for 30 min) was studied in 9 patients (5 males and 4 females) with primary familial hypercholesterolaemia and belonging to 4 families. Mean age was 28 +/- 2 years (range 18-36) and body weight was less than 105% of ideal body weight. Glucose tolerance and insulin response to oral glucose were normal in all patients. HGH release after insulin and after arginine was slightly increased as compared to 21 normal controls, but the differences were not significant. Insulin and glucagon response to arginine in these patients was within the normal range. Plasma glucose and free fatty acids were normal after both insulin and arginine. Moreover, no significant correlation was found between fasting cholesterol and HGH peaks after insulin and after arginine, nor between cholesterol and insulin and glucagon responses. Despite marked hyperlipidaemia, HGH-deficient patients examined by other authors never present signs of atherosclerotic disease. Our data suggest that HGH, in the presence of elevated cholesterol levels, might play an important role in the development of atherosclerotic lesions.

  7. Histone arginine methylation in cocaine action in the nucleus accumbens.

    Science.gov (United States)

    Damez-Werno, Diane M; Sun, HaoSheng; Scobie, Kimberly N; Shao, Ningyi; Rabkin, Jaclyn; Dias, Caroline; Calipari, Erin S; Maze, Ian; Pena, Catherine J; Walker, Deena M; Cahill, Michael E; Chandra, Ramesh; Gancarz, Amy; Mouzon, Ezekiell; Landry, Joseph A; Cates, Hannah; Lobo, Mary-Kay; Dietz, David; Allis, C David; Guccione, Ernesto; Turecki, Gustavo; Defilippi, Paola; Neve, Rachael L; Hurd, Yasmin L; Shen, Li; Nestler, Eric J

    2016-08-23

    Repeated cocaine exposure regulates transcriptional regulation within the nucleus accumbens (NAc), and epigenetic mechanisms-such as histone acetylation and methylation on Lys residues-have been linked to these lasting actions of cocaine. In contrast to Lys methylation, the role of histone Arg (R) methylation remains underexplored in addiction models. Here we show that protein-R-methyltransferase-6 (PRMT6) and its associated histone mark, asymmetric dimethylation of R2 on histone H3 (H3R2me2a), are decreased in the NAc of mice and rats after repeated cocaine exposure, including self-administration, and in the NAc of cocaine-addicted humans. Such PRMT6 down-regulation occurs selectively in NAc medium spiny neurons (MSNs) expressing dopamine D2 receptors (D2-MSNs), with opposite regulation occurring in D1-MSNs, and serves to protect against cocaine-induced addictive-like behavioral abnormalities. Using ChIP-seq, we identified Src kinase signaling inhibitor 1 (Srcin1; also referred to as p140Cap) as a key gene target for reduced H3R2me2a binding, and found that consequent Srcin1 induction in the NAc decreases Src signaling, cocaine reward, and the motivation to self-administer cocaine. Taken together, these findings suggest that suppression of Src signaling in NAc D2-MSNs, via PRMT6 and H3R2me2a down-regulation, functions as a homeostatic brake to restrain cocaine action, and provide novel candidates for the development of treatments for cocaine addiction.

  8. Properties of residuals for spatial point processes

    DEFF Research Database (Denmark)

    Baddeley, A.; Møller, Jesper; Pakes, A. G.

    2008-01-01

    For any point process in Rd that has a Papangelou conditional intensity λ, we define a random measure of ‘innovations' which has mean zero. When the point process model parameters are estimated from data, there is an analogous random measure of ‘residuals'. We analyse properties of the innovation...... and residuals, including first and second moments, conditional independence, a martingale property, and lack of correlation. Some large sample asymptotics are studied. We derive the marginal distribution of smoothed residuals by solving a distributional equivalence....

  9. Effects of L-arginine immobilization on the anticoagulant activity and hemolytic property of polyethylene terephthalate films

    International Nuclear Information System (INIS)

    Liu Yun; Yang Yun; Wu Feng

    2010-01-01

    Surface modification of polyethylene terephthalate (PET) films was performed with L-arginine (L-Arg) to gain an improved anticoagulant surface. The surface chemistry changes of modified films were characterized by X-ray photoelectron spectroscopy (XPS) and attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy. The in vitro anticoagulant activities of the surface-modified PET films were evaluated by blood clotting test, hemolytic test, and the measurement of clotting time including plasma recalcification time (PRT), activated partial thromboplastin time (APTT), and prothrombin time (PT). The data of blood coagulation index (BCI) for L-arginine modified PET films (PET-Arg) was larger than that for PET at the same blood-sample contact time. The hemolysis ratio for PET-Arg was less than that for PET and within the accepted standard for biomaterials. The PRT and APTT for PET-Arg were significantly prolonged by 189 s and 25 s, respectively, compared to those for the unmodified PET. All results suggested that the currently described modification method could be a possible candidate to create antithrombogenic PET surfaces which would be useful for further medical applications.

  10. Effects of L-arginine immobilization on the anticoagulant activity and hemolytic property of polyethylene terephthalate films

    Energy Technology Data Exchange (ETDEWEB)

    Liu Yun, E-mail: liuy@tgrc.org [Department of Chemistry, School of Science, Xi' an Jiaotong University, Xi' an 710049 (China); Yang Yun [Department of Chemistry, School of Science, Xi' an Jiaotong University, Xi' an 710049 (China); Wu Feng [Research Centre of Blood, College of Medicine, Xi' an Jiaotong University, Xi' an 710065 (China)

    2010-04-01

    Surface modification of polyethylene terephthalate (PET) films was performed with L-arginine (L-Arg) to gain an improved anticoagulant surface. The surface chemistry changes of modified films were characterized by X-ray photoelectron spectroscopy (XPS) and attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy. The in vitro anticoagulant activities of the surface-modified PET films were evaluated by blood clotting test, hemolytic test, and the measurement of clotting time including plasma recalcification time (PRT), activated partial thromboplastin time (APTT), and prothrombin time (PT). The data of blood coagulation index (BCI) for L-arginine modified PET films (PET-Arg) was larger than that for PET at the same blood-sample contact time. The hemolysis ratio for PET-Arg was less than that for PET and within the accepted standard for biomaterials. The PRT and APTT for PET-Arg were significantly prolonged by 189 s and 25 s, respectively, compared to those for the unmodified PET. All results suggested that the currently described modification method could be a possible candidate to create antithrombogenic PET surfaces which would be useful for further medical applications.

  11. Effects of arginine vasopressin on musical working memory.

    Science.gov (United States)

    Granot, Roni Y; Uzefovsky, Florina; Bogopolsky, Helena; Ebstein, Richard P

    2013-01-01

    Previous genetic studies showed an association between variations in the gene coding for the 1a receptor of the neuro-hormone arginine vasopressin (AVP) and musical working memory (WM). The current study set out to test the influence of intranasal administration (INA) of AVP on musical as compared to verbal WM using a double blind crossover (AVP-placebo) design. Two groups of 25 males were exposed to 20 IU of AVP in one session, and 20 IU of saline water (placebo) in a second session, 1 week apart. In each session subjects completed the tonal subtest from Gordon's "Musical Aptitude Profile," the interval subtest from the "Montreal Battery for Evaluation of Amusias (MBEA)," and the forward and backward digit span tests. Scores in the digit span tests were not influenced by AVP. In contrast, in the music tests there was an AVP effect. In the MBEA test, scores for the group receiving placebo in the first session (PV) were higher than for the group receiving vasopressin in the first session (VP) (p music test these scores were significantly correlated with memory scores. Together the results reflect a complex interaction between AVP, musical memory, arousal, and contextual effects such as session, and base levels of memory. The results are interpreted in light of music's universal use as a means to modulate arousal on the one hand, and AVP's influence on mood, arousal, and social interactions on the other.

  12. Mutation of lysine residues in the nucleotide binding segments of the poliovirus RNA-dependent RNA polymerase.

    Science.gov (United States)

    Richards, O C; Baker, S; Ehrenfeld, E

    1996-12-01

    The poliovirus 3D RNA-dependent RNA polymerase contains two peptide segments previously shown to cross-link to nucleotide substrates via lysine residues. To determine which lysine residue(s) might be implicated in catalytic function, we engineered mutations to generate proteins with leucine residues substituted individually for each of the lysine residues in the NTP binding regions. These proteins were expressed in Escherichia coli and were examined for their abilities to bind nucleotides and to catalyze RNA chain elongation in vitro. Replacement of each lysine residue in the NTP binding segment located in the central portion of the 3D molecule (Lys-276, -278, or -283) with leucine produced no impairment of GTP binding or polymerase activity. Substitution of leucine for Lys-61 in the N-terminal portion of the protein, however, abolished the binding of protein to GTP-agarose and all detectable polymerase activity. A nearby lysine replacement with leucine at position 66 had no effect on enzyme activity. The three mutations in the central region of 3D were introduced into full-length viral cDNAs, and the infectivities of RNA transcripts were examined in transfected HeLa cells. Growth of virus containing 3D with a mutation at residue 278 (3Dmu278) or 3Dmu283 was indistinguishable from that of the wild type; however, 3Dmu276 generated extremely slow-growing, small-plaque virus. Polyprotein processing by 3CDmu276 was unaffected. Large-plaque variants, in which the Leu-276 codon had mutated again to an arginine codon, emerged at high frequency. The results suggest that a lysine residue at position 61 of 3Dpol is essential for polymerase catalytic function and that a basic (lysine or arginine) residue at position 276 is required for some other function of 3D important for virus growth but not for RNA chain elongation or polyprotein processing.

  13. Arginine-rich cross-linking peptides with different SV40 nuclear localization signal content as vectors for intranuclear DNA delivery.

    Science.gov (United States)

    Bogacheva, Mariia; Egorova, Anna; Slita, Anna; Maretina, Marianna; Baranov, Vladislav; Kiselev, Anton

    2017-11-01

    The major barriers for intracellular DNA transportation by cationic polymers are their toxicity, poor endosomal escape and inefficient nuclear uptake. Therefore, we designed novel modular peptide-based carriers modified with SV40 nuclear localization signal (NLS). Core peptide consists of arginine, histidine and cysteine residues for DNA condensation, endosomal escape promotion and interpeptide cross-linking, respectively. We investigated three polyplexes with different NLS content (10 mol%, 50 mol% and 90 mol% of SV40 NLS) as vectors for intranuclear DNA delivery. All carriers tested were able to condense DNA, to protect it from DNAase I and were not toxic to the cells. We observed that cell cycle arrest by hydroxyurea did not affect transfection efficacy of NLS-modified carriers which we confirmed using quantitative confocal microscopy analysis. Overall, peptide carrier modified with 90 mol% of SV40 NLS provided efficient transfection and nuclear uptake in non-dividing cells. Thus, incorporation of NLS into arginine-rich cross-linking peptides is an adequate approach to the development of efficient intranuclear gene delivery vehicles. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. Performance and concentration of amino acids in plasma and urine of young pigs fed diets with excesses of either arginine or lysine.

    Science.gov (United States)

    Southern, L L; Baker, D H

    1982-10-01

    Four experiments were conducted to investigate the arginine x lysine interaction in young pigs. Excess supplemental arginine (.67 to 2% of diet) decreased weight gain and feed intake, but had no effect on efficiency of feed utilization. Lysine supplementation (.5 or 2.5%) did not ameliorate the adverse effects of excess arginine. Decreasing the arginine content to .8% from a level routinely supplied by typical swine diets (1.3%) did not improve pig performance. Excess supplemental arginine increased plasma arginine and ornithine concentrations and decreased plasma lysine and histidine concentrations; several other amino acids were decreased in plasma as well. Feeding 2.8% total dietary arginine resulted in a dramatic increase in urinary excretion of arginine, ornithine, citrulline, lysine, histidine and cystine. From these results it is concluded that the adverse effects of excess arginine represent classic amino acid imbalance rather than amino acid antagonism.

  15. The twin arginine protein transport pathway exports multiple virulence proteins in the plant pathogen Streptomyces scabies.

    Science.gov (United States)

    Joshi, Madhumita V; Mann, Stefan G; Antelmann, Haike; Widdick, David A; Fyans, Joanna K; Chandra, Govind; Hutchings, Matthew I; Toth, Ian; Hecker, Michael; Loria, Rosemary; Palmer, Tracy

    2010-07-01

    Summary Streptomyces scabies is one of a group of organisms that causes the economically important disease potato scab. Analysis of the S. scabies genome sequence indicates that it is likely to secrete many proteins via the twin arginine protein transport (Tat) pathway, including several proteins whose coding sequences may have been acquired through horizontal gene transfer and share a common ancestor with proteins in other plant pathogens. Inactivation of the S. scabies Tat pathway resulted in pleiotropic phenotypes including slower growth rate and increased permeability of the cell envelope. Comparison of the extracellular proteome of the wild type and DeltatatC strains identified 73 predicted secretory proteins that were present in reduced amounts in the tatC mutant strain, and 47 Tat substrates were verified using a Tat reporter assay. The DeltatatC strain was almost completely avirulent on Arabidopsis seedlings and was delayed in attaching to the root tip relative to the wild-type strain. Genes encoding 14 candidate Tat substrates were individually inactivated, and seven of these mutants were reduced in virulence compared with the wild-type strain. We conclude that the Tat pathway secretes multiple proteins that are required for full virulence.

  16. The Strictly Conserved Arg-321 Residue in the Active Site of Escherichia coli Topoisomerase I Plays a Critical Role in DNA Rejoining*

    Science.gov (United States)

    Narula, Gagandeep; Annamalai, Thirunavukkarasu; Aedo, Sandra; Cheng, Bokun; Sorokin, Elena; Wong, Agnes; Tse-Dinh, Yuk-Ching

    2011-01-01

    The strictly conserved arginine residue proximal to the active site tyrosine of type IA topoisomerases is required for the relaxation of supercoiled DNA and was hypothesized to be required for positioning of the scissile phosphate for DNA cleavage to take place. Mutants of recombinant Yersinia pestis topoisomerase I with hydrophobic substitutions at this position were found in genetic screening to exhibit a dominant lethal phenotype, resulting in drastic loss in Escherichia coli viability when overexpressed. In depth biochemical analysis of E. coli topoisomerase I with the corresponding Arg-321 mutation showed that DNA cleavage can still take place in the absence of this arginine function if Mg2+ is present to enhance the interaction of the enzyme with the scissile phosphate. However, DNA rejoining is inhibited in the absence of this conserved arginine, resulting in accumulation of the cleaved covalent intermediate and loss of relaxation activity. These new experimental results demonstrate that catalysis of DNA rejoining by type IA topoisomerases has a more stringent requirement than DNA cleavage. In addition to the divalent metal ions, the side chain of this arginine residue is required for the precise positioning of the phosphotyrosine linkage for nucleophilic attack by the 3′-OH end to result in DNA rejoining. Small molecules that can interfere or distort the enzyme-DNA interactions required for DNA rejoining by bacterial type IA topoisomerases could be developed into novel antibacterial drugs. PMID:21478161

  17. Residual-stress measurements

    Energy Technology Data Exchange (ETDEWEB)

    Ezeilo, A.N.; Webster, G.A. [Imperial College, London (United Kingdom); Webster, P.J. [Salford Univ. (United Kingdom)

    1997-04-01

    Because neutrons can penetrate distances of up to 50 mm in most engineering materials, this makes them unique for establishing residual-stress distributions non-destructively. D1A is particularly suited for through-surface measurements as it does not suffer from instrumental surface aberrations commonly found on multidetector instruments, while D20 is best for fast internal-strain scanning. Two examples for residual-stress measurements in a shot-peened material, and in a weld are presented to demonstrate the attractive features of both instruments. (author).

  18. L-arginine enhances cell proliferation and reduces apoptosis in human endometrial RL95-2 cells

    Science.gov (United States)

    2013-01-01

    Background L-arginine is considered to be one of the most versatile amino acids due to the fact that it serves as a precursor for many important molecules in cellular physiology. When supplemented in the diet, L-arginine can increase the number of implantation sites in mice and rats, suggesting an effect at the level of the endometrium. To this end, this study determined the effect that L-arginine has on apoptosis and cell proliferation in human endometrial RL95-2 cells. Results L-arginine at physiological (200 micromol/L) and supra-physiological (800 micromol/L) concentrations increased cell proliferation at days 2 and 4 post-treatment with a dose-dependent effect being observed on day 2. Additionally, inhibition of nitric oxide (NO) synthase and arginase, which are responsible for the conversion of L-arginine to NO and polyamines, respectively, reduced the proliferative effect of L-arginine. L-arginine also decreased the proportion of cells with TUNEL positive nuclei and increased the ratio of cells with healthy mitochondria compared to cells with a disrupted mitochondrial membrane potential, indicating that L-arginine prevents mitochondrial mediated apoptosis in endometrial RL95-2 cells. Furthermore, exposure to L-arginine did not affect total BAD protein expression; however, L-arginine increased the abundance of phosphorylated BAD protein. Conclusions In summary, L-arginine added to the culture media at physiological (200 micromol/L) and supraphysiological concentrations (800 micromol/L) enhanced endometrial RL95-2 cell proliferation through mechanisms mediated by NO and polyamine biosynthesis. In addition, L-arginine reduced endometrial RL95-2 mitochondrial mediated apoptosis through increased phosphorylation of BAD protein. PMID:23442442

  19. Development and evaluation of a host-targeted antiviral that abrogates herpes simplex virus replication through modulation of arginine-associated metabolic pathways.

    Science.gov (United States)

    Sanchez, Maria Dulfary; Ochoa, Augusto C; Foster, Timothy P

    2016-08-01

    Since their inception five decades ago, most antivirals have been engineered to disrupt a single viral protein or process that is essential for viral replication. This approach has limited the overall therapeutic effectiveness and applicability of current antivirals due to restricted viral specificity, a propensity for development of drug resistance, and an inability to control deleterious host-mediated inflammation. As obligate intracellular parasites, viruses are reliant on host metabolism and macromolecular synthesis pathways. Of these biosynthetic processes, many viruses, including Herpes simplex viruses (HSV), are absolutely dependent on the bioavailability of arginine, a non-essential amino acid that is critical for many physiological and pathophysiological processes associated with either facilitating viral replication or progression of disease. To assess if targeting host arginine-associated metabolic pathways would inhibit HSV replication, a pegylated recombinant human Arginase I (peg-ArgI) was generated and its in vitro anti-herpetic activity was evaluated. Cells continuously treated with peg-ArgI for over 48 h exhibited no signs of cytotoxicity or loss of cell viability. The antiviral activity of peg-ArgI displayed a classical dose-response curve with IC50's in the sub-nanomolar range. peg-ArgI potently inhibited HSV-1 and HSV-2 viral replication, infectious virus production, cell-to-cell spread/transmission and virus-mediated cytopathic effects. Not unexpectedly given its host-targeted mechanism of action, peg-ArgI showed similar effectiveness at controlling replication of single and multidrug resistant HSV-1 mutants. These findings illustrate that targeting host arginine-associated metabolic pathways is an effective means of controlling viral replicative processes. Further exploration into the breadth of viruses inhibited by peg-ArgI, as well as the ability of peg-ArgI to suppress arginine-associated virus-mediated pathophysiological disease

  20. Pump apparatus including deconsolidator

    Energy Technology Data Exchange (ETDEWEB)

    Sonwane, Chandrashekhar; Saunders, Timothy; Fitzsimmons, Mark Andrew

    2014-10-07

    A pump apparatus includes a particulate pump that defines a passage that extends from an inlet to an outlet. A duct is in flow communication with the outlet. The duct includes a deconsolidator configured to fragment particle agglomerates received from the passage.

  1. N-(2,4)-dinitrophenyl-L-arginine Interacts with EphB4 and Functions as an EphB4 Kinase Modulator.

    Science.gov (United States)

    Kamstra, Rhiannon L; Freywald, Andrew; Floriano, Wely B

    2015-10-01

    The erythropoietin-producing hepatocellular carcinoma receptor B4 is a receptor tyrosine kinase whose expression is preserved in various malignancies, including colon, gastric, and breast carcinoma. Hepatocellular carcinoma receptor B4 presence in tumor cells and involvement in cancer suppression makes it a potential therapeutic target for activating compounds. Moreover, modulators of its activity also have a strong potential to be used in diagnosis and therapy monitoring. We used virtual ligand screening to identify novel hepatocellular carcinoma receptor B4 kinase modulators for experimental testing. Three independent assay platforms confirmed that dinitrophenyl-L-arginine is likely to affect the kinase activity of hepatocellular carcinoma receptor B4. An enzyme-coupled spectrophotometric assay has been used to examine this possibility and may prove to be useful for assessing other novel kinase modulator candidates. Overall, our observations suggest that dinitrophenyl-L-arginine has an activating effect on hepatocellular carcinoma receptor B4 and, therefore, more efficient derivatives may have therapeutic effects in tumors where hepatocellular carcinoma receptor B4 exhibits antimalignant properties. The hepatocellular carcinoma receptor B4-activating effect is discussed with respect to previously described mechanisms, using predicted and experimental structures for docked ligands. As a novel kinase activity modulator, dinitrophenyl-L-arginine may provide new insights into molecular mechanisms by which kinases are activated or regulated, and may serve as a lead compound for the generation of novel hepatocellular carcinoma receptor B4-activating therapeutic compounds. © 2014 John Wiley & Sons A/S.

  2. Production of the amino acids l-glutamate, l-lysine, l-ornithine and l-arginine from arabinose by recombinant Corynebacterium glutamicum.

    Science.gov (United States)

    Schneider, Jens; Niermann, Karin; Wendisch, Volker F

    2011-07-10

    Amino acid production processes with Corynebacterium glutamicum are based on media containing glucose from starch hydrolysis or fructose and sucrose as present in molasses. Simultaneous utilization of various carbon sources, including glucose, fructose and sucrose, in blends is a typical characteristic of this bacterium. The renewable non-food carbon source arabinose, which is present in hemicellulosic hydrolysates, cannot be utilized by most C. glutamicum strains. Heterologous expression of the araBAD operon from Escherichia coli in the wild-type and in an l-lysine producing strain of C. glutamicum was shown to enable production of l-glutamate and l-lysine, respectively, from arabinose as sole carbon source. l-Ornithine and l-arginine producing strains were constructed and shown to produce l-ornithine and l-arginine from arabinose when araBAD from E. coli was expressed. Moreover, the recombinant strains produced l-glutamate, l-lysine, l-ornithine and l-arginine respectively, from arabinose also when glucose-arabinose blends were used as carbon sources. Copyright © 2010 Elsevier B.V. All rights reserved.

  3. The protective effect of NG-nitro-L-arginine methyl ester and insulin on nitric oxide inhibition and pathology in experimental diabetic rat liver

    International Nuclear Information System (INIS)

    Ozden, H.; Guven, G.; Tekin, N.; Akyuz, F.; Gurer, F.; Kucuk, F.; Ustuner, Mehmet C.; Yaylak, F.

    2009-01-01

    Objective was to determine on protective role of NG-nitro-L-arginine methyl ester (L-NAME) and insulin on the liver in streptoozotocin (STZ) induced diabetic rats. This study was performed in the Department of Biochemistry, Faculty of Medicine, Eskisehir Osmangazi University, Eskisehir, Turkey in 2007. Forty male Wistar albino rats were divided into 5 groups. These were untreated, diabetic control, STZ+insulin, STZ+L-NAME and STZ+insulin+L-NAME induced groups. The STZ was intraperitonally injected into 3 groups and includes insulin, L-NAME and their joint administrations as protective agents. The blood glucose and nitric oxide (NO) levels were determined. The tissue samples were obtained at the end of the fourth week. The liver tissue distortions were evaluated using hematoxylin and eosin staining. The serum glucose level was significantly higher in diabetic control (p=0.000), than the untreated group. The focal pseudo lobular structures without vena centralis increased portal fibrillary necrosis and bile duct stenosis with voagulation necrosis of the peripheral hepatocytes were more observed in diabetic group than the protective agent groups. In addition, insulin and L-NAME lead to hepatocyte regeneration and minimal mononuclear cell infiltration was noted. NG-nitro-L-arginine methyl ester inhibits NO level in STZ+L-NAME induced group. NG-nitro-L-arginine methyl ester either alone or with insulin combination significantly attenuates the liver morphological disarrangements in STZ induced diabetic rats. (author)

  4. Intracellular L-arginine concentration does not determine NO production in endothelial cells: Implications on the “L-arginine paradox”

    International Nuclear Information System (INIS)

    Shin, Soyoung; Mohan, Srinidi; Fung, Ho-Leung

    2011-01-01

    Highlights: ► Our findings provide a possible solution to the “L-arginine paradox”. ► Extracellular L-arginine concentration is the major determinant of NO production. ► Cellular L-arginine action is limited by cellular ARG transport, not the K m of NOS. ► We explain how L-arginine supplementation can work to increase endothelial function. -- Abstract: We examined the relative contributory roles of extracellular vs. intracellular L-arginine (ARG) toward cellular activation of endothelial nitric oxide synthase (eNOS) in human endothelial cells. EA.hy926 human endothelial cells were incubated with different concentrations of 15 N 4 -ARG, ARG, or L-arginine ethyl ester (ARG-EE) for 2 h. To modulate ARG transport, siRNA for ARG transporter (CAT-1) vs. sham siRNA were transfected into cells. ARG transport activity was assessed by cellular fluxes of ARG, 15 N 4 -ARG, dimethylarginines, and L-citrulline by an LC–MS/MS assay. eNOS activity was determined by nitrite/nitrate accumulation, either via a fluorometric assay or by 15 N-nitrite or estimated 15 N 3 -citrulline concentrations when 15 N 4 -ARG was used to challenge the cells. We found that ARG-EE incubation increased cellular ARG concentration but no increase in nitrite/nitrate was observed, while ARG incubation increased both cellular ARG concentration and nitrite accumulation. Cellular nitrite/nitrate production did not correlate with cellular total ARG concentration. Reduced 15 N 4 -ARG cellular uptake in CAT-1 siRNA transfected cells vs. control was accompanied by reduced eNOS activity, as determined by 15 N-nitrite, total nitrite and 15 N 3 -citrulline formation. Our data suggest that extracellular ARG, not intracellular ARG, is the major determinant of NO production in endothelial cells. It is likely that once transported inside the cell, ARG can no longer gain access to the membrane-bound eNOS. These observations indicate that the “L-arginine paradox” should not consider intracellular ARG

  5. Intracellular L-arginine concentration does not determine NO production in endothelial cells: Implications on the 'L-arginine paradox'

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Soyoung; Mohan, Srinidi [Department of Pharmaceutical Sciences, University at Buffalo, The State University of New York, Buffalo, NY 14260 (United States); Fung, Ho-Leung, E-mail: hlfung@buffalo.edu [Department of Pharmaceutical Sciences, University at Buffalo, The State University of New York, Buffalo, NY 14260 (United States)

    2011-11-04

    Highlights: Black-Right-Pointing-Pointer Our findings provide a possible solution to the 'L-arginine paradox'. Black-Right-Pointing-Pointer Extracellular L-arginine concentration is the major determinant of NO production. Black-Right-Pointing-Pointer Cellular L-arginine action is limited by cellular ARG transport, not the K{sub m} of NOS. Black-Right-Pointing-Pointer We explain how L-arginine supplementation can work to increase endothelial function. -- Abstract: We examined the relative contributory roles of extracellular vs. intracellular L-arginine (ARG) toward cellular activation of endothelial nitric oxide synthase (eNOS) in human endothelial cells. EA.hy926 human endothelial cells were incubated with different concentrations of {sup 15}N{sub 4}-ARG, ARG, or L-arginine ethyl ester (ARG-EE) for 2 h. To modulate ARG transport, siRNA for ARG transporter (CAT-1) vs. sham siRNA were transfected into cells. ARG transport activity was assessed by cellular fluxes of ARG, {sup 15}N{sub 4}-ARG, dimethylarginines, and L-citrulline by an LC-MS/MS assay. eNOS activity was determined by nitrite/nitrate accumulation, either via a fluorometric assay or by{sup 15}N-nitrite or estimated {sup 15}N{sub 3}-citrulline concentrations when {sup 15}N{sub 4}-ARG was used to challenge the cells. We found that ARG-EE incubation increased cellular ARG concentration but no increase in nitrite/nitrate was observed, while ARG incubation increased both cellular ARG concentration and nitrite accumulation. Cellular nitrite/nitrate production did not correlate with cellular total ARG concentration. Reduced {sup 15}N{sub 4}-ARG cellular uptake in CAT-1 siRNA transfected cells vs. control was accompanied by reduced eNOS activity, as determined by {sup 15}N-nitrite, total nitrite and {sup 15}N{sub 3}-citrulline formation. Our data suggest that extracellular ARG, not intracellular ARG, is the major determinant of NO production in endothelial cells. It is likely that once transported inside

  6. Metabolism via arginase or nitric oxide synthase: two competing arginine pathways in macrophages

    Directory of Open Access Journals (Sweden)

    Meera eRath

    2014-10-01

    Full Text Available Macrophages play a major role in the immune system, both as antimicrobial effector cells and as immunoregulatory cells, which induce, suppress or modulate adaptive immune responses. These key aspects of macrophage biology are fundamentally driven by the phenotype of macrophage arginine metabolism that is prevalent in an evolving or ongoing immune response. M1 macrophages express the enzyme nitric oxide synthase (NOS, which metabolizes arginine to nitric oxide (NO and citrulline. NO can be metabolized to further downstream reactive nitrogen species, while citrulline might be reused for efficient NO synthesis via the citrulline-NO cycle. M2 macrophages are characterized by expression of the enzyme arginase, which hydrolyzes arginine to ornithine and urea. The arginase pathway limits arginine availability for NO synthesis and ornithine itself can further feed into the important downstream pathways of polyamine and proline syntheses, which are important for cellular proliferation and tissue repair. M1 versus M2 polarization leads to opposing outcomes of inflammatory reactions, but depending on the context, M1 and M2 macrophages can be both pro- and antiinflammatory. Notably, M1/M2 macrophage polarization can be driven by microbial infection or innate danger signals without any influence of adaptive immune cells, secondarily driving the T helper (Th1/Th2 polarization of the evolving adaptive immune response. Since both arginine metabolic pathways cross-inhibit each other on the level of the respective arginine break-down products and Th1 and Th2 lymphocytes can drive or amplify macrophage M1/M2 dichotomy via cytokine activation, this forms the basis of a self-sustaining M1/M2 polarization of the whole immune response. Understanding the arginine metabolism of M1/M2 macrophage phenotypes is therefore central to find new possibilities to manipulate immune responses in infection, autoimmune diseases, chronic inflammatory conditions and cancer.

  7. Clinical Outcome And Arginine Serum of Acute Ischemic Stroke Patients Supplemented by Snakehead Fish Extract

    Science.gov (United States)

    Pudjonarko, Dwi; Retnaningsih; Abidin, Zainal

    2018-02-01

    Background: Levels of arginine associated with clinical outcome in acute ischemic stroke (AIS). Arginine is a protein needed to synthesis nitric oxide (NO), a potential vasodilator and antioxidant. Snakehead fish is a source of protein which has antioxidant activity. Snakehead fish contains mineral, vitamin, and amino acids. One of the amino acids that were found quite high in snakehead fish extract is arginine. The aim of this study was done to determine the effect of snakehead fish extracts (SFE) on serum arginin levels and clinical outcome of AIS patients. Methods: It was double-blind randomized pretest-posttest control group design, with. AIS patients were divided into two groups i.e. snakehead fish extracts (SFE) and control. SFE group were administered 15 grams SFE for 7 days . Arginine serum levels and clinical outcome (measured by National Institute of Health Stroke Scale = NIHSS) were measured before and after treatment, other related factors were also analyzed in Logistic regression. Results: A total of 42 subjects who were performed random allocation as SFE or control group. There was no differences in subject characteristics between the two groups. There was a differences Δ arginine serum levels between SFE and control (33.6±19.95 μmol/L 0.3±2.51 μmol/L p<0.001). Change in NIHSS score in SFE improved significantly compared to the control group (4.14 ± 2.03; 2.52 ± 1.81;p=0.009 ). Logistic regression analysis showed only female gender factor that affected on improvement of NIHSS (OR=7; p=0,01). Conclusion: There is Clinical outcome improvement and enhancement of arginine serum levels in AIS patient with snakehead fish extract supplementation.

  8. Diabetic nephropathy is resistant to oral L-arginine or L-citrulline supplementation.

    Science.gov (United States)

    You, Hanning; Gao, Ting; Cooper, Timothy K; Morris, Sidney M; Awad, Alaa S

    2014-12-01

    Our recent publication showed that pharmacological blockade of arginases confers kidney protection in diabetic nephropathy via a nitric oxide (NO) synthase (NOS)3-dependent mechanism. Arginase competes with endothelial NOS (eNOS) for the common substrate L-arginine. Lack of L-arginine results in reduced NO production and eNOS uncoupling, which lead to endothelial dysfunction. Therefore, we hypothesized that L-arginine or L-citrulline supplementation would ameliorate diabetic nephropathy. DBA mice injected with multiple low doses of vehicle or streptozotocin (50 mg/kg ip for 5 days) were provided drinking water with or without L-arginine (1.5%, 6.05 g·kg(-1)·day(-1)) or L-citrulline (1.66%, 5.73 g·kg(-1)·day(-1)) for 9 wk. Nonsupplemented diabetic mice showed significant increases in albuminuria, blood urea nitrogen, glomerular histopathological changes, kidney macrophage recruitment, kidney TNF-α and fibronectin mRNA expression, kidney arginase activity, kidney arginase-2 protein expression, and urinary oxidative stress along with a significant reduction of nephrin and eNOS protein expression and kidney nitrite + nitrate compared with normal mice after 9 wk of diabetes. Surprisingly, L-arginine or L-citrulline supplementation in diabetic mice did not affect any of these parameters despite greatly increasing kidney and plasma arginine levels. These findings demonstrate that chronic L-arginine or L-citrulline supplementation does not prevent or reduce renal injury in a model of type 1 diabetes. Copyright © 2014 the American Physiological Society.

  9. Expression pattern of a nuclear encoded mitochondrial arginine-ornithine translocator gene from Arabidopsis

    Directory of Open Access Journals (Sweden)

    Schneider Anja

    2003-01-01

    Full Text Available Abstract Background Arginine and citrulline serve as nitrogen storage forms, but are also involved in biosynthetic and catabolic pathways. Metabolism of arginine, citrulline and ornithine is distributed between mitochondria and cytosol. For the shuttle of intermediates between cytosol and mitochondria transporters present on the inner mitochondrial membrane are required. Yeast contains a mitochondrial translocator for ornithine and arginine, Ort1p/Arg11p. Ort1p/Arg11p is a member of the mitochondrial carrier family (MCF essential for ornithine export from mitochondria. The yeast arg11 mutant, which is deficient in Ort1p/Arg11p grows poorly on media lacking arginine. Results High-level expression of a nuclear encoded Arabidopsis thaliana homolog (AtmBAC2 of Ort1p/Arg11p was able to suppress the growth deficiency of arg11. RT-PCR analysis demonstrated expression of AtmBAC2 in all tissues with highest levels in flowers. Promoter-GUS fusions showed preferential expression in flowers, i.e. pollen, in the vasculature of siliques and in aborted seeds. Variable expression was observed in leaf vasculature. Induction of the promoter was not observed during the first two weeks in seedlings grown on media containing NH4NO3, arginine or ornithine as sole nitrogen sources. Conclusion AtmBAC2 was isolated as a mitochondrial transporter for arginine in Arabidopsis. The absence of expression in developing seeds and in cotyledons of seedlings indicates that other transporters are responsible for storage and mobilization of arginine in seeds.

  10. Acylation of arginine in goserelin-loaded PLGA microspheres

    NARCIS (Netherlands)

    Shirangi, Mehrnoosh; Hennink, Wim E.; Somsen, Govert W.; Van Nostrum, Cornelus F.

    2016-01-01

    Acylation of peptides is a well-known but unwanted phenomenon in polyester matrices such as poly(d,l-lactic-co-glycolic acid) (PLGA) microspheres used as controlled release formulations. Acylation normally occurs on lysine residues and the N-terminus of the peptide. The purpose of the present work

  11. Dietary arginine silicate inositol complex inhibits periodontal tissue loss in rats with ligature-induced periodontitis

    Directory of Open Access Journals (Sweden)

    Dundar S

    2016-11-01

    Full Text Available Serkan Dundar,1 Abubekir Eltas,2 Sema S Hakki,3 Sıddık Malkoc,4 M Ozay Uslu,2 Mehmet Tuzcu,5 James Komorowski,6 I Hanifi Ozercan,7 Fatih Akdemir,8 Kazim Sahin9 1Department of Periodontology, Faculty of Dentistry, Firat University, Elazig, 2Department of Periodontology, Faculty of Dentistry, Inonu University, Malatya, 3Department of Periodontology, Faculty of Dentistry, Selcuk University, Konya, 4Department of Orthodontics, Faculty of Dentistry, Inonu University, Malatya, 5Department of Biology, Faculty of Science, Firat University, Elazig, Turkey; 6Research & Development, Nutrition 21 Inc., Purchase, NY, USA; 7Department of Pathology, Faculty of Medicine, 8Department of Animal Nutrition, Faculty of Fisheries, Inonu University, Malatya, 9Department of Animal Nutrition, Faculty of Veterinary Medicine, Firat University, Elazig, Turkey Abstract: The purpose of this study was to induce experimental periodontitis in rats previously fed diets containing arginine silicate inositol (ASI complex and examine the biochemical, immunological, and radiological effects. Fifty two 8-week-old female Sprague Dawley rats were equally divided into four groups. The control group included those fed a standard rat diet with no operation performed during the experiment. The periodontitis, ASI I, and ASI II groups were subjected to experimental periodontitis induction for 11 days after being fed a standard rat diet alone, a diet containing 1.81 g/kg ASI complex, or a diet containing 3.62 g/kg ASI complex, respectively, for 8 weeks. Throughout the 11-day duration of periodontitis induction, all rats were fed standard feed. The rats were euthanized on the eleventh day, and their tissue and blood samples were collected. In the periodontitis group, elevated tissue destruction parameters and reduced tissue formation parameters were found, as compared to the ASI groups. Levels of enzymes, cytokines, and mediators associated with periodontal tissue destruction were lower

  12. Association of Variants of Arginine Vasopressin and Arginine Vasopressin Receptor 1A With Severe Acetaminophen Liver InjurySummary

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    Matthew Randesi

    2017-05-01

    Full Text Available Background & Aims: Acetaminophen-related acute liver injury and liver failure (ALF result from ingestion of supratherapeutic quantities of this analgesic, frequently in association with other forms of substance abuse including alcohol, opioids, and cocaine. Thus, overdosing represents a unique high-risk behavior associated with other forms of drug use disorder. Methods: We examined a series of 21 single nucleotide polymorphisms (SNPs in 9 genes related to impulsivity and/or stress responsivity that may modify response to stress. Study subjects were 229 white patients admitted to tertiary care liver centers for ALF that was determined to be due to acetaminophen toxicity after careful review of historical and biochemical data. Identification of relevant SNPs used Sanger sequencing, TaqMan, or custom microarray. Association tests were carried out to compare genotype frequencies between patients and healthy white controls. Results: The mean age was 37 years, and 75.6% were female, with similar numbers classified as intentional overdose or unintentional (without suicidal intent, occurring for a period of several days, usually due to pain. There was concomitant alcohol abuse in 30%, opioid use in 33.6%, and use of other drugs of abuse in 30.6%. The genotype frequencies of 2 SNPs were found to be significantly different between the cases and controls, specifically SNP rs2282018 in the arginine vasopressin gene (AVP, odds ratio 1.64 and SNP rs11174811 in the AVP receptor 1A gene (AVPR1A, odds ratio 1.89, both of which have been previously linked to a drug use disorder diagnosis. Conclusions: Patients who develop acetaminophen-related ALF have increased frequency of gene variants that may cause altered stress responsivity, which has been shown to be associated with other unrelated substance use disorders. Keywords: Impulsivity, Stress Responsivity, Pituitary-Adrenal Axis, Overdose

  13. Amniotic Fluid Arginine from Gestational Weeks 13 to 15 Is a Predictor of Birth Weight, Length, and Head Circumference

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    Astrid Bjørke-Jenssen

    2017-12-01

    Full Text Available Arginine is a constituent of proteins and a precursor for polyamines and nitric oxide, and is essential for placentation, angiogenesis, and growth. Maternal plasma arginine concentrations are found to be lower in pregnancies complicated by fetal growth restriction, and arginine supplementation in later pregnancy is reported to increase birth weight. We measured arginine and the metabolites asymmetric dimethylarginine (ADMA and symmetric dimethylarginine (SDMA in the amniotic fluid obtained in pregnancy weeks 13 to 15 from 363 pregnancies with a documented normal outcome and related the concentrations to birth weight, length, and hea