Substrate Specificity of Human Protein Arginine Methyltransferase 7 (PRMT7)

PubMed Central

Feng, You; Hadjikyriacou, Andrea; Clarke, Steven G.

2014-01-01

Protein arginine methyltransferase 7 (PRMT7) methylates arginine residues on various protein substrates and is involved in DNA transcription, RNA splicing, DNA repair, cell differentiation, and metastasis. The substrate sequences it recognizes in vivo and the enzymatic mechanism behind it, however, remain to be explored. Here we characterize methylation catalyzed by a bacterially expressed GST-tagged human PRMT7 fusion protein with a broad range of peptide and protein substrates. After confirming its type III activity generating only ω-NG-monomethylarginine and its distinct substrate specificity for RXR motifs surrounded by basic residues, we performed site-directed mutagenesis studies on this enzyme, revealing that two acidic residues within the double E loop, Asp-147 and Glu-149, modulate the substrate preference. Furthermore, altering a single acidic residue, Glu-478, on the C-terminal domain to glutamine nearly abolished the activity of the enzyme. Additionally, we demonstrate that PRMT7 has unusual temperature dependence and salt tolerance. These results provide a biochemical foundation to understanding the broad biological functions of PRMT7 in health and disease. PMID:25294873

Neutralization of a single arginine residue gates open a two-pore domain, alkali-activated K+ channel

PubMed Central

Niemeyer, María Isabel; González-Nilo, Fernando D.; Zúñiga, Leandro; González, Wendy; Cid, L. Pablo; Sepúlveda, Francisco V.

2007-01-01

Potassium channels share a common selectivity filter that determines the conduction characteristics of the pore. Diversity in K+ channels is given by how they are gated open. TASK-2, TALK-1, and TALK-2 are two-pore region (2P) KCNK K+ channels gated open by extracellular alkalinization. We have explored the mechanism for this alkalinization-dependent gating using molecular simulation and site-directed mutagenesis followed by functional assay. We show that the side chain of a single arginine residue (R224) near the pore senses pH in TASK-2 with an unusual pKa of 8.0, a shift likely due to its hydrophobic environment. R224 would block the channel through an electrostatic effect on the pore, a situation relieved by its deprotonation by alkalinization. A lysine residue in TALK-2 fulfills the same role but with a largely unchanged pKa, which correlates with an environment that stabilizes its positive charge. In addition to suggesting unified alkaline pH-gating mechanisms within the TALK subfamily of channels, our results illustrate in a physiological context the principle that hydrophobic environment can drastically modulate the pKa of charged amino acids within a protein. PMID:17197424

The protein arginine methyltransferase PRMT5 promotes D2-like dopamine receptor signaling

PubMed Central

Likhite, Neah; Jackson, Christopher A.; Liang, Mao-Shih; Krzyzanowski, Michelle C.; Lei, Pedro; Wood, Jordan F.; Birkaya, Barbara; Michaels, Kerry L.; Andreadis, Stelios T.; Clark, Stewart D.; Yu, Michael C.; Ferkey, Denise M.

2017-01-01

Protein arginine methylation regulates diverse functions of eukaryotic cells, including gene expression, the DNA damage response, and circadian rhythms. We showed that arginine residues within the third intracellular loop of the human D2 dopamine receptor, which are conserved in the DOP-3 receptor in the nematode Caenorhabditis elegans, were methylated by protein arginine methyl-transferase 5 (PRMT5). By mutating these arginine residues, we further showed that their methylation enhanced the D2 receptor–mediated inhibition of cyclic adenosine monophosphate (cAMP) signaling in cultured human embryonic kidney (HEK) 293T cells. Analysis of prmt-5–deficient worms indicated that methylation promoted the dopamine-mediated modulation of chemosensory and locomotory behaviors in C. elegans through the DOP-3 receptor. In addition to delineating a previously uncharacterized means of regulating GPCR (heterotrimeric guanine nucleotide–binding protein–coupled receptor) signaling, these findings may lead to the development of a new class of pharmacological therapies that modulate GPCR signaling by changing the methylation status of these key proteins. PMID:26554819

Replacement of all arginine residues with canavanine in MazF-bs mRNA interferase changes its specificity.

PubMed

Ishida, Yojiro; Park, Jung-Ho; Mao, Lili; Yamaguchi, Yoshihiro; Inouye, Masayori

2013-03-15

Replacement of a specific amino acid residue in a protein with nonnatural analogues is highly challenging because of their cellular toxicity. We demonstrate for the first time the replacement of all arginine (Arg) residues in a protein with canavanine (Can), a toxic Arg analogue. All Arg residues in the 5-base specific (UACAU) mRNA interferase from Bacillus subtilis (MazF-bs(arg)) were replaced with Can by using the single-protein production system in Escherichia coli. The resulting MazF-bs(can) gained a 6-base recognition sequence, UACAUA, for RNA cleavage instead of the 5-base sequence, UACAU, for MazF-bs(arg). Mass spectrometry analysis confirmed that all Arg residues were replaced with Can. The present system offers a novel approach to create new functional proteins by replacing a specific amino acid in a protein with its analogues.

Protein arginine methyltransferase 1 regulates herpes simplex virus replication through ICP27 RGG-box methylation

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

Yu, Jungeun; Shin, Bongjin; Park, Eui-Soon

2010-01-01

Protein arginine methylation is involved in viral infection and replication through the modulation of diverse cellular processes including RNA metabolism, cytokine signaling, and subcellular localization. It has been suggested previously that the protein arginine methylation of the RGG-box of ICP27 is required for herpes simplex virus type-1 (HSV-1) viral replication and gene expression in vivo. However, a cellular mediator for this process has not yet been identified. In our current study, we show that the protein arginine methyltransferase 1 (PRMT1) is a cellular mediator of the arginine methylation of ICP27 RGG-box. We generated arginine substitution mutants in this domain andmore » examined which arginine residues are required for methylation by PRMT1. R138, R148 and R150 were found to be the major sites of this methylation but additional arginine residues serving as minor methylation sites are still required to sustain the fully methylated form of ICP27 RGG. We also demonstrate that the nuclear foci-like structure formation, SRPK interactions, and RNA-binding activity of ICP27 are modulated by the arginine methylation of the ICP27 RGG-box. Furthermore, HSV-1 replication is inhibited by hypomethylation of this domain resulting from the use of general PRMT inhibitors or arginine mutations. Our data thus suggest that the PRMT1 plays a key role as a cellular regulator of HSV-1 replication through ICP27 RGG-box methylation.« less

Characterization of the Drosophila protein arginine methyltransferases DART1 and DART4.

PubMed

Boulanger, Marie-Chloé; Miranda, Tina Branscombe; Clarke, Steven; Di Fruscio, Marco; Suter, Beat; Lasko, Paul; Richard, Stéphane

2004-04-15

The role of arginine methylation in Drosophila melanogaster is unknown. We identified a family of nine PRMTs (protein arginine methyltransferases) by sequence homology with mammalian arginine methyltransferases, which we have named DART1 to DART9 ( Drosophila arginine methyltransferases 1-9). In keeping with the mammalian PRMT nomenclature, DART1, DART4, DART5 and DART7 are the putative homologues of PRMT1, PRMT4, PRMT5 and PRMT7. Other DART family members have a closer resemblance to PRMT1, but do not have identifiable homologues. All nine genes are expressed in Drosophila at various developmental stages. DART1 and DART4 have arginine methyltransferase activity towards substrates, including histones and RNA-binding proteins. Amino acid analysis of the methylated arginine residues confirmed that both DART1 and DART4 catalyse the formation of asymmetrical dimethylated arginine residues and they are type I arginine methyltransferases. The presence of PRMTs in D. melanogaster suggest that flies are a suitable genetic system to study arginine methylation.

Solubilization of aromatic and hydrophobic moieties by arginine in aqueous solutions

NASA Astrophysics Data System (ADS)

Li, Jianguo; Garg, Manju; Shah, Dhawal; Rajagopalan, Raj

2010-08-01

Experiments hold intriguing, circumstantial clues to the mechanisms behind arginine-mediated solubilization of small organic drugs and suppression of protein aggregation driven by hydrophobic or aromatic associations, but how exactly arginine's molecular structure and interactions contribute to its function remains unclear since attention has focused so far on the thermodynamics of the preferential exclusion or binding of arginine. Here, we examine, through molecular dynamics simulations, how arginine solubilizes nanoscale particles with hydrophobic surfaces or aromatic-ring-type surface interactions. We show that preferential, hydrophobic, and dispersion interactions of arginine's guanidinium group with the particles lead to a surfactant-like behavior of arginine around the particles and to a solvation layer with a protective polar mask creating a hydrophilic shell. Additionally, arginine-arginine association around the solvation layer further prevents aggregative contacts. The results shed some light on the mechanistic basis of arginine's function as a suppressant of protein aggregation, although the complex energy landscapes and kinetic pathways of aggregation are protein-dependent and pose formidable challenges to developing comprehensive mechanistic pictures. Our results suggest arginine's mode of interaction with hydrophobic patches and aromatic residues could reduce aggregation-prone intermediate states of proteins and shield protein-protein aggregative contacts. The approach used here offers a systematic way of exploring implications of other amino acid/excipient interactions by studying interactions of the excipient with particles grafted with amino acids.

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

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

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

2009-05-22

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 positivemore » 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 {approx}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.« less

Steroidogenic activity of fragments of adrenocorticotropin with arginine in residue positions 3 and 5.

PubMed Central

Jean-Baptiste, E; Draper, M W; Rizack, M A

1977-01-01

The maximal steroidogenic response (Smax) to adrenocorticotropin (ACTH) is enhanced by the substitution of arginine in position 3. Though the Smax of adrenocorticotropin-(3-10)-octapeptide [ACTH-(3-10)] is only 20% of ACTH-(1-24) in isolated rabbit adrenal cells and 10% in rat cells, [Arg3]ACTH-(3-10) has an Smax comparable to that of the longer peptide. Activity determined from the midpoints of dose-response curves (A50), however, is several orders of magnitude less. The Smax of ACTH-(4-10) is not significantly different from that of the 3-10 analog. Substitution of arginine in the 5 position of ACTH-(4-10) decreases activity for rabbit cells, but does not affect activity for rat cells. The substitution of arginine in the 5 position of ACTH-(1-20) markedly decreases Smax in rabbit but not rat cells. The Smax of [Arg 3,5)]ACTH-(3-10), containing both substitutions, is greater than that of ACTH-(3-10), but much less than that of [Arg3]acth-(3-10) in both species studied. These findings contrast with those in the rabbit adipocyte, where both arginine-containing ACTH analogs have enhanced activity and the effects of both substitutions in a single peptide are additive. PMID:200914

Characterization of the Drosophila protein arginine methyltransferases DART1 and DART4.

PubMed Central

Boulanger, Marie-Chloé; Miranda, Tina Branscombe; Clarke, Steven; Di Fruscio, Marco; Suter, Beat; Lasko, Paul; Richard, Stéphane

2004-01-01

The role of arginine methylation in Drosophila melanogaster is unknown. We identified a family of nine PRMTs (protein arginine methyltransferases) by sequence homology with mammalian arginine methyltransferases, which we have named DART1 to DART9 ( Drosophila arginine methyltransferases 1-9). In keeping with the mammalian PRMT nomenclature, DART1, DART4, DART5 and DART7 are the putative homologues of PRMT1, PRMT4, PRMT5 and PRMT7. Other DART family members have a closer resemblance to PRMT1, but do not have identifiable homologues. All nine genes are expressed in Drosophila at various developmental stages. DART1 and DART4 have arginine methyltransferase activity towards substrates, including histones and RNA-binding proteins. Amino acid analysis of the methylated arginine residues confirmed that both DART1 and DART4 catalyse the formation of asymmetrical dimethylated arginine residues and they are type I arginine methyltransferases. The presence of PRMTs in D. melanogaster suggest that flies are a suitable genetic system to study arginine methylation. PMID:14705965

157 nm Photodissociation of Dipeptide Ions Containing N-Terminal Arginine

NASA Astrophysics Data System (ADS)

Webber, Nathaniel; He, Yi; Reilly, James P.

2014-02-01

Twenty singly-charged dipeptide ions with N-terminal arginine were photodissociated using 157 nm light in both a linear ion-trap mass spectrometer and a MALDI-TOF-TOF mass spectrometer. Analogous to previous work on dipeptides containing C-terminal arginine, this set of samples enabled insights into the photofragmentation propensities associated with individual residues. In addition to familiar products such as a-, d-, and immonium ions, m2 and m2+13 ions were also observed. Certain side chains tended to cleave between their β and γ carbons without necessarily forming d- or w-type ions, and a few other ions were produced by the high-energy fragmentation of multiple bonds.

Arginine mimetic structures in biologically active antagonists and inhibitors.

PubMed

Masic, Lucija Peterlin

2006-01-01

Peptidomimetics have found wide application as bioavailable, biostable, and potent mimetics of naturally occurring biologically active peptides. L-Arginine is a guanidino group-containing basic amino acid, which is positively charged at neutral pH and is involved in many important physiological and pathophysiological processes. Many enzymes display a preference for the arginine residue that is found in many natural substrates and in synthetic inhibitors of many trypsin-like serine proteases, e.g. thrombin, factor Xa, factor VIIa, trypsin, and in integrin receptor antagonists, used to treat many blood-coagulation disorders. Nitric oxide (NO), which is produced by oxidation of L-arginine in an NADPH- and O(2)-dependent process catalyzed by isoforms of nitric oxide synthase (NOS), exhibits diverse roles in both normal and pathological physiologies and has been postulated to be a contributor to the etiology of various diseases. Development of NOS inhibitors as well as analogs and mimetics of the natural substrate L-arginine, is desirable for potential therapeutic use and for a better understanding of their conformation when bound in the arginine binding site. The guanidino residue of arginine in many substrates, inhibitors, and antagonists forms strong ionic interactions with the carboxylate of an aspartic acid moiety, which provides specificity for the basic amino acid residue in the active side. However, a highly basic guanidino moiety incorporated in enzyme inhibitors or receptor antagonists is often associated with low selectivity and poor bioavailability after peroral application. Thus, significant effort is focused on the design and preparation of arginine mimetics that can confer selective inhibition for specific trypsin-like serine proteases and NOS inhibitors as well as integrin receptor antagonists and possess reduced basicity for enhanced oral bioavailability. This review will describe the survey of arginine mimetics designed to mimic the function of the

Protein Arginine Methylation and Citrullination in Epigenetic Regulation

PubMed Central

2015-01-01

The post-translational modification of arginine residues represents a key mechanism for the epigenetic control of gene expression. Aberrant levels of histone arginine modifications have been linked to the development of several diseases including cancer. In recent years, great progress has been made in understanding the physiological role of individual arginine modifications and their effects on chromatin function. The present review aims to summarize the structural and functional aspects of histone arginine modifying enzymes and their impact on gene transcription. We will discuss the potential for targeting these proteins with small molecules in a variety of disease states. PMID:26686581

Supplemental Citrulline Is More Efficient Than Arginine in Increasing Systemic Arginine Availability in Mice.

PubMed

Agarwal, Umang; Didelija, Inka C; Yuan, Yang; Wang, Xiaoying; Marini, Juan C

2017-04-01

Background: Arginine is considered to be an essential amino acid in various (patho)physiologic conditions of high demand. However, dietary arginine supplementation suffers from various drawbacks, including extensive first-pass extraction. Citrulline supplementation may be a better alternative than arginine, because its only fate in vivo is conversion into arginine. Objective: The goal of the present research was to determine the relative efficiency of arginine and citrulline supplementation to improve arginine availability. Methods: Six-week-old C57BL/6J male mice fitted with gastric catheters were adapted to 1 of 7 experimental diets for 2 wk. The basal diet contained 2.5 g l-arginine/kg, whereas the supplemented diets contained an additional 2.5, 7.5, and 12.5 g/kg diet of either l-arginine or l-citrulline. On the final day, after a 3-h food deprivation, mice were continuously infused intragastrically with an elemental diet similar to the dietary treatment, along with l-[ 13 C 6 ]arginine, to determine the splanchnic first-pass metabolism (FPM) of arginine. In addition, tracers were continuously infused intravenously to determine the fluxes and interconversions between citrulline and arginine. Linear regression slopes were compared to determine the relative efficiency of each supplement. Results: Whereas all the supplemented citrulline (105% ± 7% SEM) appeared in plasma and resulted in a marginal increase of 86% in arginine flux, supplemental arginine underwent an ∼70% FPM, indicating that only 30% of the supplemental arginine entered the peripheral circulation. However, supplemental arginine did not increase arginine flux. Both supplements linearly increased ( P < 0.01) plasma arginine concentration from 109 μmol/L for the basal diet to 159 and 214 μmol/L for the highest arginine and citrulline supplementation levels, respectively. However, supplemental citrulline increased arginine concentrations to a greater extent (35%, P < 0.01). Conclusions: Citrulline

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

PubMed Central

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

Asymmetric Arginine dimethylation of Epstein-Barr virus nuclear antigen 2 promotes DNA targeting

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

Gross, Henrik; Barth, Stephanie; Palermo, Richard D.

The Epstein-Barr virus (EBV) growth-transforms B-lymphocytes. The virus-encoded nuclear antigen 2 (EBNA2) is essential for transformation and activates gene expression by association with DNA-bound transcription factors such as RBPJkappa (CSL/CBF1). We have previously shown that EBNA2 contains symmetrically dimethylated Arginine (sDMA) residues. Deletion of the RG-repeat results in a reduced ability of the virus to immortalise B-cells. We now show that the RG repeat also contains asymmetrically dimethylated Arginines (aDMA) but neither non-methylated (NMA) Arginines nor citrulline residues. We demonstrate that only aDMA-containing EBNA2 is found in a complex with DNA-bound RBPJkappa in vitro and preferentially associates with the EBNA2-responsivemore » EBV C, LMP1 and LMP2A promoters in vivo. Inhibition of methylation in EBV-infected cells results in reduced expression of the EBNA2-regulated viral gene LMP1, providing additional evidence that methylation is a prerequisite for DNA-binding by EBNA2 via association with the transcription factor RBPJkappa.« less

Rmt1 catalyzes zinc-finger independent arginine methylation of ribosomal protein Rps2 in Saccharomyces cerevisiae

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

Lipson, Rebecca S.; Webb, Kristofor J.; Clarke, Steven G., E-mail: clarke@mbi.ucla.edu

2010-01-22

Rps2/rpS2 is a well conserved protein of the eukaryotic ribosomal small subunit. Rps2 has previously been shown to contain asymmetric dimethylarginine residues, the addition of which is catalyzed by zinc-finger-containing arginine methyltransferase 3 (Rmt3) in the fission yeast Schizosaccharomyces pombe and protein arginine methyltransferase 3 (PRMT3) in mammalian cells. Here, we demonstrate that despite the lack of a zinc-finger-containing homolog of Rmt3/PRMT3 in the budding yeast Saccharomyces cerevisiae, Rps2 is partially modified to generate asymmetric dimethylarginine and monomethylarginine residues. We find that this modification of Rps2 is dependent upon the major arginine methyltransferase 1 (Rmt1) in S. cerevisiae. These resultsmore » are suggestive of a role for Rmt1 in modifying the function of Rps2 in a manner distinct from that occurring in S. pombe and mammalian cells.« less

Supplemental Citrulline Is More Efficient Than Arginine in Increasing Systemic Arginine Availability in Mice123

PubMed Central

Agarwal, Umang; Didelija, Inka C; Yuan, Yang; Wang, Xiaoying; Marini, Juan C

2017-01-01

Background: Arginine is considered to be an essential amino acid in various (patho)physiologic conditions of high demand. However, dietary arginine supplementation suffers from various drawbacks, including extensive first-pass extraction. Citrulline supplementation may be a better alternative than arginine, because its only fate in vivo is conversion into arginine. Objective: The goal of the present research was to determine the relative efficiency of arginine and citrulline supplementation to improve arginine availability. Methods: Six-week-old C57BL/6J male mice fitted with gastric catheters were adapted to 1 of 7 experimental diets for 2 wk. The basal diet contained 2.5 g l-arginine/kg, whereas the supplemented diets contained an additional 2.5, 7.5, and 12.5 g/kg diet of either l-arginine or l-citrulline. On the final day, after a 3-h food deprivation, mice were continuously infused intragastrically with an elemental diet similar to the dietary treatment, along with l-[13C6]arginine, to determine the splanchnic first-pass metabolism (FPM) of arginine. In addition, tracers were continuously infused intravenously to determine the fluxes and interconversions between citrulline and arginine. Linear regression slopes were compared to determine the relative efficiency of each supplement. Results: Whereas all the supplemented citrulline (105% ± 7% SEM) appeared in plasma and resulted in a marginal increase of 86% in arginine flux, supplemental arginine underwent an ∼70% FPM, indicating that only 30% of the supplemental arginine entered the peripheral circulation. However, supplemental arginine did not increase arginine flux. Both supplements linearly increased (P < 0.01) plasma arginine concentration from 109 μmol/L for the basal diet to 159 and 214 μmol/L for the highest arginine and citrulline supplementation levels, respectively. However, supplemental citrulline increased arginine concentrations to a greater extent (35%, P < 0.01). Conclusions: Citrulline

The DEAD-Box Protein CYT-19 Uses Arginine Residues in Its C-Tail To Tether RNA Substrates.

PubMed

Busa, Veronica F; Rector, Maxwell J; Russell, Rick

2017-07-18

DEAD-box proteins are nonprocessive RNA helicases that play diverse roles in cellular processes. The Neurospora crassa DEAD-box protein CYT-19 promotes mitochondrial group I intron splicing and functions as a general RNA chaperone. CYT-19 includes a disordered, arginine-rich "C-tail" that binds RNA, positioning the helicase core to capture and unwind nearby RNA helices. Here we probed the C-tail further by varying the number and positions of arginines within it. We found that removing sets of as few as four of the 11 arginines reduced RNA unwinding activity (k cat /K M ) to a degree equivalent to that seen upon removal of the C-tail, suggesting that a minimum or "threshold" number of arginines is required. In addition, a mutant with 16 arginines displayed RNA unwinding activity greater than that of wild-type CYT-19. The C-tail modifications impacted unwinding only of RNA helices within constructs that included an adjacent helix or structured RNA element that would allow C-tail binding, indicating that the helicase core remained active in the mutants. In addition, changes in RNA unwinding efficiency of the mutants were mirrored by changes in functional RNA affinity, as determined from the RNA concentration dependence of ATPase activity, suggesting that the C-tail functions primarily to increase RNA affinity. Interestingly, the salt concentration dependence of RNA unwinding activity is unaffected by C-tail composition, suggesting that the C-tail uses primarily hydrogen bonding, not electrostatic interactions, to bind double-stranded RNA. Our results provide insights into how an unstructured C-tail contributes to DEAD-box protein activity and suggest parallels with other families of RNA- and DNA-binding proteins.

Two Arginine Residues Suppress the Flexibility of Nucleosomal DNA in the Canonical Nucleosome Core

PubMed Central

Kono, Hidetoshi; Shirayama, Kazuyoshi; Arimura, Yasuhiro; Tachiwana, Hiroaki; Kurumizaka, Hitoshi

2015-01-01

The dynamics of nucleosomes containing either canonical H3 or its centromere-specific variant CENP-A were investigated using molecular dynamics simulations. The simulations showed that the histone cores were structurally stable during simulation periods of 100 ns and 50 ns, while DNA was highly flexible at the entry and exit regions and partially dissociated from the histone core. In particular, approximately 20–25 bp of DNA at the entry and exit regions of the CENP-A nucleosome exhibited larger fluctuations than DNA at the entry and exit regions of the H3 nucleosome. Our detailed analysis clarified that this difference in dynamics was attributable to a difference in two basic amino acids in the αN helix; two arginine (Arg) residues in H3 were substituted by lysine (Lys) residues at the corresponding sites in CENP-A. The difference in the ability to form hydrogen bonds with DNA of these two residues regulated the flexibility of nucleosomal DNA at the entry and exit regions. Our exonuclease III assay consistently revealed that replacement of these two Arg residues in the H3 nucleosome by Lys enhanced endonuclease susceptibility, suggesting that the DNA ends of the CENP-A nucleosome are more flexible than those of the H3 nucleosome. This difference in the dynamics between the two types of nucleosomes may be important for forming higher order structures in different phases. PMID:25786215

Proteomic Analysis of Arginine Methylation Sites in Human Cells Reveals Dynamic Regulation During Transcriptional Arrest*

PubMed Central

Sylvestersen, Kathrine B.; Horn, Heiko; Jungmichel, Stephanie; Jensen, Lars J.; Nielsen, Michael L.

2014-01-01

The covalent attachment of methyl groups to the side-chain of arginine residues is known to play essential roles in regulation of transcription, protein function, and RNA metabolism. The specific N-methylation of arginine residues is catalyzed by a small family of gene products known as protein arginine methyltransferases; however, very little is known about which arginine residues become methylated on target substrates. Here we describe a proteomics methodology that combines single-step immunoenrichment of methylated peptides with high-resolution mass spectrometry to identify endogenous arginine mono-methylation (MMA) sites. We thereby identify 1027 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 with 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 levels are not altered, confirming that MMA sites contain regulated functions on their own. Collectively, we present a site-specific MMA data set in human cells and demonstrate for the first time that MMA is a dynamic post-translational modification regulated during transcriptional arrest by a hitherto uncharacterized arginine demethylase. PMID:24563534

Structure of the C-terminal domain of the arginine repressor protein from Mycobacterium tuberculosis

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

Cherney, Leonid T.; Cherney, Maia M.; Garen, Craig R.

2008-09-01

The structure of the core domain of the arginine repressor protein from M. tuberculosis has been determined with (1.85 Å resolution) and without (2.15 Å resolution) the arginine corepressor bound. Three additional arginine molecules have been found to bind to the core domain hexamer at high (0.2 M) arginine concentration. The Mycobacterium tuberculosis (Mtb) gene product encoded by open reading frame Rv1657 is an arginine repressor (ArgR). All genes involved in the l-arginine (hereafter arginine) biosynthetic pathway are essential for optimal growth of the Mtb pathogen, thus making MtbArgR a potential target for drug design. The C-terminal domains of argininemore » repressors (CArgR) participate in oligomerization and arginine binding. Several crystal forms of CArgR from Mtb (MtbCArgR) have been obtained. The X-ray crystal structures of MtbCArgR were determined at 1.85 Å resolution with bound arginine and at 2.15 Å resolution in the unliganded form. These structures show that six molecules of MtbCArgR are arranged into a hexamer having approximate 32 point symmetry that is formed from two trimers. The trimers rotate relative to each other by about 11° upon binding arginine. All residues in MtbCArgR deemed to be important for hexamer formation and for arginine binding have been identified from the experimentally determined structures presented. The hexamer contains six regular sites in which the arginine molecules have one common binding mode and three sites in which the arginine molecules have two overlapping binding modes. The latter sites only bind the ligand at high (200 mM) arginine concentrations.« less

Characterization of conserved arginine residues on Cdt1 that affect licensing activity and interaction with Geminin or Mcm complex.

PubMed

You, Zhiying; Ode, Koji L; Shindo, Mayumi; Takisawa, Haruhiko; Masai, Hisao

2016-05-02

All organisms ensure once and only once replication during S phase through a process called replication licensing. Cdt1 is a key component and crucial loading factor of Mcm complex, which is a central component for the eukaryotic replicative helicase. In higher eukaryotes, timely inhibition of Cdt1 by Geminin is essential to prevent rereplication. Here, we address the mechanism of DNA licensing using purified Cdt1, Mcm and Geminin proteins in combination with replication in Xenopus egg extracts. We mutagenized the 223th arginine of mouse Cdt1 (mCdt1) to cysteine or serine (R-S or R-C, respectively) and 342nd and 346th arginines constituting an arginine finger-like structure to alanine (RR-AA). The RR-AA mutant of Cdt1 could not only rescue the DNA replication activity in Cdt1-depleted extracts but also its specific activity for DNA replication and licensing was significantly increased compared to the wild-type protein. In contrast, the R223 mutants were partially defective in rescue of DNA replication and licensing. Biochemical analyses of these mutant Cdt1 proteins indicated that the RR-AA mutation disabled its functional interaction with Geminin, while R223 mutations resulted in ablation in interaction with the Mcm2∼7 complex. Intriguingly, the R223 mutants are more susceptible to the phosphorylation-induced inactivation or chromatin dissociation. Our results show that conserved arginine residues play critical roles in interaction with Geminin and Mcm that are crucial for proper conformation of the complexes and its licensing activity.

Arginine (Di)methylated Human Leukocyte Antigen Class I Peptides Are Favorably Presented by HLA-B*07.

PubMed

Marino, Fabio; Mommen, Geert P M; Jeko, Anita; Meiring, Hugo D; van Gaans-van den Brink, Jacqueline A M; Scheltema, Richard A; van Els, Cécile A C M; Heck, Albert J R

2017-01-06

Alterations in protein post-translational modification (PTM) are recognized hallmarks of diseases. These modifications potentially provide a unique source of disease-related human leukocyte antigen (HLA) class I-presented peptides that can elicit specific immune responses. While phosphorylated HLA peptides have already received attention, arginine methylated HLA class I peptide presentation has not been characterized in detail. In a human B-cell line we detected 149 HLA class I peptides harboring mono- and/or dimethylated arginine residues by mass spectrometry. A striking preference was observed in the presentation of arginine (di)methylated peptides for HLA-B*07 molecules, likely because the binding motifs of this allele resemble consensus sequences recognized by arginine methyl-transferases. Moreover, HLA-B*07-bound peptides preferentially harbored dimethylated groups at the P3 position, thus consecutively to the proline anchor residue. Such a proline-arginine sequence has been associated with the arginine methyl-transferases CARM1 and PRMT5. Making use of the specific neutral losses in fragmentation spectra, we found most of the peptides to be asymmetrically dimethylated, most likely by CARM1. These data expand our knowledge of the processing and presentation of arginine (di)methylated HLA class I peptides and demonstrate that these types of modified peptides can be presented for recognition by T-cells. HLA class I peptides with mono- and dimethylated arginine residues may therefore offer a novel target for immunotherapy.

Regenerating muscle with arginine methylation

PubMed Central

Blanc, Roméo S.; Richard, Stéphane

2017-01-01

ABSTRACT Protein arginine methyltransferase (PRMT) is a family of nine proteins catalyzing the methylation of arginine residues. They were recently shown to be essential for proper regeneration of skeletal muscles. However, the mechanisms triggering the methylation event, as well as how the methylated substrates regulate muscle stem cell function and fate decision remain to be determined. This point-of-view will discuss the recent findings on the specific role of PRMT1, CARM1/PRMT4, PRMT5, and PRMT7 in muscle stem cell fate guidance, and shed light on the future challenges which could help defining the therapeutic potential of PRMT inhibitors against muscular disorders and aging. PMID:28301308

Regenerating muscle with arginine methylation.

PubMed

Blanc, Roméo S; Richard, Stéphane

2017-05-27

Protein arginine methyltransferase (PRMT) is a family of nine proteins catalyzing the methylation of arginine residues. They were recently shown to be essential for proper regeneration of skeletal muscles. However, the mechanisms triggering the methylation event, as well as how the methylated substrates regulate muscle stem cell function and fate decision remain to be determined. This point-of-view will discuss the recent findings on the specific role of PRMT1, CARM1/PRMT4, PRMT5, and PRMT7 in muscle stem cell fate guidance, and shed light on the future challenges which could help defining the therapeutic potential of PRMT inhibitors against muscular disorders and aging.

Potential of single cationic amino acid molecule "Arginine" for stimulating oral absorption of insulin.

PubMed

Kamei, Noriyasu; Khafagy, El-Sayed; Hirose, Jun; Takeda-Morishita, Mariko

2017-04-15

We have reported that cell-penetrating peptides, such as oligoarginine, act as powerful absorption enhancers for the development of oral insulin delivery systems. However, the minimal essential sequence of oligoarginine that stimulates intestinal insulin absorption remains unclear. Therefore, the present study was conducted to clarify this minimum sequence of oligoarginine and to examine the effect of single cationic amino acid arginine on the intestinal and oral absorption of insulin. The results demonstrated that a remarkable enhancement of intestinal insulin absorption was observed after coadministration of insulin with l-arginine. The efficacy of d-forms of oligoarginine/arginine tended to decrease with a decreasing number of amino acid residues, whereas the effect of l-arginine was the strongest of any of the l-forms of oligoarginine/arginine. Interestingly, the effect of l-arginine was stronger than that of d-arginine at various concentrations, and the effect of other cationic amino acids such as lysine and histidine was relatively lower than that of arginine. In addition, no leakage of lactate dehydrogenase from the intestinal epithelium and no change in the transepithelial electrical resistance of a Caco-2 cell monolayer were detected after administration of l-arginine as the single amino acid, which suggests that there were no undesirable effects of arginine on the integrity of cell membranes and paracellular tight junctions. Oral administration study in mice demonstrated that the stronger hypoglycemic effects were observed after coadministration of insulin with l-arginine. In this study, we found that arginine is a key cationic amino acid for delivering insulin across intestinal epithelial barriers and hopefully accelerating the clinical development of oral insulin delivery systems. Copyright © 2017 Elsevier B.V. All rights reserved.

Direct cytosolic delivery of cargoes in vivo by a chimera consisting of D- and L-arginine residues.

PubMed

Ma, Yan; Gong, Cheng; Ma, Yilong; Fan, Fengkai; Luo, Meijie; Yang, Fei; Zhang, Yu-Hui

2012-09-10

The ability of cell-penetrating peptides (CPPs) to deliver a range of membrane-impermeable molecules into living cells makes them attractive potential vehicles for therapeutics. However, in vivo, the efficiency of CPP delivery to the cytosol remains unsatisfactory owing to endosomal entrapment and/or systemic toxicity, which severely restrict their bioavailability and efficacy in in vivo applications. In this study, we developed a series of novel chimeras consisting of various numbers of d- and l-arginine residues and investigated their cellular uptake behaviors and systemic toxicities. We demonstrated that the intracellular distribution, uptake efficiency, and systemic toxicity of these oligoarginines were all significantly affected by the number of d-arginine residues in the peptide sequence. We also found that a hybrid peptide, (rR)(3)R(2), possessed low systemic toxicity, high uptake efficiency, and, remarkably, achieved efficient cytosolic delivery not only in cultured cells but also in living tissue cells in mice after intravenous injection, implying that this heterogeneous motif might have promising applications in the delivery of cargoes of small sizes directed to cytosolic targets in vivo. Our studies into the uptake mechanism of (rR)(3)R(2) indicate that its cellular uptake was not affected by pharmacological or physical inhibitors of endocytosis but by the elimination of the membrane potential, suggesting that (rR)(3)R(2) does not enter the cells via endocytosis but rather through direct membrane translocation driven by the membrane potential. The results here might provide useful guidelines for the design and application of CPPs in drug delivery. Copyright © 2012 Elsevier B.V. All rights reserved.

Multiple Arginine Residues Are Methylated in Drosophila Mre11 and Required for Survival Following Ionizing Radiation.

PubMed

Yuan, Qing; Tian, Ran; Zhao, Haiying; Li, Lijuan; Bi, Xiaolin

2018-05-31

Mre11 is a key player for DNA double strand break repair. Previous studies have shown that mammalian Mre11 is methylated at multiple arginines in its C-terminal Glycine-Arginine-Rich motif (GAR) by protein arginine methyltransferase PRMT1. Here, we found that the Drosophila Mre11 is methylated at arginines 559, 563, 565, and 569 in the GAR motif by DART1, the Drosophila homolog of PRMT1. Mre11 interacts with DART1 in S2 cells, and this interaction does not require the GAR motif. Arginines methylated Mre11 localizes exclusively in the nucleus as soluble nuclear protein or chromatin-binding protein. To study the in vivo functions of methylation, we generated the single Arg-Ala and all Arginines mutated flies. We found these mutants were sensitive to ionizing radiation. Furthermore, Arg-Ala mutated flies had no irradiation induced G2/M checkpoint defect in wing disc and eye disc. Thus, we provided evidence that arginines in Drosophila Mre11 are methylated by DART1 methytransferase and flies loss of arginine methylation are sensitive to irradiation. Copyright © 2018 Yuan et al.

Creatine kinase: Essential arginine residues at the nucleotide binding site identified by chemical modification and high-resolution tandem mass spectrometry

PubMed Central

Wood, Troy D.; Guan, Ziqiang; Borders, Charles L.; Chen, Lorenzo H.; Kenyon, George L.; McLafferty, Fred W.

1998-01-01

Phenylglyoxal is an arginine-specific reagent that inactivates creatine kinase (CK). Previous results suggest that modification of the dimeric enzyme at a single arginine residue per subunit causes complete inactivation accompanied by the loss of nucleotide binding; the actual site of modification was not identified. Here, high-resolution tandem mass spectrometry (MS/MS) was used to identify three phenylglyoxal-modified Arg residues in monomeric rabbit muscle CK. Electrospray ionizaton Fourier-transform MS of the phenylglyoxal-modified CK that had lost ≈80% activity identified three species: unmodified, once-modified (+116 Da), and twice-modified (+232 Da) enzyme in a ratio of approximately 1:4:1. MS/MS restricts the derivatized sites to P122-P212 and P283-V332, whereas MS of Lys-C digestions revealed two modified peptides, A266-K297 and G116-K137. The only Arg in A266-K297 is Arg-291 (invariant), whereas MS/MS of modified G116-K137 shows that two of the three sites Arg-129, Arg-131, or Arg-134 (all invariant) can contain the modification. The recently reported x-ray crystal structure for the octameric chicken mitochondrial CK indicates that its nucleotide triphosphate-binding site indeed contains the equivalent of R291, R129, and R131 reported here to be at the active site of rabbit muscle CK. PMID:9520370

L-arginine prevents xanthoma development and inhibits atherosclerosis in LDL receptor knockout mice.

PubMed

Aji, W; Ravalli, S; Szabolcs, M; Jiang, X C; Sciacca, R R; Michler, R E; Cannon, P J

1997-01-21

The potential antiatherosclerotic actions of NO were investigated in four groups of mice (n = 10 per group) lacking functional LDL receptor genes, an animal model of familial hypercholesterolemia. Group 1 was fed a regular chow diet. Groups 2 through 4 were fed a 1.25% high-cholesterol diet. In addition, group 3 received supplemental L-arginine and group 4 received L-arginine and N omega-nitro-L-arginine (L-NA), an inhibitor of NO synthase (NOS). Animals were killed at 6 months; aortas were stained with oil red O for planimetry and with antibodies against constitutive and inducible NOSs. Plasma cholesterol was markedly increased in the animals receiving the high-cholesterol diet. Xanthomas appeared in all mice fed the high-cholesterol diet alone but not in those receiving L-arginine. Aortic atherosclerosis was present in all mice on the high-cholesterol diet. The mean atherosclerotic lesion area was reduced significantly (P < .01) in the cholesterol-fed mice given L-arginine compared with those receiving the high-cholesterol diet alone. The mean atherosclerotic lesion area was significantly larger (P < .01) in cholesterol-fed mice receiving L-arginine + L-NA than in those on the high-cholesterol diet alone. Within the atherosclerotic plaques, endothelial cells immunoreacted for endothelial cell NOS; macrophages, foam cells, and smooth muscle cells immunostained strongly for inducible NOS and nitrotyrosine residues. The data indicate that L-arginine prevents xanthoma formation and reduces atherosclerosis in LDL receptor knockout mice fed a high-cholesterol diet. The abrogation of the beneficial effects of L-arginine by L-NA suggests that the antiatherosclerotic actions of L-arginine are mediated by NOS. The data suggest that L-arginine may be beneficial in familial hypercholesterolemia.

Escherichia coli twin arginine (Tat) mutant translocases possessing relaxed signal peptide recognition specificities.

PubMed

Kreutzenbeck, Peter; Kröger, Carsten; Lausberg, Frank; Blaudeck, Natascha; Sprenger, Georg A; Freudl, Roland

2007-03-16

The twin arginine (Tat) secretion pathway allows the translocation of folded proteins across the cytoplasmic membrane of bacteria. Tat-specific signal peptides contain a characteristic amino acid motif ((S/T)RRXFLK) including two highly conserved consecutive arginine residues that are thought to be involved in the recognition of the signal peptides by the Tat translocase. Here, we have analyzed the specificity of Tat signal peptide recognition by using a genetic approach. Replacement of the two arginine residues in a Tat-specific precursor protein by lysine-glutamine resulted in an export-defective mutant precursor that was no longer accepted by the wild-type translocase. Selection for restored export allowed for the isolation of Tat translocases possessing single mutations in either the amino-terminal domain of TatB or the first cytosolic domain of TatC. The mutant Tat translocases still efficiently accepted the unaltered precursor protein, indicating that the substrate specificity of the translocases was not strictly changed; rather, the translocases showed an increased tolerance toward variations of the amino acids occupying the positions of the twin arginine residues in the consensus motif of a Tat signal peptide.

HK022 Nun Requires Arginine-Rich Motif Residues Distinct from λ N

PubMed Central

Tawk, Caroline S.; Ghattas, Ingrid R.

2015-01-01

ABSTRACT Bacteriophage λ N protein binds boxB RNA hairpins in the nut (N utilization) sites of immediate early λ transcripts and interacts with host factors to suppress transcriptional termination at downstream terminators. In opposition to λ N, the Nun protein of HK022 binds the boxBs of coinfecting λ transcripts, interacts with a similar or identical set of host factors, and terminates transcription to suppress λ replication. Comparison of N-boxB and Nun-boxB nuclear magnetic resonance (NMR) structural models suggests similar interactions, though limited mutagenesis of Nun is available. Here, libraries of Nun's arginine-rich motif (ARM) were screened for the ability to exclude λ coinfection, and mutants were assayed for Nun termination with a boxB plasmid reporter system. Several Nun ARM residues appear to be immutable: Asp26, Arg28, Arg29, Arg32, Trp33, and Arg36. Asp26 and Trp33 appear to be unable to contact boxB and are not found at equivalent positions in λ N ARM. To understand if the requirement of Asp26, Trp33, and Arg36 indicated differences between HK022 Nun termination and λ N antitermination complexes, the same Nun libraries were fused to the activation domain of λ N and screened for clones able to complement N-deficient λ. Mutants were assayed for N antitermination. Surprisingly, Asp26 and Trp33 were still essential when Nun ARM was fused to N. Docking suggests that Nun ARM contacts a hydrophobic surface of the NusG carboxy-terminal domain containing residues necessary for Nun function. These findings indicate that Nun ARM relies on distinct contacts in its ternary complex and illustrate how protein-RNA recognition can evolve new regulatory functions. IMPORTANCE λ N protein interacts with host factors to allow λ nut-containing transcripts to elongate past termination signals. A competing bacteriophage, HK022, expresses Nun protein, which causes termination of λ nut transcripts. λ N and HK022 Nun use similar arginine-rich motifs (ARMs) to

HK022 Nun Requires Arginine-Rich Motif Residues Distinct from λ N.

PubMed

Tawk, Caroline S; Ghattas, Ingrid R; Smith, Colin A

2015-11-01

Bacteriophage λ N protein binds boxB RNA hairpins in the nut (N utilization) sites of immediate early λ transcripts and interacts with host factors to suppress transcriptional termination at downstream terminators. In opposition to λ N, the Nun protein of HK022 binds the boxBs of coinfecting λ transcripts, interacts with a similar or identical set of host factors, and terminates transcription to suppress λ replication. Comparison of N-boxB and Nun-boxB nuclear magnetic resonance (NMR) structural models suggests similar interactions, though limited mutagenesis of Nun is available. Here, libraries of Nun's arginine-rich motif (ARM) were screened for the ability to exclude λ coinfection, and mutants were assayed for Nun termination with a boxB plasmid reporter system. Several Nun ARM residues appear to be immutable: Asp26, Arg28, Arg29, Arg32, Trp33, and Arg36. Asp26 and Trp33 appear to be unable to contact boxB and are not found at equivalent positions in λ N ARM. To understand if the requirement of Asp26, Trp33, and Arg36 indicated differences between HK022 Nun termination and λ N antitermination complexes, the same Nun libraries were fused to the activation domain of λ N and screened for clones able to complement N-deficient λ. Mutants were assayed for N antitermination. Surprisingly, Asp26 and Trp33 were still essential when Nun ARM was fused to N. Docking suggests that Nun ARM contacts a hydrophobic surface of the NusG carboxy-terminal domain containing residues necessary for Nun function. These findings indicate that Nun ARM relies on distinct contacts in its ternary complex and illustrate how protein-RNA recognition can evolve new regulatory functions. λ N protein interacts with host factors to allow λ nut-containing transcripts to elongate past termination signals. A competing bacteriophage, HK022, expresses Nun protein, which causes termination of λ nut transcripts. λ N and HK022 Nun use similar arginine-rich motifs (ARMs) to bind the same box

Transmembrane helices containing a charged arginine are thermodynamically stable.

PubMed

Ulmschneider, Martin B; Ulmschneider, Jakob P; Freites, J Alfredo; von Heijne, Gunnar; Tobias, Douglas J; White, Stephen H

2017-10-01

Hydrophobic amino acids are abundant in transmembrane (TM) helices of membrane proteins. Charged residues are sparse, apparently due to the unfavorable energetic cost of partitioning charges into nonpolar phases. Nevertheless, conserved arginine residues within TM helices regulate vital functions, such as ion channel voltage gating and integrin receptor inactivation. The energetic cost of arginine in various positions along hydrophobic helices has been controversial. Potential of mean force (PMF) calculations from atomistic molecular dynamics simulations predict very large energetic penalties, while in vitro experiments with Sec61 translocons indicate much smaller penalties, even for arginine in the center of hydrophobic TM helices. Resolution of this conflict has proved difficult, because the in vitro assay utilizes the complex Sec61 translocon, while the PMF calculations rely on the choice of simulation system and reaction coordinate. Here we present the results of computational and experimental studies that permit direct comparison with the Sec61 translocon results. We find that the Sec61 translocon mediates less efficient membrane insertion of Arg-containing TM helices compared with our computational and experimental bilayer-insertion results. In the simulations, a combination of arginine snorkeling, bilayer deformation, and peptide tilting is sufficient to lower the penalty of Arg insertion to an extent such that a hydrophobic TM helix with a central Arg residue readily inserts into a model membrane. Less favorable insertion by the translocon may be due to the decreased fluidity of the endoplasmic reticulum (ER) membrane compared with pure palmitoyloleoyl-phosphocholine (POPC). Nevertheless, our results provide an explanation for the differences between PMF- and experiment-based penalties for Arg burial.

Interaction of free arginine and guanidine with glucose under thermal processing conditions and formation of Amadori-derived imidazolones.

PubMed

Zhu, Yuchen; Yaylayan, Varoujan A

2017-04-01

To investigate the reactivity of free guanidine and arginine in the formation of imidazolinone derivatives, model systems of guanidine or arginine/glucose or 13 [C-6]-glucose were heated in aqueous solutions at110°C for 3h and the residues were analyzed by ESI/qTOF/MS using MS/MS and isotope labeling techniques. The analysis of the data indicated that guanidine and arginine formed both covalent and non-covalent interaction products. Covalent interactions included Amadori rearrangement at the α-nitrogen with glucose and imidazolinone formation with 3-deoxy-glucosone at the guanidine side-chain. Non-covalent interactions, such as self-interaction and interaction with free guanidine or arginine and glucose, were also observed. Guanidine underwent three sequential Amadori rearrangements and the free and mono-glycated guanidine also formed imidazolinone derivatives and their corresponding dehydration products and at the same time exhibiting various non-covalent interactions. On the other hand, arginine formed free Amadori product, free imidazolinone and Amadori-derived imidazolinone derivative in addition to methylglyoxal-derived hydroimidazolones. Copyright © 2016 Elsevier Ltd. All rights reserved.

Effect of counter ions of arginine as an additive for the solubilization of protein and aromatic compounds.

PubMed

Yoshizawa, Shunsuke; Arakawa, Tsutomu; Shiraki, Kentaro

2016-10-01

Arginine is widely used in biotechnological application, but mostly with chloride counter ion. Here, we examined the effects of various anions on solubilization of aromatic compounds and reduced lysozyme and on refolding of the lysozyme. All arginine salts tested increased the solubility of propyl gallate with acetate much more effectively than chloride. The effects of arginine salts were compared with those of sodium or guanidine salts, indicating that the ability of anions to modulate the propyl gallate solubility is independent of the cation. Comparison of transfer free energy of propyl gallate between sodium and arginine salts indicates that the interaction of propyl gallate is more favorable with arginine than sodium. On the contrary, the solubility of aromatic amino acids is only slightly modulated by anions, implying that there is specific interaction between acetic acid and propyl gallate. Unlike their effects on the solubility of small aromatic compounds, the solubility of reduced lysozyme was much higher in arginine chloride than in arginine acetate or sulfate. Consistent with high solubility, refolding of reduced lysozyme was most effective in arginine chloride. These results suggest potential broader applications of arginine modulated by different anions. Copyright © 2016 Elsevier B.V. All rights reserved.

Protein arginine methylation facilitates KCNQ channel-PIP2 interaction leading to seizure suppression

PubMed Central

Kim, Hyun-Ji; Jeong, Myong-Ho; Kim, Kyung-Ran; Jung, Chang-Yun; Lee, Seul-Yi; Kim, Hanna; Koh, Jewoo; Vuong, Tuan Anh; Jung, Seungmoon; Yang, Hyunwoo; Park, Su-Kyung; Choi, Dahee; Kim, Sung Hun; Kang, KyeongJin; Sohn, Jong-Woo; Park, Joo Min; Jeon, Daejong; Koo, Seung-Hoi; Ho, Won-Kyung; Kang, Jong-Sun; Kim, Seong-Tae; Cho, Hana

2016-01-01

KCNQ channels are critical determinants of neuronal excitability, thus emerging as a novel target of anti-epileptic drugs. To date, the mechanisms of KCNQ channel modulation have been mostly characterized to be inhibitory via Gq-coupled receptors, Ca2+/CaM, and protein kinase C. Here we demonstrate that methylation of KCNQ by protein arginine methyltransferase 1 (Prmt1) positively regulates KCNQ channel activity, thereby preventing neuronal hyperexcitability. Prmt1+/- mice exhibit epileptic seizures. Methylation of KCNQ2 channels at 4 arginine residues by Prmt1 enhances PIP2 binding, and Prmt1 depletion lowers PIP2 affinity of KCNQ2 channels and thereby the channel activities. Consistently, exogenous PIP2 addition to Prmt1+/- neurons restores KCNQ currents and neuronal excitability to the WT level. Collectively, we propose that Prmt1-dependent facilitation of KCNQ-PIP2 interaction underlies the positive regulation of KCNQ activity by arginine methylation, which may serve as a key target for prevention of neuronal hyperexcitability and seizures. DOI: http://dx.doi.org/10.7554/eLife.17159.001 PMID:27466704

Functional polymorphisms affecting the clinically important arginine-137 residue of AVPR2 do not influence serum sodium concentration at the population level

PubMed Central

Fu, Yi; Cheetham, Tim; Bourn, David; Orwoll, Eric

2013-01-01

The protein product of the AVPR2 gene, coding for the arginine vasopressin receptor type 2, is essential for vasopressin-dependent concentration of the urine. The arginine residue at position 137 in the protein product of this gene is uniquely pivotal for function. The R137H mutant inactivates the receptor conferring congenital nephrogenic diabetes insipidus, whereas activating mutations at this same residue (i.e., R137C and R137L) confer pathological water retention in the nephrogenic syndrome of inappropriate antidiuresis. These mutations were discovered in human subjects with conspicuous phenotypes in clinical water balance. Prevalence of these polymorphisms among asymptomatic individuals has not been assessed, nor has their contribution to broad interindividual variation in serum sodium concentration; no data addressing minor allele frequency are available. We genotyped two large cohorts using a validated high-throughput Pyrosequencing-based assay that we designed to capture the totality of pathological variation at this important residue. In the Osteoporotic Fractures in Men (MrOS) Study, all participants were male (i.e., hemizygous for AVPR2 gene on the X-chromosome), and participants were oversampled at the extremes of the population distribution for serum sodium concentration. In the Offspring Cohort of the Framingham Heart Study, male and female participants were genotyped. No pathological variants affecting R137 were detected among the 5,142 AVPR2 alleles successfully genotyped. Even at the population extremes of serum sodium distribution, we estimate minor allele frequency < 0.06%. We conclude that these disease-associated variants are exceedingly uncommon and do not contribute broadly to interindividual variability in serum sodium concentration or to its heritability. PMID:23362144

Determining rotational dynamics of the guanidino group of arginine side chains in proteins by carbon-detected NMR.

PubMed

Gerecht, Karola; Figueiredo, Angelo Miguel; Hansen, D Flemming

2017-09-16

Arginine residues are imperative for many active sites and protein-interaction interfaces. A new NMR-based method is presented to determine the rotational dynamics around the N ε -C ζ bond of arginine side chains. An application to a 19 kDa protein shows that the strengths of interactions involving arginine side chains can be characterised.

Arginine and proline applied as food additives stimulate high freeze tolerance in larvae of Drosophila melanogaster.

PubMed

Koštál, Vladimír; Korbelová, Jaroslava; Poupardin, Rodolphe; Moos, Martin; Šimek, Petr

2016-08-01

The fruit fly Drosophila melanogaster is an insect of tropical origin. Its larval stage is evolutionarily adapted for rapid growth and development under warm conditions and shows high sensitivity to cold. In this study, we further developed an optimal acclimation and freezing protocol that significantly improves larval freeze tolerance (an ability to survive at -5°C when most of the freezable fraction of water is converted to ice). Using the optimal protocol, freeze survival to adult stage increased from 0.7% to 12.6% in the larvae fed standard diet (agar, sugar, yeast, cornmeal). Next, we fed the larvae diets augmented with 31 different amino compounds, administered in different concentrations, and observed their effects on larval metabolomic composition, viability, rate of development and freeze tolerance. While some diet additives were toxic, others showed positive effects on freeze tolerance. Statistical correlation revealed tight association between high freeze tolerance and high levels of amino compounds involved in arginine and proline metabolism. Proline- and arginine-augmented diets showed the highest potential, improving freeze survival to 42.1% and 50.6%, respectively. Two plausible mechanisms by which high concentrations of proline and arginine might stimulate high freeze tolerance are discussed: (i) proline, probably in combination with trehalose, could reduce partial unfolding of proteins and prevent membrane fusions in the larvae exposed to thermal stress (prior to freezing) or during freeze dehydration; (ii) both arginine and proline are exceptional among amino compounds in their ability to form supramolecular aggregates which probably bind partially unfolded proteins and inhibit their aggregation under increasing freeze dehydration. © 2016. Published by The Company of Biologists Ltd.

Drosophila arginine methyltransferase 1 (DART1) is an ecdysone receptor co-repressor

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

Kimura, Shuhei; Department of Obstetrics and Gynecology, Tohoku University Graduate School of Medicine, 1-1 Seiryo-machi, Aoba-ku, Sendai 980-8574; Sawatsubashi, Shun

2008-07-11

Histone arginine methylation is an epigenetic marker that regulates gene expression by defining the chromatin state. Arginine methyltransferases, therefore, serve as transcriptional co-regulators. However, unlike other transcriptional co-regulators, the physiological roles of arginine methyltransferases are poorly understood. Drosophila arginine methyltransferase 1 (DART1), the mammalian PRMT1 homologue, methylates the arginine residue of histone H4 (H4R3me2). Disruption of DART1 in Drosophila by imprecise P-element excision resulted in low viability during metamorphosis in the pupal stages. In the pupal stage, an ecdysone hormone signal is critical for developmental progression. DART1 interacted with the nuclear ecdysone receptor (EcR) in a ligand-dependent manner, and co-repressedmore » EcR in intact flies. These findings suggest that DART1, a histone arginine methyltransferase, is a co-repressor of EcR that is indispensable for normal pupal development in the intact fly.« less

Regulation of post-translational protein arginine methylation during HeLa cell cycle.

PubMed

Kim, Chongtae; Lim, Yongchul; Yoo, Byong Chul; Won, Nam Hee; Kim, Sangduk; Kim, Gieun

2010-09-01

Post-translational arginine methylation which modifies protein-arginyl residues by protein arginine methyltransferase (PRMT) was investigated during synchronized HeLa cell cycle. The lysates of cells synchronized at each stage were subjected to one and/or two dimensional electrophoresis followed by Western immunoblot using against anti-asymmetric-dimethyl-arginine (ASYM24), anti-symmetric-dimethyl-arginine (SYM10), and subclasses of PRMTs, including PRMT1, PRMT3, PRMT4 (CARM1), PRMT5, PRMT6, and PRMT7 antibodies. Proteins with approximate molecular masses of 80 kDa, 68 kDa, and 64 kDa, containing asymmetric-dimethyl-arginine (aDMA) were increased at G0/G1 to G1, which lasted until S phase. In addition, 25 kDa protein of symmetric-dimethyl-arginine (sDMA) was also markedly up-regulated from G0/G1 to G1. The levels of PRMT3, PRMT6 and PRMT7 were concurrently increased during the cell cycle. Two-dimensional gel electrophoresis followed by MALDI-TOF-MS was identified as aDMA-80 kDa and aDMA-68 kDa proteins as heterogeneous nuclear ribonucleoprotein R (hnRNPR), aDMA-64 kDa proteins as cleavage stimulation factor 64 kDa subunit (CstF-64), and sDMA-25 kDa protein as triosephosphate isomerase (TPI). The levels of increased aDMA of hnRNPR were reduced, when HeLa cells were transfected with siRNA for PRMT1, and the aDMA of CstF-64 with siRNA for PRMT3, while depletion of PRMT5 down-regulated sDMA of TPI. Protein arginine dimethylations of hnRNPR, CstF-64, and TPI were regulated during HeLa cell cycle by respective PRMTs. These results suggest that regulation of arginine dimethylation of hnRNPR, CstF-64, and TPI at G0/G1 to G1 are most likely to modulate the cellular growth and proliferation in HeLa cell cycle. Copyright © 2010 Elsevier B.V. All rights reserved.

Effects of L-arginine on solubilization and purification of plant membrane proteins.

PubMed

Arakawa, Junji; Uegaki, Masamichi; Ishimizu, Takeshi

2011-11-01

Biochemical analysis of membrane proteins is problematic at the level of solubilization and/or purification because of their hydrophobic nature. Here, we developed methods for efficient solubilization and purification of membrane proteins using L-arginine. The addition of 100 mM of basic amino acids (L-arginine, L-lysine, and L-ornithine) to a detergent-containing solubilization buffer enhanced solubilization (by 2.6-4.3 fold) of a model membrane protein-polygalacturonic acid synthase. Of all the amino acids, arginine was the most effective additive for solubilization of this membrane protein. Arginine addition also resulted in the best solubilization of other plant membrane proteins. Next, we examined the effects of arginine on purification of a model membrane protein. In anion-exchange chromatography, the addition of arginine to the loading and elution buffers resulted in a greater recovery of a membrane protein. In ultrafiltration, the addition of arginine to a protein solution significantly improved the recovery of a membrane protein. These results were thought to be due to the properties of arginine that prevent aggregation of hydrophobic proteins. Taken together, the results of our study showed that arginine is useful for solubilization and purification of aggregate-prone membrane proteins. Copyright © 2011 Elsevier Inc. All rights reserved.

Structure-based analysis reveals hydration changes induced by arginine hydrochloride.

PubMed

Nakakido, Makoto; Tanaka, Yoshikazu; Mitsuhori, Mariko; Kudou, Motonori; Ejima, Daisuke; Arakawa, Tsutomu; Tsumoto, Kouhei

2008-10-01

Arginine hydrochloride has been used to suppress protein aggregation during refolding and in various other applications. We investigated the structure of hen egg-white lysozyme (HEL) and solvent molecules in arginine hydrochloride solution by X-ray crystallography. Neither the backbone nor side-chain structure of HEL was altered by the presence of arginine hydrochloride. In addition, no stably bound arginine molecules were observed. The number of hydration water molecules, however, changed with the arginine hydrochloride concentration. We suggest that arginine hydrochloride suppresses protein aggregation by altering the hydration structure and the transient binding of arginine molecules that could not be observed.

Arginine and Lysine Transporters Are Essential for Trypanosoma brucei.

PubMed

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.

Arginine and Lysine Transporters Are Essential for Trypanosoma brucei

PubMed Central

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. PMID:28045943

Arginine residues on the opposite side of the active site stimulate the catalysis of ribosome depurination by ricin A chain by interacting with the P-protein stalk.

PubMed

Li, Xiao-Ping; Kahn, Peter C; Kahn, Jennifer Nielsen; Grela, Przemyslaw; Tumer, Nilgun E

2013-10-18

Ricin inhibits protein synthesis by depurinating the α-sarcin/ricin loop (SRL). Ricin holotoxin does not inhibit translation unless the disulfide bond between the A (RTA) and B (RTB) subunits is reduced. Ricin holotoxin did not bind ribosomes or depurinate them but could depurinate free RNA. When RTA is separated from RTB, arginine residues located at the interface are exposed to the solvent. Because this positively charged region, but not the active site, is blocked by RTB, we mutated arginine residues at or near the interface of RTB to determine if they are critical for ribosome binding. These variants were structurally similar to wild type RTA but could not bind ribosomes. Their K(m) values and catalytic rates (k(cat)) for an SRL mimic RNA were similar to those of wild type, indicating that their activity was not altered. However, they showed an up to 5-fold increase in K(m) and up to 38-fold decrease in kcat toward ribosomes. These results suggest that the stalk binding stimulates the catalysis of ribosome depurination by RTA. The mutated arginines have side chains behind the active site cleft, indicating that the ribosome binding surface of RTA is on the opposite side of the surface that interacts with the SRL. We propose that stalk binding stimulates the catalysis of ribosome depurination by orienting the active site of RTA toward the SRL and thereby allows docking of the target adenine into the active site. This model may apply to the translation factors that interact with the stalk.

Protein arginine deiminase 2 binds calcium in an ordered fashion: Implications for inhibitor design

DOE PAGES

Slade, Daniel J.; Fang, Pengfei; Dreyton, Christina J.; ...

2015-01-26

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 ionsmore » 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.« less

Protein Arginine Deiminase 2 Binds Calcium in an Ordered Fashion: Implications for Inhibitor Design

PubMed Central

2015-01-01

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. PMID:25621824

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

PubMed

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.

Clipping of arginine-methylated histone tails by JMJD5 and JMJD7

PubMed Central

Liu, Haolin; Wang, Chao; Lee, Schuyler; Deng, Yu; Wither, Matthew; Oh, Sangphil; Ning, Fangkun; Dege, Carissa; Zhang, Qianqian; Liu, Xinjian; Johnson, Aaron M.; Zang, Jianye; Janknecht, Ralf; Hansen, Kirk; Marrack, Philippa; Li, Chuan-Yuan; Kappler, John W.; Hagman, James; Zhang, Gongyi

2017-01-01

Two of the unsolved, important questions about epigenetics are: do histone arginine demethylases exist, and is the removal of histone tails by proteolysis a major epigenetic modification process? Here, we report that two orphan Jumonji C domain (JmjC)-containing proteins, JMJD5 and JMJD7, have divalent cation-dependent protease activities that preferentially cleave the tails of histones 2, 3, or 4 containing methylated arginines. After the initial specific cleavage, JMJD5 and JMJD7, acting as aminopeptidases, progressively digest the C-terminal products. JMJD5-deficient fibroblasts exhibit dramatically increased levels of methylated arginines and histones. Furthermore, depletion of JMJD7 in breast cancer cells greatly decreases cell proliferation. The protease activities of JMJD5 and JMJD7 represent a mechanism for removal of histone tails bearing methylated arginine residues and define a potential mechanism of transcription regulation. PMID:28847961

Partial alanine scan of mast cell degranulating peptide (MCD): importance of the histidine- and arginine residues.

PubMed

Buku, Angeliki; Mendlowitz, Milton; Condie, Barry A; Price, Joseph A

2004-06-01

The influence of the two histidine and two arginine residues of mast cell degranulating peptide (MCD) in activity and binding was studied by replacing these amino acids in the MCD sequence with L-alanine. Their histamine releasing activity was determined on rat peritoneal mast cells. Their binding affinity to the FcepsilonRIalpha binding subunit of the human mast cell receptor protein, was carried out using fluorescence polarization. The histamine assay showed that replacement of His13 by Ala o ccurred without loss of activity compared with the activity of MCD. Alanine substitutions for Arg7 and His8 resulted in an approximately 40 fold increase, and for Arg16 in a 14-fold increase in histamine-releasing activity of MCD. The binding affinities of the analogs were tested by competitive displacement of bound fluorescent MCD peptide from the FcepsilonRIalpha binding protein of the mast cell receptor by the Ala analogs using fluorescence polarization. The analogs Ala8 (for His) and Ala16 (for Arg) showed the same binding affinities as MCD, whereas analog Ala7 (for Arg) and analog Ala13 (for His) showed slightly better binding affinity than the parent compound. This study showed that the introduction of alanine residues in these positions resulted in MCD agonists of diverse potency. These findings will be useful in further MCD structure-activity studies.

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.

PubMed

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.

Improvement of the ammonia assimilation for enhancing L-arginine production of Corynebacterium crenatum.

PubMed

Guo, Jing; Man, Zaiwei; Rao, Zhiming; Xu, Meijuan; Yang, Taowei; Zhang, Xian; Xu, Zhenghong

2017-03-01

There are four nitrogen atoms in L-arginine molecule and the nitrogen content is 32.1%. By now, metabolic engineering for L-arginine production strain improvement was focused on carbon flux optimization. In previous work, we obtained an L-arginine-producing Corynebacterium crenatum SDNN403 (ARG) through screening and mutation breeding. In this paper, a strain engineering strategy focusing on nitrogen supply and ammonium assimilation for L-arginine production was performed. Firstly, the effects of nitrogen atom donor (L-glutamate, L-glutamine and L-aspartate) addition on L-arginine production of ARG were studied, and the addition of L-glutamine and L-aspartate was beneficial for L-arginine production. Then, the glutamine synthetase gene glnA and aspartase gene aspA from E. coli were overexpressed in ARG for increasing the L-glutamine and L-aspartate synthesis, and the L-arginine production was effectively increased. In addition, the L-glutamate supply re-emerged as a limiting factor for L-arginine biosynthesis. Finally, the glutamate dehydrogenase gene gdh was co-overexpressed for further enhancement of L-arginine production. The final strain could produce 53.2 g l -1 of L-arginine, which was increased by 41.5% compared to ARG in fed-batch fermentation.

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

PubMed Central

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

Arginine inactivates human herpesvirus 2 and inhibits genital herpesvirus infection.

PubMed

Ikeda, Keiko; Yamasaki, Hisashi; Minami, Sawako; Suzuki, Yukiko; Tsujimoto, Kazuko; Sekino, Yoshihisa; Irie, Hiroshi; Arakawa, Tsutomu; Koyama, A Hajime

2012-12-01

Arginine, among the amino acids, has demonstrated unique properties, including suppression of protein-protein interactions and virus inactivation. We investigated the effects of arginine on the infectivity of human herpesvirus 2 (HHV-2) and the potential application of arginine as a chemotherapeutic agent against genital herpes. Arginine directly inactivated HHV-2 and characterization of the inactivation demonstrated that 1 M arginine at pH 4.3 inactivated the virus more efficiently compared to 0.1 M citrate or 1 M sodium chloride, indicating that neither acidic pH nor ionic strength alone is sufficient for virus inactivation. The effect of arginine was rapid and concentration-dependent. Although virus inactivation was efficient at an acidic pH, arginine inactivated the virus even at a neutral pH, provided that a higher arginine concentration and prolonged incubation time were used. In addition, arginine suppressed the multiplication of HHV-2 under the conditions at which its effect on cell viability was insignificant. Pilot mouse model studies revealed a marked suppression of death by arginine when the mice were infected with HHV-2 through the vaginal route, followed by an intermittent application of acidic arginine by vaginal instillation.

Computational Study of Symmetric Methylation on Histone Arginine Catalyzed by Protein Arginine Methyltransferase PRMT5 through QM/MM MD and Free Energy Simulations

DOE PAGES

Yue, Yufei; CHu, Yuzhuo; Guo, Hong

2015-01-01

Protein arginine methyltransferases (PRMTs) catalyze the transfer of the methyl group from S-adenosyl-l-methionine (AdoMet) to arginine residues. There are three types of PRMTs (I, II and III) that produce different methylation products, including asymmetric dimethylarginine (ADMA), symmetric dimethylarginine (SDMA) and monomethylarginine (MMA). Since these different methylations can lead to different biological consequences, understanding the origin of product specificity of PRMTs is of considerable interest. In this article, the quantum mechanical/molecular mechanical (QM/MM) molecular dynamics (MD) and free energy simulations are performed to study SDMA catalyzed by the Type II PRMT5 on the basis of experimental observation that the dimethylated productmore » is generated through a distributive fashion. The simulations have identified some important interactions and proton transfers during the catalysis. Similar to the cases involving Type I PRMTs, a conserved Glu residue (Glu435) in PRMT5 is suggested to function as general base catalyst based on the result of the simulations. Moreover, our results show that PRMT5 has an energetic preference for the first methylation on N-1 followed by the second methylation on a different -guanidino nitrogen of arginine (N-2).The first and second methyl transfers are estimated to have free energy barriers of 19-20 and 18-19 kcal/mol respectively. The computer simulations suggest a distinctive catalytic mechanism of symmetric dimethylation that seems to be different from asymmetric dimethylation.« less

Crystal Structure of the Arginine Repressor Protein in Complex With the DNA Operator From Mycobacterium Tuberculosis

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

Cherney, L.T.; Cherney, M.M.; Garen, C.R.

2009-05-12

The Mycobacterium tuberculosis (Mtb) gene product encoded by open reading frame Rv1657 is an arginine repressor (ArgR). All genes involved in the L-arginine (hereafter arginine) biosynthetic pathway are essential for optimal growth of the Mtb pathogen, thus making MtbArgR a potential target for drug design. The C-terminal domains of arginine repressors (CArgR) participate in oligomerization and arginine binding. Several crystal forms of CArgR from Mtb (MtbCArgR) have been obtained. The X-ray crystal structures of MtbCArgR were determined at 1.85 {angstrom} resolution with bound arginine and at 2.15 {angstrom} resolution in the unliganded form. These structures show that six molecules ofmore » MtbCArgR are arranged into a hexamer having approximate 32 point symmetry that is formed from two trimers. The trimers rotate relative to each other by about 11{sup o} upon binding arginine. All residues in MtbCArgR deemed to be important for hexamer formation and for arginine binding have been identified from the experimentally determined structures presented. The hexamer contains six regular sites in which the arginine molecules have one common binding mode and three sites in which the arginine molecules have two overlapping binding modes. The latter sites only bind the ligand at high (200 mM) arginine concentrations.« less

Combined proportional and additive residual error models in population pharmacokinetic modelling.

PubMed

Proost, Johannes H

2017-11-15

In pharmacokinetic modelling, a combined proportional and additive residual error model is often preferred over a proportional or additive residual error model. Different approaches have been proposed, but a comparison between approaches is still lacking. The theoretical background of the methods is described. Method VAR assumes that the variance of the residual error is the sum of the statistically independent proportional and additive components; this method can be coded in three ways. Method SD assumes that the standard deviation of the residual error is the sum of the proportional and additive components. Using datasets from literature and simulations based on these datasets, the methods are compared using NONMEM. The different coding of methods VAR yield identical results. Using method SD, the values of the parameters describing residual error are lower than for method VAR, but the values of the structural parameters and their inter-individual variability are hardly affected by the choice of the method. Both methods are valid approaches in combined proportional and additive residual error modelling, and selection may be based on OFV. When the result of an analysis is used for simulation purposes, it is essential that the simulation tool uses the same method as used during analysis. Copyright © 2017 Elsevier B.V. All rights reserved.

Structural studies on the decameric S. typhimurium arginine decarboxylase (ADC): Pyridoxal 5'-phosphate binding induces conformational changes.

PubMed

Deka, G; Bharath, S R; Savithri, H S; Murthy, M R N

2017-09-02

Enteric pathogens such as Salmonella typhimurium colonize the human gut in spite of the lethal acidic pH environment (pH < 2.5) due to the activation of inducible acid tolerance response (ATR) systems. The pyridoxal 5'-phosphate (PLP)-dependent enzyme, biodegradative arginine decarboxylase (ADC, encoded by AdiA), is a component of an ATR system. The enzyme consumes a cytoplasmic proton in the process of arginine degradation to agmatine. Arginine-agmatine antiporter (AdiC) exchanges the product agmatine for arginine. In this manuscript, we describe the structure of Salmonella typhimurium ADC (StADC). The decameric structure assembled from five dimers related by a non crystallographic 5-fold symmetry represents the first apo-form of the enzyme. The structure suggests that PLP-binding is not a prerequisite for oligomerization. Comparison with E. coli ADC reveals that PLP-binding is accompanied by the movement and ordering of two loops (residues 150-159 and 191-197) and a few active site residues such as His256 and Lys257. A number of residues important for substrate binding are disordered in the apo-StADC structure indicating that PLP binding is important for substrate binding. Unlike the interactions between 5-fold related protomers, interactions that stabilize the dimeric structure are not pH dependent. Copyright © 2017 Elsevier Inc. All rights reserved.

Arginine Consumption by the Intestinal Parasite Giardia intestinalis Reduces Proliferation of Intestinal Epithelial Cells

PubMed Central

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 host´s 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

Proteomic Identification and Analysis of Arginine-Methylated Proteins of Plasmodium falciparum at Asexual Blood Stages.

PubMed

Zeeshan, Mohammad; Kaur, Inderjeet; Joy, Joseph; Saini, Ekta; Paul, Gourab; Kaushik, Abhinav; Dabral, Surbhi; Mohmmed, Asif; Gupta, Dinesh; Malhotra, Pawan

2017-02-03

Plasmodium falciparum undergoes a tightly regulated developmental process in human erythrocytes, and recent studies suggest an important regulatory role of post-translational modifications (PTMs). As compared with Plasmodium phosphoproteome, little is known about other PTMs in the parasite. In the present study, we performed a global analysis of asexual blood stages of Plasmodium falciparum to identify arginine-methylated proteins. Using two different methyl arginine-specific antibodies, we immunoprecipitated the arginine-methylated proteins from the stage-specific parasite lysates and identified 843 putative arginine-methylated proteins by LC-MS/MS. Motif analysis of the protein sequences unveiled that the methylation sites are associated with the previously known methylation motifs such as GRx/RGx, RxG, GxxR, or WxxxR. We identified Plasmodium homologues of known arginine-methylated proteins in trypanosomes, yeast, and human. Hydrophilic interaction liquid chromatography (HILIC) was performed on the immunoprecipitates from the trophozoite stage to enrich arginine-methylated peptides. Mass spectrometry analysis of immunoprecipitated and HILIC fractions identified 55 arginine-methylated peptides having 62 methylated arginine sites. Functional classification revealed that the arginine-methylated proteins are involved in RNA metabolism, protein synthesis, intracellular protein trafficking, proteolysis, protein folding, chromatin organization, hemoglobin metabolic process, and several other functions. Summarily, the findings suggest that protein methylation of arginine residues is a widespread phenomenon in Plasmodium, and the PTM may play an important regulatory role in a diverse set of biological pathways, including host-pathogen interactions.

A Study on the Effect of Surface Lysine to Arginine Mutagenesis on Protein Stability and Structure Using Green Fluorescent Protein

PubMed Central

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. PMID:22792305

An improved synthesis of haloaceteamidine-based inactivators of protein arginine deiminase 4 (PAD4)

PubMed Central

Causey, Corey P.; Thompson, Paul R.

2008-01-01

Protein arginine deiminase 4 (PAD4) is an enzyme that hydrolyzes peptidyl arginine residues to form citrulline and ammonia. This enzyme has been implicated in several disease states, e.g. rheumatoid arthritis, and therefore represents a unique target for the development of a novel therapeutic. A solution-phase synthesis of Cl-amidine, the most potent PAD4 inactivator described to date, has been developed. This synthesis proceeds in 80% yield over 4 steps at a significantly (12-fold) lower cost. PMID:19587776

An improved synthesis of haloaceteamidine-based inactivators of protein arginine deiminase 4 (PAD4).

PubMed

Causey, Corey P; Thompson, Paul R

2008-07-07

Protein arginine deiminase 4 (PAD4) is an enzyme that hydrolyzes peptidyl arginine residues to form citrulline and ammonia. This enzyme has been implicated in several disease states, e.g. rheumatoid arthritis, and therefore represents a unique target for the development of a novel therapeutic. A solution-phase synthesis of Cl-amidine, the most potent PAD4 inactivator described to date, has been developed. This synthesis proceeds in 80% yield over 4 steps at a significantly (12-fold) lower cost.

Purification and Characterization of an Arginine Aminopeptidase from Lactobacillus sakei

PubMed Central

Sanz, Yolanda; Toldrá, Fidel

2002-01-01

An arginine aminopeptidase (EC 3.4.11.6) that exclusively hydrolyzes basic amino acids from the amino (N) termini of peptide substrates has been purified from Lactobacillus sakei. The purification procedure consisted of ammonium sulfate fractionation and three chromatographic steps, which included hydrophobic interaction, gel filtration, and anion-exchange chromatography. This procedure resulted in a recovery rate of 4.2% and a 500-fold increase in specific activity. The aminopeptidase appeared to be a trimeric enzyme with a molecular mass of 180 kDa. The activity was optimal at pH 5.0 and 37°C. The enzyme was inhibited by sulfhydryl group reagents and several divalent cations (Cu2+, Hg2+, and Zn2+) but was activated by reducing agents, metal-chelating agents, and sodium chloride. The enzyme showed a preference for arginine at the N termini of aminoacyl derivatives and peptides. The Km values for Arg-7-amido-4-methylcoumarin (AMC) and Lys-AMC were 15.9 and 26.0 μM, respectively. The nature of the amino acid residue at the C terminus of dipeptides has an effect on hydrolysis rates. The activity was maximal toward dipeptides with Arg, Lys, or Ala as the C-terminal residue. The properties of the purified enzyme, its potential function in the release of arginine, and its further metabolism are discussed because, as a whole, it could constitute a survival mechanism for L. sakei in the meat environment. PMID:11916721

Arginine homopeptides for plasmid DNA purification using monolithic supports.

PubMed

Cardoso, Sara; Sousa, Ângela; Queiroz, João A; Azzoni, Adriano R; Sousa, Fani

2018-06-15

Purification of plasmid DNA targeting therapeutic applications still presents many challenges, namely on supports and specific ligand development. Monolithic supports have emerged as interesting approaches for purifying pDNA due to its excellent mass transfer properties and higher binding capacity values. Moreover, arginine ligands were already described to establish specific and preferential interactions with pDNA. Additionally, some studies revealed the ability of arginine based cationic peptides to condense plasmid DNA, which increased lengthening can result in strongest interactions with higher binding capacities for chromatographic purposes of large molecules such as pDNA. In this work, arginine homopeptides were immobilized in monolithic supports and their performance was evaluated and compared with a single arginine monolithic column regarding supercoiled (sc) plasmid DNA purification. Specific interactions of arginine based peptides with several nucleic acids present in a clarified Escherichia coli lysate sample showed potential for the sc pDNA purification. Effectively, the immobilization of the arginine homopeptides became more functional compared with the single arginine amino acid, showing higher binding capacities, which was also reflected in the intensity of the interactions. The combination of structural versatilities of monoliths with the specificity of arginine peptides raised as a promising strategy for sc pDNA purification. Copyright © 2018 Elsevier B.V. All rights reserved.

Influence of organic waste and residue mud additions on chemical, physical and microbial properties of bauxite residue sand.

PubMed

Jones, Benjamin E H; Haynes, Richard J; Phillips, Ian R

2011-02-01

In an alumina refinery, bauxite ore is treated with sodium hydroxide at high temperatures and pressures and for every tone of alumina produced, about 2 tones of alkaline, saline bauxite processing waste is also produced. At Alcoa, a dry stacking system of disposal is used, and it is the sand fraction of the processing waste that is rehabilitated. There is little information available regarding the most appropriate amendments to add to the processing sand to aid in revegetation. The purpose of this study was to investigate how the addition of organic wastes (biosolids and poultry manure), in the presence or absence of added residue mud, would affect the properties of the residue sand and its suitability for revegetation. Samples of freshly deposited residue sand were collected from Alcoa's Kwinana refinery. Samples were treated with phosphogypsum (2% v/v), incubated, and leached. A laboratory experiment was then set up in which the two organic wastes were applied at 0 or the equivalent to 60 tones ha(-1) in combination with residue mud added at rates of 0%, 10% and 20% v/v. Samples were incubated for 8 weeks, after which, key chemical, physical and microbial properties of the residue sand were measured along with seed germination. Additions of residue mud increased exchangeable Na(+), ESP and the pH, and HCO (3) (-) and Na(+) concentrations in saturation paste extracts. Additions of biosolids and poultry manure increased concentrations of extractable P, NH (4) (+) , K, Mg, Cu, Zn, Mn and Fe. Addition of residue mud, in combination with organic wastes, caused a marked decrease in macroporosity and a concomitant increase in mesoporosity, available water holding capacity and the quantity of water held at field capacity. With increasing residue mud additions, the percentage of sample present as sand particles (<1 mm diameter) decreased, and the percentage present in aggregated form (>2 mm diameter) increased; greatest aggregation occurred where a combination of residue

Effect of arginine methylation on the RNA recognition and cellular uptake of Tat-derived peptides.

PubMed

Li, Jhe-Hao; Chiu, Wen-Chieh; Yao, Yun-Chiao; Cheng, Richard P

2015-05-01

Arginine (Arg) methylation is a common post-translational modification that regulates gene expression and viral infection. The HIV-1 Tat protein is an essential regulatory protein for HIV proliferation, and is methylated in the cell. The basic region (residues 47-57) of the Tat protein contains six Arg residues, and is responsible for two biological functions: RNA recognition and cellular uptake. In this study, we explore the effect of three different methylation states at each Arg residue in Tat-derived peptides on the two biological functions. The Tat-derived peptides were synthesized by solid phase peptide synthesis. TAR RNA binding of the peptides was assessed by electrophoresis mobility shift assays. The cellular uptake of the peptides into Jurkat cells was determined by flow cytometry. Our results showed that RNA recognition was affected by both methylation state and position. In particular, asymmetric dimethylation at position 53 decreased TAR RNA binding affinity significantly, but unexpectedly less so upon asymmetric dimethylation at position 52. The RNA binding affinity even slightly increased upon methylation at some of the flanking Arg residues. Upon Arg methylation, the cellular uptake of Tat-derived peptides mostly decreased. Interestingly, cellular uptake of Tat-derived peptides with a single asymmetrically dimethylated Arg residue was similar to the native all Arg peptide (at 120 μM). Based on our results, TAR RNA binding apparently required both guanidinium terminal NH groups on Arg53, whereas cellular uptake apparently required guanidinium terminal NH₂ groups instead. These results should provide insight into how nature uses arginine methylation to regulate different biological functions, and should be useful for the development of functional molecules with methylated arginines. Copyright © 2015. Published by Elsevier Ltd.

Histone Arginine Methylation

PubMed Central

Lorenzo, Alessandra Di; Bedford, Mark T.

2012-01-01

Arginine methylation is a common posttranslational modification (PTM). This type of PTM occurs on both nuclear and cytoplasmic proteins, and is particularly abundant on shuttling proteins. In this review, we will focus on one aspect of this PTM: the diverse roles that arginine methylation of the core histone tails play in regulating chromatin function. A family of nine protein arginine methyltransferases (PRMTs) catalyze methylation reactions, and a subset target histones. Importantly, arginine methylation of histone tails can promote or prevent the docking of key transcriptional effector molecules, thus playing a central role in the orchestration of the histone code. PMID:21074527

Insight on an Arginine Synthesis Metabolon from the Tetrameric Structure of Yeast Acetylglutamate Kinase

PubMed Central

de Cima, Sergio; Gil-Ortiz, Fernando; Crabeel, Marjolaine; Fita, Ignacio; Rubio, Vicente

2012-01-01

N-acetyl-L-glutamate kinase (NAGK) catalyzes the second, generally controlling, step of arginine biosynthesis. In yeasts, NAGK exists either alone or forming a metabolon with N-acetyl-L-glutamate synthase (NAGS), which catalyzes the first step and exists only within the metabolon. Yeast NAGK (yNAGK) has, in addition to the amino acid kinase (AAK) domain found in other NAGKs, a ∼150-residue C-terminal domain of unclear significance belonging to the DUF619 domain family. We deleted this domain, proving that it stabilizes yNAGK, slows catalysis and modulates feed-back inhibition by arginine. We determined the crystal structures of both the DUF619 domain-lacking yNAGK, ligand-free as well as complexed with acetylglutamate or acetylglutamate and arginine, and of complete mature yNAGK. While all other known arginine-inhibitable NAGKs are doughnut-like hexameric trimers of dimers of AAK domains, yNAGK has as central structure a flat tetramer formed by two dimers of AAK domains. These dimers differ from canonical AAK dimers in the −110° rotation of one subunit with respect to the other. In the hexameric enzymes, an N-terminal extension, found in all arginine-inhibitable NAGKs, forms a protruding helix that interlaces the dimers. In yNAGK, however, it conforms a two-helix platform that mediates interdimeric interactions. Arginine appears to freeze an open inactive AAK domain conformation. In the complete yNAGK structure, two pairs of DUF619 domains flank the AAK domain tetramer, providing a mechanism for the DUF619 domain modulatory functions. The DUF619 domain exhibits the histone acetyltransferase fold, resembling the catalytic domain of bacterial NAGS. However, the putative acetyl CoA site is blocked, explaining the lack of NAGS activity of yNAGK. We conclude that the tetrameric architecture is an adaptation to metabolon formation and propose an organization for this metabolon, suggesting that yNAGK may be a good model also for yeast and human NAGSs. PMID:22529931

Insight on an arginine synthesis metabolon from the tetrameric structure of yeast acetylglutamate kinase.

PubMed

de Cima, Sergio; Gil-Ortiz, Fernando; Crabeel, Marjolaine; Fita, Ignacio; Rubio, Vicente

2012-01-01

N-acetyl-L-glutamate kinase (NAGK) catalyzes the second, generally controlling, step of arginine biosynthesis. In yeasts, NAGK exists either alone or forming a metabolon with N-acetyl-L-glutamate synthase (NAGS), which catalyzes the first step and exists only within the metabolon. Yeast NAGK (yNAGK) has, in addition to the amino acid kinase (AAK) domain found in other NAGKs, a ~150-residue C-terminal domain of unclear significance belonging to the DUF619 domain family. We deleted this domain, proving that it stabilizes yNAGK, slows catalysis and modulates feed-back inhibition by arginine. We determined the crystal structures of both the DUF619 domain-lacking yNAGK, ligand-free as well as complexed with acetylglutamate or acetylglutamate and arginine, and of complete mature yNAGK. While all other known arginine-inhibitable NAGKs are doughnut-like hexameric trimers of dimers of AAK domains, yNAGK has as central structure a flat tetramer formed by two dimers of AAK domains. These dimers differ from canonical AAK dimers in the -110° rotation of one subunit with respect to the other. In the hexameric enzymes, an N-terminal extension, found in all arginine-inhibitable NAGKs, forms a protruding helix that interlaces the dimers. In yNAGK, however, it conforms a two-helix platform that mediates interdimeric interactions. Arginine appears to freeze an open inactive AAK domain conformation. In the complete yNAGK structure, two pairs of DUF619 domains flank the AAK domain tetramer, providing a mechanism for the DUF619 domain modulatory functions. The DUF619 domain exhibits the histone acetyltransferase fold, resembling the catalytic domain of bacterial NAGS. However, the putative acetyl CoA site is blocked, explaining the lack of NAGS activity of yNAGK. We conclude that the tetrameric architecture is an adaptation to metabolon formation and propose an organization for this metabolon, suggesting that yNAGK may be a good model also for yeast and human NAGSs.

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

PubMed

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.

L-Arginine

MedlinePlus

... SAFE when taken by mouth appropriately for a short-term during pregnancy. Not enough is known about using L-arginine long-term in pregnancy or during breast-feeding. Stay on the safe side and avoid use. Children: L-arginine is POSSIBLY SAFE when used by ...

The Effect of Carbohydrates and Arginine on Arginine Metabolism by Excised Bean Leaves in the Dark

PubMed Central

Stewart, Cecil R.

1975-01-01

The effect of carbohydrate on arginine utilization by excised bean (Phaseolus vulgaris L. var. Tendergreen) leaves in the dark was studied by adding arginine to leaves differing in carbohydrate levels, and measuring the arginine content of the leaves at intervals. In nonstarved leaves, the arginine content decreased steadily after vacuum infiltration of 10 mm arginine and was essentially completely utilized by 36 hours after infiltration. In starved leaves, the arginine content did not decrease except for a brief period of about 4 hours after infiltration. The distribution of 14C after adding 14C-arginine to starved and nonstarved leaves indicated that the presence of carbohydrates in the leaves stimulates the utilization of arginine for protein synthesis and conversion to other amino acids, organic acids, and CO2 (catabolism). Adding sucrose along with arginine to starved leaves stimulated this utilization of arginine for both protein synthesis and catabolism. This effect of sugar on catabolism is different than results of similar studies done previously with proline. Increasing the concentration of added arginine greatly increased arginine catabolism but had a relatively small effect on utilization of arginine for protein synthesis. This result is the same as similar results from adding different concentrations of proline to excised leaves. PMID:16659159

Ablation of Arginase II Spares Arginine and Abolishes the Arginine Requirement for Growth in Male Mice.

PubMed

Didelija, Inka C; Mohammad, Mahmoud A; Marini, Juan C

2017-08-01

Background: Arginine is considered a semiessential amino acid in many species, including humans, because under certain conditions its demand exceeds endogenous production. Arginine availability, however, is determined not only by its production but also by its disposal. Manipulation of disposal pathways has the potential to increase availability and thus abolish the requirement for arginine. Objective: The objective of the study was to test the hypothesis that arginase II ablation increases arginine availability for growth. Methods: In a completely randomized design with a factorial arrangement of treatments, postweaning growth was determined for 3 wk in male and female wild-type (WT) mice and arginase II knockout mice (ARGII) on a C57BL/6J background fed arginine-sufficient [Arg(+); 8 g arginine/kg] or arginine-free [Arg(-)] diets. Tracers were used to determine citrulline and arginine kinetics. Results: A sex dimorphism in arginine metabolism was detected; female mice had a greater citrulline flux (∼30%, P < 0.001), which translated to greater de novo synthesis of arginine (∼31%, P < 0.001). Female mice also had greater arginine fluxes ( P < 0.015) and plasma arginine concentrations ( P < 0.01), but a reduced arginine clearance rate ( P < 0.001). Ablation of arginase II increased plasma arginine concentrations in both sexes (∼27%, P < 0.01) but increased arginine flux only in males ( P < 0.01). The absence of arginine in the diet limited the growth of male WT mice ( P < 0.01), but had no effect on male ARGII mice ( P = 0.12). In contrast, WT females on the Arg(-) diet grew at the same rate and achieved final weight similar to that of female WT mice fed the Arg(+) diet ( P = 0.47). Conclusion: The ablation of arginase II in male mice spares arginine that can then be used for growth and to meet other metabolic functions, thus abolishing arginine requirements. © 2017 American Society for Nutrition.

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

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

Debler, Erik W.; Jain, Kanishk; Warmack, Rebeccah A.

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 ofmore » 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.« less

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

PubMed

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

2016-02-23

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.

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

PubMed Central

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

2016-01-01

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. PMID:26858449

Arginine, scurvy and Cartier's "tree of life"

PubMed Central

Durzan, Don J

2009-01-01

Several conifers have been considered as candidates for "Annedda", which was the source for a miraculous cure for scurvy in Jacques Cartier's critically ill crew in 1536. Vitamin C was responsible for the cure of scurvy and was obtained as an Iroquois decoction from the bark and leaves from this "tree of life", now commonly referred to as arborvitae. Based on seasonal and diurnal amino acid analyses of candidate "trees of life", high levels of arginine, proline, and guanidino compounds were also probably present in decoctions prepared in the severe winter. The semi-essential arginine, proline and all the essential amino acids, would have provided additional nutritional benefits for the rapid recovery from scurvy by vitamin C when food supply was limited. The value of arginine, especially in the recovery of the critically ill sailors, is postulated as a source of nitric oxide, and the arginine-derived guanidino compounds as controlling factors for the activities of different nitric oxide synthases. This review provides further insights into the use of the candidate "trees of life" by indigenous peoples in eastern Canada. It raises hypotheses on the nutritional and synergistic roles of arginine, its metabolites, and other biofactors complementing the role of vitamin C especially in treating Cartier's critically ill sailors. PMID:19187550

Numerical simulation of residual stress in laser based additive manufacturing process

NASA Astrophysics Data System (ADS)

Kalyan Panda, Bibhu; Sahoo, Seshadev

2018-03-01

Minimizing the residual stress build-up in metal-based additive manufacturing plays a pivotal role in selecting a particular material and technique for making an industrial part. In beam-based additive manufacturing, although a great deal of effort has been made to minimize the residual stresses, it is still elusive how to do so by simply optimizing the processing parameters, such as beam size, beam power, and scan speed. Amid different types of additive manufacturing processes, Direct Metal Laser Sintering (DMLS) process uses a high-power laser to melt and sinter layers of metal powder. The rapid solidification and heat transfer on powder bed endows a high cooling rate which leads to the build-up of residual stresses, that will affect the mechanical properties of the build parts. In the present work, the authors develop a numerical thermo-mechanical model for the measurement of residual stress in the AlSi10Mg build samples by using finite element method. Transient temperature distribution in the powder bed was assessed using the coupled thermal to structural model. Subsequently, the residual stresses were estimated with varying laser power. From the simulation result, it found that the melt pool dimensions increase with increasing the laser power and the magnitude of residual stresses in the built part increases.

Nicotinic receptor transduction zone: invariant arginine couples to multiple electron-rich residues.

PubMed

Mukhtasimova, Nuriya; Sine, Steven M

2013-01-22

Gating of the muscle-type acetylcholine receptor (AChR) channel depends on communication between the ACh-binding site and the remote ion channel. A key region for this communication is located within the structural transition zone between the ligand-binding and pore domains. Here, stemming from β-strand 10 of the binding domain, the invariant αArg209 lodges within the hydrophobic interior of the subunit and is essential for rapid and efficient channel gating. Previous charge-reversal experiments showed that the contribution of αArg209 to channel gating depends strongly on αGlu45, also within this region. Here we determine whether the contribution of αArg209 to channel gating depends on additional anionic or electron-rich residues in this region. Also, to reconcile diverging findings in the literature, we compare the dependence of αArg209 on αGlu45 in AChRs from different species, and compare the full agonist ACh with the weak agonist choline. Our findings reveal that the contribution of αArg209 to channel gating depends on additional nearby electron-rich residues, consistent with both electrostatic and steric contributions. Furthermore, αArg209 and αGlu45 show a strong interdependence in both human and mouse AChRs, whereas the functional consequences of the mutation αE45R depend on the agonist. The emerging picture shows a multifaceted network of interdependent residues that are required for communication between the ligand-binding and pore domains. Copyright © 2013 Biophysical Society. Published by Elsevier Inc. All rights reserved.

Plasma membrane transporters for arginine.

PubMed

Closs, Ellen I; Simon, Alexandra; Vékony, Nicole; Rotmann, Alexander

2004-10-01

The supply of arginine may become rate limiting for enzymatic reactions that use this semiessential amino acid as a substrate (e.g., nitric oxide, agmatine, creatine, and urea synthesis), particularly under conditions of high demand such as growth, sepsis, or wound healing. In addition, arginine acts as a signaling molecule that regulates essential cellular functions such as protein synthesis, apoptosis, and growth. In the past decade, a number of carrier proteins for amino acids have been identified on the molecular level. They belong to different gene families, exhibit overlapping but distinctive substrate specificities, and can further be distinguished by their requirement for the cotransport or countertransport of inorganic ions. A number of these transporters function as exchangers rather than uniporters. Uptake of amino acids by these transporters therefore depends largely on the intracellular substrate composition. Hence, there is a complex crosstalk between transporters for cationic and neutral amino acids as well as for peptides. This article briefly reviews current knowledge regarding mammalian plasma membrane transporters that accept arginine as a substrate.

Endoplasmic reticulum protein targeting of phospholamban: a common role for an N-terminal di-arginine motif in ER retention?

PubMed

Sharma, Parveen; Ignatchenko, Vladimir; Grace, Kevin; Ursprung, Claudia; Kislinger, Thomas; Gramolini, Anthony O

2010-07-09

Phospholamban (PLN) is an effective inhibitor of the sarco(endo)plasmic reticulum Ca(2+)-ATPase, which transports Ca(2+) into the SR lumen, leading to muscle relaxation. A mutation of PLN in which one of the di-arginine residues at positions 13 and 14 was deleted led to a severe, early onset dilated cardiomyopathy. Here we were interested in determining the cellular mechanisms involved in this disease-causing mutation. Mutations deleting codons for either or both Arg13 or Arg14 resulted in the mislocalization of PLN from the ER. Our data show that PLN is recycled via the retrograde Golgi to ER membrane traffic pathway involving COP-I vesicles, since co-immunoprecipitation assays determined that COP I interactions are dependent on an intact di-arginine motif as PLN RDelta14 did not co-precipitate with COP I containing vesicles. Bioinformatic analysis determined that the di-arginine motif is present in the first 25 residues in a large number of all ER/SR Gene Ontology (GO) annotated proteins. Mutations in the di-arginine motif of the Sigma 1-type opioid receptor, the beta-subunit of the signal recognition particle receptor, and Sterol-O-acyltransferase, three proteins identified in our bioinformatic screen also caused mislocalization of these known ER-resident proteins. We conclude that PLN is enriched in the ER due to COP I-mediated transport that is dependent on its intact di-arginine motif and that the N-terminal di-arginine motif may act as a general ER retrieval sequence.

Dependence of endotoxin-induced vascular hyporeactivity on extracellular L-arginine.

PubMed

Schott, C A; Gray, G A; Stoclet, J C

1993-01-01

1. The dependence on extracellular L-arginine of vascular hyporeactivity induced by bacterial lipopolysaccharide (LPS) was studied in vivo in rats infused with LPS and in vitro in endothelium-denuded rat thoracic aortic rings exposed to LPS. 2. Infusion of LPS during 50 min at a dose of 10 mg kg-1 h-1 produced a significant impairment of the pressor effect of noradrenaline, while in tissues collected 60 min after the start of LPS infusion, no significant alteration in either plasma arginine concentration or aortic arginine content was found compared to saline-infused controls (where plasma arginine was 78.5 +/- 7 microM and aortic arginine 394 +/- 124 nmol g-1 tissue). 3. Incubation of isolated, endothelium-denuded aortic rings with LPS (10 micrograms ml-1) in the absence of L-arginine for 4 h at 37 degrees C produced a 6 fold (P < 0.01) rightward shift in the noradrenaline concentration-effect curve compared to polymyxin B (1 micrograms ml-1, a LPS neutralizing agent) and reduced by 15% the maximum observed tension. 4. The presence of L-arginine (100 microM) during the incubation with LPS and throughout the following contraction experiments caused a 15 fold (P < 0.01) increase in the EC50 of noradrenaline and greater depression (45%) of the maximum observed tension compared to polymyxin B-treated controls. Responses in control, non LPS-treated rings were unaffected by the presence of L-arginine. 5. The addition of L-arginine to rings incubated with LPS in the absence of L-arginine and maximally precontracted with noradrenaline (10 microM) induced a dose-dependent relaxation. The EC50 of L-arginine was 8.0+/-0.3mu.6. The reactivity of LPS-treated rings to noradrenaline both in the absence and presence of L-arginine was restored to control levels by N0-nitro-L-arginine methyl ester (L-NAME, 300 mu), an inhibitor of NO production and by methylene blue (3 JAM), an inhibitor of guanylate cyclase.7. Incubation of isolated aortae in the absence of L-arginine did not

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

PubMed Central

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

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

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

Laskin, Julia; Yang, Zhibo; Song, Tao

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 modelingmore » 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.« less

Combinatorial effects of arginine and fluoride on oral bacteria.

PubMed

Zheng, X; Cheng, X; Wang, L; Qiu, W; Wang, S; Zhou, Y; Li, M; Li, Y; Cheng, L; Li, J; Zhou, X; Xu, X

2015-02-01

Dental caries is closely associated with the microbial disequilibrium between acidogenic/aciduric pathogens and alkali-generating commensal residents within the dental plaque. Fluoride is a widely used anticaries agent, which promotes tooth hard-tissue remineralization and suppresses bacterial activities. Recent clinical trials have shown that oral hygiene products containing both fluoride and arginine possess a greater anticaries effect compared with those containing fluoride alone, indicating synergy between fluoride and arginine in caries management. Here, we hypothesize that arginine may augment the ecological benefit of fluoride by enriching alkali-generating bacteria in the plaque biofilm and thus synergizes with fluoride in controlling dental caries. Specifically, we assessed the combinatory effects of NaF/arginine on planktonic and biofilm cultures of Streptococcus mutans, Streptococcus sanguinis, and Porphyromonas gingivalis with checkerboard microdilution assays. The optimal NaF/arginine combinations were selected, and their combinatory effects on microbial composition were further examined in single-, dual-, and 3-species biofilm using bacterial species-specific fluorescence in situ hybridization and quantitative polymerase chain reaction. We found that arginine synergized with fluoride in suppressing acidogenic S. mutans in both planktonic and biofilm cultures. In addition, the NaF/arginine combination synergistically reduced S. mutans but enriched S. sanguinis within the multispecies biofilms. More importantly, the optimal combination of NaF/arginine maintained a "streptococcal pressure" against the potential growth of oral anaerobe P. gingivalis within the alkalized biofilm. Taken together, we conclude that the combinatory application of fluoride and arginine has a potential synergistic effect in maintaining a healthy oral microbial equilibrium and thus represents a promising ecological approach to caries management. © International & American

Combinatorial Effects of Arginine and Fluoride on Oral Bacteria

PubMed Central

Zheng, X.; Cheng, X.; Wang, L.; Qiu, W.; Wang, S.; Zhou, Y.; Li, M.; Li, Y.; Cheng, L.; Li, J.; Zhou, X.

2015-01-01

Dental caries is closely associated with the microbial disequilibrium between acidogenic/aciduric pathogens and alkali-generating commensal residents within the dental plaque. Fluoride is a widely used anticaries agent, which promotes tooth hard-tissue remineralization and suppresses bacterial activities. Recent clinical trials have shown that oral hygiene products containing both fluoride and arginine possess a greater anticaries effect compared with those containing fluoride alone, indicating synergy between fluoride and arginine in caries management. Here, we hypothesize that arginine may augment the ecological benefit of fluoride by enriching alkali-generating bacteria in the plaque biofilm and thus synergizes with fluoride in controlling dental caries. Specifically, we assessed the combinatory effects of NaF/arginine on planktonic and biofilm cultures of Streptococcus mutans, Streptococcus sanguinis, and Porphyromonas gingivalis with checkerboard microdilution assays. The optimal NaF/arginine combinations were selected, and their combinatory effects on microbial composition were further examined in single-, dual-, and 3-species biofilm using bacterial species–specific fluorescence in situ hybridization and quantitative polymerase chain reaction. We found that arginine synergized with fluoride in suppressing acidogenic S. mutans in both planktonic and biofilm cultures. In addition, the NaF/arginine combination synergistically reduced S. mutans but enriched S. sanguinis within the multispecies biofilms. More importantly, the optimal combination of NaF/arginine maintained a “streptococcal pressure” against the potential growth of oral anaerobe P. gingivalis within the alkalized biofilm. Taken together, we conclude that the combinatory application of fluoride and arginine has a potential synergistic effect in maintaining a healthy oral microbial equilibrium and thus represents a promising ecological approach to caries management. PMID:25477312

Unique Features of Human Protein Arginine Methyltransferase 9 (PRMT9) and Its Substrate RNA Splicing Factor SF3B2*

PubMed Central

Hadjikyriacou, Andrea; Yang, Yanzhong; Espejo, Alexsandra; Bedford, Mark T.; Clarke, Steven G.

2015-01-01

Human protein arginine methyltransferase (PRMT) 9 symmetrically dimethylates arginine residues on splicing factor SF3B2 (SAP145) and has been functionally linked to the regulation of alternative splicing of pre-mRNA. Site-directed mutagenesis studies on this enzyme and its substrate had revealed essential unique residues in the double E loop and the importance of the C-terminal duplicated methyltransferase domain. In contrast to what had been observed with other PRMTs and their physiological substrates, a peptide containing the methylatable Arg-508 of SF3B2 was not recognized by PRMT9 in vitro. Although amino acid substitutions of residues surrounding Arg-508 had no great effect on PRMT9 recognition of SF3B2, moving the arginine residue within this sequence abolished methylation. PRMT9 and PRMT5 are the only known mammalian enzymes capable of forming symmetric dimethylarginine (SDMA) residues as type II PRMTs. We demonstrate here that the specificity of these enzymes for their substrates is distinct and not redundant. The loss of PRMT5 activity in mouse embryo fibroblasts results in almost complete loss of SDMA, suggesting that PRMT5 is the primary SDMA-forming enzyme in these cells. PRMT9, with its duplicated methyltransferase domain and conserved sequence in the double E loop, appears to have a unique structure and specificity among PRMTs for methylating SF3B2 and potentially other polypeptides. PMID:25979344

Supplemental citrulline is more efficient than arginine to increase systemic arginine availability in mice

USDA-ARS?s Scientific Manuscript database

Arginine is considered an essential amino acid in various (patho)physiological conditions of high demand. However, dietary arginine supplementation (ARG) suffers various drawbacks, including extensive first-pass extraction. Citrulline supplementation (CIT) may be a better alternative than arginine, ...

Role of aspartate 400, arginine 262, and arginine 401 in the catalytic mechanism of human coproporphyrinogen oxidase

PubMed Central

Stephenson, Jason R.; Stacey, Julie A.; Morgenthaler, Justin B.; Friesen, Jon A.; Lash, Timothy D.; Jones, Marjorie A.

2007-01-01

Coproporphyrinogen oxidase (CPO) is the sixth enzyme in the heme biosynthetic pathway, catalyzing two sequential oxidative decarboxylations of propionate moieties on coproporphyrinogen-III forming protoporphyrinogen-IX through a monovinyl intermediate, harderoporphyrinogen. Site-directed mutagenesis studies were carried out on three invariant amino acids, aspartate 400, arginine 262, and arginine 401, to determine residue contribution to substrate binding and/or catalysis by human recombinant CPO. Kinetic analyses were performed on mutant enzymes incubated with three substrates, coproporphyrinogen-III, harderoporphyrinogen, or mesoporphyrinogen-VI, in order to determine catalytic ability to perform the first and/or second oxidative decarboxylation. When Asp400 was mutated to alanine no divinyl product was detected, but the production of a small amount of monovinyl product suggested the Km value for coproporphyrinogen-III did not change significantly compared to the wild-type enzyme. Upon mutation of Arg262 to alanine, CPO was again a poor catalyst for the production of a divinyl product, with a catalytic efficiency <0.01% compared to wild-type, including a 15-fold higher Km for coproporphyrinogen-III. The efficiency of divinyl product formation for mutant enzyme Arg401Ala was ∼3% compared to wild-type CPO, with a threefold increase in the Km value for coproporphyrinogen-III. These data suggest Asp400, Arg262, and Arg401 are active site amino acids critical for substrate binding and/or catalysis. Possible roles for arginine 262 and 401 include coordination of carboxylate groups of coproporphyrinogen-III, while aspartate 400 may initiate deprotonation of substrate, resulting in an oxidative decarboxylation. PMID:17242372

Role of aspartate 400, arginine 262, and arginine 401 in the catalytic mechanism of human coproporphyrinogen oxidase.

PubMed

Stephenson, Jason R; Stacey, Julie A; Morgenthaler, Justin B; Friesen, Jon A; Lash, Timothy D; Jones, Marjorie A

2007-03-01

Coproporphyrinogen oxidase (CPO) is the sixth enzyme in the heme biosynthetic pathway, catalyzing two sequential oxidative decarboxylations of propionate moieties on coproporphyrinogen-III forming protoporphyrinogen-IX through a monovinyl intermediate, harderoporphyrinogen. Site-directed mutagenesis studies were carried out on three invariant amino acids, aspartate 400, arginine 262, and arginine 401, to determine residue contribution to substrate binding and/or catalysis by human recombinant CPO. Kinetic analyses were performed on mutant enzymes incubated with three substrates, coproporphyrinogen-III, harderoporphyrinogen, or mesoporphyrinogen-VI, in order to determine catalytic ability to perform the first and/or second oxidative decarboxylation. When Asp400 was mutated to alanine no divinyl product was detected, but the production of a small amount of monovinyl product suggested the K(m) value for coproporphyrinogen-III did not change significantly compared to the wild-type enzyme. Upon mutation of Arg262 to alanine, CPO was again a poor catalyst for the production of a divinyl product, with a catalytic efficiency <0.01% compared to wild-type, including a 15-fold higher K(m) for coproporphyrinogen-III. The efficiency of divinyl product formation for mutant enzyme Arg401Ala was approximately 3% compared to wild-type CPO, with a threefold increase in the K(m) value for coproporphyrinogen-III. These data suggest Asp400, Arg262, and Arg401 are active site amino acids critical for substrate binding and/or catalysis. Possible roles for arginine 262 and 401 include coordination of carboxylate groups of coproporphyrinogen-III, while aspartate 400 may initiate deprotonation of substrate, resulting in an oxidative decarboxylation.

Influence of L-arginine during bovine in vitro fertilization.

PubMed

Silva, Thiago Velasco Guimarães; da Silva, Bruno Baraúna; de Sá, André Luiz Alves; da Costa, Nathalia Nogueira; Sampaio, Rafael Vilar; Cordeiro, Marcela da Silva; Santana, Priscila Di Paula Bessa; Adona, Paulo Roberto; Santos, Simone do Socorro Damasceno; Miranda, Moysés dos Santos; Ohashi, Otávio Mitio

2014-12-01

The objective of this work was to evaluate the effect of using L-arginine during in vitro fertilization (IVF) on in vitro embryonic development using Bos taurus and Bos indicus semen. Effect of different concentrations (0, 1, 10 and 50 mM) of L-arginine, added to the IVF medium, was evaluated on the fertilization rate at 18 h post-fertilization (hpf), NO3(-)/NO2(-) production during IVF by the Griess colorimetric method (30 hpf), cleavage and blastocyst rates (on Day 2 and Day 7 of culture, respectively) and total blastocyst cell number (Day 7 of culture). The results reveal that the addition of 50 mM L-arginine to IVF medium, with either Bos taurus or Bos indicus spermatozoa, decreased the cleavage rate and blastocyst rate compared to the control group. Other concentrations did not affect embryo production. However, 1 mM L-arginine with Bos indicus semen increased the proportion of hatched blastocysts. These results indicate that high L-arginine concentrations may exhibit toxic effects on bovine gametes during in vitro fertilization.

Nicotinic Receptor Transduction Zone: Invariant Arginine Couples to Multiple Electron-Rich Residues

PubMed Central

Mukhtasimova, Nuriya; Sine, Steven M.

2013-01-01

Summary Gating of the muscle-type acetylcholine receptor (AChR) channel depends on communication between the ACh-binding site and the remote ion channel. A key region for this communication is located within the structural transition zone between the ligand-binding and pore domains. Here, stemming from β-strand 10 of the binding domain, the invariant αArg209 lodges within the hydrophobic interior of the subunit and is essential for rapid and efficient channel gating. Previous charge-reversal experiments showed that the contribution of αArg209 to channel gating depends strongly on αGlu45, also within this region. Here we determine whether the contribution of αArg209 to channel gating depends on additional anionic or electron-rich residues in this region. Also, to reconcile diverging findings in the literature, we compare the dependence of αArg209 on αGlu45 in AChRs from different species, and compare the full agonist ACh with the weak agonist choline. Our findings reveal that the contribution of αArg209 to channel gating depends on additional nearby electron-rich residues, consistent with both electrostatic and steric contributions. Furthermore, αArg209 and αGlu45 show a strong interdependence in both human and mouse AChRs, whereas the functional consequences of the mutation αE45R depend on the agonist. The emerging picture shows a multifaceted network of interdependent residues that are required for communication between the ligand-binding and pore domains. PMID:23442857

Reengineering of the feedback-inhibition enzyme N-acetyl-L-glutamate kinase to enhance L-arginine production in Corynebacterium crenatum.

PubMed

Zhang, Jingjing; Xu, Meijuan; Ge, Xiaoxun; Zhang, Xian; Yang, Taowei; Xu, Zhenghong; Rao, Zhiming

2017-02-01

N-acetyl-L-glutamate kinase (NAGK) catalyzes the second step of L-arginine biosynthesis and is inhibited by L-arginine in Corynebacterium crenatum. To ascertain the basis for the arginine sensitivity of CcNAGK, residue E19 which located at the entrance of the Arginine-ring was subjected to site-saturated mutagenesis and we successfully illustrated the inhibition-resistant mechanism. Typically, the E19Y mutant displayed the greatest deregulation of L-arginine feedback inhibition. An equally important strategy is to improve the catalytic activity and thermostability of CcNAGK. For further strain improvement, we used site-directed mutagenesis to identify mutations that improve CcNAGK. Results identified variants I74V, F91H and K234T display higher specific activity and thermostability. The L-arginine yield and productivity of the recombinant strain C. crenatum SYPA-EH3 (which possesses a combination of all four mutant sites, E19Y/I74V/F91H/K234T) reached 61.2 and 0.638 g/L/h, respectively, after 96 h in 5 L bioreactor fermentation, an increase of approximately 41.8% compared with the initial strain.

Diminished Global Arginine Bioavailability and Increased Arginine Catabolism as Metabolic Profile of Increased Cardiovascular Risk

PubMed Central

Tang, W. H. Wilson; Wang, Zeneng; Cho, Leslie; Brennan, Danielle M.; Hazen, Stanley L.

2009-01-01

Objective We hypothesized that an integrated assessment of arginine with its catabolic products may better predict cardiovascular risks than arginine levels alone. Background Arginine is the sole nitrogen source for nitric oxide (NO) synthesis. The major catabolic products of arginine are ornithine and citrulline. Methods Plasma levels of free arginine, ornithine, citrulline and the endogenous NO synthase inhibitor asymmetric dimethylarginine (ADMA) were measured using LC/MS/MS. We examined the relationship of global arginine bioavailability ratio (GABR, defined as arginine/[ornithine+citrulline]) vs. arginine and its catabolic metabolites to prevalence of coronary artery disease (CAD) and incidence of major adverse cardiovascular events (MACE = death, myocardial infarction, stroke) over a 3-year follow-up in 1,010 subjects undergoing elective cardiac catheterization. Results Patients with CAD had significantly lower GABR [median(IQR); 1.06(0.75, 1.31) versus 1.27(0.96, 1.73), p<0.001] and arginine levels [mean: 68 ±20 μM versus 74 ±24 μM, p<0.001) than those without CAD. After adjusting for Framingham risk score, C-reactive protein, and renal function, lower GABR (but not arginine levels) and higher citrulline levels remained significantly associated with both prevalence of CAD [adjusted odds-ratio (OR) 3.93, p<0.001 and 5.98, p<0.001, respectively] and 3-year risk for incidence of MACE [adjusted Hazard ratio (HR) 1.98, p=0.025 and 2.40, p=0.01, respectively], and remained significant after adjusting for ADMA. Conclusions GABR may serve as a more comprehensive concept of reduced NO synthetic capacity compared to systemic arginine levels. Diminished GABR and high citrulline levels are associated with both development of atherosclerotic CAD and heightened long-term risk for major adverse cardiac events. PMID:19477356

Arginine Improves pH Homeostasis via Metabolism and Microbiome Modulation.

PubMed

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.

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

PubMed Central

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

C-terminal amino acid residue loss for deprotonated peptide ions containing glutamic acid, aspartic acid, or serine residues at the C-terminus.

PubMed

Li, Zhong; Yalcin, Talat; Cassady, Carolyn J

2006-07-01

Deprotonated peptides containing C-terminal glutamic acid, aspartic acid, or serine residues were studied by sustained off-resonance irradiation collision-induced dissociation (SORI-CID) in a Fourier transform ion cyclotron resonance (FT-ICR) mass spectrometer with ion production by electrospray ionization (ESI). Additional studies were performed by post source decay (PSD) in a matrix-assisted laser desorption ionization/time-of-flight (MALDI/TOF) mass spectrometer. This work included both model peptides synthesized in our laboratory and bioactive peptides with more complex sequences. During SORI-CID and PSD, [M - H]- and [M - 2H]2- underwent an unusual cleavage corresponding to the elimination of the C-terminal residue. Two mechanisms are proposed to occur. They involve nucleophilic attack on the carbonyl carbon of the adjacent residue by either the carboxylate group of the C-terminus or the side chain carboxylate group of C-terminal glutamic acid and aspartic acid residues. To confirm the proposed mechanisms, AAAAAD was labelled by 18O specifically on the side chain of the aspartic acid residue. For peptides that contain multiple C-terminal glutamic acid residues, each of these residues can be sequentially eliminated from the deprotonated ions; a driving force may be the formation of a very stable pyroglutamatic acid neutral. For peptides with multiple aspartic acid residues at the C-terminus, aspartic acid residue loss is not sequential. For peptides with multiple serine residues at the C-terminus, C-terminal residue loss is sequential; however, abundant loss of other neutral molecules also occurs. In addition, the presence of basic residues (arginine or lysine) in the sequence has no effect on C-terminal residue elimination in the negative ion mode.

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

PubMed

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.

Blockade of the antigen-antibody reaction using benzil condensation with the guanidyl residue of arginine.

PubMed

Montero, C; Segura, D I; Gutierrez, M

1991-03-01

Benzil blockade of the guanidyl group of arginine was tried on sections of paraffin-embedded tissue fixed in two different fixatives, in an attempt to evaluate the relevance of this amino acid to the reaction of several proteins with their corresponding antibodies. The two fixatives were 10% formaldehyde, and Bouin's fluid without acetic acid. Both polyclonal and monoclonal antibodies against proteins or peptides (lysozyme, adrenocorticotropic hormone, growth hormone, placental lactogen, and prolactin) were used on human biopsies or material from autopsies. The blockade was effective when monoclonal antibodies were used, whereas no effect or only a small decrease of the intensity of the reaction was observed with polyclonal antibodies. The least definitive result was obtained with prolactin, where a complete blockade was never achieved with monoclonal antibodies. Calcitonin, a peptide that does not contain arginine, was used as a control not susceptible to benzil blockade; no blockade of immunostaining was observed.

Arginine and citrulline for the treatment of MELAS syndrome

PubMed Central

El-Hattab, Ayman W.; Almannai, Mohammed; Scaglia, Fernando

2017-01-01

MELAS (mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes) 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 aspect 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. PMID:28736735

Arginine and citrulline for the treatment of MELAS syndrome.

PubMed

El-Hattab, Ayman W; Almannai, Mohammed; Scaglia, Fernando

2017-01-01

MELAS (mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes) 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 aspect 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.

Thermal aggregation of human immunoglobulin G in arginine solutions: Contrasting effects of stabilizers and destabilizers.

PubMed

Yoshizawa, Shunsuke; Arakawa, Tsutomu; Shiraki, Kentaro

2017-11-01

Arginine is widely used as aggregation suppressor of proteins in biotechnology and pharmaceutics. However, why the effect of arginine depends on the types of proteins and stresses, including monoclonal antibodies, is still unclear. Here we investigated the precise processes of the thermal aggregation of human immunoglobulin G (IgG) in the presence of additives. As expected, arginine was the best additive to suppress the formation of insoluble aggregates during heat treatment, though it was unable to preserve the monomer content. A systematic analysis of the additives showed that sugars and kosmotropic ion inhibit the formation of soluble oligomers. These behaviors indicate that the thermal aggregation of IgG occurs by (i) the formation of soluble oligomers, which is triggered by the unfolding process that can be stabilized by typical osmolytes, and (ii) the formation of insoluble aggregates through weak cluster-cluster interactions, which can be suppressed by arginine. Understanding the detailed mechanism of arginine will provide useful information for the rational formulation design of antibodies. Copyright © 2017 Elsevier B.V. All rights reserved.

Long-term enteral arginine supplementation in rats with intestinal ischemia and reperfusion.

PubMed

Lee, Chien-Hsing; Hsiao, Chien-Chou; Hung, Ching-Yi; Chang, Yu-Jun; Lo, Hui-Chen

2012-06-01

The effects of short-term enteral arginine supplementation on intestinal ischemia-reperfusion (IR) injury have been widely studied, especially the ischemic preconditioning supplementation. The aim of this study was to investigate the effects of long-term intra-duodenal supplementation of arginine on intestinal morphology, arginine-associated amino acid metabolism, and inflammatory responses in rats with intestinal IR. Male Wistar rats with or without three hours of ileal ischemia underwent duodenal cannulation for continuous infusion of formula with 2% arginine or commercial protein powder for 7 d. The serological examinations, plasma amino acid and cytokine profiles, and intestinal morphology were assessed. Intestinal IR injury had significant impacts on the decreases in circulating red blood cells, hemoglobin, ileum mass, and villus height and crypt depth of the distal jejunum. In addition, arginine supplementation decreased serum cholesterol and increased plasma arginine concentrations. In rats with intestinal IR injury, arginine supplementation significantly decreased serum nitric oxide, plasma citrulline and ornithine, and the mucosal protein content of the ileum. These results suggest that long-term intra-duodenal arginine administration may not have observable benefits on intestinal morphology or inflammatory response in rats with intestinal ischemia and reperfusion injury. Therefore, the necessity of long-term arginine supplementation for patients with intestinal ischemia and reperfusion injury remains questionable and requires further investigation. Copyright © 2012 Elsevier Inc. All rights reserved.

Diminished L-arginine bioavailability in hypertension.

PubMed

Moss, Monique B; Brunini, Tatiana M C; Soares De Moura, Roberto; Novaes Malagris, Lúcia E; Roberts, Norman B; Ellory, J Clive; Mann, Giovanni E; Mendes Ribeiro, Antônio C

2004-10-01

L-Arginine is the precursor of NO (nitric oxide), a key endogenous mediator involved in endothelium-dependent vascular relaxation and platelet function. Although the concentration of intracellular L-arginine is well above the Km for NO synthesis, in many cells and pathological conditions the transport of L-arginine is essential for NO production (L-arginine paradox). The present study was designed to investigate the modulation of L-arginine/NO pathway in systemic arterial hypertension. Transport of L-arginine into RBCs (red blood cells) and platelets, NOS (NO synthase) activity and amino acid profiles in plasma were analysed in hypertensive patients and in an animal model of hypertension. Influx of L-arginine into RBCs was mediated by the cationic amino acid transport systems y+ and y+L, whereas, in platelets, influx was mediated only via system y+L. Chromatographic analyses revealed higher plasma levels of L-arginine in hypertensive patients (175+/-19 micromol/l) compared with control subjects (137+/-8 micromol/l). L-Arginine transport via system y+L, but not y+, was significantly reduced in RBCs from hypertensive patients (60+/-7 micromol.l(-1).cells(-1).h(-1); n=16) compared with controls (90+/-17 micromol.l(-1).cells(-1).h(-1); n=18). In human platelets, the Vmax for L-arginine transport via system y+L was 86+/-17 pmol.10(9) cells(-1).min(-1) in controls compared with 36+/-9 pmol.10(9) cells(-1).min(-1) in hypertensive patients (n=10; P<0.05). Basal NOS activity was decreased in platelets from hypertensive patients (0.12+/-0.02 pmol/10(8) cells; n=8) compared with controls (0.22+/-0.01 pmol/10(8) cells; n=8; P<0.05). Studies with spontaneously hypertensive rats demonstrated that transport of L-arginine via system y+L was also inhibited in RBCs. Our findings provide the first evidence that hypertension is associated with an inhibition of L-arginine transport via system y+L in both humans and animals, with reduced availability of L-arginine limiting NO synthesis

Conformational profile of a proline-arginine hybrid

PubMed Central

Revilla-López, Guillermo; Jiménez, Ana I.; Cativiela, Carlos; Nussinov, Ruth; Alemán, Carlos; Zanuy, David

2010-01-01

The intrinsic conformational preferences of a new non-proteinogenic amino acid have been explored by computational methods. This tailored molecule, named (βPro)Arg, is conceived as a replacement for arginine in bioactive peptides when the stabilization of folded turn-like conformations is required. The new residue features a proline skeleton that bears the guanidilated side chain of arginine at the Cβ position of the five-membered pyrrolidine ring, either in a cis or a trans orientation with respect to the carboxylic acid. The conformational profile of the N-acetyl-N'-methylamide derivatives of the cis and trans isomers of (βPro)Arg has been examined in the gas phase and in solution by B3LYP/6–31+G(d,p) calculations and molecular dynamics simulations. The main conformational features of both isomers represent a balance between geometric restrictions imposed by the five-membered pyrrolidine ring and the ability of the guanidilated side chain to interact with the backbone through hydrogen-bonds. Thus, both cis and trans (βPro)Arg exhibit a preference for the αL conformation as a consequence of the interactions established between the guanidinium moiety and the main-chain amide groups. PMID:20886854

Conformational profile of a proline-arginine hybrid.

PubMed

Revilla-López, Guillermo; Jiménez, Ana I; Cativiela, Carlos; Nussinov, Ruth; Alemán, Carlos; Zanuy, David

2010-10-25

The intrinsic conformational preferences of a new nonproteinogenic amino acid have been explored by computational methods. This tailored molecule, named ((β)Pro)Arg, is conceived as a replacement for arginine in bioactive peptides when the stabilization of folded turn-like conformations is required. The new residue features a proline skeleton that bears the guanidilated side chain of arginine at the C(β) position of the five-membered pyrrolidine ring, in either a cis or a trans orientation with respect to the carboxylic acid. The conformational profiles of the N-acetyl-N'-methylamide derivatives of the cis and trans isomers of ((β)Pro)Arg have been examined in the gas phase and in solution by B3LYP/6-31+G(d,p) calculations and molecular dynamics simulations. The main conformational features of both isomers represent a balance between geometric restrictions imposed by the five-membered pyrrolidine ring and the ability of the guanidilated side chain to interact with the backbone through hydrogen bonds. Thus, both cis- and trans-((β)Pro)Arg exhibit a preference for the α(L) conformation as a consequence of the interactions established between the guanidinium moiety and the main-chain amide groups.

Determining rotational dynamics of the guanidino group of arginine side chains in proteins by carbon-detected NMR† †Electronic supplementary information (ESI) available. See DOI: 10.1039/c7cc04821a

PubMed Central

Gerecht, Karola; Figueiredo, Angelo Miguel

2017-01-01

Arginine residues are imperative for many active sites and protein-interaction interfaces. A new NMR-based method is presented to determine the rotational dynamics around the Nε–Cζ bond of arginine side chains. An application to a 19 kDa protein shows that the strengths of interactions involving arginine side chains can be characterised. PMID:28840203

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.

PubMed

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.

L-arginine as dietary supplement for improving microvascular function.

PubMed

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 < 0.05), while in the other groups it remained the same. There were no differences in the endothelium-independent vasodilation after ingestion of 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.

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

PubMed Central

Lubyova, Barbora; Hodek, Jan; Zabransky, Ales; Prouzova, Hana; Hubalek, Martin; Hirsch, Ivan

2017-01-01

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. PMID:29065155

Sidedness of interfacial arginine residues and anti-atherogenicity of apolipoprotein A-I mimetic peptides

PubMed Central

Nayyar, Gaurav; Mishra, Vinod K.; Handattu, Shaila P.; Palgunachari, Mayakonda N.; Shin, Ronald; McPherson, David T.; Deivanayagam, Champion C. S.; Garber, David W.; Segrest, Jere P.; Anantharamaiah, G. M.

2012-01-01

To test the hypothesis that sidedness of interfacial arginine (Arg) in apoA-I mimetic peptides, similar to that observed in apoA-I (Bashtovyy, D. et al. 2011. Sequence conservation of apolipoprotein A-I affords novel insights into HDL structure-function. J. Lipid Res. 52: 435–450.), may be important for biological activity, we compared properties of 4F and analogs, [K4,15>R]4F and [K9,13>R]4F, with Lys>Arg substitutions on the right and left side, respectively, of the 4F amphipathic helix. Intraperitoneal administration of these peptides into female apoE null mice (n = 13 in each group) reduced en face lesions significantly compared with controls; 4F and [K4,15>R]4F were equally effective whereas [K9,13>R]4F was less effective. Turnover experiments indicated that [K4,15>R]4F reached the highest, whereas [K9,13>R]4F had the lowest, plasma peak levels with a similar half life as the [K4,15>R]4F analog. The half life of 4F was two times longer than the other two peptides. The order in their abilities to associate with HDL in human plasma, generation of apoA-I particles with pre-β mobility from isolated HDL, lipid associating ability, and sensitivity of lipid complexes to trypsin digestion was: 4F>[K4,15,>R]4F>[K9,13>R]4F. These studies support our hypothesis that the sidedness of interfacial Arg residues in the polar face of apoA-I mimetics results in differential biological properties. PMID:22377531

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

PubMed Central

DeRouchey, Jason; Hoover, Brandon

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 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 poly-lysine compared to poly-arginine. 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 due to both a weaker attraction and a stronger short ranged repulsion relative to the arginine peptides. A previously proposed model for poly-arginine and protamine binding to DNA provides a convenient framework for understanding the differences between the ability of lysine and arginine peptides to assemble DNA. PMID:23540557

Expanding the clinical and molecular spectrum of PRMT7 mutations: 3 additional patients and review.

PubMed

Agolini, E; Dentici, M L; Bellacchio, E; Alesi, V; Radio, F C; Torella, A; Musacchia, F; Tartaglia, M; Dallapiccola, B; Nigro, V; Digilio, M C; Novelli, A

2018-03-01

Protein arginine methyltransferase 7 (PRMT7) is a member of a family of enzymes that catalyze the transfer of methyl groups from S-adenosyl-l-methionine to nitrogen atoms on arginine residues. Arginine methylation is involved in multiple biological processes, such as signal transduction, mRNA splicing, transcriptional control, DNA repair, and protein translocation. Currently, 7 patients have been described harboring compound heterozygous or homozygous variants in the PRMT7 gene, causing a novel intellectual disability syndrome, known as SBIDDS syndrome (Short Stature, Brachydactyly, Intellectual Developmental Disability, and Seizures). We report on 3 additional patients from 2 consanguineous families with severe/moderate intellectual disability, short stature, brachydactyly and dysmorphisms. Exome sequencing revealed 2 novel homozygous mutations in PRMT7. Our findings expand the clinical and molecular spectrum of homozygous PRMT7 mutations, associated to the SBIDDS syndrome, showing a possible correlation between the type of mutation and the severity of the phenotype. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Dietary arginine depletion reduces depressive-like responses in male, but not female, mice.

PubMed

Workman, Joanna L; Weber, Michael D; Nelson, Randy J

2011-09-30

Previous behavioral studies have manipulated nitric oxide (NO) production either by pharmacological inhibition of its synthetic enzyme, nitric oxide synthase (NOS), or by deletion of the genes that code for NOS. However manipulation of dietary intake of the NO precursor, L-arginine, has been understudied in regard to behavioral regulation. L-Arginine is a common amino acid present in many mammalian diets and is essential during development. In the brain L-arginine is converted into NO and citrulline by the enzyme, neuronal NOS (nNOS). In Experiment 1, paired mice were fed a diet comprised either of an L-arginine-depleted, L-arginine-supplemented, or standard level of L-arginine during pregnancy. Offspring were continuously fed the same diets and were tested in adulthood in elevated plus maze, forced swim, and resident-intruder aggression tests. L-Arginine depletion reduced depressive-like responses in male, but not female, mice and failed to significantly alter anxiety-like or aggressive behaviors. Arginine depletion throughout life reduced body mass overall and eliminated the sex difference in body mass. Additionally, arginine depletion significantly increased corticosterone concentrations, which negatively correlated with time spent floating. In Experiment 2, adult mice were fed arginine-defined diets two weeks prior to and during behavioral testing, and again tested in the aforementioned tests. Arginine depletion reduced depressive-like responses in the forced swim test, but did not alter behavior in the elevated plus maze or the resident intruder aggression test. Corticosterone concentrations were not altered by arginine diet manipulation in adulthood. These results indicate that arginine depletion throughout development, as well as during a discrete period during adulthood ameliorates depressive-like responses. These results may yield new insights into the etiology and sex differences of depression. Copyright © 2011 Elsevier B.V. All rights reserved.

Biocatalytic synthesis, antimicrobial properties and toxicity studies of arginine derivative surfactants.

PubMed

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.

Accumulation of Citrulline by Microbial Arginine Metabolism during Alcoholic Fermentation of Soy Sauce.

PubMed

Fang, Fang; Zhang, Jiran; Zhou, Jingwen; Zhou, Zhaohui; Li, Tieqiao; Lu, Liling; Zeng, Weizhu; Du, Guocheng; Chen, Jian

2018-03-07

Citrulline, the major precursor of ethyl carbamate in soy sauce, is an intermediate catabolite of arginine produced by bacteria present in soy sauce moromi mash. Pediococcus acidilactici is responsible for the formation of citrulline during the lactic acid fermentation process of soy sauce. However, citrulline accumulation during the alcoholic fermentation process and the corresponding bacteria involved have not been identified. Salt-tolerant, arginine-utilizing bacteria were isolated from moromi mash during the alcoholic fermentation process. Under normal cultivation conditions, arginine utilization by these strains did not contribute to citrulline accumulation. However, the conversion of arginine to citrulline by these bacteria increased when cultivated during the alcoholic fermentation process. Additionally, the ethanol-enhanced solubility of free fatty acids in moromi mash stimulated the accumulation of citrulline. Staphylococcus exhibited the highest capability in the conversion of arginine to citrulline.

l-Arginine administration attenuates airway inflammation by altering l-arginine metabolism in an NC/Nga mouse model of asthma.

PubMed

Zhang, Ran; Kubo, Masayuki; Murakami, Ikuo; Setiawan, Heri; Takemoto, Kei; Inoue, Kiyomi; Fujikura, Yoshihisa; Ogino, Keiki

2015-05-01

Changes in l-arginine metabolism, including increased arginase levels and decreased nitric oxide production, are involved in the pathophysiology of asthma. In this study, using an intranasal mite-induced NC/Nga mouse model of asthma, we examined whether administration of l-arginine ameliorated airway hyperresponsiveness and inflammation by altering l-arginine metabolism. Experimental asthma was induced in NC/Nga mice via intranasal administration of mite crude extract (50 µg/day) on 5 consecutive days (days 0-4, sensitization) and on day 11 (challenge). Oral administration of l-arginine (250 mg/kg) was performed twice daily on days 5-10 for prevention or on days 11-13 for therapy. On day 14, we evaluated the inflammatory airway response (airway hyperresponsiveness, the number of cells in the bronchoalveolar lavage fluid, and the changes in pathological inflammation of the lung), arginase expression and activity, l-arginine bioavailability, and the concentration of NOx, the end products of nitric oxide. Treatment with l-arginine ameliorated the mite-induced inflammatory airway response. Furthermore, l-arginine administration attenuated the increases in arginase expression and activity and elevated the NOx levels by enhancing l-arginine bioavailability. These findings indicate that l-arginine administration may contribute to the improvement of asthmatic symptoms by altering l-arginine metabolism.

Biochemical and structural characterization of a novel arginine kinase from the spider Polybetes pythagoricus

DOE PAGES

Laino, Aldana; Lopez-Zavala, Alonso A.; Garcia-Orozco, Karina D.; ...

2017-09-11

Energy buffering systems are key for homeostasis during variations in energy supply. Spiders are the most important predators for insects and therefore key in terrestrial ecosystems. From biomedical interest, spiders are important for their venoms and as a source of potent allergens, such as arginine kinase (AK, EC 2.7.3.3). AK is an enzyme crucial for energy metabolism, keeping the pool of phosphagens in invertebrates, and also an allergen for humans. In this work, we studied AK from the Argentininan spider Polybetes pythagoricus ( PpAK), from its complementary DNA to the crystal structure. The PpAK cDNA from muscle was cloned, andmore » it is comprised of 1068 nucleotides that encode a 384-amino acids protein, similar to other invertebrate AKs. The apparent Michaelis-Menten kinetic constant ( K m) was 1.7 mM with a k cat of 75 s –1. Two crystal structures are presented, the apo PvAK and PpAK bound to arginine, both in the open conformation with the active site lid (residues 310–320) completely disordered. The guanidino group binding site in the apo structure appears to be organized to accept the arginine substrate. Lastly, these results contribute to knowledge of mechanistic details of the function of arginine kinase.« less

Biochemical and structural characterization of a novel arginine kinase from the spider Polybetes pythagoricus

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

Laino, Aldana; Lopez-Zavala, Alonso A.; Garcia-Orozco, Karina D.

Energy buffering systems are key for homeostasis during variations in energy supply. Spiders are the most important predators for insects and therefore key in terrestrial ecosystems. From biomedical interest, spiders are important for their venoms and as a source of potent allergens, such as arginine kinase (AK, EC 2.7.3.3). AK is an enzyme crucial for energy metabolism, keeping the pool of phosphagens in invertebrates, and also an allergen for humans. In this work, we studied AK from the Argentininan spider Polybetes pythagoricus ( PpAK), from its complementary DNA to the crystal structure. The PpAK cDNA from muscle was cloned, andmore » it is comprised of 1068 nucleotides that encode a 384-amino acids protein, similar to other invertebrate AKs. The apparent Michaelis-Menten kinetic constant ( K m) was 1.7 mM with a k cat of 75 s –1. Two crystal structures are presented, the apo PvAK and PpAK bound to arginine, both in the open conformation with the active site lid (residues 310–320) completely disordered. The guanidino group binding site in the apo structure appears to be organized to accept the arginine substrate. Lastly, these results contribute to knowledge of mechanistic details of the function of arginine kinase.« less

Arginine methylation promotes translation repression activity of eIF4G-binding protein, Scd6.

PubMed

Poornima, Gopalakrishna; Shah, Shanaya; Vignesh, Venkadasubramanian; Parker, Roy; Rajyaguru, Purusharth I

2016-11-02

Regulation of translation plays a critical role in determining mRNA fate. A new role was recently reported for a subset of RGG-motif proteins in repressing translation initiation by binding eIF4G1. However the signaling mechanism(s) that leads to spatial and temporal regulation of repression activity of RGG-motif proteins remains unknown. Here we report the role of arginine methylation in regulation of repression activity of Scd6, a conserved RGG-motif protein. We demonstrate that Scd6 gets arginine methylated at its RGG-motif and Hmt1 plays an important role in its methylation. We identify specific methylated arginine residues in the Scd6 RGG-motif in vivo We provide evidence that methylation augments Scd6 repression activity. Arginine methylation defective (AMD) mutant of Scd6 rescues the growth defect caused by overexpression of Scd6, a feature of translation repressors in general. Live-cell imaging of the AMD mutant revealed that it is defective in inducing formation of stress granules. Live-cell imaging and pull-down results indicate that it fails to bind eIF4G1 efficiently. Consistent with these results, a strain lacking Hmt1 is also defective in Scd6-eIF4G1 interaction. Our results establish that arginine methylation augments Scd6 repression activity by promoting eIF4G1-binding. We propose that arginine methylation of translation repressors with RGG-motif could be a general modulator of their repression activity. © The Author(s) 2016. Published by Oxford University Press on behalf of Nucleic Acids Research.

The influence of a novel pentadecapeptide, BPC 157, on N(G)-nitro-L-arginine methylester and L-arginine effects on stomach mucosa integrity and blood pressure.

PubMed

Sikirić, P; Seiwerth, S; Grabarević, Z; Rucman, R; Petek, M; Jagić, V; Turković, B; Rotkvić, I; Mise, S; Zoricić, I; Konjevoda, P; Perović, D; Jurina, L; Separović, J; Hanzevacki, M; Artuković, B; Bratulić, M; Tisljar, M; Gjurasin, M; Miklić, P; Stancić-Rokotov, D; Slobodnjak, Z; Jelovac, N; Marović, A

1997-07-30

The known effects of a novel stomach pentadecapeptide BPC157 (10 microg or 10 ng/kg), namely its salutary activity against ethanol (96%, i.g.)-induced gastric lesions (simultaneously applied i.p.) and in blood pressure maintenance (given i.v.), were investigated in rats challenged with a combination of N(G)-nitro-L-arginine methylester (L-NAME) (5 mg/kg i.v.), a competitive inhibitor of endothelium nitric oxide (NO)-generation and NO precursor, L-arginine (200 mg/kg i.v.) (D-arginine was ineffective). In the gastric lesions assay, NO agents were given 5 min before ethanol injury and BPC 157 medication. Given alone, BPC157 had an antiulcer effect, as did L-arginine, but L-NAME had no effect. L-NAME completely abolished the effect of L-arginine, whereas it only attenuated the effect of BPC 157. After application of the combination of L-NAME + L-arginine, the BPC157 effect was additionally impaired. In blood pressure studies, compared with L-arginine, pentadecapeptide BPC 157 (without effect on basal normal values) had both a mimicking effect (impaired L-NAME-blood pressure increase, when applied prophylactically and decreased already raised L-NAME values, given at the time of the maximal L-NAME-blood pressure increase (i.e., 10 min after L-NAME)) and preventive activity (L-arginine-induced moderate blood pressure decrease was prevented by BPC 157 pretreatment). When BPC 157 was given 10 min after L-NAME + L-arginine combination, which still led to a blood pressure increase, its previously clear effect (noted in L-NAME treated rats) disappeared. In vitro, in gastric mucosa from rat stomach tissue homogenates, BPC 157, given in the same dose (100 microM) as L-arginine, induced a comparable generation of NO. But, BPC 157 effect could not be inhibited by L-NAME, even when L-NAME was given in a tenfold (100 versus 1000 microM) higher dose than that needed for inhibition of the L-arginine effect. NO synthesis was blunted when the pentadecapeptide BPC 157 and L-arginine

Addition of an organic amendment and/or residue mud to bauxite residue sand in order to improve its properties as a growth medium.

PubMed

Jones, B E H; Haynes, R J; Phillips, I R

2012-03-01

The effects of addition of carbonated residue mud (RMC) or seawater neutralized residue mud (RMS), at two rates, in the presence or absence of added green waste compost, on the chemical, physical and microbial properties of gypsum-treated bauxite residue sand were studied in a laboratory incubation study. The growth of two species commonly used in revegetation of residue sand (Lolium rigidum and Acacia saligna) in the treatments was then studied in a 18-week greenhouse study. Addition of green waste-based compost increased ammonium acetate-extractable (exchangeable) Mg, K and Na. Addition of residue mud at 5 and 10% w/w reduced exchangeable Ca but increased that of Mg and Na (and K for RMS). Concentrations of K, Na, Mg and level of EC in saturation paste extracts were increased by residue mud additions. Concentrations of cations in water extracts were considerably higher than those in saturation paste extracts but trends with treatment were broadly similar. Addition of both compost and residue mud caused a significant decrease in macroporosity with a concomitant increase in mesoporosity and microporosity, available water holding capacity and the quantity of water held at field capacity. Increasing rates of added residue mud reduced the percentage of sample present as discrete sand particles and increased that in aggregated form (particularly in the 1-2 and >10mm diameter ranges). Organic C content, C/N ratio, soluble organic C, microbial biomass C and basal respiration were increased by compost additions. Where compost was added, residue mud additions caused a substantial increase in microbial biomass and basal respiration. L. rigidum grew satisfactorily in all treatments although yields tended to be reduced by additions of mud (especially RMC) particularly in the absence of added compost. Growth of A. saligna was poor in sand alone and mud-amended sand and was greatly promoted by additions of compost. However, in the presence of compost, addition of carbonated

Type II protein arginine methyltransferase 5 (PRMT5) is required for circadian period determination in Arabidopsis thaliana.

PubMed

Hong, Sunghyun; Song, Hae-Ryong; Lutz, Kerry; Kerstetter, Randall A; Michael, Todd P; McClung, C Robertson

2010-12-07

Posttranslational modification is an important element in circadian clock function from cyanobacteria through plants and mammals. For example, a number of key clock components are phosphorylated and thereby marked for subsequent ubiquitination and degradation. Through forward genetic analysis we demonstrate that protein arginine methyltransferase 5 (PRMT5; At4g31120) is a critical determinant of circadian period in Arabidopsis. PRMT5 is coregulated with a set of 1,253 genes that shows alterations in phase of expression in response to entrainment to thermocycles versus photocycles in constant temperature. PRMT5 encodes a type II protein arginine methyltransferase that catalyzes the symmetric dimethylation of arginine residues (Rsme2). Rsme2 modification has been observed in many taxa, and targets include histones, components of the transcription complex, and components of the spliceosome. Neither arginine methylation nor PRMT5 has been implicated previously in circadian clock function, but the period lengthening associated with mutational disruption of prmt5 indicates that Rsme2 is a decoration important for the Arabidopsis clock and possibly for clocks in general.

Type II protein arginine methyltransferase 5 (PRMT5) is required for circadian period determination in Arabidopsis thaliana

PubMed Central

Hong, Sunghyun; Lutz, Kerry; Kerstetter, Randall A.; Michael, Todd P.; McClung, C. Robertson

2010-01-01

Posttranslational modification is an important element in circadian clock function from cyanobacteria through plants and mammals. For example, a number of key clock components are phosphorylated and thereby marked for subsequent ubiquitination and degradation. Through forward genetic analysis we demonstrate that protein arginine methyltransferase 5 (PRMT5; At4g31120) is a critical determinant of circadian period in Arabidopsis. PRMT5 is coregulated with a set of 1,253 genes that shows alterations in phase of expression in response to entrainment to thermocycles versus photocycles in constant temperature. PRMT5 encodes a type II protein arginine methyltransferase that catalyzes the symmetric dimethylation of arginine residues (Rsme2). Rsme2 modification has been observed in many taxa, and targets include histones, components of the transcription complex, and components of the spliceosome. Neither arginine methylation nor PRMT5 has been implicated previously in circadian clock function, but the period lengthening associated with mutational disruption of prmt5 indicates that Rsme2 is a decoration important for the Arabidopsis clock and possibly for clocks in general. PMID:21097700

Hsl7 is a substrate-specific type II protein arginine methyltransferase in yeast

PubMed Central

Sayegh, Joyce; Clarke, Steven G.

2008-01-01

The Saccharomyces cerevisiae protein Hsl7 is a regulator of the Swe1 protein kinase in cell cycle checkpoint control. Hsl7 has been previously described as a type III protein arginine methyltransferase, catalyzing the formation of ω-monomethylarginine residues on non-physiological substrates. However, we show here that Hsl7 can also display type II activity, generating symmetric dimethylarginine residues on calf thymus histone H2A. Symmetric dimethylation is only observed when enzyme and the methyl-accepting substrate were incubated for extended times. We confirmed the Hsl7-dependent formation of symmetric dimethylarginine by amino acid analysis and thin layer chromatography with wild type and mutant recombinant enzymes expressed from both bacteria and yeast. This result is significant because no type II activity has been previously demonstrated in S. cerevisiae. We also show that Hsl7 has little or no activity on GST-GAR, a commonly used substrate for protein arginine methyltransferases, and only minimal activity on myelin basic protein. This enzyme thus may only recognize only a small subset of potential substrate proteins in yeast, in contrast to the situation with Rmt1, the major type I methyltransferase. PMID:18515076

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

PubMed

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.

Effects of exercise and L-arginine on ventricular remodeling and oxidative stress.

PubMed

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 < 0.05). The protein levels of SOD in the Sed and Ex groups were both significantly decreased with the administration of L-NAME. The protein levels of catalase were significantly higher in the Ex and Ex + LA groups than that in the Sed, Sed + LA, and L-NAME-treated groups. The collagen volume fraction was significantly lowered by the exercise and/or 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

Arginine depletion by arginine deiminase does not affect whole protein metabolism or muscle fractional protein synthesis rate in mice

USDA-ARS?s Scientific Manuscript database

Due to the absolute need for arginine that certain cancer cells have, arginine depletion is a therapy in clinical trials to treat several types of cancers. Arginine is an amino acids utilized not only as a precursor for other important molecules, but also for protein synthesis. Because arginine depl...

Protein arginine N-methyltransferase 1 promotes the proliferation and metastasis of hepatocellular carcinoma cells.

PubMed

Gou, Qing; He, ShuJiao; Zhou, ZeJian

2017-02-01

Hepatocellular carcinoma is the most common subtype of liver cancer. Protein arginine N-methyltransferase 1 was shown to be upregulated in various cancers. However, the role of protein arginine N-methyltransferase 1 in hepatocellular carcinoma progression remains incompletely understood. We investigated the clinical and functional significance of protein arginine N-methyltransferase 1 in a series of clinical hepatocellular carcinoma samples and a panel of hepatocellular carcinoma cell lines. We performed suppression analysis of protein arginine N-methyltransferase 1 using small interfering RNA to determine the biological roles of protein arginine N-methyltransferase 1 in hepatocellular carcinoma. In addition, the expression of epithelial-mesenchymal transition indicators was verified by western blotting in hepatocellular carcinoma cell lines after small interfering RNA treatment. Protein arginine N-methyltransferase 1 expression was found to be significantly upregulated in hepatocellular carcinoma cell lines and clinical tissues. Moreover, downregulation of protein arginine N-methyltransferase 1 in hepatocellular carcinoma cells by small interfering RNA could inhibit cell proliferation, migration, and invasion in vitro. These results indicate that protein arginine N-methyltransferase 1 may contribute to hepatocellular carcinoma progression and serves as a promising target for the treatment of hepatocellular carcinoma patients.

Structures of Bacterial Biosynthetic Arginine Decarboxylases

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

F Forouhar; S Lew; J Seetharaman

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. Themore » 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.« less

Dysregulated Arginine Metabolism and Cardiopulmonary Dysfunction in Patients with Thalassaemia

PubMed Central

Morris, Claudia R.; Kim, Hae-Young; Klings, Elizabeth S.; Wood, John; Porter, John B.; Trachtenberg, Felicia; Sweeters, Nancy; Olivieri, Nancy F; Kwiatkowski, Janet L; Virzi, Lisa; Hassell, Kathryn; Taher, Ali; Neufeld, Ellis J; Thompson, Alexis A.; Larkin, Sandra; Suh, Jung H.; Vichinsky, Elliott P; Kuypers, Frans A.

2015-01-01

Pulmonary hypertension (PH) commonly develops in thalassaemia syndromes, but is poorly characterized. The goal of this study was to provide a comprehensive description of the cardiopulmonary and biological profile of patients with thalassaemia at risk for PH. A case-control study of thalassaemia patients at high versus low PH-risk was performed. A single cross-sectional measurement for variables reflecting cardiopulmonary status and biological pathophysiology were obtained, including Doppler-echocardiography, 6-minute-walk-test, Borg Dyspnea Score, New York Heart Association functional class, cardiac magnetic resonance imaging (MRI), chest-computerized tomography, pulmonary function testing and laboratory analyses targeting mechanism of coagulation, inflammation, haemolysis, adhesion and the arginine-nitric oxide pathway. Twenty-seven thalassaemia patients were evaluated, 14 with an elevated tricuspid-regurgitant-jet-velocity (TRV) ≥2.5m/s. Patients with increased TRV had a higher frequency of splenectomy, and significantly larger right atrial size, left atrial volume and left septal-wall thickness on echocardiography and/or MRI, with elevated biomarkers of abnormal coagulation, lactate dehydrogenase levels and arginase concentration, and lower arginine-bioavailability compared to low-risk patients. Arginase concentration correlated significantly to several echocardiography/MRI parameters of cardiovascular function in addition to global-arginine-bioavailability and biomarkers of haemolytic rate, including lactate dehydrogenase, haemoglobin and bilirubin. Thalassaemia patients with a TRV ≥2.5m/s have additional echocardiography and cardiac-MRI parameters suggestive of right and left-sided cardiac dysfunction. In addition, low arginine bioavailability may contribute to cardiopulmonary dysfunction in β-thalassaemia. PMID:25907665

Dysregulated arginine metabolism and cardiopulmonary dysfunction in patients with thalassaemia.

PubMed

Morris, Claudia R; Kim, Hae-Young; Klings, Elizabeth S; Wood, John; Porter, John B; Trachtenberg, Felicia; Sweeters, Nancy; Olivieri, Nancy F; Kwiatkowski, Janet L; Virzi, Lisa; Hassell, Kathryn; Taher, Ali; Neufeld, Ellis J; Thompson, Alexis A; Larkin, Sandra; Suh, Jung H; Vichinsky, Elliott P; Kuypers, Frans A

2015-06-01

Pulmonary hypertension (PH) commonly develops in thalassaemia syndromes, but is poorly characterized. The goal of this study was to provide a comprehensive description of the cardiopulmonary and biological profile of patients with thalassaemia at risk for PH. A case-control study of thalassaemia patients at high versus low PH-risk was performed. A single cross-sectional measurement for variables reflecting cardiopulmonary status and biological pathophysiology were obtained, including Doppler-echocardiography, 6-min-walk-test, Borg Dyspnoea Score, New York Heart Association functional class, cardiac magnetic resonance imaging (MRI), chest-computerized tomography, pulmonary function testing and laboratory analyses targeting mechanisms of coagulation, inflammation, haemolysis, adhesion and the arginine-nitric oxide pathway. Twenty-seven thalassaemia patients were evaluated, 14 with an elevated tricuspid-regurgitant-jet-velocity (TRV) ≥ 2·5 m/s. Patients with increased TRV had a higher frequency of splenectomy, and significantly larger right atrial size, left atrial volume and left septal-wall thickness on echocardiography and/or MRI, with elevated biomarkers of abnormal coagulation, lactate dehydrogenase (LDH) levels and arginase concentration, and lower arginine-bioavailability compared to low-risk patients. Arginase concentration correlated significantly to several echocardiography/MRI parameters of cardiovascular function in addition to global-arginine-bioavailability and biomarkers of haemolytic rate, including LDH, haemoglobin and bilirubin. Thalassaemia patients with a TRV ≥ 2·5 m/s have additional echocardiography and cardiac-MRI parameters suggestive of right and left-sided cardiac dysfunction. In addition, low arginine bioavailability may contribute to cardiopulmonary dysfunction in β-thalassaemia. © 2015 John Wiley & Sons Ltd.

Arginine depletion by arginine deiminase does not affect whole protein metabolism or muscle fractional protein synthesis rate in mice.

PubMed

Marini, Juan C; Didelija, Inka Cajo

2015-01-01

Due to the absolute need for arginine that certain cancer cells have, arginine depletion is a therapy in clinical trials to treat several types of cancers. Arginine is an amino acids utilized not only as a precursor for other important molecules, but also for protein synthesis. Because arginine depletion can potentially exacerbate the progressive loss of body weight, and especially lean body mass, in cancer patients we determined the effect of arginine depletion by pegylated arginine deiminase (ADI-PEG 20) on whole body protein synthesis and fractional protein synthesis rate in multiple tissues of mice. ADI-PEG 20 successfully depleted circulating arginine (<1 μmol/L), and increased citrulline concentration more than tenfold. Body weight and body composition, however, were not affected by ADI-PEG 20. Despite the depletion of arginine, whole body protein synthesis and breakdown were maintained in the ADI-PEG 20 treated mice. The fractional protein synthesis rate of muscle was also not affected by arginine depletion. Most tissues (liver, kidney, spleen, heart, lungs, stomach, small and large intestine, pancreas) were able to maintain their fractional protein synthesis rate; however, the fractional protein synthesis rate of brain, thymus and testicles was reduced due to the ADI-PEG 20 treatment. Furthermore, these results were confirmed by the incorporation of ureido [14C]citrulline, which indicate the local conversion into arginine, into protein. In conclusion, the intracellular recycling pathway of citrulline is able to provide enough arginine to maintain protein synthesis rate and prevent the loss of lean body mass and body weight.

Tuning interionic interaction by rationally controlling solution pH for highly selective colorimetric sensing of arginine.

PubMed

Qian, Qin; Hao, Jie; Ma, Wenjie; Yu, Ping; Mao, Lanqun

2016-04-01

Direct selective sensing of arginine in central nervous systems remains very essential to understanding of the molecular basis of some physiological events. This study presents the first demonstration on a simple yet effective method for arginine sensing with gold nanoparticles (Au-NPs) as the signal readout. The rationale for the method is based on the pH-dependent feature of the interionic interaction between cysteine and arginine. At pH 6.0, cysteine can only interact with arginine through the ion-pair interaction and such interaction can lead to the changes in both the solution color and UV-vis spectrum of the cysteine-protected Au-NPs upon the addition of arginine. These changes are further developed into an analytical strategy for effective sensing of arginine by rationally controlling the pH values of Au-NP dispersions with the ratio of the absorbance at 650 nm (A 650) to that at 520 nm (A 520) (A 650/A 520) as a parameter for analysis. The method is responsive to arginine without the interference from other species in the cerebral system; under the optimized conditions, the A 650/A 520 values are linear with the concentration of arginine within a concentration range from 0.80 to 64 μM, yet remain unchanged with the addition of other kinds of amino acids or the species in the central nervous system into the Au-NPs dispersion containing cysteine. The method demonstrated here is reliable and robust and could thus be used for detection of the increase of arginine in central nervous systems.

Asymmetric dimethylarginine, related arginine derivatives, and incident atrial fibrillation.

PubMed

Schnabel, Renate B; Maas, Renke; Wang, Na; Yin, Xiaoyan; Larson, Martin G; Levy, Daniel; Ellinor, Patrick T; Lubitz, Steven A; McManus, David D; Magnani, Jared W; Atzler, Dorothee; Böger, Rainer H; Schwedhelm, Edzard; Vasan, Ramachandran S; Benjamin, Emelia J

2016-06-01

Oxidative stress plays an important role in the development of atrial fibrillation (AF). Arginine derivatives including asymmetric dimethylarginine (ADMA) are central to nitric oxide metabolism and nitrosative stress. Whether blood concentrations of arginine derivatives are related to incidence of AF is uncertain. In 3,310 individuals (mean age 58 ± 10 years, 54% women) from the community-based Framingham Study, we prospectively examined the relations of circulating levels of ADMA, l-arginine, symmetric dimethylarginine (SDMA), and the ratio of l-arginine/ADMA to incidence of AF using proportional hazards regression models. Over a median follow-up time of 10 years, 247 AF cases occurred. Using age- and sex-adjusted regression models, ADMA was associated with a hazard ratio of 1.15 per 1-SD increase in loge-biomarker concentration (95% CI 1.02-1.29, P = .02) for AF, which was no longer significant after further risk factor adjustment (hazard ratio 1.09, 95% CI 0.97-1.23, P = .15). Neither l-arginine nor SDMA was related to new-onset AF. A clinical model comprising clinical risk factors for AF (for age, sex, height, weight, systolic blood pressure, diastolic blood pressure, current smoking, diabetes, hypertension treatment, myocardial infarction, and heart failure; c statistic = 0.781; 95% CI 0.753-0.808) was not improved by the addition of ADMA (0.782; 95% CI 0.755-0.809). Asymmetric dimethylarginine and related arginine derivatives were not associated with incident AF in the community after accounting for other clinical risk factors and confounders. Its role in the pathogenesis of AF needs further refinement. Copyright © 2016 Elsevier Inc. All rights reserved.

Calcium Sensing Receptor Mutations Implicated in Pancreatitis and Idiopathic Epilepsy Syndrome Disrupt an Arginine-rich Retention Motif

PubMed Central

Stepanchick, Ann; McKenna, Jennifer; McGovern, Olivia; Huang, Ying; Breitwieser, Gerda E.

2010-01-01

Calcium sensing receptor (CaSR) mutations implicated in familial hypocalciuric hypercalcemia, pancreatitis and idiopathic epilepsy syndrome map to an extended arginine-rich region in the proximal carboxyl terminus. Arginine-rich motifs mediate endoplasmic reticulum retention and/or retrieval of multisubunit proteins so we asked whether these mutations, R886P, R896H or R898Q, altered CaSR targeting to the plasma membrane. Targeting was enhanced by all three mutations, and Ca2+-stimulated ERK1/2 phosphorylation was increased for R896H and R898Q. To define the role of the extended arginine-rich region in CaSR trafficking, we independently determined the contributions of R890/R891 and/or R896/K897/R898 motifs by mutation to alanine. Disruption of the motif(s) significantly increased surface expression and function relative to wt CaSR. The arginine-rich region is flanked by phosphorylation sites at S892 (protein kinase C) and S899 (protein kinase A). The phosphorylation state of S899 regulated recognition of the arginine-rich region; S899D showed increased surface localization. CaSR assembles in the endoplasmic reticulum as a covalent disulfide-linked dimer and we determined whether retention requires the presence of arginine-rich regions in both subunits. A single arginine-rich region within the dimer was sufficient to confer intracellular retention comparable to wt CaSR. We have identified an extended arginine-rich region in the proximal carboxyl terminus of CaSR (residues R890 - R898) which fosters intracellular retention of CaSR and is regulated by phosphorylation. Mutation(s) identified in chronic pancreatitis and idiopathic epilepsy syndrome therefore increase plasma membrane targeting of CaSR, likely contributing to the altered Ca2+ signaling characteristic of these diseases. PMID:20798521

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

PubMed

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.

Effects of withdrawal from repeated phencyclidine administration on behavioural function and brain arginine metabolism in rats.

PubMed

Knox, Logan T; Jing, Yu; Bawazier-Edgecombe, Jamal; Collie, Nicola D; Zhang, Hu; Liu, Ping

2017-02-01

Phencyclidine (PCP) induces behavioural changes in humans and laboratory animals that resemble positive and negative symptoms, and cognitive impairments in schizophrenia. It has been shown repeated treatment of PCP leading to persistent symptoms even after the drug discontinuation, and there is a growing body of evidence implicating altered arginine metabolism in the pathogenesis of schizophrenia. The present study investigated the effects of withdrawal from repeated daily injection of PCP (2mg/kg) for 12 consecutive days on animals'behavioural performance and arginine metabolism in the hippocampus and prefrontal cortex in male young adult rats. Repeated PCP treatment reduced spontaneous alternations in the Y-maze and exploratory and locomotor activities in the open field under the condition of a washout period of 24h, but not 4days. Interestingly, the PCP treated rats also displayed spatial working memory deficits when tested 8-10days after withdrawal from PCP and showed altered levels of arginase activities and eight out of ten l-arginine metabolites in neurochemical- and region-specific manner. Cluster analyses showed altered relationships among l-arginine and its three main metabolites as a function of withdrawal from repeated PCP treatment in a duration-specific manner. Multiple regression analysis revealed significant neurochemical-behavioural correlations. Collectively, the results suggest both the residual and long-term effects of withdrawal from repeated PCP treatment on behavioural function and brain arginine metabolism. These findings demonstrate, for the first time, the influence of the withdrawal duration on animals' behaviour and brain arginine metabolism. Copyright © 2016 Elsevier Inc. All rights reserved.

Apple snack enriched with L-arginine using vacuum impregnation/ohmic heating technology.

PubMed

Moreno, Jorge; Echeverria, Julian; Silva, Andrea; Escudero, Andrea; Petzold, Guillermo; Mella, Karla; Escudero, Carlos

2017-07-01

Modern life has created a high demand for functional food, and in this context, emerging technologies such as vacuum impregnation and ohmic heating have been applied to generate functional foods. The aim of this research was to enrich the content of the semi-essential amino acid L-arginine in apple cubes using vacuum impregnation, conventional heating, and ohmic heating. Additionally, combined vacuum impregnation/conventional heating and vacuum impregnation/ohmic heating treatments were evaluated. The above treatments were applied at 30, 40 and 50  ℃ and combined with air-drying at 40 ℃ in order to obtain an apple snack rich in L-arginine. Both the impregnation kinetics of L-arginine and sample color were evaluated. The impregnated samples created using vacuum impregnation/ohmic heating at 50 ℃ presented a high content of L-arginine, an effect attributed primarily to electropermeabilization. Overall, vacuum impregnation/ohmic heating treatment at 50 ℃, followed by drying at 40 ℃, was the best process for obtaining an apple snack rich in L-arginine.

The synthesis and cell interaction of statistical L-arginine - glycine - L-aspartic acid terpolypeptides.

PubMed

Mbizana, Siyasanga; Hlalele, Lebohang; Pfukwa, Rueben; du Toit, Andre; Lumkwana, Dumisile; Loos, Benjamin; Klumperman, Bert

2018-05-01

Copolymerizations and terpolymerizations of N-carboxyanhydrides (NCAs) of glycine (Gly), Nδ-carbobenzyloxy-L-ornithine ((Z)-Orn) and β-benzyl-L-aspartate ((Bz)-Asp) were investigated. In situ 1H NMR spectroscopy was used to monitor individual comonomer consumptions during binary and ternary copolymerizations. The six relevant reactivity ratios were determined from copolymerizations of the NCAs of amino acids via nonlinear least squares curve fitting. The reactivity ratios were subsequently used to maximize the occurrence of the Asp-Gly-Orn (DGR') sequence in the terpolymers. Terpolymers with variable probability of occurrence of DGR' were prepared in the lab. Subsequently, the ornithine residues on the terpolymers were converted to L-arginine (R) residues via guanidination reaction after removal of the protecting groups. The resulting DGR terpolymers translate to traditional peptides and proteins with variable RGD content, due to the convention in nomenclature that peptides are depicted from N- to C-terminus, whereas the NCA ring-opening polymerization is conducted from C- to N-terminus. The L-arginine containing terpolymers were evaluated for cell interaction, where it was found that neuronal cells display enhanced adhesion and process formation when plated in the presence of statistical DGR terpolymers.

Protein arginine methylation/demethylation and cancer

PubMed Central

Poulard, Coralie; Corbo, Laura; Le Romancer, Muriel

2016-01-01

Protein arginine methylation is a common post-translational modification involved in numerous cellular processes including transcription, DNA repair, mRNA splicing and signal transduction. Currently, there are nine known members of the protein arginine methyltransferase (PRMT) family, but only one arginine demethylase has been identified, namely the Jumonji domain-containing 6 (JMJD6). Although its demethylase activity was initially challenged, its dual activity as an arginine demethylase and a lysine hydroxylase is now recognized. Interestingly, a growing number of substrates for arginine methylation and demethylation play key roles in tumorigenesis. Though alterations in the sequence of these enzymes have not been identified in cancer, their overexpression is associated with various cancers, suggesting that they could constitute targets for therapeutic strategies. In this review, we present the recent knowledge of the involvement of PRMTs and JMJD6 in tumorigenesis. PMID:27556302

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

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

Soriano, Erika V.; McCloskey, Diane E.; Kinsland, Cynthia

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 themore » 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.« less

Arginine and Citrulline and the Immune Response in Sepsis

PubMed Central

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

Stability and resilience of oral microcosms toward acidification and Candida outgrowth by arginine supplementation.

PubMed

Koopman, Jessica E; Röling, Wilfred F M; Buijs, Mark J; Sissons, Christopher H; ten Cate, Jacob M; Keijser, Bart J F; Crielaard, Wim; Zaura, Egija

2015-02-01

Dysbiosis induced by low pH in the oral ecosystem can lead to caries, a prevalent bacterial disease in humans. The amino acid arginine is one of the pH-elevating agents in the oral cavity. To obtain insights into the effect of arginine on oral microbial ecology, a multi-plaque "artificial mouth" (MAM) biofilm model was inoculated with saliva from a healthy volunteer and microcosms were grown for 4 weeks with 1.6 % (w/v) arginine supplement (Arginine) or without (Control), samples were taken at several time-points. A cariogenic environment was mimicked by sucrose pulsing. The bacterial composition was determined by 16S rRNA gene amplicon sequencing, the presence and amount of Candida and arginine deiminase system genes arcA and sagP by qPCR. Additionally, ammonium and short-chain fatty acid concentrations were determined. The Arginine microcosms were dominated by Streptococcus, Veillonella, and Neisseria and remained stable in time, while the composition of the Control microcosms diverged significantly in time, partially due to the presence of Megasphaera. The percentage of Candida increased 100-fold in the Control microcosms compared to the Arginine microcosms. The pH-raising effect of arginine was confirmed by the pH and ammonium results. The abundances of sagP and arcA were highest in the Arginine microcosms, while the concentration of butyrate was higher in the Control microcosms. We demonstrate that supplementation with arginine serves a health-promoting function; it enhances microcosm resilience toward acidification and suppresses outgrowth of the opportunistic pathogen Candida. Arginine facilitates stability of oral microbial communities and prevents them from becoming cariogenic.

Protein arginine methyltransferase 7 has a novel homodimer-like structure formed by tandem repeats.

PubMed

Hasegawa, Morio; Toma-Fukai, Sachiko; Kim, Jun-Dal; Fukamizu, Akiyoshi; Shimizu, Toshiyuki

2014-05-21

Protein arginine methyltransferase 7 (PRMT7) is a member of a family of enzymes that catalyze the transfer of methyl groups from S-adenosyl-l-methionine to nitrogen atoms on arginine residues. Here, we describe the crystal structure of Caenorhabditis elegans PRMT7 in complex with its reaction product S-adenosyl-L-homocysteine. The structural data indicated that PRMT7 harbors two tandem repeated PRMT core domains that form a novel homodimer-like structure. S-adenosyl-L-homocysteine bound to the N-terminal catalytic site only; the C-terminal catalytic site is occupied by a loop that inhibits cofactor binding. Mutagenesis demonstrated that only the N-terminal catalytic site of PRMT7 is responsible for cofactor binding. Copyright © 2014 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.

Cloning, expression, purification and preliminary X-ray crystallographic analysis of mouse protein arginine methyltransferase 7.

PubMed

Cura, Vincent; Troffer-Charlier, Nathalie; Lambert, Marie-Annick; Bonnefond, Luc; Cavarelli, Jean

2014-01-01

Protein arginine methyltransferase 7 (PRMT7) is a unique but less characterized member of the family of protein arginine methyltransferases (PRMTs) that plays a role in male germline gene imprinting. PRMT7 is the only known PRMT member that catalyzes the monomethylation but not the dimethylation of the target arginine residues and harbours two catalytic domains in tandem. PRMT7 genes from five different species were cloned and expressed in Escherichia coli and Sf21 insect cells. Four gave soluble proteins from Sf21 cells, of which two were homogeneous and one gave crystals. The mouse PRMT7 structure was solved by the single anomalous dispersion method using a crystal soaked with thimerosal that diffracted to beyond 2.1 Å resolution. The crystal belonged to space group P4(3)2(1)2, with unit-cell parameters a = b = 97.4, c = 168.1 Å and one PRMT7 monomer in the asymmetric unit. The structure of another crystal form belonging to space group I222 was solved by molecular replacement.

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

PubMed Central

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

Expression of arginine kinase enzymatic activity and mRNA in gills of the euryhaline crabs Carcinus maenas and Callinectes sapidus.

PubMed

Kotlyar, S; Weihrauch, D; Paulsen, R S; Towle, D W

2000-08-01

Phosphagen kinases catalyze the reversible dephosphorylation of guanidino phosphagens such as phosphocreatine and phosphoarginine, contributing to the restoration of adenosine triphosphate concentrations in cells experiencing high and variable demands on their reserves of high-energy phosphates. The major invertebrate phosphagen kinase, arginine kinase, is expressed in the gills of two species of euryhaline crabs, the blue crab Callinectes sapidus and the shore crab Carcinus maenas, in which energy-requiring functions include monovalent ion transport, acid-base balance, nitrogen excretion and gas exchange. The enzymatic activity of arginine kinase approximately doubles in the ion-transporting gills of C. sapidus, a strong osmoregulator, when the crabs are transferred from high to low salinity, but does not change in C. maenas, a more modest osmoregulator. Amplification and sequencing of arginine kinase cDNA from both species, accomplished by reverse transcription of gill mRNA and the polymerase chain reaction, revealed an open reading frame coding for a 357-amino-acid protein. The predicted amino acid sequences showed a minimum of 75 % identity with arginine kinase sequences of other arthropods. Ten of the 11 amino acid residues believed to participate in arginine binding are completely conserved among the arthropod sequences analyzed. An estimation of arginine kinase mRNA abundance indicated that acclimation salinity has no effect on arginine kinase gene transcription. Thus, the observed enhancement of enzyme activity in C. sapidus probably results from altered translation rates or direct activation of pre-existing enzyme protein.

Selective determination of arginine-containing and tyrosine-containing peptides using capillary electrophoresis and laser-induced fluorescence detection.

PubMed

Cobb, K A; Novotny, M V

1992-01-01

The use of two different amino acid-selective fluorogenic reagents for the derivatization of peptides is investigated. One such scheme utilizes a selective reaction of benzoin with the guanidine moiety to derivatize arginine residues occurring in a peptide. The second scheme involves the formylation of tyrosine, followed by reaction with 4-methoxy-1,2-phenylenediamine. The use of capillary electrophoresis and laser-induced fluorescence detection allows enhanced efficiencies and sensitivities to be obtained for the separations of either arginine- or tyrosine-containing peptides. A helium-cadmium laser (325 nm) is ideally suited for the laser-based detection system due to a close match of the excitation maxima of derivatized peptides from both reactions. A detection limit of 270 amol is achieved for model arginine-containing peptides, while the detection limit for model tyrosine-containing peptides is measured at 390 amol. Both derivatization reactions are found to be useful for high-sensitivity peptide mapping applications in which only the peptides containing the derivatized amino acids are detected.

Kinetics of the utilization of dietary arginine for nitric oxide and urea synthesis: insight into the arginine-nitric oxide metabolic system in humans.

PubMed

Mariotti, François; Petzke, Klaus J; Bonnet, Damien; Szezepanski, Isabelle; Bos, Cécile; Huneau, Jean-François; Fouillet, Hélène

2013-05-01

The systemic availability of oral/dietary arginine and its utilization for nitric oxide (NO) synthesis remains unknown and may be related to a competitive hydrolysis of arginine into urea in the splanchnic area and systemic circulation. We investigated the kinetics and dose-dependency of dietary arginine utilization for NO compared with urea synthesis and studied the characteristics of the arginine-NO metabolic system in healthy humans. We traced the metabolic fate and analyzed the utilization dynamics of dietary arginine after its ingestion at 2 nutritional amounts in healthy humans (n = 9) in a crossover design by using [(15)N-(15)N-(guanido)]-arginine, isotope ratio mass spectrometry techniques, and data analysis with a compartmental modeling approach. Whatever the amount of dietary arginine, 60 ± 3% (±SEM) was converted to urea, with kinetics indicative of a first-pass splanchnic phenomenon. Despite this dramatic extraction, intact dietary arginine made a major contribution to the postprandial increase in plasma arginine. However, the model identified that the plasma compartment was a very minor (~2%) precursor for the conversion of dietary arginine into NO, which, in any case, was small (<0.1% of the dose). The whole-body and plasma kinetics of arginine metabolism were consistent with the suggested competitive metabolism by the arginase and NO synthase pathways. The conversion of oral/dietary arginine into NO is not limited by the systemic availability of arginine but by a tight metabolic compartmentation at the systemic level. We propose an organization of the arginine metabolic system that explains the daily maintenance of NO homeostasis in healthy humans.

Estimation of dietary arginine requirements for Longyan laying ducks.

PubMed

Xia, Weiguang; Fouad, Ahmed Mohamed; Chen, Wei; Ruan, Dong; Wang, Shuang; Fan, Qiuli; Wang, Ying; Cui, Yiyan; Zheng, Chuntian

2017-01-01

This study aimed to establish the arginine requirements of Longyan ducks from 17 to 31 wk of age based on egg production, egg quality, plasma, and ovarian indices, as well as the expression of vitellogenesis-related genes. In total, 660 Longyan ducks with similar body weight at 15 wk of age were assigned randomly to 5 treatments, each with 6 replicates of 22 birds, and fed a corn-corn gluten meal basal diet (0.66% arginine) supplemented with either 0, 0.20%, 0.40%, 0.60%, or 0.80% arginine. Dietary arginine did not affect egg production by laying ducks, but it increased (linear, P < 0.01) the egg weight at 22 to 31 and 17 to 31 wk of age. Dietary arginine increased the yolk color score (linearly, P < 0.05) and the yolk percentage (quadratic, P < 0.05), where the maximum values were obtained with 1.26% arginine. Dietary arginine affected the total shell percentage and shell thickness, with the highest values using 1.46% arginine (P < 0.01). The weight and number of small yellow follicles (SYFs) increased (quadratic, P < 0.05) with the dietary arginine level and there was a quadratic response (P < 0.05) in terms of the SYFs weight/ovarian weight; the highest values were obtained in ducks fed 1.26% arginine. The plasma arginine concentration exhibited a quadratic (P < 0.05) response to dietary arginine. The plasma progesterone concentration decreased (linear, P < 0.05) as dietary arginine increased. The mRNA abundance of the very low density lipoprotein receptor-b increased in the second large yellow follicle membranes (quadratic, P < 0.05) with the dietary arginine level, where the highest value occurred with 1.26% arginine. According to the regression model, the dietary arginine requirements for Longyan laying ducks aged 17 to 31 wk are 1.06%, 1.13%, 1.22%, and 1.11% to obtain the maximum yolk percentage, SYFs number, SYFs weight, and SYFs weight/ovarian weight, respectively. © 2016 Poultry Science Association Inc.

Using FT-NIR spectroscopy technique to determine arginine content in fermented Cordyceps sinensis mycelium.

PubMed

Xie, Chuanqi; Xu, Ning; Shao, Yongni; He, Yong

2015-01-01

This research investigated the feasibility of using Fourier transform near-infrared (FT-NIR) spectral technique for determining arginine content in fermented Cordyceps sinensis (C. sinensis) mycelium. Three different models were carried out to predict the arginine content. Wavenumber selection methods such as competitive adaptive reweighted sampling (CARS) and successive projections algorithm (SPA) were used to identify the most important wavenumbers and reduce the high dimensionality of the raw spectral data. Only a few wavenumbers were selected by CARS and CARS-SPA as the optimal wavenumbers, respectively. Among the prediction models, CARS-least squares-support vector machine (CARS-LS-SVM) model performed best with the highest values of the coefficient of determination of prediction (Rp(2)=0.8370) and residual predictive deviation (RPD=2.4741), the lowest value of root mean square error of prediction (RMSEP=0.0841). Moreover, the number of the input variables was forty-five, which only accounts for 2.04% of that of the full wavenumbers. The results showed that FT-NIR spectral technique has the potential to be an objective and non-destructive method to detect arginine content in fermented C. sinensis mycelium. Copyright © 2015 Elsevier B.V. All rights reserved.

Importance of Loop L1 Dynamics for Substrate Capture and Catalysis in Pseudomonas aeruginosa d-Arginine Dehydrogenase.

PubMed

Ouedraogo, Daniel; Souffrant, Michael; Vasquez, Sheena; Hamelberg, Donald; Gadda, Giovanni

2017-05-16

Mobile loops located at the active site entrance in enzymes often participate in conformational changes required to shield the reaction from bulk solvent, to control the access of the substrate to the active site, and to position residues for substrate binding and catalysis. In d-arginine dehydrogenase from Pseudomonas aeruginosa (PaDADH), previous crystallographic data suggested that residues 45-47 in the FAD-binding domain and residues 50-56 in the substrate-binding domain in loop L1 could adopt two distinct conformations. In this study, we have used molecular dynamics, kinetics, and fluorescence spectroscopy on the S45A and A46G enzyme variants of PaDADH to investigate the impact of mutations in loop L1 on the catalytic function of the enzyme. Molecular dynamics showed that the mutant enzymes have probabilities of being in open conformations that are higher than that of wild-type PaDADH of loop L1, yielding an increased level of solvent exposure of the active site. In agreement, the flavin fluorescence intensity was ∼2-fold higher in the S45A and A46G enzymes than in wild-type PaDADH, with a 9 nm bathochromic shift of the emission band. In the variant enzymes, the k cat /K m values with d-arginine were ∼13-fold lower than in wild-type PaDADH. Moreover, the pH profiles for the k cat value with d-arginine showed a hollow, consistent with restricted proton movements in catalysis, and no saturation was achieved with the alternate substrate d-leucine in the reductive half-reaction of the variant enzymes. Taken together, the computational and experimental data are consistent with the dynamics of loop L1 being important for substrate capture and catalysis in PaDADH.

Arginine production in the neonate

USDA-ARS?s Scientific Manuscript database

Endogenous arginine synthesis in adults is a complex multiorgan process, in which citrulline is synthesized in the gut, enters the general circulation, and is converted into arginine in the kidney, by what is known as the intestinal-renal axis. In neonates, the enzymes required to convert citrulline...

Cultivation to improve in vivo solubility of overexpressed arginine deiminases in Escherichia coli and the enzyme characteristics.

PubMed

Wang, Ying; Li, Yue-Zhong

2014-06-07

Overexpression of foreign genes in Escherichia coli cells is an efficient means to obtain recombinant proteins. The technique is, however, often hampered by misfolding, degradation, aggregation and formation in inclusion bodies of products. In this study, we reported that in vivo solubility of overexpressed arginine deiminases (ADI) improved by changing the cultivation conditions. ADI is enzymes that convert L-arginine to L-citrulline. After codon optimization, we synthesized the ADI gene of Pseudomonas putida and constructed it for overexpression in E. coli cells. The rADI products were mainly in inclusion body forms. We performed a series of optimization to enhance solubility of the protein. Co-expression with the GroES-GroEL chaperone team increased approximately 5-fold of the rADI activity. In addition the combination of L-arginine and D-glucose in the Luria-Bertani (LB) growth medium further increased the total activity to about 15 times. Separate L-arginine and D-glucose or the addition of other saccharides or amino acids had no such effects. The solubilization effects of the combination of L-arginine and D-glucose were further confirmed in the overexpression of another ADI from Listeria welshimeri. The enzymatic and conversion characteristics of the rADI products were further determined. Combined addition of L-arginine and D-glucose in the LB medium significantly improved in vivo solubility of rADI proteins. The present study suggested a new strategy to increase the solubilization of overexpressed recombinant proteins in E. coli cells.

Activities of arginine and ornithine decarboxylases in various plant species.

PubMed

Birecka, H; Bitonti, A J; McCann, P P

1985-10-01

In extracts from the youngest leaves of Avena sativa, Hordeum vulgare, Zea Mays, Pisum sativum, Phaseolus vulgaris, Lactuca sativa, and four pyrrolizidine alkaloid-bearing species of Heliotropium, the activities of ornithine decarboxylase, close to V(max), ranged between traces and 1.5 nanomoles per hour per gram fresh weight when based on putrescine formed during incubation with labeled ornithine. The arginine decarboxylase activities in the same extracts ranged between 8 and 8000 nanomoles per hour per gram fresh weight being lowest in the borages and highest in oat and barley. alpha-Difluoromethylornithine and alpha-difluoromethylarginine inhibited ornithine and arginine decarboxylases, respectively, in all species. Agmatine, putrescine, spermidine, and spermine were found in all, diaminopropane in eight, and cadaverine in three species.No correlation was observed between arginine or ornithine decarboxylase level and the levels of total polyamines. The in vitro decarboxylase activities found in the borages cannot explain the high accumulation of putrescine-derived pyrrolizidines in their youngest leaves if the pyrrolizidines are produced in situ from arginine and/or ornithine as precursors; other possibilities are discussed.In assays of ornithine decarboxylase, an interference of decarboxylation not due to this enzyme was observed in extracts from all species. In arginine decarboxylase assays, the interfering decarboxylation as well as the interference of arginase were apparent in two species. Addition of aminoguanidine was needed to suppress oxidative degradation of putrescine and agmatine during incubation of extracts from pea, bean, lettuce, Heliotropium angiospermum, and Heliotropium indicum.

Loss of RUNX1/AML1 arginine-methylation impairs in peripheral T cell homeostasis

PubMed Central

Mizutani, Shinsuke; Yoshida, Tatsushi; Zhao, Xinyang; Nimer, Stephen D.; Taniwaki, Masafumi; Okuda, Tsukasa

2016-01-01

Summary RUNX1 (previously termed AML1) is a frequent target of human leukaemia-associated gene aberrations, and it encodes the DNA-binding subunit of the Core-Binding Factor transcription factor complex. RUNX1 expression is essential for the initiation of definitive haematopoiesis, for steady-state thrombopoiesis, and for normal lymphocytes development. Recent studies revealed that protein arginine methyltransferase 1 (PRMT1), which accounts for the majority of the type I PRMT activity in cells, methylates two arginine residues in RUNX1 (R206 and R210), and these modifications inhibit corepressor-binding to RUNX1 thereby enhancing its transcriptional activity. In order to elucidate the biological significance of these methylations, we established novel knock-in mouse lines with non-methylable, double arginine-to-lysine (RTAMR-to-KTAMK) mutations in RUNX1. Homozygous Runx1KTAMK/KTAMK mice are born alive and appear normal during adulthood. However, Runx1KTAMK/KTAMK mice showed a reduction in CD3+ T lymphoid cells and a decrease in CD4+ T cells in peripheral lymphoid organs, in comparison to their wild-type littermates, leading to a reduction in the CD4+ to CD8+ T-cell ratio. These findings suggest that arginine-methylation of RUNX1 in the RTAMR-motif is dispensable for the development of definitive haematopoiesis and for steady-state platelet production, however this modification affects the role of RUNX1 in the maintenance of the peripheral CD4+ T-cell population. PMID:26010396

Cloning, expression, purification and preliminary X-­ray crystallographic analysis of mouse protein arginine methyltransferase 7

PubMed Central

Cura, Vincent; Troffer-Charlier, Nathalie; Lambert, Marie-Annick; Bonnefond, Luc; Cavarelli, Jean

2014-01-01

Protein arginine methyltransferase 7 (PRMT7) is a unique but less characterized member of the family of protein arginine methyltransferases (PRMTs) that plays a role in male germline gene imprinting. PRMT7 is the only known PRMT member that catalyzes the monomethylation but not the dimethylation of the target arginine residues and harbours two catalytic domains in tandem. PRMT7 genes from five different species were cloned and expressed in Escherichia coli and Sf21 insect cells. Four gave soluble proteins from Sf21 cells, of which two were homogeneous and one gave crystals. The mouse PRMT7 structure was solved by the single anomalous dispersion method using a crystal soaked with thimerosal that diffracted to beyond 2.1 Å resolution. The crystal belonged to space group P43212, with unit-cell parameters a = b = 97.4, c = 168.1 Å and one PRMT7 monomer in the asymmetric unit. The structure of another crystal form belonging to space group I222 was solved by molecular replacement. PMID:24419624

Metabolic engineering of Corynebacterium glutamicum for L-arginine production.

PubMed

Park, Seok Hyun; Kim, Hyun Uk; Kim, Tae Yong; Park, Jun Seok; Kim, Suok-Su; Lee, Sang Yup

2014-08-05

L-arginine is an important amino acid for diverse industrial and health product applications. Here we report the development of metabolically engineered Corynebacterium glutamicum ATCC 21831 for the production of L-arginine. Random mutagenesis is first performed to increase the tolerance of C. glutamicum to L-arginine analogues, followed by systems metabolic engineering for further strain improvement, involving removal of regulatory repressors of arginine operon, optimization of NADPH level, disruption of L-glutamate exporter to increase L-arginine precursor and flux optimization of rate-limiting L-arginine biosynthetic reactions. Fed-batch fermentation of the final strain in 5 l and large-scale 1,500 l bioreactors allows production of 92.5 and 81.2 g l(-1) of L-arginine with the yields of 0.40 and 0.35 g L-arginine per gram carbon source (glucose plus sucrose), respectively. The systems metabolic engineering strategy described here will be useful for engineering Corynebacteria strains for the industrial production of L-arginine and related products.

Protein arginine Methyltransferase 8 gene is expressed in pluripotent stem cells and its expression is modulated by the transcription factor Sox2.

PubMed

Solari, Claudia; Echegaray, Camila Vázquez; Luzzani, Carlos; Cosentino, María Soledad; Waisman, Ariel; Petrone, María Victoria; Francia, Marcos; Sassone, Alina; Canizo, Jésica; Sevlever, Gustavo; Barañao, Lino; Miriuka, Santiago; Guberman, Alejandra

2016-04-22

Addition of methyl groups to arginine residues is catalyzed by a group of enzymes called Protein Arginine Methyltransferases (Prmt). Although Prmt1 is essential in development, its paralogue Prmt8 has been poorly studied. This gene was reported to be expressed in nervous system and involved in neurogenesis. In this work, we found that Prmt8 is expressed in mouse embryonic stem cells (ESC) and in induced pluripotent stem cells, and modulated along differentiation to neural precursor cells. We found that Prmt8 promoter activity is induced by the pluripotency transcription factors Oct4, Sox2 and Nanog. Moreover, endogenous Prmt8 mRNA levels were reduced in ESC transfected with Sox2 shRNA vector. As a whole, our results indicate that Prmt8 is expressed in pluripotent stem cells and its transcription is modulated by pluripotency transcription factors. These findings suggest that besides its known function in nervous system, Prmt8 could play a role in pluripotent stem cells. Copyright © 2016 Elsevier Inc. All rights reserved.

Backbone Brackets and Arginine Tweezers delineate Class I and Class II aminoacyl tRNA synthetases

PubMed Central

Haupt, V. Joachim; Schroeder, Michael; Labudde, Dirk

2018-01-01

The origin of the machinery that realizes protein biosynthesis in all organisms is still unclear. One key component of this machinery are aminoacyl tRNA synthetases (aaRS), which ligate tRNAs to amino acids while consuming ATP. Sequence analyses revealed that these enzymes can be divided into two complementary classes. Both classes differ significantly on a sequence and structural level, feature different reaction mechanisms, and occur in diverse oligomerization states. The one unifying aspect of both classes is their function of binding ATP. We identified Backbone Brackets and Arginine Tweezers as most compact ATP binding motifs characteristic for each Class. Geometric analysis shows a structural rearrangement of the Backbone Brackets upon ATP binding, indicating a general mechanism of all Class I structures. Regarding the origin of aaRS, the Rodin-Ohno hypothesis states that the peculiar nature of the two aaRS classes is the result of their primordial forms, called Protozymes, being encoded on opposite strands of the same gene. Backbone Brackets and Arginine Tweezers were traced back to the proposed Protozymes and their more efficient successors, the Urzymes. Both structural motifs can be observed as pairs of residues in contemporary structures and it seems that the time of their addition, indicated by their placement in the ancient aaRS, coincides with the evolutionary trace of Proto- and Urzymes. PMID:29659563

The scent of danger: arginine as an olfactory cue of reduced predation risk.

PubMed

Ferrer, Ryan P; Zimmer, Richard K

2007-05-01

Animal perception of chemosensory cues is a function of ecological context. Larvae of the California newt (Taricha torosa), for example, exhibit predator-avoidance behavior in response to a chemical from cannibalistic adults. The poison tetrodotoxin (TTX), well known as an adult chemical defense, stimulates larval escape to refuges. Although they are cannibals, adult newts feed preferentially on worms (Eisenia rosea) over conspecific young. Hence, larval avoidance reactions to TTX are suppressed in the presence of odor from these alternative prey. The free amino acid, arginine, is abundant in fluids emitted by injured worms. Here, we demonstrate that arginine is a natural suppressant of TTX-stimulated larval escape behavior. Compared to a tapwater control, larvae initiated vigorous swimming in response to 10(-7) mol l(-1) TTX. This excitatory response was eliminated when larval nasal cavities were blocked with an inert gel, but not when gel was placed on the forehead (control). In additional trials, a binary mixture of arginine and 10(-7) mol l(-1) TTX failed to induce larval swimming. The inhibitory effect of arginine was, however, dose dependent. An arginine concentration as low as 0.3-times that of TTX was significantly suppressant. Further analysis showed that suppression by arginine of TTX-stimulated behavior was eliminated by altering the positively-charged guanidinium moiety, but not by modifying the carbon chain, carboxyl group, or amine group. These results are best explained by a mechanism of competitive inhibition between arginine and TTX for common, olfactory receptor binding sites. Although arginine alone has no impact on larval behavior, it nevertheless signals active adult predation on alternative prey, and hence, reduced cannibalism risk.

Ablation of arginase II spares arginine and abolishes the arginine requirement for growth in male mice

USDA-ARS?s Scientific Manuscript database

Arginine is considered a semi-essential amino acid in many species, including humans, because under certain conditions its demand exceeds endogenous production. Arginine availability, however, is not only determined by its production, but also by its disposal. Manipulation of disposal pathways has t...

Arginine de novo and nitric oxide production in disease states

PubMed Central

Luiking, Yvette C.; Ten Have, Gabriella A. M.; Wolfe, Robert R.

2012-01-01

Arginine is derived from dietary protein intake, body protein breakdown, or endogenous de novo arginine production. The latter may be linked to the availability of citrulline, which is the immediate precursor of arginine and limiting factor for de novo arginine production. Arginine metabolism is highly compartmentalized due to the expression of the enzymes involved in arginine metabolism in various organs. A small fraction of arginine enters the NO synthase (NOS) pathway. Tetrahydrobiopterin (BH4) is an essential and rate-limiting cofactor for the production of NO. Depletion of BH4 in oxidative-stressed endothelial cells can result in so-called NOS3 “uncoupling,” resulting in production of superoxide instead of NO. Moreover, distribution of arginine between intracellular transporters and arginine-converting enzymes, as well as between the arginine-converting and arginine-synthesizing enzymes, determines the metabolic fate of arginine. Alternatively, NO can be derived from conversion of nitrite. Reduced arginine availability stemming from reduced de novo production and elevated arginase activity have been reported in various conditions of acute and chronic stress, which are often characterized by increased NOS2 and reduced NOS3 activity. Cardiovascular and pulmonary disorders such as atherosclerosis, diabetes, hypercholesterolemia, ischemic heart disease, and hypertension are characterized by NOS3 uncoupling. Therapeutic applications to influence (de novo) arginine and NO metabolism aim at increasing substrate availability or at influencing the metabolic fate of specific pathways related to NO bioavailability and prevention of NOS3 uncoupling. These include supplementation of arginine or citrulline, provision of NO donors including inhaled NO and nitrite (sources), NOS3 modulating agents, or the targeting of endogenous NOS inhibitors like asymmetric dimethylarginine. PMID:23011059

The GAP arginine finger movement into the catalytic site of Ras increases the activation entropy

PubMed Central

Kötting, Carsten; Kallenbach, Angela; Suveyzdis, Yan; Wittinghofer, Alfred; Gerwert, Klaus

2008-01-01

Members of the Ras superfamily of small G proteins play key roles in signal transduction pathways, which they control by GTP hydrolysis. They are regulated by GTPase activating proteins (GAPs). Mutations that prevent hydrolysis cause severe diseases including cancer. A highly conserved “arginine finger” of GAP is a key residue. Here, we monitor the GTPase reaction of the Ras·RasGAP complex at high temporal and spatial resolution by time-resolved FTIR spectroscopy at 260 K. After triggering the reaction, we observe as the first step a movement of the switch-I region of Ras from the nonsignaling “off” to the signaling “on” state with a rate of 3 s−1. The next step is the movement of the “arginine finger” into the active site of Ras with a rate of k2 = 0.8 s−1. Once the arginine points into the binding pocket, cleavage of GTP is fast and the protein-bound Pi intermediate forms. The switch-I reversal to the “off” state, the release of Pi, and the movement of arginine back into an aqueous environment is observed simultaneously with k3 = 0.1 s−1, the rate-limiting step. Arrhenius plots for the partial reactions show that the activation energy for the cleavage reaction is lowered by favorable positive activation entropy. This seems to indicate that protein-bound structured water molecules are pushed by the “arginine finger” movement out of the binding pocket into the bulk water. The proposed mechanism shows how the high activation barrier for phosphoryl transfer can be reduced by splitting into partial reactions separated by a Pi-intermediate. PMID:18434546

Arginine vasopressin and oxytocin modulate human social behavior.

PubMed

Ebstein, Richard P; Israel, Salomon; Lerer, Elad; Uzefovsky, Florina; Shalev, Idan; Gritsenko, Inga; Riebold, Mathias; Salomon, Shahaf; Yirmiya, Nurit

2009-06-01

Increasing evidence suggests that two nonapeptides, arginine vasopressin and oxytocin, shape human social behavior in both nonclinical and clinical subjects. Evidence is discussed that in autism spectrum disorders genetic polymorphisms in the vasopressin-oxytocin pathway, notably the arginine vasopressin receptor 1a (AVPR1a), the oxytocin receptor (OXTR), neurophysin I and II, and CD38 (recently shown to be critical for social behavior by mediating oxytocin secretion) contribute to deficits in socialization skills in this group of patients. We also present first evidence that CD38 expression in lymphoblastoid cells derived from subjects diagnosed with autism is correlated with social skill phenotype inventoried by the Vineland Adaptive Behavioral Scales. Additionally, we discuss molecular genetic evidence that in nonclinical subjects both AVPR1a and OXTR genes contribute to prosocial or altruistic behavior inventoried by two experimental paradigms, the dictator game and social values orientation. The role of the AVPR1a is also analyzed in prepulse inhibition. Prepulse inhibition of the startle response to auditory stimuli is a largely autonomic response that resonates with social cognition in both animal models and humans. First results are presented showing that intranasal administration of arginine vasopressin increases salivary cortisol levels in the Trier Social Stress test. To summarize, accumulating studies employing a broad array of cutting-edge tools in psychology, neuroeconomics, molecular genetics, pharmacology, electrophysiology, and brain imaging are beginning to elaborate the intriguing role of oxytocin and arginine vasopressin in human social behavior. We expect that future studies will continue this advance and deepen our understanding of these complex events.

KSHV encoded ORF59 modulates histone arginine methylation of the viral genome to promote viral reactivation

PubMed Central

McDowell-Sargent, Maria; Uppal, Timsy; Purushothaman, Pravinkumar

2017-01-01

Kaposi’s sarcoma associated herpesvirus (KSHV) persists in a highly-ordered chromatin structure inside latently infected cells with the majority of the viral genome having repressive marks. However, upon reactivation the viral chromatin landscape changes into ‘open’ chromatin through the involvement of lysine demethylases and methyltransferases. Besides methylation of lysine residues of histone H3, arginine methylation of histone H4 plays an important role in controlling the compactness of the chromatin. Symmetric methylation of histone H4 at arginine 3 (H4R3me2s) negatively affects the methylation of histone H3 at lysine 4 (H3K4me3), an active epigenetic mark deposited on the viral chromatin during reactivation. We identified a novel binding partner to KSHV viral DNA processivity factor, ORF59-a protein arginine methyl transferase 5 (PRMT5). PRMT5 is an arginine methyltransferase that dimethylates arginine 3 (R3) of histone H4 in a symmetric manner, one hallmark of condensed chromatin. Our ChIP-seq data of symmetrically methylated H4 arginine 3 showed a significant decrease in H4R3me2s on the viral genome of reactivated cells as compared to the latent cells. Reduction in arginine methylation correlated with the binding of ORF59 on the viral chromatin and disruption of PRMT5 from its adapter protein, COPR5 (cooperator of PRMT5). Binding of PRMT5 through COPR5 is important for symmetric methylation of H4R3 and the expression of ORF59 competitively reduces the association of PRMT5 with COPR5, leading to a reduction in PRMT5 mediated arginine methylation. This ultimately resulted in a reduced level of symmetrically methylated H4R3 and increased levels of H3K4me3 marks, contributing to the formation of an open chromatin for transcription and DNA replication. Depletion of PRMT5 levels led to a decrease in symmetric methylation and increase in viral gene transcription confirming the role of PRMT5 in viral reactivation. In conclusion, ORF59 modulates histone

KSHV encoded ORF59 modulates histone arginine methylation of the viral genome to promote viral reactivation.

PubMed

Strahan, Roxanne C; McDowell-Sargent, Maria; Uppal, Timsy; Purushothaman, Pravinkumar; Verma, Subhash C

2017-07-01

Kaposi's sarcoma associated herpesvirus (KSHV) persists in a highly-ordered chromatin structure inside latently infected cells with the majority of the viral genome having repressive marks. However, upon reactivation the viral chromatin landscape changes into 'open' chromatin through the involvement of lysine demethylases and methyltransferases. Besides methylation of lysine residues of histone H3, arginine methylation of histone H4 plays an important role in controlling the compactness of the chromatin. Symmetric methylation of histone H4 at arginine 3 (H4R3me2s) negatively affects the methylation of histone H3 at lysine 4 (H3K4me3), an active epigenetic mark deposited on the viral chromatin during reactivation. We identified a novel binding partner to KSHV viral DNA processivity factor, ORF59-a protein arginine methyl transferase 5 (PRMT5). PRMT5 is an arginine methyltransferase that dimethylates arginine 3 (R3) of histone H4 in a symmetric manner, one hallmark of condensed chromatin. Our ChIP-seq data of symmetrically methylated H4 arginine 3 showed a significant decrease in H4R3me2s on the viral genome of reactivated cells as compared to the latent cells. Reduction in arginine methylation correlated with the binding of ORF59 on the viral chromatin and disruption of PRMT5 from its adapter protein, COPR5 (cooperator of PRMT5). Binding of PRMT5 through COPR5 is important for symmetric methylation of H4R3 and the expression of ORF59 competitively reduces the association of PRMT5 with COPR5, leading to a reduction in PRMT5 mediated arginine methylation. This ultimately resulted in a reduced level of symmetrically methylated H4R3 and increased levels of H3K4me3 marks, contributing to the formation of an open chromatin for transcription and DNA replication. Depletion of PRMT5 levels led to a decrease in symmetric methylation and increase in viral gene transcription confirming the role of PRMT5 in viral reactivation. In conclusion, ORF59 modulates histone

The control of fruiting body formation in the ascomycete Sordaria macrospora Auersw. by arginine and biotin: a two-factor analysis.

PubMed

Molowitz, R; Bahn, M; Hock, B

1976-01-01

Fruiting body formation of Sordaria macrospora Auersw. is controlled by L-arginine and biotin when the fungus is grown on a synthetic nutrient medium containing optimal concentrations of fructose, KNO3, KH2PO4, MgSO4, and ZnSO4. Arginine and biotin operate in very low concentrations which exclude unspecific nutrient effects. In spite of the complicated interactions of arginine and biotin which are shown qualitatively (Figs. 3 and 4a) and quantitatively (Figs. 2 and 4b), the following conclusions are reached: 1. In the absence of biotin, the development of Sordaria macrospora is blocked at the stage of small protoperithecia. The external addition of biotin (optimal concentration: 3-12 μg/l) allows the formation of fertile fruiting bodies. This effect cannot be imitated by arginine. The biotin effect is discussed in connection with stimulated RNA synthesis.-2. The developmental velocity is influenced by the external addition of arginine. Without arginine but at permissible biotin concentrations, the total life cycle takes about 10 days, in the presence of arginine (1 mM), however, about 6 days.-3. The hyphal density, as well as the total number of fruiting bodies being produced, is controlled in a similar manner by biotin and arginine. The induction of fruiting body formation obviously takes place after the transgression of a critical hyphal density.

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

PubMed

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.

Esophagogastric anastomosis in rats: Improved healing by BPC 157 and L-arginine, aggravated by L-NAME

PubMed Central

Djakovic, Zeljko; Djakovic, Ivka; Cesarec, Vedran; Madzarac, Goran; Becejac, Tomislav; Zukanovic, Goran; Drmic, Domagoj; Batelja, Lovorka; Zenko Sever, Anita; Kolenc, Danijela; Pajtak, Alen; Knez, Nikica; Japjec, Mladen; Luetic, Kresimir; Stancic-Rokotov, Dinko; Seiwerth, Sven; Sikiric, Predrag

2016-01-01

AIM To cure typically life-threatening esophagogastric anastomosis in rats, lacking anastomosis healing and sphincter function rescue, in particular. METHODS Because we assume esophagogastric fistulas represent a particular NO-system disability, we attempt to identify the benefits of anti-ulcer stable gastric pentadecapeptide BPC 157, which was in trials for ulcerative colitis and currently for multiple sclerosis, in rats with esophagocutaneous fistulas. Previously, BPC 157 therapies have promoted the healing of intestinal anastomosis and fistulas, and esophagitis and gastric lesions, along with rescued sphincter function. Additionally, BPC 157 particularly interacts with the NO-system. In the 4 d after esophagogastric anastomosis creation, rats received medication (/kg intraperitoneally once daily: BPC 157 (10 μg, 10 ng), L-NAME (5 mg), or L-arginine (100 mg) alone and/or combined or BPC 157 (10 μg, 10 ng) in drinking water). For rats underwent esophagogastric anastomosis, daily assessment included progressive stomach damage (sum of the longest diameters, mm), esophagitis (scored 0-5), weak anastomosis (mL H2O before leak), low pressure in esophagus at anastomosis and in the pyloric sphincter (cm H2O), progressive weight loss (g) and mortality. Immediate effect assessed blood vessels disappearance (scored 0-5) at the stomach surface immediately after anastomosis creation. RESULTS BPC 157 (all regimens) fully counteracted the perilous disease course from the very beginning (i.e., with the BPC 157 bath, blood vessels remained present at the gastric surface after anastomosis creation) and eliminated mortality. Additionally, BPC 157 treatment in combination with L-NAME nullified any effect of L-NAME that otherwise intensified the regular course. Consistently, with worsening (with L-NAME administration) and amelioration (with L-arginine), either L-arginine amelioration prevails (attenuated esophageal and gastric lesions) or they counteract each other (L-NAME + L-arginine

Esophagogastric anastomosis in rats: Improved healing by BPC 157 and L-arginine, aggravated by L-NAME.

PubMed

Djakovic, Zeljko; Djakovic, Ivka; Cesarec, Vedran; Madzarac, Goran; Becejac, Tomislav; Zukanovic, Goran; Drmic, Domagoj; Batelja, Lovorka; Zenko Sever, Anita; Kolenc, Danijela; Pajtak, Alen; Knez, Nikica; Japjec, Mladen; Luetic, Kresimir; Stancic-Rokotov, Dinko; Seiwerth, Sven; Sikiric, Predrag

2016-11-07

To cure typically life-threatening esophagogastric anastomosis in rats, lacking anastomosis healing and sphincter function rescue, in particular. Because we assume esophagogastric fistulas represent a particular NO-system disability, we attempt to identify the benefits of anti-ulcer stable gastric pentadecapeptide BPC 157, which was in trials for ulcerative colitis and currently for multiple sclerosis, in rats with esophagocutaneous fistulas. Previously, BPC 157 therapies have promoted the healing of intestinal anastomosis and fistulas, and esophagitis and gastric lesions, along with rescued sphincter function. Additionally, BPC 157 particularly interacts with the NO-system. In the 4 d after esophagogastric anastomosis creation, rats received medication (/kg intraperitoneally once daily: BPC 157 (10 μg, 10 ng), L-NAME (5 mg), or L-arginine (100 mg) alone and/or combined or BPC 157 (10 μg, 10 ng) in drinking water). For rats underwent esophagogastric anastomosis, daily assessment included progressive stomach damage (sum of the longest diameters, mm), esophagitis (scored 0-5), weak anastomosis (mL H 2 O before leak), low pressure in esophagus at anastomosis and in the pyloric sphincter (cm H 2 O), progressive weight loss (g) and mortality. Immediate effect assessed blood vessels disappearance (scored 0-5) at the stomach surface immediately after anastomosis creation. BPC 157 (all regimens) fully counteracted the perilous disease course from the very beginning ( i.e ., with the BPC 157 bath, blood vessels remained present at the gastric surface after anastomosis creation) and eliminated mortality. Additionally, BPC 157 treatment in combination with L-NAME nullified any effect of L-NAME that otherwise intensified the regular course. Consistently, with worsening (with L-NAME administration) and amelioration (with L-arginine), either L-arginine amelioration prevails (attenuated esophageal and gastric lesions) or they counteract each other (L-NAME + L-arginine); with

Kinetics and molecular characteristics of arginine transport by Leishmania donovani promastigotes.

PubMed

Kandpal, M; Fouce, R B; Pal, A; Guru, P Y; Tekwani, B L

1995-05-01

Characteristics of transport of L-arginine were studied in Leishmania donovani promastigotes grown in vitro in a defined medium. The promastigotes exhibited a time-dependent, temperature-sensitive, pH-dependent and saturable uptake of arginine. Metabolic inhibitors caused 81-92% inhibition, indicating that arginine influx in promastigotes is an energy requiring process. The presence of Na+ ions was necessary for full activity. Considerable inhibition was also noticed with valinomycin, gramicidin and amiloride. The transporter seems to involve an -SH group at the active site. The most distinctive feature of the leishmanial transporter was that lysine and ornithine did not show significant competition with arginine transport. Other neutral and acidic amino acids, as well as polyamines were also ineffective. The arginine analogues, viz., nitro-L-arginine methyl ester, N-nitro-L-arginine, aminoguanidine, agmatine and D-arginine were not recognised by the transporter, while N-methyl-L-arginine acetate and phospho-L-arginine showed competition, indicating stereo-specificity of the transporter and recognition of both the guanidino group, as well as the arginine side chain by the transporter. No exchange of intracellular [14C]arginine taken up by the promastigotes was noticed during incubation with 2 or 5 mM arginine in the extracellular medium. Eighty percent of the arginine taken up remained in the trichloroacetic acid-soluble fraction. Pentamidine caused competitive inhibition of arginine transport, exhibiting an IC50 value of 40 microM. Results indicate the presence of a novel distinct arginine transporter in Leishmania promastigotes.

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

PubMed Central

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

2016-01-01

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. PMID:26899474

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

NASA Astrophysics Data System (ADS)

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.

Nutrient assessment of olive leaf residues processed by solid-state fermentation as an innovative feedstuff additive.

PubMed

Xie, P-J; Huang, L-X; Zhang, C-H; Zhang, Y-L

2016-07-01

Olive leaf residue feedstuff additives were prepared by solid-state fermentation (SSF), and its feeding effects on broiler chickens were examined. The fermentation's nutrient value, that is, protein enrichment, cellulase activity, tannic acid degradation and amino acid enhancement, was determined. The effect of different strains, including molds (Aspergillus niger, Aspergillus oryzae and Trichoderma viride) and yeasts (Candida utilis, Candida tropicalis and Geotrichum candidum), and the fermentation time on the nutrient values of the feedstuff additives was investigated. The experimental results showed that the optimal parameters for best performance were A. niger and C. utilis in a 1 : 1 ratio (v/v) in co-culture fermentation for 5 days. Under these conditions, the total content of amino acids in the fermented olive leaf residues increased by 22·0% in comparison with that in the raw leaf residues. Both Glutamic acid and Aspartic acid contents were increased by more than 25·4%. Broiler chickens fed with different amounts of feedstuff additives were assessed. The results demonstrated that the chicken weight gains increased by 120%, and normal serum biochemical parameters were improved significantly after 10% of the feedstuff additives were supplemented to the daily chicken feed for 28 days. The co-culture combination of A. niger and C. utilis with SSF for olive leaf residue had the best nutrient values. The addition of 10% fermented olive leaf residue facilitated the chicken growth and development. This study reveals that olive leaf residues fermented by SSF exhibited considerable potential as feed additives for feeding poultry. © 2016 The Society for Applied Microbiology.

Parenteral or Enteral Arginine Supplementation Safety and Efficacy.

PubMed

Rosenthal, Martin D; Carrott, Phillip W; Patel, Jayshil; Kiraly, Laszlo; Martindale, Robert G

2016-12-01

Arginine supplementation has the potential to improve the health of patients. Its use in hospitalized patients has been a controversial topic in the nutrition literature, especially concerning supplementation of septic patients. In this article, we review the relevant literature both for and against the use of arginine in critically ill, surgical, and hospitalized patients. The effect of critical illness on arginine metabolism is reviewed, as is its use in septic and critically ill patients. Although mounting evidence supports immunonutrition, there are only a few studies that suggest that this is safe in patients with severe sepsis. The use of arginine has been shown to benefit a variety of critically ill patients. It should be considered for inclusion in combinations of immunonutrients or commercial formulations for groups in whom its benefit has been reported consistently, such as those who have suffered trauma and those in acute surgical settings. The aims of this review are to discuss the role of arginine in health, the controversy surrounding arginine supplementation of septic patients, and the use of arginine in critically ill patients. © 2016 American Society for Nutrition.

Agmatine: at the crossroads of the arginine pathways.

PubMed

Satriano, Joseph

2003-12-01

In acute inflammatory responses, such as wound healing and glomerulonephritis, arginine is the precursor for production of the cytostatic molecule nitric oxide (NO) and the pro-proliferative polyamines. NO is an early phase response whereas increased generation of polyamines is requisite for the later, repair phase response. The temporal switch of arginine as a substrate for the inducible nitric oxide synthase (iNOS)/NO axis to arginase/ornithine decarboxylase (ODC)/polyamine axis is subject to regulation by inflammatory cytokines as well as interregulation by the arginine metabolites themselves. Herein we describe the capacity of another arginine pathway, the metabolism of arginine to agmatine by arginine decarboxylase (ADC), to aid in this interregulation. Agmatine is an antiproliferative molecule due to its suppressive effects on intracellular polyamine levels, whereas the aldehyde metabolite of agmatine is a potent inhibitor of iNOS. We propose that the catabolism of agmatine to its aldehyde metabolite may act as a gating mechanism at the transition from the iNOS/NO axis to the arginase/ODC/polyamine axis. Thus, agmatine has the potential to serve in the coordination of the early and repair phase pathways of arginine in inflammation.

Occurrence, Functions and Biological Significance of Arginine-Rich Proteins.

PubMed

Chandana, Thimmegowda; Venkatesh, Yeldur P

2016-01-01

Arginine, the most basic among the 20 amino acids, occurs less frequently than lysine in proteins despite being coded by six codons. Only a few important proteins of biological significance have been found to be abundant in arginine. It has been established that these arginine-rich proteins have been assigned important roles in the biological systems. Arginine-rich cationic proteins are known to stabilize macromolecular structures by establishing appropriate interactions (salt bridges, hydrogen bonds and cation-π interactions). These proteins are also known to be the key members of many regulatory pathways such as gene expression, chromatin stability, expurgation of introns from naïve mRNA, mRNA splicing, membrane-penetrating activity and pathogenesis-related defense, to name a few. Further, arginine occurs in various combinations with other amino acids (serine, lysine, proline, tryptophan, valine, glycine and glutamic acid) which diversify the potential functions of arginine-rich proteins. Arginine-rich proteins known till date from dietary sources have been described in terms of their structure and functional properties. A variety of activities such as bactericidal, membrane-penetrating, antimicrobial, anti-hypertensive, pro-angiogenic and others have been reported for arginine-rich proteins. This review attempts to collate the occurrence, functions and the biological significance of this unique class of proteins rich in arginine.

Arginine-Ornithine Antiporter ArcD Controls Arginine Metabolism and Interspecies Biofilm Development of Streptococcus gordonii*♦

PubMed Central

Sakanaka, Akito; Kuboniwa, Masae; Takeuchi, Hiroki; Hashino, Ei; Amano, Atsuo

2015-01-01

Arginine is utilized by the oral inhabitant Streptococcus gordonii as a substrate of the arginine deiminase system (ADS), eventually producing ATP and NH3, the latter of which is responsible for microbial resistance to pH stress. S. gordonii expresses a putative arginine-ornithine antiporter (ArcD) whose function has not been investigated despite relevance to the ADS and potential influence on inter-bacterial communication with periodontal pathogens that utilize amino acids as a main energy source. Here, we generated an S. gordonii ΔarcD mutant to explore the role of ArcD in physiological homeostasis and bacterial cross-feeding. First, we confirmed that S. gordonii ArcD plays crucial roles for mediating arginine uptake and promoting bacterial growth, particularly under arginine-limited conditions. Next, metabolomic profiling and transcriptional analysis of the ΔarcD mutant revealed that deletion of this gene caused intracellular accumulation of ornithine leading to malfunction of the ADS and suppression of de novo arginine biosynthesis. The mutant strain also showed increased susceptibility to low pH stress due to reduced production of ammonia. Finally, accumulation of Fusobacterium nucleatum was found to be significantly decreased in biofilm formed by the ΔarcD mutant as compared with the wild-type strain, although ornithine supplementation restored fusobacterium biovolume in dual-species biofilms with the ΔarcD mutant and also enhanced single species biofilm development by F. nucleatum. Our results are the first direct evidence showing that S. gordonii ArcD modulates not only alkali and energy production but also interspecies interaction with F. nucleatum, thus initiating a middle stage of periodontopathic biofilm formation, by metabolic cross-feeding. PMID:26085091

The central active site arginine in sulfite oxidizing enzymes alters kinetic properties by controlling electron transfer and redox interactions.

PubMed

Hsiao, Ju-Chun; McGrath, Aaron P; Kielmann, Linda; Kalimuthu, Palraj; Darain, Farzana; Bernhardt, Paul V; Harmer, Jeffrey; Lee, Mihwa; Meyers, Kimberley; Maher, Megan J; Kappler, Ulrike

2018-01-01

A central conserved arginine, first identified as a clinical mutation leading to sulfite oxidase deficiency, is essential for catalytic competency of sulfite oxidizing molybdoenzymes, but the molecular basis for its effects on turnover and substrate affinity have not been fully elucidated. We have used a bacterial sulfite dehydrogenase, SorT, which lacks an internal heme group, but transfers electrons to an external, electron accepting cytochrome, SorU, to investigate the molecular functions of this arginine residue (Arg78). Assay of the SorT Mo centre catalytic competency in the absence of SorU showed that substitutions in the central arginine (R78Q, R78K and R78M mutations) only moderately altered SorT catalytic properties, except for R78M which caused significant reduction in SorT activity. The substitutions also altered the Mo-centre redox potentials (Mo VI/V potential lowered by ca. 60-80mV). However, all Arg78 mutations significantly impaired the ability of SorT to transfer electrons to SorU, where activities were reduced 17 to 46-fold compared to SorT WT , precluding determination of kinetic parameters. This was accompanied by the observation of conformational changes in both the introduced Gln and Lys residues in the crystal structure of the enzymes. Taking into account data collected by others on related SOE mutations we propose that the formation and maintenance of an electron transfer complex between the Mo centre and electron accepting heme groups is the main function of the central arginine, and that the reduced turnover and increases in K Msulfite are caused by the inefficient operation of the oxidative half reaction of the catalytic cycle in enzymes carrying these mutations. Copyright © 2017 Elsevier B.V. All rights reserved.

Arginine Kinase. Joint Crystallographic & NMR RDC Analyses link Substrate-Associated Motions to Intrinsic Flexibility

PubMed Central

Niu, Xiaogang; Brüschweiler-Li, Lei; Davulcu, Omar; Skalicky, Jack J.; Brüschweiler, Rafael; Chapman, Michael S.

2010-01-01

The phosphagen kinase family, including creatine and arginine kinases, catalyze the reversible transfer of a “high energy” phosphate between ATP and a phospho-guanidino substrate. They have become a model for the study of both substrate-induced conformational change and intrinsic protein dynamics. Prior crystallographic studies indicated large substrate-induced domain rotations, but differences among a recent set of arginine kinase structures was interpreted as a plastic deformation. Here, the structure of Limulus substrate-free arginine kinase is refined against high resolution crystallographic data and compared quantitatively with NMR chemical shifts and residual dipolar couplings (RDCs). This demonstrates the feasibility of this type of RDC analysis of proteins that are large by NMR standards (42 kDa), and illuminates the solution structure, free from crystal-packing constraints. Detailed comparison of the 1.7 Å resolution substrate-free crystal structure against the 1.2 Å transition state analog complex shows large substrate-induced domain motions which can be broken down into movements of smaller quasi-rigid bodies. The solution state structure of substrate-free arginine kinase is most consistent with an equilibrium of substrate-free and –bound structures, with the substrate-free form dominating, but with varying displacements of the quasi-rigid groups. Rigid-group rotations evident from the crystal structures are about axes previously associated with intrinsic millisecond dynamics using NMR relaxation dispersion. Thus, “substrate-induced” motions are along modes that are intrinsically flexible in the substrate-free enzyme, and likely involve some degree of conformational selection. PMID:21075117

Activities of Arginine and Ornithine Decarboxylases in Various Plant Species 1

PubMed Central

Birecka, Helena; Bitonti, Alan J.; McCann, Peter P.

1985-01-01

In extracts from the youngest leaves of Avena sativa, Hordeum vulgare, Zea Mays, Pisum sativum, Phaseolus vulgaris, Lactuca sativa, and four pyrrolizidine alkaloid-bearing species of Heliotropium, the activities of ornithine decarboxylase, close to Vmax, ranged between traces and 1.5 nanomoles per hour per gram fresh weight when based on putrescine formed during incubation with labeled ornithine. The arginine decarboxylase activities in the same extracts ranged between 8 and 8000 nanomoles per hour per gram fresh weight being lowest in the borages and highest in oat and barley. α-Difluoromethylornithine and α-difluoromethylarginine inhibited ornithine and arginine decarboxylases, respectively, in all species. Agmatine, putrescine, spermidine, and spermine were found in all, diaminopropane in eight, and cadaverine in three species. No correlation was observed between arginine or ornithine decarboxylase level and the levels of total polyamines. The in vitro decarboxylase activities found in the borages cannot explain the high accumulation of putrescine-derived pyrrolizidines in their youngest leaves if the pyrrolizidines are produced in situ from arginine and/or ornithine as precursors; other possibilities are discussed. In assays of ornithine decarboxylase, an interference of decarboxylation not due to this enzyme was observed in extracts from all species. In arginine decarboxylase assays, the interfering decarboxylation as well as the interference of arginase were apparent in two species. Addition of aminoguanidine was needed to suppress oxidative degradation of putrescine and agmatine during incubation of extracts from pea, bean, lettuce, Heliotropium angiospermum, and Heliotropium indicum. PMID:16664442

Ecological Effect of Arginine on Oral Microbiota.

PubMed

Zheng, Xin; He, Jinzhi; Wang, Lin; Zhou, Shuangshuang; Peng, Xian; Huang, Shi; Zheng, Liwei; Cheng, Lei; Hao, Yuqing; Li, Jiyao; Xu, Jian; Xu, Xin; Zhou, Xuedong

2017-08-03

Dental caries is closely associated with the microbial dybiosis between acidogenic/aciduric pathogens and alkali-generating commensal bacteria colonized in the oral cavity. Our recent studies have shown that arginine may represent a promising anti-caries agent by modulating microbial composition in an in vitro consortium. However, the effect of arginine on the oral microbiota has yet to be comprehensively delineated in either clinical cohort or in vitro biofilm models that better represent the microbial diversity of oral cavity. Here, by employing a clinical cohort and a saliva-derived biofilm model, we demonstrated that arginine treatment could favorably modulate the oral microbiota of caries-active individuals. Specifically, treatment with arginine-containing dentifrice normalized the oral microbiota of caries-active individuals similar to that of caries-free controls in terms of microbial structure, abundance of typical species, enzymatic activities of glycolysis and alkali-generation related enzymes and their corresponding transcripts. Moreover, we found that combinatory use of arginine with fluoride could better enrich alkali-generating Streptococcus sanguinis and suppress acidogenic/aciduric Streptococcus mutans, and thus significantly retard the demineralizing capability of saliva-derived oral biofilm. Hence, we propose that fluoride and arginine have a potential synergistic effect in maintaining an eco-friendly oral microbial equilibrium in favor of better caries management.

Arginine promotes Proteus mirabilis motility and fitness by contributing to conservation of the proton gradient and proton motive force

PubMed Central

Armbruster, Chelsie E; Hodges, Steven A; Smith, Sara N; Alteri, Christopher J; Mobley, Harry L T

2014-01-01

Swarming contributes to Proteus mirabilis pathogenicity by facilitating access to the catheterized urinary tract. We previously demonstrated that 0.1–20 mmol/L arginine promotes swarming on normally nonpermissive media and that putrescine biosynthesis is required for arginine-induced swarming. We also previously determined that arginine-induced swarming is pH dependent, indicating that the external proton concentration is critical for arginine-dependent effects on swarming. In this study, we utilized survival at pH 5 and motility as surrogates for measuring changes in the proton gradient (ΔpH) and proton motive force (μH+) in response to arginine. We determined that arginine primarily contributes to ΔpH (and therefore μH+) through the action of arginine decarboxylase (speA), independent of the role of this enzyme in putrescine biosynthesis. In addition to being required for motility, speA also contributed to fitness during infection. In conclusion, consumption of intracellular protons via arginine decarboxylase is one mechanism used by P. mirabilis to conserve ΔpH and μH+ for motility. PMID:25100003

The growth of ZnO nanostructures using Arginine

NASA Astrophysics Data System (ADS)

Singh, Baljinder; Moudgil, Lovika; Singh, Gurinder; Kaura, Aman

2018-05-01

The growth mechanism of Zinc oxide (ZnO) nanomaterial with amino acid (Arginine) is explained at different shapes. The present study of ZnO nanostructures (NSs) in the presence of Arginine has enabled us to not only determine the growth mechanism of ZnO NSs but also to determine the effect of Arginine at different temperature of reactants. The synthesized samples are characterized using transmission electron microscopy (TEM) and X-ray diffraction (XRD). Results reveal that Arginine is responsible for formation of NSs. Based on these results, a plausible mechanism is explained.

Self-assembled arginine-rich peptides as effective antimicrobial agents.

PubMed

Mi, Gujie; Shi, Di; Herchek, Whitney; Webster, Thomas J

2017-04-01

Bacteria can adapt to their ever-changing environment to develop a resistance to commonly used antibiotics. This escalating evolution of bacteria coupled with a diminished number of effective antibiotics has caused a global healthcare crisis. New antimicrobials and novel approaches to tackle this problem are urgently needed. Antimicrobial peptides are of particular interest in this endeavor due to their broad spectrum antimicrobial properties as well as ability to combat multi-drug resistant bacteria. Most peptides have both hydrophobic and hydrophilic regions that enable them to be soluble in an aqueous solution, yet can insert into and subsequently disintegrate lipid rich membranes through diverse mechanisms. In this study, a novel class of cationic nanoparticles (formed by the self-assembly of an amphiphilic peptide) were shown to have strong antimicrobial properties against gram-positive bacteria, specifically Staphylococcus aureus, Staphylococcus epidermidis, and methicillin-resistant Staphylococcus aureus (MRSA) with minimal toxicity to human dermal fibroblasts. The particular self-assembled structure tested here included an arginine rich nanoparticle (C 17 H 35 GR7RGDS or amphiphilic peptide nanoparticles, APNPs) which incorporated seven arginine residues (imparting a positive charge to improve membrane interactions), a hydrophobic block which drove the self-assembly process, and the presence of an amino acid quadruplet arginine-glycine-aspartic acid-serine (RGDS) which may render these nanoparticles capable of attracting healthy cells while competing bacterial adherence to fibronectin, an adhesive protein found on cell surfaces. As such, this in vitro study demonstrated that the presently formulated APNPs should be further studied for a wide range of antibacterial applications where antibiotics are no longer useful. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 1046-1054, 2017. © 2017 Wiley Periodicals, Inc.

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

PubMed Central

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

EG-01EPIGENETIC INACTIVATION OF ARGININE BIOSYNTHESIS PATHWAY IN PAEDIATRIC HIGH GRADE GLIOMA

PubMed Central

Channathodiyil, Prasanna; Kardooni, Hoda; Khozoie, Combiz; Nelofer, Syed; Darling, John; Morris, Mark; Warr, Tracy

2014-01-01

Aberrant cellular metabolism contributes significantly to the growth and proliferation of several tumour types. Identification of genes that control critical metabolic pathways is a major factor in the development of novel therapies that target metabolic defects in tumour cells. Our aim is to identify such genes in paediatric high grade glioma that are altered due to promoter hyper-methylation of cytosine residues in CpG dinucleotides. Genome wide DNA methylation profiling using Illumina infinium methylation 450K bead chip array was performed on 18 well-characterised short term cultures derived from paediatric high grade astrocytoma including 3 from diffuse intrinsic pontine glioma. Data analyses were based on beta scores of probes for each gene as measures of intensities of methylation. Genes were selected with beta scores of tumour > =0.70 and that of normal human astrocytes < =0.30. We identified that two vital genes involved in the regulation of arginine biosynthetic pathway, argininosuccinate synthetase 1(ASS1) and argininosuccinate lyase (ASL) were methylated in 9/18 (50%) cases. Hyper methylation was confirmed by methylation-specific PCR and up-regulation of gene expression following treatment with 2 µM 5-aza-2'-deoxyctidine. Down-regulation of ASS1 in hyper methylated samples was confirmed by Western blot analysis. Our findings report epigenetic deregulation of ASS1 and ASL in a subset of paediatric high grade glioma. The enzymes encoded by these genes are essential elements of urea cycle that function together in the de novo synthesis of arginine from citrulline. Tumour cells with deficient ASS1/ASL depend on external sources of arginine for survival and have been reported to be sensitive to autophagic cell death induced by arginine starvation. Therefore, further investigation may render the possibility of arginine-deprivation therapy in such sub type of paediatric high grade glioma. This therapeutic approach is of interest as tumour cells with abnormal

Arginine methylation of HSP70 regulates retinoid acid-mediated RARβ2 gene activation

PubMed Central

Gao, Wei-wei; Xiao, Rong-quan; Peng, Bing-ling; Xu, Huan-teng; Shen, Hai-feng; Huang, Ming-feng; Shi, Tao-tao; Yi, Jia; Zhang, Wen-juan; Wu, Xiao-nan; Gao, Xiang; Lin, Xiang-zhi; Dorrestein, Pieter C.; Rosenfeld, Michael G.; Liu, Wen

2015-01-01

Although “histone” methyltransferases and demethylases are well established to regulate transcriptional programs and to use nonhistone proteins as substrates, their possible roles in regulation of heat-shock proteins in the nucleus have not been investigated. Here, we report that a highly conserved arginine residue, R469, in HSP70 (heat-shock protein of 70 kDa) proteins, an evolutionarily conserved protein family of ATP-dependent molecular chaperone, was monomethylated (me1), at least partially, by coactivator-associated arginine methyltransferase 1/protein arginine methyltransferase 4 (CARM1/PRMT4) and demethylated by jumonji-domain–containing 6 (JMJD6), both in vitro and in cultured cells. Functional studies revealed that HSP70 could directly regulate retinoid acid (RA)-induced retinoid acid receptor β2 (RARβ2) gene transcription through its binding to chromatin, with R469me1 being essential in this process. HSP70’s function in gene transcriptional regulation appears to be distinct from its protein chaperon activity. R469me1 was shown to mediate the interaction between HSP70 and TFIIH, which involves in RNA polymerase II phosphorylation and thus transcriptional initiation. Our findings expand the repertoire of nonhistone substrates targeted by PRMT4 and JMJD6, and reveal a new function of HSP70 proteins in gene transcription at the chromatin level aside from its classic role in protein folding and quality control. PMID:26080448

"Keep a low profile": pesticide residue, additives, and freon use in Australian tobacco manufacturing

PubMed Central

Chapman, S

2003-01-01

Objectives: To review the Australian tobacco industry's knowledge of pesticide residue on Australian tobacco and its policies and practices on resisting calls by tobacco control advocates that consumers should be informed about pesticide residue as well as additives. Methods: Review of previously internal industry documents relevant to pesticides and additives in Australian tobacco located from the Master Settlement Agreement websites. Results: Between 1972 and 1994 Philip Morris Australia was aware that its leaf samples were often contaminated with pesticide residue, sometimes including organochlorine levels described by PM's European laboratories as being "extremely high". Consumers were not advised of the contamination nor products withdrawn. From 1981, the industry also resisted calls to declare fully the extent of use and long term safety data on all additives used in their products. They developed standard public responses that were evasive and misleading and, in 2000, implemented voluntary additive disclosure which allowed the companies to continue to avoid disclosure of any ingredient they deemed to be a trade secret. There was extensive use of ozone depleting freon in Australian tobacco manufacturing. Again, the industry kept this information away from consumers. Conclusions: Australian smokers are unable to make informed decisions about smoking because pesticide and additive disclosure remains voluntary. The Australian government should regulate tobacco to require full disclosure including information on the likely health consequences of inhaling pesticide and additive pyrolysis products. PMID:14645948

Substitution of a single amino acid residue in the aromatic/arginine selectivity filter alters the transport profiles of tonoplast aquaporin homologs.

PubMed

Azad, Abul Kalam; Yoshikawa, Naoki; Ishikawa, Takahiro; Sawa, Yoshihiro; Shibata, Hitoshi

2012-01-01

Aquaporins are integral membrane proteins that facilitate the transport of water and some small solutes across cellular membranes. X-ray crystallography of aquaporins indicates that four amino acids constitute an aromatic/arginine (ar/R) pore constriction known as the selectivity filter. On the basis of these four amino acids, tonoplast aquaporins called tonoplast intrinsic proteins (TIPs) are divided into three groups in Arabidopsis. Herein, we describe the characterization of two group I TIP1s (TgTIP1;1 and TgTIP1;2) from tulip (Tulipa gesneriana). TgTIP1;1 and TgTIP1;2 have a novel isoleucine in loop E (LE2 position) of the ar/R filter; the residue at LE2 is a valine in all group I TIPs from model plants. The homologs showed mercury-sensitive water channel activity in a fast kinetics swelling assay upon heterologous expression in Pichia pastoris. Heterologous expression of both homologs promoted the growth of P. pastoris on ammonium or urea as sole sources of nitrogen and decreased growth and survival in the presence of H(2)O(2). TgTIP1;1- and TgTIP1;2-mediated H(2)O(2) conductance was demonstrated further by a fluorescence assay. Substitutions in the ar/R selectivity filter of TgTIP1;1 showed that mutants that mimicked the ar/R constriction of group I TIPs could conduct the same substrates that were transported by wild-type TgTIP1;1. In contrast, mutants that mimicked group II TIPs showed no evidence of urea or H(2)O(2) conductance. These results suggest that the amino acid residue at LE2 position is critical for the transport selectivity of the TIP homologs and group I TIPs might have a broader spectrum of substrate selectivity than group II TIPs. Copyright © 2011 Elsevier B.V. All rights reserved.

Evaluation of growth hormone release in children using arginine and L-dopa in combination.

PubMed

Weldon, V V; Gupta, S K; Klingensmith, G; Clarke, W L; Duck, S C; Haymond, M W; Pagliara, A S

1975-10-01

L-Dopa in a dose ranging from 125-500 mg and arginine monochloride in a dose of 0.5 gm/kg were given simultaneously to 56 children with short stature (height less than third percentile). Sixteen of these children were subsequently diagnosed as having growth hormone deficiency. The diagnosis of hyposomatotropism was based on clinical findings and on responses to the combination test and to arginine and L-dopa administered as separate tests. All of the remaining 40 children had a normal GH response of greater than 6 ng/ml to the combination test. However, in this group, nine children were identified who responded to the combination test but who failed to respond to arginine and L-dopa in individual tests. The data suggest that a positive response to arginine and L-dopa in combination in children, who do not respond to the usual provocative tests when administered individually, may fail to identify children with partial GH deficiency who would benefit from treatment. The integrated stimulated GH response in the 31 children in whom a normal GH response to all three tests occurred suggests that the effects of L-dopa and arginine are additive.

Arginine "Magic": Guanidinium Like-Charge Ion Pairing from Aqueous Salts to Cell Penetrating Peptides.

PubMed

Vazdar, Mario; Heyda, Jan; Mason, Philip E; Tesei, Giulio; Allolio, Christoph; Lund, Mikael; Jungwirth, Pavel

2018-06-19

It is a textbook knowledge that charges of the same polarity repel each other. For two monovalent ions in the gas phase at a close contact this repulsive interaction amounts to hundreds of kilojoules per mole. In aqueous solutions, however, this Coulomb repulsion is strongly attenuated by a factor equal to the dielectric constant of the medium. The residual repulsion, which now amounts only to units of kilojoules per mole, may be in principle offset by attractive interactions. Probably the smallest cationic pair, where a combination of dispersion and cavitation forces overwhelms the Coulomb repulsion, consists of two guanidinium ions in water. Indeed, by a combination of molecular dynamics with electronic structure calculations and electrophoretic, as well as spectroscopic, experiments, we have demonstrated that aqueous guanidinium cations form (weakly) thermodynamically stable like-charge ion pairs. The importance of pairing of guanidinium cations in aqueous solutions goes beyond a mere physical curiosity, since it has significant biochemical implications. Guanidinium chloride is known to be an efficient and flexible protein denaturant. This is due to the ability of the orientationally amphiphilic guanidinium cations to disrupt various secondary structural motifs of proteins by pairing promiscuously with both hydrophobic and hydrophilic groups, including guanidinium-containing side chains of arginines. The fact that the cationic guanidinium moiety forms the dominant part of the arginine side chain implies that the like-charge ion pairing may also play a role for interactions between peptides and proteins. Indeed, arginine-arginine pairing has been frequently found in structural protein databases. In particular, when strengthened by a presence of negatively charged glutamate, aspartate, or C-terminal carboxylic groups, this binding motif helps to stabilize peptide or protein dimers and is also found in or near active sites of several enzymes. The like

The role of arginine and the modified arginine deiminase enzyme ADI-PEG 20 in cancer therapy with special emphasis on Phase I/II clinical trials.

PubMed

Synakiewicz, Anna; Stachowicz-Stencel, Teresa; Adamkiewicz-Drozynska, Elzbieta

2014-11-01

The metabolic differences between normal, healthy cells and neoplastic cells have been exploited by anticancer therapies targeting metabolic pathways. Various studies of malignant processes have demonstrated disturbances in both arginine synthesis and metabolism that enhance or inhibit tumor cell growth. Consequently, there has been an increased interest in the arginine-depleting enzyme arginine deiminase (ADI) as a potential antineoplastic therapy. This review summarizes the literature on the potential anti-cancer therapeutics arginine and ADI, an arginine-catabolizing enzyme. The authors searched the MEDLINE database PubMed using the key words: 'arginine, 'ADI', 'arginine in cancer' and 'ADI and cancer'. The authors evaluate prospective randomized studies on cancer patients between 2004 and 2013 as well as ongoing research found through the US National Institutes of Health trial database. The results of current studies are promising but do not give unequivocal answers and so it is impossible to recommend arginine or its enzyme ADI as a therapeutic. In the opinion of the authors, further identification of arginine-dependent malignant tumors and their metabolism should be investigated. Furthermore, the use of these chemicals, in combination with other chemotherapeutics drugs, should be investigated and indeed may improve the success of arginine-depleting enzymes such as pegylated ADI (ADI-PEG20).

Comparative Monomethylarginine Proteomics Suggests that Protein Arginine Methyltransferase 1 (PRMT1) is a Significant Contributor to Arginine Monomethylation in Toxoplasma gondii

PubMed Central

Yakubu, Rama R.; Silmon de Monerri, Natalie C.; Nieves, Edward; Kim, Kami; Weiss, Louis M.

2017-01-01

Arginine methylation is a common posttranslational modification found on nuclear and cytoplasmic proteins that has roles in transcriptional regulation, RNA metabolism and DNA repair. The protozoan parasite Toxoplasma gondii has a complex life cycle requiring transcriptional plasticity and has unique transcriptional regulatory pathways. Arginine methylation may play an important part in transcriptional regulation and splicing biology in this organism. The T. gondii genome contains five putative protein arginine methyltransferases (PRMTs), of which PRMT1 is important for cell division and growth. In order to better understand the function(s) of the posttranslational modification monomethyl arginine (MMA) in T. gondii, we performed a proteomic analysis of MMA proteins using affinity purification employing anti-MMA specific antibodies followed by mass spectrometry. The arginine monomethylome of T. gondii contains a large number of RNA binding proteins and multiple ApiAP2 transcription factors, suggesting a role for arginine methylation in RNA biology and transcriptional regulation. Surprisingly, 90% of proteins that are arginine monomethylated were detected as being phosphorylated in a previous phosphoproteomics study which raises the possibility of interplay between MMA and phosphorylation in this organism. Supporting this, a number of kinases are also arginine methylated. Because PRMT1 is thought to be a major PRMT in T. gondii, an organism which lacks a MMA-specific PRMT, we applied comparative proteomics to understand how PRMT1 might contribute to the MMA proteome in T. gondii. We identified numerous putative PRMT1 substrates, which include RNA binding proteins, transcriptional regulators (e.g. AP2 transcription factors), and kinases. Together, these data highlight the importance of MMA and PRMT1 in arginine methylation in T. gondii, as a potential regulator of a large number of processes including RNA biology and transcription. PMID:28143887

A unique serpin P1' glutamate and a conserved β-sheet C arginine are key residues for activity, protease recognition and stability of serpinA12 (vaspin).

PubMed

Ulbricht, David; Pippel, Jan; Schultz, Stephan; Meier, René; Sträter, Norbert; Heiker, John T

2015-09-15

SerpinA12 (vaspin) is thought to be mainly expressed in adipose tissue and has multiple beneficial effects on metabolic, inflammatory and atherogenic processes related to obesity. KLK7 (kallikrein 7) is the only known protease target of vaspin to date and is inhibited with a moderate inhibition rate. In the crystal structure, the cleavage site (P1-P1') of the vaspin reactive centre loop is fairly rigid compared with the flexible residues before P2, possibly supported by an ionic interaction of P1' glutamate (Glu(379)) with an arginine residue (Arg(302)) of the β-sheet C. A P1' glutamate seems highly unusual and unfavourable for the protease KLK7. We characterized vaspin mutants to investigate the roles of these two residues in protease inhibition and recognition by vaspin. Reactive centre loop mutations changing the P1' residue or altering the reactive centre loop conformation significantly increased inhibition parameters, whereas removal of the positive charge within β-sheet C impeded the serpin-protease interaction. Arg(302) is a crucial contact to enable vaspin recognition by KLK7 and it supports moderate inhibition of the serpin despite the presence of the detrimental P1' Glu(379), which clearly represents a major limiting factor for vaspin-inhibitory activity. We also show that the vaspin-inhibition rate for KLK7 can be modestly increased by heparin and demonstrate that vaspin is a heparin-binding serpin. Noteworthily, we observed vaspin as a remarkably thermostable serpin and found that Glu(379) and Arg(302) influence heat-induced polymerization. These structural and functional results reveal the mechanistic basis of how reactive centre loop sequence and exosite interaction in vaspin enable KLK7 recognition and regulate protease inhibition as well as stability of this adipose tissue-derived serpin. © 2015 Authors; published by Portland Press Limited.

Supplementation with apple enriched with L-arginine may improve metabolic control and survival rate in alloxan-induced diabetic rats.

PubMed

Escudero, Andrea; Petzold, Guillermo; Moreno, Jorge; Gonzalez, Marcelo; Junod, Julio; Aguayo, Claudio; Acurio, Jesenia; Escudero, Carlos

2013-01-01

Supplementation with L-arginine or fresh food with high content of this amino acid is associated with favorable effects in the metabolic control of diabetes. We aimed to determine whether supplementation with apples enriched with L-arginine offer additional benefits compared to L-arginine by itself in a preclinical study of diabetes. This study combines food-engineer technologies with in vivo and in vitro analysis. In vitro experiments show that cells derived from non-diabetic animals and exposed to high glucose (25 mM, 12 H) and cells isolated from alloxan-induced diabetic animals exhibited a reduction (∼50%) in the L-arginine uptake. This effect was reverted by L-arginine pretreatment (12 H) in both the normal and diabetes-derived cells. In preclinical studies, normoglycemic (n = 25) and diabetic groups (n = 50) were divided into subgroups that received either L-arginine (375 mg/kg per 10 days) or apple enriched with L-arginine or vehicle (control). In a preliminary analysis, supplementation with L-arginine by itself (50%) or apple enriched with L-arginine (100%) improve survival rate in the diabetic group compared to control (0%) at the end of the follow up (17 days). This phenomenon was associated with a partial but sustained high plasma level of L-arginine, as well as plasma concentration of nitrites and insulin in the L-arginine or apple + L-arginine groups after supplementation. Apple + L-arginine supplementation in diabetic animals induced the highest and longest effects in the level of these three markers among the studied groups. Therefore, apple enriched by L-arginine offers more benefits than L-arginine by itself in this preclinical study. Copyright © 2013 International Union of Biochemistry and Molecular Biology, Inc.

The primary structure of aspartate aminotransferase from pig heart muscle. Digestion with a proteinase having specificity for lysine residues.

PubMed Central

Doonan, S; Doonan, H J; Hanford, R; Vernon, C A; Walker, J M; da Airold, L P; Bossa, F; Barra, D; Carloni, M; Fasella, P; Riva, F

1975-01-01

Carboxymethylated aspartate aminotransferase was digested with a proteinase claimed to be specific for lysine residues. Complete cleavage occurred at 12 of the 19 lysine residues in the protein, but at the remaining seven residues cleavage was either restricted or absent. In addition, cleavage was observed at three of the 26 arginine residues. These results are discussed with reference to the amino acid residues adjacent to points of complete or restricted cleavage. The complete primary structure of aspartate aminotransferase, based on these and other studies, is given. Evidence for the assignment of some acid and amide side chains has been deposited as Supplementary Publication SUP 50050 (11 pp.) at the British Library (Lending Division), Boston Spa, Wetherby, W. Yorkshire LS23 7BQ, U.K., from whom copies can be obtained on the terms indicated in Biochem. J. (1975) 145, 5. The evidence for the assignment of residue 366 was less conclusive than for the other acid and amide side chains and is, therefore, given in the main paper. PMID:1239277

Arginine and aerobic training prevent endothelial and metabolic alterations in rats at high risk for the development of the metabolic syndrome.

PubMed

Medeiros, Renata F; Gaique, Thaiane G; Bento-Bernardes, Thais; Kindlovits, Raquel; Gomes, Tamiris M B; Motta, Nadia Alice V; Brito, Fernanda Carla; Fernandes-Santos, Caroline; Oliveira, Karen J; Nóbrega, Antonio Claudio L

2017-07-01

Endothelial function is a key mechanism in the development of CVD. Arginine and exercise are important non-pharmacological strategies for mitigating the impact of metabolic changes in the metabolic syndrome, but the effect of their combined administration is unknown. Thus, the aim of this study was to investigate the isolated and combined effects of aerobic training and arginine supplementation on metabolic variables and vascular reactivity in rats at high risk for developing the metabolic syndrome. Wistar rats were divided into two groups: control and fructose (F - water with 10 % fructose). After 2 weeks, the F group was divided into four groups: F, fructose+arginine (FA, 880 mg/kg per d of l-arginine), fructose+training (FT) and fructose+arginine+training (FTA); treatments lasted for 8 weeks, and no difference was observed in body mass gain. Arginine did not improve the body protein content, and both the FA and FT groups show a reversal of the increase in adipose tissue. Insulin increase was prevented by training and arginine, without additive effect, and the increase in serum TAG was prevented only by training. The F group showed impaired endothelium-dependent vasodilation and hyperreactivity to phenylephrine, but arginine and training were capable of preventing these effects, even separately. Higher nitric oxide level was observed in the FA and FT groups, and no potentiating effect was detected. Thus, only training was able to prevent the increase in TAG and improve the protein mass, and training and arginine exert similar effects on fat content, insulin and endothelial function, but these effects are not additive.

Arginine-rich proteins in spherical inclusions of human locus coeruleus neurons demonstrated by benzil modification.

PubMed

Panayotacopoulou, M T; Issidorides, M R

1984-11-01

Previous studies have shown that aminergic neurons in the normal human brain contain acidophilic cytoplasmic inclusions--called protein bodies (PBs)--that are reduced or absent in parkinsonism and disrupted in depression. The purpose of the present study was to elucidate the constitution of PBs in five formalin-fixed normal human brains using histochemical methods specific for histones, protamines, and the amino acid arginine. PBs were revealed with alkaline fast green and bromphenol blue, exhibiting a high content in histones and in protamines. They developed blue metachromasia with phosphotungstic acid-hematoxylin and green fluorescence with phenanthrenequinone, which established the presence of arginyl residues. Using benzil, which selectively modifies the guanido group of arginine, staining was blocked for each of the above two methods. The application of Mallory's trichrome procedure after benzil differentiated the PBs into an unstained core and a still fuchsinophilic rim. Since the fuchsinophilia of the rim was shown to persist after acetylation as well, we suggest that this rim probably contains acidic macromolecules that attach to the basic charges of the amphoteric acid fuchsin. We conclude that the PB are complex structures consisting of a core segregating arginine-rich proteins and a rim which probably contains macromolecules of an acidic nature.

Protein arginine methylation: Cellular functions and methods of analysis.

PubMed

Pahlich, Steffen; Zakaryan, Rouzanna P; Gehring, Heinz

2006-12-01

During the last few years, new members of the growing family of protein arginine methyltransferases (PRMTs) have been identified and the role of arginine methylation in manifold cellular processes like signaling, RNA processing, transcription, and subcellular transport has been extensively investigated. In this review, we describe recent methods and findings that have yielded new insights into the cellular functions of arginine-methylated proteins, and we evaluate the currently used procedures for the detection and analysis of arginine methylation.

Arginine promotes Proteus mirabilis motility and fitness by contributing to conservation of the proton gradient and proton motive force.

PubMed

Armbruster, Chelsie E; Hodges, Steven A; Smith, Sara N; Alteri, Christopher J; Mobley, Harry L T

2014-10-01

Swarming contributes to Proteus mirabilis pathogenicity by facilitating access to the catheterized urinary tract. We previously demonstrated that 0.1-20 mmol/L arginine promotes swarming on normally nonpermissive media and that putrescine biosynthesis is required for arginine-induced swarming. We also previously determined that arginine-induced swarming is pH dependent, indicating that the external proton concentration is critical for arginine-dependent effects on swarming. In this study, we utilized survival at pH 5 and motility as surrogates for measuring changes in the proton gradient (ΔpH) and proton motive force (μH(+) ) in response to arginine. We determined that arginine primarily contributes to ΔpH (and therefore μH(+) ) through the action of arginine decarboxylase (speA), independent of the role of this enzyme in putrescine biosynthesis. In addition to being required for motility, speA also contributed to fitness during infection. In conclusion, consumption of intracellular protons via arginine decarboxylase is one mechanism used by P. mirabilis to conserve ΔpH and μH(+) for motility. © 2014 The Authors. MicrobiologyOpen published by John Wiley & Sons Ltd.

Functional interactions between arginine-133 and aspartate-88 in the human reduced folate carrier: evidence for a charge-pair association.

PubMed Central

Liu, X Y; Matherly, L H

2001-01-01

The human reduced folate carrier (hRFC) is an integral membrane protein that mediates cellular uptake of reduced folates and antifolates. hRFC contains several highly conserved charged residues predicted to lie in the transmembrane domains (TMDs). To explore the possible roles of the conserved arginine-133, located in TMD 4, in hRFC structure and function, this residue was systematically mutagenized to histidine, leucine, lysine and glutamate. When transfected into transport-impaired K562 cells, the mutant hRFC constructs were expressed at high levels; however, only lysine-133 hRFC was able to transport methotrexate and (6S)-5-formyl tetrahydrofolate. Substitution of aspartate-453 (in hRFC TMD 12) by valine largely preserved transport activity for both substrates. Although mutagenesis of aspartate-88 (in TMD 2) to leucine completely abolished transport activity in transfected cells, substitution with a glutamate preserved low levels ( approximately 12%) of transport. To assess the possibility that arginine-133 and aspartate-88 may form a charge-pair to stabilize hRFC tertiary structure, both charges were neutralized (by substituting leucine and valine, respectively) in the same construct. In contrast to the singly mutated hRFCs, the double mutant exhibited high levels of transport with both methotrexate and 5-formyl tetrahydrofolate. These results strongly suggest that arginine-133 and aspartate-88 form a charge-pair and that TMD 4 lies next to TMD 2 in the hRFC tertiary structure. PMID:11513752

Arginine Catabolism by Sourdough Lactic Acid Bacteria: Purification and Characterization of the Arginine Deiminase Pathway Enzymes from Lactobacillus sanfranciscensis CB1

PubMed Central

De Angelis, Maria; Mariotti, Liberato; Rossi, Jone; Servili, Maurizio; Fox, Patrick F.; Rollán, Graciela; Gobbetti, Marco

2002-01-01

The cytoplasmic extracts of 70 strains of the most frequently isolated sourdough lactic acid bacteria were screened initially for arginine deiminase (ADI), ornithine transcarbamoylase (OTC), and carbamate kinase (CK) activities, which comprise the ADI (or arginine dihydrolase) pathway. Only obligately heterofermentative strains such as Lactobacillus sanfranciscensis CB1; Lactobacillus brevis AM1, AM8, and 10A; Lactobacillus hilgardii 51B; and Lactobacillus fructivorans DD3 and DA106 showed all three enzyme activities. Lactobacillus plantarum B14 did not show CK activity. L. sanfranciscensis CB1 showed the highest activities, and the three enzymes were purified from this microorganism to homogeneity by several chromatographic steps. ADI, OTC, and CK had apparent molecular masses of ca. 46, 39, and 37 kDa, respectively, and the pIs were in the range of 5.07 to 5.2. The OTCs, CKs, and especially ADIs were well adapted to pH (acidic, pH 3.5 to 4.5) and temperature (30 to 37°C) conditions which are usually found during sourdough fermentation. Internal peptide sequences of the three enzymes had the highest level of homology with ADI, OTC, and CK of Lactobacillus sakei. L. sanfranciscensis CB1 expressed the ADI pathway either on MAM broth containing 17 mM arginine or during sourdough fermentation with 1 to 43 mM added arginine. Two-dimensional electrophoresis showed that ADI, OTC, and CK were induced by factors of ca. 10, 4, and 2 in the whole-cell extract of cells grown in MAM broth containing 17 mM arginine compared to cells cultivated without arginine. Arginine catabolism in L. sanfranciscensis CB1 depended on the presence of a carbon source and arginine; glucose at up to ca. 54 mM did not exert an inhibitory effect, and the pH was not relevant for induction. The pH of sourdoughs fermented by L. sanfranciscensis CB1 was dependent on the amount of arginine added to the dough. A low supply of arginine (6 mM) during sourdough fermentation by L. sanfranciscensis CB1

Identification of arginine and its "Downstream" molecules as potential markers of breast cancer.

PubMed

Hu, Lu; Gao, Yu; Cao, Yunfeng; Zhang, Yinxu; Xu, Minghao; Wang, Yuanyuan; Jing, Yu; Guo, Shengnan; Jing, Fangyu; Hu, Xiaodan; Zhu, Zhitu

2016-10-01

Breast cancer (BC) is the most commonly diagnosed cancer in women worldwide. Arginine is a semiessential amino acid in humans and is essential for several biological pathways in malignant and normal cells, such as ornithine and N1, N12-diacetylspermine (DiAcSpm). This study aimed to determine the role of arginine and these downstream molecules in BC. Plasma arginine, ornithine, and arginine-to-ornithine ratio (AOR) were analysed by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Urine samples were measured by the colloid gold aggregation to test determination of urinary diAcSpm. A principal component analysis was performed to evaluate the results observed between breast tumor and control characteristics. Differences in individual metabolite concentrations between BC patients and controls were tested by receiver operating characteristics (ROC) analyses. Student's t tests were used to detect the differences between two groups of normally distributed variables, and Wilcoxon sign rank tests were performed for asymmetrically distributed variables. As we analyzed, BC patients had lower plasma arginine and arginine/ornithine level, and higher plasma ornithine and urinary DiAcSpm concentrations as compared with control patients (P = 0.028, 0.020, 0.002, and 0.011, respectively). And the ROC curve was drawn and the area under the curve of the metabolites was calculated to be 0.659 (P = 0.028), 0.645 (P = 0.045), 0.7233 (P = 0.002), 0.683 (P = 0.011), respectively. In addition, our analysis showed that arginine concentrations and AOR had a positive correlation with ER status, while ornithine had a negative correlation with T stage (P = 0.042, 0.023, respectively).In conclusion, arginine and these downstream molecules were biomarkers for BC. More studies are needed to highlight the theoretical strengths. © 2016 IUBMB Life, 68(10):817-822, 2016. © 2016 International Union of Biochemistry and Molecular Biology.

Potential protective effect of arginine against 4-nitrophenol-induced ovarian damage in rats.

PubMed

Xu, Wei-Feng; Li, Yan-Sen; Dai, Peng-Yuan; Li, Chun-Mei

2016-01-01

4-nitrophenol (PNP) is generally regarded as a diesel exhaust particle (DEP). Arginine plays an important role as a new feed additive, possessing highly efficient antioxidant activities. Here we investigated the effects of dietary supplementation with arginine against ovarian damage induced by PNP in rats. A total of thirty-two female rats postnatal day 28 (PND 28) were randomly divided into four groups. Two groups were fed with basal diet or 13 g/kg arginine in diet for 4 weeks, respectively; the other two groups were given PNP (100 mg/kg b.w.) daily by subcutaneous injection for 2 weeks following pretreatment with either basal diet or arginine diet for 2 weeks. The values of body weight gain (BWG), average daily gain (ADG) and percentage weight gain (PWG) upon PNP treatment were significantly reduced than those in other groups. The relative liver weight in the PNP group was significantly decreased compared with the control group. Treatment with PNP significant reduced the number of corpora lutea, although serum 17β-estradiol (E2) and progesterone (P4) concentrations were unchanged. The morphology of the ovaries in PNP-treated rats displayed necrosis, follicular deformation and granulosa cells irregular arrangement. Moreover, exposure to PNP enhanced production of malondialdehyde (MDA) and hydrogen peroxide (H2O2), and decreased the activities of total superoxide dismutase (T-SOD) and catalase (CAT), and the co-administration of arginine can attenuate the oxidative stress caused by PNP. These results suggest that arginine may have a protective effect against ovarian damage induced by PNP owing to its antioxidant capacity effect.

Deciphering the Arginine-Binding Preferences at the Substrate-Binding Groove of Ser/Thr Kinases by Computational Surface Mapping

PubMed Central

Ben-Shimon, Avraham; Niv, Masha Y.

2011-01-01

Protein kinases are key signaling enzymes that catalyze the transfer of γ-phosphate from an ATP molecule to a phospho-accepting residue in the substrate. Unraveling the molecular features that govern the preference of kinases for particular residues flanking the phosphoacceptor is important for understanding kinase specificities toward their substrates and for designing substrate-like peptidic inhibitors. We applied ANCHORSmap, a new fragment-based computational approach for mapping amino acid side chains on protein surfaces, to predict and characterize the preference of kinases toward Arginine binding. We focus on positions P−2 and P−5, commonly occupied by Arginine (Arg) in substrates of basophilic Ser/Thr kinases. The method accurately identified all the P−2/P−5 Arg binding sites previously determined by X-ray crystallography and produced Arg preferences that corresponded to those experimentally found by peptide arrays. The predicted Arg-binding positions and their associated pockets were analyzed in terms of shape, physicochemical properties, amino acid composition, and in-silico mutagenesis, providing structural rationalization for previously unexplained trends in kinase preferences toward Arg moieties. This methodology sheds light on several kinases that were described in the literature as having non-trivial preferences for Arg, and provides some surprising departures from the prevailing views regarding residues that determine kinase specificity toward Arg. In particular, we found that the preference for a P−5 Arg is not necessarily governed by the 170/230 acidic pair, as was previously assumed, but by several different pairs of acidic residues, selected from positions 133, 169, and 230 (PKA numbering). The acidic residue at position 230 serves as a pivotal element in recognizing Arg from both the P−2 and P−5 positions. PMID:22125489

L-arginine-induced vasodilation in healthy humans: pharmacokinetic–pharmacodynamic relationship

PubMed Central

Bode-Böger, Stefanie M; Böger, Rainer H; Galland, Andrea; Tsikas, Dimitrios; Frölich, Jürgen C

1998-01-01

Aims Administration of l-arginine by intravenous infusion or via oral absorption has been shown to induce peripheral vasodilation in humans, and to improve endothelium-dependent vasodilation. We investigated the pharmacokinetics and pharmacokinetic-pharmacodynamic relationship of l-arginine after a single intravenous infusion of 30 g or 6 g, or after a single oral application of 6 g, as compared with the respective placebo, in eight healthy male human subjects. Methods l-arginine levels were determined by h.p.l.c. The vasodilator effects of l-arginine were assessed non-invasively by blood pressure monitoring and impedance cardiography. Urinary nitrate and cyclic GMP excretion rates were measured as non-invasive indicators of endogenous NO production. Results Plasma l-arginine levels increased to (mean±s.e.mean) 6223±407 (range, 5100–7680) and 822±59 (527–955) μmol l−1 after intravenous infusion of 30 g and 6 g l-arginine, respectively, and to 310±152 (118–1219) μmol l−1 after oral ingestion of 6 g l-arginine. Oral bioavailability of l-arginine was 68±9 (51–87)%. Clearance was 544±24 (440–620), 894±164 (470–1190), and 1018±230 (710–2130) ml min−1, and elimination half-life was calculated as 41.6±2.3 (34–55), 59.6±9.1 (24–98), and 79.5±9.3 (50–121) min, respectively, for 30 g i.v., 6 g i.v., and 6 g p.o. of l-arginine. Blood pressure and total peripheral resistance were significantly decreased after intravenous infusion of 30 g l-arginine by 4.4±1.4% and 10.4±3.6%, respectively, but were not significantly changed after oral or intravenous administration of 6 g l-arginine. l-arginine (30 g) also significantly increased urinary nitrate and cyclic GMP excretion rates by 97±28 and 66±20%, respectively. After infusion of 6 g l-arginine, urinary nitrate excretion also significantly increased, (nitrate by 47±12% [P < 0.05], cyclic GMP by 67±47% [P = ns]), although to a lesser and more variable extent than after 30 g of l-arginine

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

PubMed

Ganetzky, Rebecca D; Falk, Marni J

2018-03-01

positive clinical response to IV arginine occurred in 47% of stroke-like episodes; an additional 6% of episodes showed clinical benefit from multiple simultaneous treatments that included arginine, confounding sole interpretation of arginine effect. All IV arginine-responsive stroke-like episodes (n = 8) received treatment immediately on presentation (p = .003). Interestingly, the presence of unilateral symptoms strongly predicted arginine response (p = .02, Chi-Square); however, almost all of these cases immediately received IV arginine, confounding interpretation of causality direction. Suggestive trends toward increased IV arginine response were seen in subjects with mtDNA relative to nDNA mutations and in older pediatric subjects, although statistical significance was not reached possibly due to small sample size. No adverse events, including hypotensive episodes, from IV arginine therapy were reported. Single-center retrospective analysis suggests that IV arginine therapy yields significant therapeutic benefit with little risk in pediatric mitochondrial disease stroke subjects across a wide range of genetic etiologies beyond classical MELAS. Acute hemiplegic stroke, in particular, was highly responsive to IV arginine treatment. Prospective studies with consistent arginine dosing, and pre- and post-neuroimaging, will further inform the clinical utility of IV arginine therapy for acute metabolic stroke in pediatric mitochondrial disease. Copyright © 2018 Elsevier Inc. All rights reserved.

Tracking the behavior of Maillard browning in lysine/arginine-sugar model systems under high hydrostatic pressure.

PubMed

Ma, Xiao-Juan; Gao, Jin-Yan; Tong, Ping; Li, Xin; Chen, Hong-Bing

2017-12-01

High-pressure processing is gaining popularity in the food industry. However, its effect on the Maillard reaction during high-pressure-assisted pasteurization and sterilization is not well documented. This study aimed to investigate the effects of high hydrostatic pressure on the Maillard reaction during these processes using amino acid (lysine or arginine)-sugar (glucose or fructose) solution models. High pressure retarded the intermediate and final stages of the Maillard reaction in the lysine-sugar model. For the lysine-glucose model, the degradation rate of Amadori compounds was decelerated, while acceleration was observed in the arginine-sugar model. Increased temperature not only accelerated the Maillard reaction over time but also formed fluorescent compounds with different emission wavelengths. Lysine reacted with the sugars more readily than arginine under the same conditions. In addition, it was easier for lysine to react with glucose, whereas arginine reacted more readily with fructose under high pressure. High pressure exerts different effects on lysine-sugar and arginine-sugar models. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

The effect of selective D- or N(alpha)-methyl arginine substitution on the activity of the proline-rich antimicrobial peptide, Chex1-Arg20.

NASA Astrophysics Data System (ADS)

Li, Wenyi; Sun, Zhe; O'Brien-Simpson, Neil M.; Otvos, Laszlo; Reynolds, Eric C.; Hossain, Mohammed A.; Separovic, Frances; Wade, John D.

2017-01-01

In vivo pharmacokinetics studies have shown that the proline-rich antimicrobial peptide, A3-APO, which is a discontinuous dimer of the peptide, Chex1-Arg20, undergoes degradation to small fragments at positions Pro6-Arg7 and Val19-Arg20. With the aim of minimizing or abolishing this degradation, a series of Chex1-Arg20 analogues were prepared via Fmoc/tBu solid phase peptide synthesis with D-arginine or, in some cases, peptide backbone N-methylated arginine, substitution at these sites. All the peptides were tested for antibacterial activity against the Gram-negative bacterium Klebsiella pneumoniae. The resulting activity of position-7 substitution of Chex1-Arg20 analogues showed that arginine-7 is a crucial residue for maintaining activity against K. pneumoniae. However, arginine-20 substitution had a much less deleterious effect on the antibacterial activity of the peptide. Moreover, none of these peptides displayed any cytotoxicity to HEK and H-4-II-E mammalian cells. These results will aid the development of more effective and stable PrAMPs via judicious amino acid substitutions.

An Experimental Investigation into Additive Manufacturing-Induced Residual Stresses in 316L Stainless Steel

NASA Astrophysics Data System (ADS)

Wu, Amanda S.; Brown, Donald W.; Kumar, Mukul; Gallegos, Gilbert F.; King, Wayne E.

2014-12-01

Additive manufacturing (AM) technology provides unique opportunities for producing net-shape geometries at the macroscale through microscale processing. This level of control presents inherent trade-offs necessitating the establishment of quality controls aimed at minimizing undesirable properties, such as porosity and residual stresses. Here, we perform a parametric study into the effects of laser scanning pattern, power, speed, and build direction in powder bed fusion AM on residual stress. In an effort to better understand the factors influencing macroscale residual stresses, a destructive surface residual stress measurement technique (digital image correlation in conjunction with build plate removal and sectioning) has been coupled with a nondestructive volumetric evaluation method ( i.e., neutron diffraction). Good agreement between the two measurement techniques is observed. Furthermore, a reduction in residual stress is obtained by decreasing scan island size, increasing island to wall rotation to 45 deg, and increasing applied energy per unit length (laser power/speed). Neutron diffraction measurements reveal that, while in-plane residual stresses are affected by scan island rotation, axial residual stresses are unchanged. We attribute this in-plane behavior to misalignment between the greatest thermal stresses (scan direction) and largest part dimension.

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.

PubMed

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.

Contributions of arginines-43 and -94 of human choriogonadotropin. beta. to receptor binding and activation as determined by oligonucleotide-based mutagenesis

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

Fang Chen; Puett, D.

1991-10-22

Members of the glycoprotein hormone family contain a common {alpha} subunit and a hormone-specific {beta} subunit. Human choriogonadotropin (hCG) {beta} is a 145 amino acid residue protein glycosylated at 6 positions (2 N-linked and 4 O-linked oligosaccharides). In an effort to elucidate receptor determinants on hCG{beta}, the authors have used site-directed mutagenesis to prepare and express several mutant cDNAs with replacements at arginines-43 and -94. Arg-43 is invariant in all known mammalian CG/lutropin {beta} amino acid sequences, and Arg-94 is conserved in 10 of the 12 sequences. Moreover, various studies involving synthetic peptides and enzymatic digestions of intact {beta} chainsmore » suggest that these residues may be important in hCG receptor binding. Point mutants were made in which these two arginines were replaced with the corresponding residues in human follitropin {beta}, Leu-43 and Asp-94. The wild-type and mutant {beta} chains were expressed in CHO cells containing a stably integrated gene for bovine {alpha}, and heterodimer formation occurred. These heterologous gonadotropins were active in assays using transformed Leydig cells, competitive binding with standard {sup 125}I-hCG, and cAMP and progesterone production, but the potency was considerably less than that associated with the hCG{beta} wild-type-containing gonadotropin. The double-mutant protein Arg-43 to Leu/Arg-94 to Asp also associated with bovine {alpha}, but the resultant heterodimer exhibited only low activity. Replacement but the Lys-43-containing {beta} chain appeared to exhibit a low degree of subunit association or reduced stability relative to the expressed hCG{beta} wild type. These results demonstrate that arginines-43 and -94 contribute to receptor binding through a positive charge.« less

Mechanistic Basis for Type 2 Long QT Syndrome Caused by KCNH2 Mutations that Disrupt Conserved Arginine Residue in the Voltage Sensor

PubMed Central

McBride, Christie M.; Smith, Ashley M.; Smith, Jennifer L.; Reloj, Allison R.; Velasco, Ellyn J.; Powell, Jonathan; Elayi, Claude S.; Bartos, Daniel C.; Burgess, Don E.

2013-01-01

KCNH2 encodes the Kv11.1 channel, which conducts the rapidly activating delayed rectifier K+ current (IKr) in the heart. KCNH2 mutations cause type 2 long QT syndrome (LQT2), which increases the risk for life-threatening ventricular arrhythmias. LQT2 mutations are predicted to prolong the cardiac action potential (AP) by reducing IKr during repolarization. Kv11.1 contains several conserved basic amino acids in the fourth transmembrane segment (S4) of the voltage sensor that are important for normal channel trafficking and gating. This study sought to determine the mechanism(s) by which LQT2 mutations at conserved arginine residues in S4 (R531Q, R531W or R534L) alter Kv11.1 function. Western blot analyses of HEK293 cells transiently expressing R531Q, R531W or R534L suggested that only R534L inhibited Kv11.1 trafficking. Voltage-clamping experiments showed that R531Q or R531W dramatically altered Kv11.1 current (IKv11.1) activation, inactivation, recovery from inactivation and deactivation. Coexpression of wild type (to mimic the patients’ genotypes) mostly corrected the changes in IKv11.1 activation and inactivation, but deactivation kinetics were still faster. Computational simulations using a human ventricular AP model showed that accelerating deactivation rates was sufficient to prolong the AP, but these effects were minimal compared to simply reducing IKr. These are the first data to demonstrate that coexpressing wild type can correct activation and inactivation dysfunction caused by mutations at a critical voltage-sensing residue in Kv11.1. We conclude that some Kv11.1 mutations might accelerate deactivation to cause LQT2 but that the ventricular AP duration is much more sensitive to mutations that decrease IKr. This likely explains why most LQT2 mutations are nonsense or trafficking-deficient. PMID:23546015

Hybrid Residual Flexibility/Mass-Additive Method for Structural Dynamic Testing

NASA Technical Reports Server (NTRS)

Tinker, M. L.

2003-01-01

A large fixture was designed and constructed for modal vibration testing of International Space Station elements. This fixed-base test fixture, which weighs thousands of pounds and is anchored to a massive concrete floor, initially utilized spherical bearings and pendulum mechanisms to simulate Shuttle orbiter boundary constraints for launch of the hardware. Many difficulties were encountered during a checkout test of the common module prototype structure, mainly due to undesirable friction and excessive clearances in the test-article-to-fixture interface bearings. Measured mode shapes and frequencies were not representative of orbiter-constrained modes due to the friction and clearance effects in the bearings. As a result, a major redesign effort for the interface mechanisms was undertaken. The total cost of the fixture design, construction and checkout, and redesign was over $2 million. Because of the problems experienced with fixed-base testing, alternative free-suspension methods were studied, including the residual flexibility and mass-additive approaches. Free-suspension structural dynamics test methods utilize soft elastic bungee cords and overhead frame suspension systems that are less complex and much less expensive than fixed-base systems. The cost of free-suspension fixturing is on the order of tens of thousands of dollars as opposed to millions, for large fixed-base fixturing. In addition, free-suspension test configurations are portable, allowing modal tests to be done at sites without modal test facilities. For example, a mass-additive modal test of the ASTRO-1 Shuttle payload was done at the Kennedy Space Center launch site. In this Technical Memorandum, the mass-additive and residual flexibility test methods are described in detail. A discussion of a hybrid approach that combines the best characteristics of each method follows and is the focus of the study.

The effect of arginine on oral biofilm communities.

PubMed

Nascimento, M M; Browngardt, C; Xiaohui, X; Klepac-Ceraj, V; Paster, B J; Burne, R A

2014-02-01

Alkali production by oral bacteria via the arginine deiminase system (ADS) increases the pH of oral biofilms and reduces the risk for development of carious lesions. This study tested the hypothesis that increased availability of arginine in the oral environment through an exogenous source enhances the ADS activity levels in saliva and dental plaque. Saliva and supra-gingival plaque samples were collected from 19 caries-free (CF) individuals (DMFT = 0) and 19 caries-active (CA) individuals (DMFT ≥ 2) before and after treatment, which comprised the use of a fluoride-free toothpaste containing 1.5% arginine, or a regular fluoride-containing toothpaste twice daily for 4 weeks. ADS activity was measured by quantification of ammonia produced from arginine by oral samples at baseline, after washout period, 4 weeks of treatment, and 2 weeks post-treatment. Higher ADS activity levels were observed in plaque samples from CF compared to those of CA individuals (P = 0.048) at baseline. The use of the arginine toothpaste significantly increased ADS activity in plaque of CA individuals (P = 0.026). The plaque microbial profiles of CA treated with the arginine toothpaste showed a shift in bacterial composition to a healthier community, more similar to that of CF individuals. Thus, an anti-caries effect may be expected from arginine-containing formulations due in large part to the enhancement of ADS activity levels and potential favorable modification to the composition of the oral microbiome. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Variability of arginine content and yield components in Valencia peanut germplasm.

PubMed

Aninbon, Chorkaew; Jogloy, Sanun; Vorasoot, Nimitr; Nuchadomrong, Suporn; Holbrook, C Corley; Kvien, Craig; Puppala, Naveen; Patanothai, Aran

2017-06-01

Peanut seeds are rich in arginine, an amino acid that has several positive effects on human health. Establishing the genetic variability of arginine content in peanut will be useful for breeding programs that have high arginine as one of their goals. The objective of this study was to evaluate the variation of arginine content, pods/plant, seeds/pod, seed weight, and yield in Valencia peanut germplasm. One hundred and thirty peanut genotypes were grown under field condition for two years. A randomized complete block design with three replications was used for this study. Arginine content was analyzed in peanut seeds at harvest using spectrophotometry. Yield and yield components were recorded for each genotype. Significant differences in arginine content and yield components were found in the tested Valencia peanut germplasm. Arginine content ranged from 8.68-23.35 μg/g seed. Kremena was the best overall genotype of high arginine content, number of pods/plant, 100 seed weight and pod yield.

A few positively charged residues slow movement of a polypeptide chain across the endoplasmic reticulum membrane.

PubMed

Yamagishi, Marifu; Onishi, Yukiko; Yoshimura, Shotaro; Fujita, Hidenobu; Imai, Kenta; Kida, Yuichiro; Sakaguchi, Masao

2014-08-26

Many polypeptide chains are translocated across and integrated into the endoplasmic reticulum membrane through protein-conducting channels. During the process, amino acid sequences of translocating polypeptide chains are scanned by the channels and classified to be retained in the membrane or translocated into the lumen. We established an experimental system with which the kinetic effect of each amino acid residue on the polypeptide chain movement can be analyzed with a time resolution of tens of seconds. Positive charges greatly slow movement; only two lysine residues caused a remarkable slow down, and their effects were additive. The lysine residue was more effective than arginine. In contrast, clusters comprising three residues of each of the other 18 amino acids had little effect on chain movement. We also demonstrated that a four lysine cluster can exert the effect after being fully exposed from the ribosome. We concluded that as few as two to three residues of positively charged amino acids can slow the movement of the nascent polypeptide chain across the endoplasmic reticulum membrane. This effect provides a fundamental basis of the topogenic function of positively charged amino acids.

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

PubMed

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.

Inhibition of Protein Aggregation: Supramolecular Assemblies of Arginine Hold the Key

PubMed Central

Das, Utpal; Hariprasad, Gururao; Ethayathulla, Abdul S.; Manral, Pallavi; Das, Taposh K.; Pasha, Santosh; Mann, Anita; Ganguli, Munia; Verma, Amit K.; Bhat, Rajiv; Chandrayan, Sanjeev Kumar; Ahmed, Shubbir; Sharma, Sujata; Kaur, Punit; Singh, Tej P.; Srinivasan, Alagiri

2007-01-01

Background Aggregation of unfolded proteins occurs mainly through the exposed hydrophobic surfaces. Any mechanism of inhibition of this aggregation should explain the prevention of these hydrophobic interactions. Though arginine is prevalently used as an aggregation suppressor, its mechanism of action is not clearly understood. We propose a mechanism based on the hydrophobic interactions of arginine. Methodology We have analyzed arginine solution for its hydrotropic effect by pyrene solubility and the presence of hydrophobic environment by 1-anilino-8-naphthalene sulfonic acid fluorescence. Mass spectroscopic analyses show that arginine forms molecular clusters in the gas phase and the cluster composition is dependent on the solution conditions. Light scattering studies indicate that arginine exists as clusters in solution. In the presence of arginine, the reverse phase chromatographic elution profile of Alzheimer's amyloid beta 1-42 (Aβ1-42) peptide is modified. Changes in the hydrodynamic volume of Aβ1-42 in the presence of arginine measured by size exclusion chromatography show that arginine binds to Aβ1-42. Arginine increases the solubility of Aβ1-42 peptide in aqueous medium. It decreases the aggregation of Aβ1-42 as observed by atomic force microscopy. Conclusions Based on our experimental results we propose that molecular clusters of arginine in aqueous solutions display a hydrophobic surface by the alignment of its three methylene groups. The hydrophobic surfaces present on the proteins interact with the hydrophobic surface presented by the arginine clusters. The masking of hydrophobic surface inhibits protein-protein aggregation. This mechanism is also responsible for the hydrotropic effect of arginine on various compounds. It is also explained why other amino acids fail to inhibit the protein aggregation. PMID:18000547

Assignments of /sup 1/H nuclear magnetic resonances of the cystyl, asparaginyl, and aromatic residues of arginine vasopressin in D/sub 2/O. A comparison with lysine vasopressin and oxytocin in terms of solution conformation

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

Wyssbrod, H.R.; Fischman, A.J.; Live, D.H.

1979-07-18

The resonances of the C/sup ..cap alpha../ and C/sup ..beta../ protons of the cystyl, asparaginyl, and aromatic residues of (8-arginine)vasopressin (AVP) in D/sub 2/O at pD 3.8 and 20/sup 0/C were assigned in a rigorous manner by the use of isotopic isomers of AVP that contain specific replacements of protons by deuterons and by comparison of /sup 1/H NMR characteristics of AVP to those of (8-lysine)vasopressin (LVP) and oxytocin (OT). Although there is extensive overlap of resonances of C/sup ..beta../ protons even at 360 MHz, all of the chemical shifts of these protons and most of the couplings between themmore » and their vicinal C/sup ..cap alpha../ protons could be determined, at least to a first approximation. It was concluded that the cyclic moieties (residues 1-6) of AVP, LVP, and OT possess essentially the same overall backbone conformation, and that the side-chain conformation - or rotamer populations - about the C/sup ..cap alpha../-C/sup ..beta../ bonds of the cystyl residue (positions 1 and 6), the tyrosyl residue (position 2), and the asparaginyl residue (position 5) are similar. This study indicates that selective replacements of C/sup ..beta../ protons by deuterons are necessary to improve the accuracy of coupling constants extracted from 360-MHz spectra of a AVP for use in conformational analysis.« less

Arginine dependence of tumor cells: targeting a chink in cancer’s armor

PubMed Central

Patil, MD; Bhaumik, J; Babykutty, S; Banerjee, UC; Fukumura, D

2017-01-01

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. PMID:27109103

Inhibition of adipogenic differentiation by myostatin is alleviated by arginine supplementation in porcine-muscle-derived mesenchymal stem cells.

PubMed

Lei, Hulong; Yu, Bing; Yang, Xuerong; Liu, Zehui; Huang, Zhiqing; Mao, Xiangbing; Tian, Gang; He, Jun; Han, Guoquan; Chen, Hong; Mao, Qian; Chen, Daiwen

2011-10-01

Porcine mesenchymal stem cells in postnatal muscle have been demonstrated to differentiate into adipocytes. This increases adipocyte number and lipid accumulation, and is thought to be the origin of intramuscular fat. In this study, the effects of myostatin and arginine on adipogenic differentiation in mesenchymal stem cells derived from porcine muscle (pMDSCs) were investigated in vitro. Intracellular triglyceride levels were reduced by exogenous myostatin and increased by arginine supplementation or myostatin antibody (P<0.01). The inhibition of lipid accumulation by myostatin in pMDSCs was alleviated by arginine supplementation (P<0.01). Expression patterns of adipogenic transcription factors showed that exogenous myostatin suppressed PPARγ2 and aP2 expression (P<0.01), while supplemental arginine or myostatin antibody promoted ADD1 expression (P<0.01). Furthermore, compared with the addition of either myostatin protein or antibody alone, ADD1 and PPARδ expression were promoted by the combination of arginine and myostatin (P<0.01), and arginine combined with myostatin antibody promoted the expression of ADD1, PPARδ, C/EBPα, PPARγ2 and LPL in pMDSCs (P<0.05). These results suggest that myostatin inhibits adipogenesis in pMDSCs, and that this can be alleviated by arginine supplementation, at least in part, through promoting ADD1 and PPARδ expression.

Glutamine and arginine improve permeability and tight junction protein expression in methotrexate-treated Caco-2 cells.

PubMed

Beutheu, Stéphanie; Ghouzali, Ibtissem; Galas, Ludovic; Déchelotte, Pierre; Coëffier, Moïse

2013-10-01

Chemotherapy induces an increase of intestinal permeability that is partially related to an alteration of tight junction proteins, occludin and zonula occludens-1 (ZO-1). Protective effects of glutamine on intestinal barrier function have been previously shown but the effects of other amino acids remained poorly documented. Thus, we aimed to evaluate the effects of nine amino acids on intestinal permeability during methotrexate (MTX) treatment in Caco-2 cells. Caco-2 cells were incubated in culture medium supplemented with glutamine, arginine, glutamate, leucine, taurine, citrulline, glycine, histidine or cysteine during 24 h and then treated with MTX (100 ng/ml). The dose of each amino acid was 16.6 fold the physiological plasma concentrations. Barrier function was assessed by transepithelial electrical resistance (TEER), FITC-dextran paracellular flux, occludin and ZO-1 expression and localization. Signaling pathways were also studied. Only glutamine, glutamate, arginine and leucine reversed the decrease of TEER observed after MTX treatment (P < 0.05). Interestingly, the addition of 6-diazo-5-oxo-1-norleucine, an inhibitor of glutaminase, blunted the effect of glutamine on MTX-treated cells (P < 0.05). Glutamine and arginine combination restored TEER and FITC-dextran flux to a similar extent than glutamine alone. In addition, pretreatment of Caco-2 cells with glutamine and arginine, alone or combined, differently limited the decrease of ZO-1 and occludin expression (P < 0.05) and the alteration of their cellular distribution, through c-Jun N-terminal kinase (JNK), Extracellular signal-regulated kinase (ERK) and nuclear factor kappa B (NF-κB) pathways. Glutamine prevented MTX-induced barrier disruption in Caco-2 cells. Arginine also had protective effects but in a lesser extent. The effect of glutamine and arginine should be evaluated in vivo. Copyright © 2013 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. All rights reserved.

Plasma l-citrulline concentrations in l-arginine-supplemented healthy dogs.

PubMed

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.

Protein Arginine Methyltransferase Product Specificity Is Mediated by Distinct Active-site Architectures*

PubMed Central

Jain, Kanishk; Warmack, Rebeccah A.; Stavropoulos, Peter

2016-01-01

In the family of protein arginine methyltransferases (PRMTs) that predominantly generate either asymmetric or symmetric dimethylarginine (SDMA), PRMT7 is unique in producing solely monomethylarginine (MMA) products. The type of methylation on histones and other proteins dictates changes in gene expression, and numerous studies have linked altered profiles of methyl marks with disease phenotypes. Given the importance of specific inhibitor development, it is crucial to understand the mechanisms by which PRMT product specificity is conferred. We have focused our attention on active-site residues of PRMT7 from the protozoan Trypanosoma brucei. We have designed 26 single and double mutations in the active site, including residues in the Glu-Xaa8-Glu (double E) loop and the Met-Gln-Trp sequence of the canonical Thr-His-Trp (THW) loop known to interact with the methyl-accepting substrate arginine. Analysis of the reaction products by high resolution cation exchange chromatography combined with the knowledge of PRMT crystal structures suggests a model where the size of two distinct subregions in the active site determines PRMT7 product specificity. A dual mutation of Glu-181 to Asp in the double E loop and Gln-329 to Ala in the canonical THW loop enables the enzyme to produce SDMA. Consistent with our model, the mutation of Cys-431 to His in the THW loop of human PRMT9 shifts its product specificity from SDMA toward MMA. Together with previous results, these findings provide a structural basis and a general model for product specificity in PRMTs, which will be useful for the rational design of specific PRMT inhibitors. PMID:27387499

Protein Arginine Methyltransferase Product Specificity Is Mediated by Distinct Active-site Architectures.

PubMed

Jain, Kanishk; Warmack, Rebeccah A; Debler, Erik W; Hadjikyriacou, Andrea; Stavropoulos, Peter; Clarke, Steven G

2016-08-26

In the family of protein arginine methyltransferases (PRMTs) that predominantly generate either asymmetric or symmetric dimethylarginine (SDMA), PRMT7 is unique in producing solely monomethylarginine (MMA) products. The type of methylation on histones and other proteins dictates changes in gene expression, and numerous studies have linked altered profiles of methyl marks with disease phenotypes. Given the importance of specific inhibitor development, it is crucial to understand the mechanisms by which PRMT product specificity is conferred. We have focused our attention on active-site residues of PRMT7 from the protozoan Trypanosoma brucei We have designed 26 single and double mutations in the active site, including residues in the Glu-Xaa8-Glu (double E) loop and the Met-Gln-Trp sequence of the canonical Thr-His-Trp (THW) loop known to interact with the methyl-accepting substrate arginine. Analysis of the reaction products by high resolution cation exchange chromatography combined with the knowledge of PRMT crystal structures suggests a model where the size of two distinct subregions in the active site determines PRMT7 product specificity. A dual mutation of Glu-181 to Asp in the double E loop and Gln-329 to Ala in the canonical THW loop enables the enzyme to produce SDMA. Consistent with our model, the mutation of Cys-431 to His in the THW loop of human PRMT9 shifts its product specificity from SDMA toward MMA. Together with previous results, these findings provide a structural basis and a general model for product specificity in PRMTs, which will be useful for the rational design of specific PRMT inhibitors. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

Changes in the oral ecosystem induced by the use of 8% arginine toothpaste.

PubMed

Koopman, Jessica E; Hoogenkamp, Michel A; Buijs, Mark J; Brandt, Bernd W; Keijser, Bart J F; Crielaard, Wim; Ten Cate, Jacob M; Zaura, Egija

2017-01-01

Bacterial metabolism of arginine in the oral cavity has a pH-raising and thus, potential anti-caries effect. However, the influence of arginine on the oral microbial ecosystem remains largely unresolved. In this pilot study, nine healthy individuals used toothpaste containing 8% arginine for eight weeks. Saliva was collected to determine arginolytic potential and sucrose metabolic activity at the Baseline, Week 4, Week 8 and after a two weeks Wash-out period. To follow the effects on microbial ecology, 16S rDNA sequencing on saliva and plaque samples at Baseline and Week 8 and metagenome sequencing on selected saliva samples of the same time-points was performed. During the study period, the arginolytic potential of saliva increased, while the sucrose metabolism in saliva decreased. These effects were reversed during the Wash-out period. Although a few operational taxonomic units (OTUs) in plaque changed in abundance during the study period, there was no real shift in the plaque microbiome. In the saliva microbiome there was a significant compositional shift, specifically the genus Veillonella had increased significantly in abundance at Week 8. Indeed, the presence of arginine in toothpaste affects the arginolytic capacity of saliva and reduces its sucrose metabolic activity. Additionally, it leads to a shift in the salivary microbiome composition towards a healthy ecology from a caries point of view. Therefore, arginine can be regarded as a genuine oral prebiotic. Copyright © 2016 Elsevier Ltd. All rights reserved.

Intracellular L-arginine concentration does not determine NO production in endothelial cells: Implications on the 'L-arginine paradox'

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

Shin, Soyoung; Mohan, Srinidi; Fung, Ho-Leung, E-mail: hlfung@buffalo.edu

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.more » 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

Effects of three permeases on arginine utilization in Saccharomyces cerevisiae

PubMed Central

Zhang, Peng; Du, Guocheng; Zou, Huijun; Chen, Jian; Xie, Guangfa; Shi, Zhongping; Zhou, Jingwen

2016-01-01

Arginine plays an important role in cellular function and metabolism. Arginine uptake mainly occurs through three amino acid permeases, Alp1p, Gap1p and Can1p, which act as both transporters and receptors for amino acid utilization. In this study, seven mutants were constructed with different combinations of permease deficiencies that inhibit arginine utilization. Their effects on arginine metabolism were measured. The three amino acid permeases were also individually overexpressed in wild-type (WT), Δalp1Δgap1Δcan1 and Δnpr1 strains. The growth and arginine utilization of Δcan1, Δgap1Δcan1 and Δalp1Δgap1Δcan1 mutants were suppressed in YNB medium when arginine was the sole nitrogen source. Meanwhile, overexpression of Alp1p and Can1p enhanced growth and arginine utilization in WT, Δalp1Δgap1Δcan1 and Δnpr1. Besides, overexpression of Can1p caused a 26.7% increase in OD600 and 29.3% increase in arginine utilization compared to that of Alp1p in Δalp1Δgap1Δcan1. Transcription analysis showed that the effects of three amino acid permeases on the arginine utilization and the regulation of related genes, were tightly related to their individual characteristics. However, their overall effects were different for different combinations of mutants. The results presented here suggest some possible synergistic effects of different amino acid permeases on regulation of amino acid utilization and metabolism. PMID:26865023

Loop engineering reveals the importance of active-site-decorating loops and gating residue in substrate affinity modulation of arginine deiminase (an anti-tumor enzyme).

PubMed

Cheng, Feng; Yang, Jianhua; Bocola, Marco; Schwaneberg, Ulrich; Zhu, Leilei

2018-05-05

Protein engineering of enzyme loop regions is an effective strategy to improve enzymatic properties. Previous studies that aimed to boost the activity of PpADI (an arginine deiminase from Pseudomonas plecoglossicida) under physiological conditions yielded several significantly improved variants that harbor substitutions predominantly located in active-site-decorating loops. A multi-site saturation mutagenesis at four positions in loop 1 (37, 38, 42, and 43) and three positions in loop 4 (402, 403, and 404) was performed to elucidate the importance of these loops in modulating the substrate affinity of PpADI. The identified "best" variant (M6-L1-4) showed a decreased S 0.5 ('K M ') of 0.48 mM compared with the parent M6 (0.81 mM). Subsequently, a rational design to recombine beneficial substitutions within loops 1 and 4 yielded variant L6 with a substantially decreased S 0.5 value (0.17 mM). A comprehensive simulation analysis resulted in a conclusion that high loop flexibility (especially the gating residue Arg400) is beneficial for substrate affinity due to less efficient blocking of the active site. Copyright © 2018 Elsevier Inc. All rights reserved.

The story of protein arginine methylation: characterization, regulation, and function.

PubMed

Peng, Chao; Wong, Catherine Cl

2017-02-01

Arginine methylation is an important post-translational modification (PTM) in cells, which is catalyzed by a group of protein arginine methyltransferases (PRMTs). It plays significant roles in diverse cellular processes and various diseases. Misregulation and aberrant expression of PRMTs can provide potential biomarkers and therapeutic targets for drug discovery. Areas covered: Herein, we review the arginine methylation literature and summarize the methodologies for the characterization of this modification, as well as describe the recent insights into arginine methyltransferases and their biological functions in diseases. Expert commentary: Benefits from the enzyme-based large-scale screening approach, the novel affinity enrichment strategies, arginine methylated protein family is the focus of attention. Although a number of arginine methyltransferases and related substrates are identified, the catalytic mechanism of different types of PRMTs remains unclear and few related demethylases are characterized. Novel functional studies continuously reveal the importance of this modification in the cell cycle and diseases. A deeper understanding of arginine methylated proteins, modification sites, and their mechanisms of regulation is needed to explore their role in life processes, especially their relationship with diseases, thus accelerating the generation of potent, selective, cell-penetrant drug candidates.

Role of L-arginine in the pathogenesis and treatment of renal disease.

PubMed

Cherla, Gautam; Jaimes, Edgar A

2004-10-01

L-arginine is a semi essential amino acid and also a substrate for the synthesis of nitric oxide (NO), polyamines, and agmatine. These L-arginine metabolites may participate in the pathogenesis of renal disease and constitute the rationale for manipulating L-arginine metabolism as a strategy to ameliorate kidney disease. Modification of dietary L-arginine intake in experimental models of kidney diseases has been shown to have both beneficial as well as deleterious effects depending on the specific model studied. L-arginine supplementation in animal models of glomerulonephritis has been shown to be detrimental, probably by increasing the production of NO from increased local expression of inducible NO synthase (iNOS). L-arginine supplementation does not modify the course of renal disease in humans with chronic glomerular diseases. However, beneficial effects of L-arginine supplementation have been reported in several models of chronic kidney disease including renal ablation, ureteral obstruction, nephropathy secondary to diabetes, and salt-sensitive hypertension. L-arginine is reduced in preeclampsia and recent experimental studies indicate that L-arginine supplementation may be beneficial in attenuating the symptoms of preeclampsia. Administration of exogenous L-arginine has been shown to be protective in ischemic acute renal failure. In summary, the role of L-arginine in the pathogenesis and treatment of renal disease is not completely understood and remains to be established.

Arginine side chain stacking with peptide plane stabilizes the protein helix conformation in a cooperative way.

PubMed

Wang, Jia; Chen, Jingfei; Li, Jingwen; An, Liaoyuan; Wang, Yefei; Huang, Qingshan; Yao, Lishan

2018-06-01

A combined experimental and computational study is performed for arginine side chain stacking with the protein α-helix. Theremostability measurements of Aristaless homeodomain, a helical protein, suggest that mutating the arginine residue R106, R137 or R141, which has the guanidino side chain stacking with the peptide plane, to alanine, destabilizes the protein. The R-PP stacking has an energy of ∼0.2-0.4 kcal/mol. This stacking interaction mainly comes from dispersion and electrostatics, based on MP2 calculations with the energy decomposition analysis. The calculations also suggest that the stacking stabilizes 2 backbone-backbone h-bonds (i→i-4 and i-3→i-7) in a cooperative way. Desolvation and electrostatic polarization are responsible for cooperativity with the i→i-4 and i-3→i-7 h-bonds, respectively. This cooperativity is supported by a protein α-helices h-bond survey in the pdb databank where stacking shortens the corresponding h-bond distances. © 2018 Wiley Periodicals, Inc.

The CASTOR proteins are arginine sensors for the mTORC1 pathway

PubMed Central

Chantranupong, Lynne; Scaria, Sonia M.; Saxton, Robert A.; Gygi, Melanie P.; Shen, Kuang; Wyant, Gregory A.; Wang, Tim; Harper, J. Wade; Gygi, Steven P.; Sabatini, David M.

2016-01-01

Amino acids signal to the mTOR complex I (mTORC1) growth pathway through the Rag GTPases. Multiple distinct complexes regulate the Rags, including GATOR1, a GTPase activating protein (GAP), and GATOR2, a positive regulator of unknown molecular function. Arginine stimulation of cells activates mTORC1, but how it is sensed is not well understood. Recently, SLC38A9 was identified as a putative lysosomal arginine sensor required for arginine to activate mTORC1 but how arginine deprivation represses mTORC1 is unknown. Here, we show that CASTOR1, a previously uncharacterized protein, interacts with GATOR2 and is required for arginine deprivation to inhibit mTORC1. CASTOR1 homodimerizes and can also heterodimerize with the related protein, CASTOR2. Arginine disrupts the CASTOR1-GATOR2 complex by binding to CASTOR1 with a dissociation constant of ~30 μM, and its arginine-binding capacity is required for arginine to activate mTORC1 in cells. Collectively, these results establish CASTOR1 as an arginine sensor for the mTORC1 pathway. PMID:26972053

Arginine: Its pKa value revisited

PubMed Central

Fitch, Carolyn A; Platzer, Gerald; Okon, Mark; Garcia-Moreno E, Bertrand; McIntosh, Lawrence P

2015-01-01

Using complementary approaches of potentiometry and NMR spectroscopy, we have determined that the equilibrium acid dissociation constant (pKa value) of the arginine guanidinium group is 13.8 ± 0.1. This is substantially higher than that of ∼12 often used in structure-based electrostatics calculations and cited in biochemistry textbooks. The revised intrinsic pKa value helps explains why arginine side chains in proteins are always predominantly charged, even at pH values as great as 10. The high pKa value also reinforces the observation that arginine side chains are invariably protonated under physiological conditions of near neutral pH. This occurs even when the guanidinium moiety is buried in a hydrophobic micro-environment, such as that inside a protein or a lipid membrane, thought to be incompatible with the presence of a charged group. PMID:25808204

Inhibition of nitric oxide synthase abrogates lipopolysaccharides-induced up-regulation of L-arginine uptake in rat alveolar macrophages

PubMed Central

Hammermann, Rainer; Stichnote, Christina; Closs, Ellen Ildicho; Nawrath, Hermann; Racké, Kurt

2001-01-01

It was tested whether the inducible nitric oxide synthase (iNOS) pathway might be involved in lipopolysaccharides-(LPS)-induced up-regulation of L-arginine transport in rat alveolar macrophages (AMΦ). AMΦ were cultured in absence or presence of LPS. Nitrite accumulation was determined in culture media and cells were used to study [3H]-L-arginine uptake or to isolate RNA for RT – PCR. Culture in presence of LPS (1 μg ml−1, 20 h) caused 11 fold increase of nitrite accumulation and 2.5 fold increase of [3H]-L-arginine uptake. The inducible NO synthase (iNOS) inhibitor 2-amino-5,6-dihydro-6-methyl-4H-1,3-thiazine (AMT) present alone during culture had only marginal effects on [3H]-L-arginine uptake. However, AMT present during culture additionally to LPS, suppressed LPS-induced nitrite accumulation and LPS-stimulated [3H]-L-arginine uptake in the same concentration-dependent manner. AMT present only for the last 30 min of the culture period had similar effects on [3H]-L-arginine uptake. AMT present only during the uptake period also inhibited LPS-stimulated [3H]-L-arginine uptake, but with lower potency. The inhibitory effect of AMT could not be opposed by the NO releasing compound DETA NONOate. LPS caused an up-regulation of the mRNA for the cationic amino acid transporter CAT-2B, and this effect was not affected by AMT. AMT (100 μM) did not affect L-arginine transport studied by electrophysiological techniques in Xenopus laevis oocytes expressing either the human cationic amino acid transporter hCAT-1 or hCAT-2B. In conclusion, iNOS inhibition in rat AMΦ abolished LPS-activated L-arginine uptake. This effect appears to be caused by reduced flow of L-arginine through the iNOS pathway. PMID:11375254

Indian women of childbearing age do not metabolically conserve arginine as do American and Jamaican women.

PubMed

Kao, Christina C; Hsu, Jean W; Dwarkanath, Pratibha; Karnes, Jeffrey M; Baker, Tameka M; Bohren, Kurt M; Badaloo, Asha; Thame, Minerva M; Kurpad, Anura V; Jahoor, Farook

2015-05-01

In a previous study in pregnant American women, we reported that arginine flux and nitric oxide synthesis increased in trimester 2. More recently, we reported that Indian women do not increase arginine flux during pregnancy as their American or Jamaican counterparts do. The purpose of this study was to determine whether Indian women of childbearing age are producing less arginine and/or catabolizing more arginine and therefore have less available for anabolic pathways than do Jamaican and American women. Thirty healthy women aged 28.3 ± 0.8 y from the United States, India, and Jamaica (n = 10/group) were given 6 h primed, constant intravenous infusions of guanidino-¹⁵N₂-arginine, 5,5-²H₂-citrulline, ¹⁵N₂-ornithine, and ring-²H₅-phenylalanine, in addition to primed, oral doses of U-¹³C₆-arginine in both the fasting and postprandial states. An oral dose of deuterium oxide was also given to determine fat-free mass (FFM). Compared with American women, Indian and Jamaican women had greater ornithine fluxes (μmol · kg fat FFM⁻¹ · h⁻¹) in the fasting and postprandial states (27.3 ± 2.5 vs. 39.6 ± 3.7 and 37.2 ± 2.0, respectively, P = 0.01), indicating greater arginine catabolism. However, Jamaican women had a higher endogenous arginine flux than did Indian and American women in the fasting (66.1 ± 3.1 vs. 54.2 ± 3.1 and 56.1 ± 2.1, respectively, P = 0.01) and postprandial (53.8 ± 2.2 vs. 43.7 ± 4.9 and 42.8 ± 3.1, respectively, P = 0.06) states. As a consequence, Indian women had lower arginine bioavailability (μmol · kg FFM⁻¹ · h⁻¹) in the fasting state (42.0 ± 2.6) than did American (49.9 ± 1.3, P = 0.045) and Jamaican (55.5 ± 3.5, P = 0.004) women, as well as in the postprandial state (40.7 ± 3.5 vs. 51.8 ± 1.2 and 57.5 ± 3.2, respectively, P = 0.001). Compared with American and Jamaican women, Indian women of childbearing age have a decreased arginine supply because of increased arginine catabolism without an

Arginine affects appetite via nitric oxide in ducks.

PubMed

Wang, C; Hou, S S; Huang, W; Xu, T S; Rong, G H; Xie, M

2014-08-01

The objective of the study was to investigate the mechanism by which arginine regulates feed intake in Pekin ducks. In experiment 1, one hundred forty-four 1-d-old male Pekin ducks were randomly allotted to 3 dietary treatments with 6 replicate pens of 8 birds per pen. Birds in each group were fed a corn-corn gluten meal diet containing 0.65, 0.95, and 1.45% arginine. Ducks fed the diet containing 0.65% arginine had lower feed intake and plasma nitric oxide level (P < 0.05) than the other 2 groups. In experiment 2, twenty 11-d-old ducks were allotted to 1 of 2 treatments. After 2 h fasting, birds in the 2 groups were intraperitoneally administrated saline and l-NG-nitro-arginine methyl ester HCl (L-NAME) for 3 d, respectively. Feed intake (P < 0.07) and plasma nitric oxide concentration (P < 0.05) 2 h postinjection in the L-NAME administered group were lower than those of the control group. In conclusion, the study implied that arginine modifies feeding behavior possibly through controlling endogenous synthesis of nitric oxide in Pekin ducks. © Poultry Science Association Inc.

Dietary arginine and linear growth: the Copenhagen School Child Intervention Study.

PubMed

van Vught, Anneke J A H; Dagnelie, Pieter C; Arts, Ilja C W; Froberg, Karsten; Andersen, Lars B; El-Naaman, Bianca; Bugge, Anna; Nielsen, Birgit M; Heitman, Berit L

2013-03-28

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 Child Intervention Study during 2001-2 (baseline), and at 3-year and 7-year follow-up, were used. Arginine intake was estimated via a 7 d precoded food diary at baseline and 3-year follow-up. Data were analysed in a multilevel structure in which children were embedded within schools. Random intercept 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 was significant for the third and fourth quintile of arginine intake (2.5-2.8 and 2.8-3.2 g/d, respectively) compared with the first quintile ( < 2.2 g/d) (P for trend = 0.04). Protein intake (excluding arginine) was significantly associated with growth velocity; however, the association was weaker than the association between arginine intake and growth velocity (P for trend = 0.14). The results of the present study suggest a dose-dependent physiological role of habitual protein intake, and specifically arginine intake, on linear growth in normally growing children. However, since the study was designed in healthy children, we cannot firmly conclude whether arginine supplementation represents a relevant clinical strategy. Further research is needed to investigate whether dietary arginine may represent a nutritional strategy potentially advantageous for the prevention and treatment of short stature.

Effect of Exercise Training and L-arginine on Oxidative Stress and Left Ventricular Function in the Post-ischemic Failing Rat Heart.

PubMed

Ranjbar, Kamal; Nazem, Farzad; Nazari, Afshin

2016-04-01

The aim of the present study was to evaluate the effect of exercise training (ET) and L-arginine on oxidative stress and ventricular function in rat with myocardial infarction (MI). Four weeks after the surgical procedures, 40 Wistar male rats were randomized to the following groups: MI-sedentary (Sed); MI-exercise (Ex); MI-sedentary + L-arginine (Sed + LA); and MI-exercise + L-arginine (Ex + LA); the rats were subjected to aerobic training in the form of treadmill running. Rats in the L-arginine-treated groups drank water containing 4 % L-arginine. Before and after the training program, all subjects underwent resting echocardiography. Catalase (CAT) glutathione peroxidase (GPx), malondialdehyde (MDA) and myeloperoxidase (MPO) were measured. Cardiac output, stroke volume and fractional shortening in Ex and Ex + LA groups significantly increased in comparison with the Sed group. Cardiac systolic function indices in Ex + LA group were significantly greater than Ex group. Also, GPx activity and MDA, respectively, increased and decreased in response to ET, but no change was observed in MPO and CAT. These results suggest that ET increased LV function by decreasing oxidative stress and increasing antioxidant defense system in rats with MI. In addition in response to training, L-arginine appears to have additive effect on cardiac function, but have no effect on oxidative stress indices.

Mature coconut water exhibits antidiabetic and antithrombotic potential via L-arginine-nitric oxide pathway in alloxan induced diabetic rats.

PubMed

Preetha, Prabhakaran Prabha; Devi, Vishalakshiamma Girija; Rajamohan, Thankappan

2015-11-01

The aims of the present study were to assess whether the antidiabetic activity of mature coconut water (MCW) is mediated through L-arginine-nitric oxide pathway in diabetic rats, and to study the effects of MCW on blood coagulation. Diabetes was induced in male Sprague-Dawley rats by injecting them with alloxan (150 mg/kg body weight). MCW (4 mL/100 g body weight) and L-arginine (7.5 mg/100 g body weight) was given orally for 45 days. L-NAME was given at a dose of 0.5 mg/kg body weight. Concentrations of blood glucose, plasma insulin, glycosylated hemoglobin (HbA1c), L-arginine, urine volume and urinary creatinine levels, activity of nitric oxide synthase (NOS), and arginase as well as the abnormalities in hemostasis and thrombosis were measured in all the experimental groups. Treatment with MCW and L-arginine reduced the concentration of blood glucose and HbA1c in diabetic rats. MCW and L-arginine treatment exhibited significant antithrombotic activity in diabetic rats, which was evident from the reduced levels of WBC, platelets, fibrin, and fibrinogen. MCW and L-arginine treatment prolonged the prothrombin time in diabetic rats and reduced the activity of Factor V. In addition to this, the activity of nitric oxide synthase, liver and plasma arginine content, and urinary nitrite were higher in MCW-treated diabetic rats whereas L-NAME treatment inhibited the beneficial effects induced by MCW and arginine. The results clearly indicate that L-arginine is a major factor responsible for the antidiabetic and antithrombotic potential of coconut water, and is mediated through the L-arginine-nitric oxide pathway.

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

PubMed

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

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. 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. 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 157 μg+L-NAME; BPC 157 μg+L-arginine, BPC 157 μg+L-NAME+L-arginine), exhibited decreased haemorrhage and markedly counteracted thrombocytopenia. 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.

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

PubMed

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

2016-10-01

l-Arginine, a ubiquitous amino acid in human saliva, serves as a substrate for alkali production by arginolytic bacteria. Recently, exogenous l-arginine has been shown to enhance the alkalinogenic potential of oral biofilm and destabilize its microbial community, which might help control dental caries. However, l-arginine exposure may inflict additional changes in the biofilm milieu when bacteria are growing under cariogenic conditions. Here, we investigated how exogenous l-arginine modulates biofilm development using a mixed-species model containing both cariogenic (Streptococcus mutans) and arginolytic (Streptococcus gordonii) bacteria in the presence of sucrose. We observed that 1.5% (wt/vol) l-arginine (also a clinically effective concentration) exposure suppressed the outgrowth of S. mutans, favored S. gordonii dominance, and maintained Actinomyces naeslundii growth within biofilms (versus vehicle control). In parallel, topical l-arginine treatments substantially reduced the amounts of insoluble exopolysaccharides (EPS) by >3-fold, which significantly altered the three-dimensional (3D) architecture of the biofilm. Intriguingly, l-arginine repressed S. mutans genes associated with insoluble EPS (gtfB) and bacteriocin (SMU.150) production, while spxB expression (H2O2 production) by S. gordonii increased sharply during biofilm development, which resulted in higher H2O2 levels in arginine-treated biofilms. These modifications resulted in a markedly defective EPS matrix and areas devoid of any bacterial clusters (microcolonies) on the apatitic surface, while the in situ pH values at the biofilm-apatite interface were nearly one unit higher in arginine-treated biofilms (versus the vehicle control). Our data reveal new biological properties of l-arginine that impact biofilm matrix assembly and the dynamic microbial interactions associated with pathogenic biofilm development, indicating the multiaction potency of this promising biofilm disruptor. Dental caries is one

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

PubMed Central

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

2016-01-01

ABSTRACT l-Arginine, a ubiquitous amino acid in human saliva, serves as a substrate for alkali production by arginolytic bacteria. Recently, exogenous l-arginine has been shown to enhance the alkalinogenic potential of oral biofilm and destabilize its microbial community, which might help control dental caries. However, l-arginine exposure may inflict additional changes in the biofilm milieu when bacteria are growing under cariogenic conditions. Here, we investigated how exogenous l-arginine modulates biofilm development using a mixed-species model containing both cariogenic (Streptococcus mutans) and arginolytic (Streptococcus gordonii) bacteria in the presence of sucrose. We observed that 1.5% (wt/vol) l-arginine (also a clinically effective concentration) exposure suppressed the outgrowth of S. mutans, favored S. gordonii dominance, and maintained Actinomyces naeslundii growth within biofilms (versus vehicle control). In parallel, topical l-arginine treatments substantially reduced the amounts of insoluble exopolysaccharides (EPS) by >3-fold, which significantly altered the three-dimensional (3D) architecture of the biofilm. Intriguingly, l-arginine repressed S. mutans genes associated with insoluble EPS (gtfB) and bacteriocin (SMU.150) production, while spxB expression (H2O2 production) by S. gordonii increased sharply during biofilm development, which resulted in higher H2O2 levels in arginine-treated biofilms. These modifications resulted in a markedly defective EPS matrix and areas devoid of any bacterial clusters (microcolonies) on the apatitic surface, while the in situ pH values at the biofilm-apatite interface were nearly one unit higher in arginine-treated biofilms (versus the vehicle control). Our data reveal new biological properties of l-arginine that impact biofilm matrix assembly and the dynamic microbial interactions associated with pathogenic biofilm development, indicating the multiaction potency of this promising biofilm disruptor. IMPORTANCE

Arginine depletion increases susceptibility to serious infections in preterm newborns

PubMed Central

Badurdeen, Shiraz; Mulongo, Musa; Berkley, James A.

2015-01-01

Preterm newborns are highly susceptible to bacterial infections. This susceptibility is regarded as being due to immaturity of multiple pathways of the immune system. However, it is unclear whether a mechanism that unifies these different, suppressed pathways exists. Here, we argue that the immune vulnerability of the preterm neonate is critically related to arginine depletion. Arginine, a “conditionally essential” amino acid, is depleted in acute catabolic states, including sepsis. Its metabolism is highly compartmentalized and regulated, including by arginase-mediated hydrolysis. Recent data suggest that arginase II-mediated arginine depletion is essential for the innate immune suppression that occurs in newborn models of bacterial challenge, impairing pathways critical for the immune response. Evidence that arginine depletion mediates protection from immune activation during first gut colonization suggests a regulatory role in controlling gut-derived pathogens. Clinical studies show that plasma arginine is depleted during sepsis. In keeping with animal studies, small clinical trials of L-arginine supplementation have shown benefit in reducing necrotizing enterocolitis in premature neonates. We propose a novel, broader hypothesis that arginine depletion during bacterial challenge is a key factor limiting the neonate's ability to mount an adequate immune response, contributing to the increased susceptibility to infections, particularly with respect to gut-derived sepsis. PMID:25360828

Impaired nitric oxide production in children with MELAS syndrome and the effect of arginine and citrulline supplementation.

PubMed

El-Hattab, Ayman W; Emrick, Lisa T; Hsu, Jean W; Chanprasert, Sirisak; Almannai, Mohammed; Craigen, William J; Jahoor, Farook; Scaglia, Fernando

2016-04-01

Mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes (MELAS) syndrome is one of the most frequent maternally inherited mitochondrial disorders. The pathogenesis of this syndrome is not fully understood and believed to result from several interacting mechanisms including impaired mitochondrial energy production, microvasculature angiopathy, and nitric oxide (NO) deficiency. NO deficiency in MELAS syndrome is likely to be multifactorial in origin with the decreased availability of the NO precursors, arginine and citrulline, playing a major role. In this study we used stable isotope infusion techniques to assess NO production in children with MELAS syndrome and healthy pediatric controls. We also assessed the effect of oral arginine and citrulline supplementations on NO production in children with MELAS syndrome. When compared to control subjects, children with MELAS syndrome were found to have lower NO production, arginine flux, plasma arginine, and citrulline flux. In children with MELAS syndrome, arginine supplementation resulted in increased NO production, arginine flux, and arginine concentration. Citrulline supplementation resulted in a greater increase of these parameters. Additionally, citrulline supplementation was associated with a robust increase in citrulline concentration and flux and de novo arginine synthesis rate. The greater effect of citrulline in increasing NO production is due to its greater ability to increase arginine availability particularly in the intracellular compartment in which NO synthesis takes place. This study, which is the first one to assess NO metabolism in children with mitochondrial diseases, adds more evidence to the notion that NO deficiency occurs in MELAS syndrome, suggests a better effect for citrulline because of its greater role as NO precursor, and indicates that impaired NO production occurs in children as well as adults with MELAS syndrome. Thus, the initiation of treatment with NO precursors may be

Impaired nitric oxide production in children with MELAS syndrome and the effect of arginine and citrulline supplementation

PubMed Central

El-Hattab, Ayman W.; Emrick, Lisa T; Hsu, Jean W.; Chanprasert, Sirisak; Almannai, Mohammed; Craigen, William J.; Jahoor, Farook; Scaglia, Fernando

2016-01-01

Mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes (MELAS) syndrome is one of the most frequent maternally inherited mitochondrial disorders. The pathogenesis of this syndrome is not fully understood and believed to result from several interacting mechanisms including impaired mitochondrial energy production, microvasculature angiopathy, and nitric oxide (NO) deficiency. NO deficiency in MELAS syndrome is likely to be multifactorial in origin with the decreased availability of the NO precursors, arginine and citrulline, playing a major role. In this study we used stable isotope infusion techniques to assess NO production in children with MELAS syndrome and healthy pediatric controls. We also assessed the effect of oral arginine and citrulline supplementations on NO production in children with MELAS syndrome. When compared to control subjects, children with MELAS syndrome were found to have lower NO production, arginine flux, plasma arginine, and citrulline flux. In children with MELAS syndrome, arginine supplementation resulted in increased NO production, arginine flux, and arginine concentration. Citrulline supplementation resulted in a greater increase of these parameters. Additionally, citrulline supplementation was associated with a robust increase in citrulline concentration and flux and de novo arginine synthesis rate. The greater effect of citrulline in increasing NO production is due to its greater ability to increase arginine availability particularly in the intracellular compartment in which NO synthesis takes place. This study, which is the first one to assess NO metabolism in children with mitochondrial diseases, adds more evidence to the notion that NO deficiency occurs in MELAS syndrome, suggests a better effect for citrulline because of its greater role as NO precursor, and indicates that impaired NO production occurs in children as well as adults with MELAS syndrome. Thus, the initiation of treatment with NO precursors may be

Biosynthesis of agmatine in isolated mitochondria and perfused rat liver: studies with 15N-labelled arginine

PubMed Central

2005-01-01

An important but unresolved question is whether mammalian mitochondria metabolize arginine to agmatine by the ADC (arginine decarboxylase) reaction. 15N-labelled arginine was used as a precursor to address this question and to determine the flux through the ADC reaction in isolated mitochondria obtained from rat liver. In addition, liver perfusion system was used to examine a possible action of insulin, glucagon or cAMP on a flux through the ADC reaction. In mitochondria and liver perfusion, 15N-labelled agmatine was generated from external 15N-labelled arginine. The production of 15N-labelled agmatine was time- and dose-dependent. The time-course of [U-15N4]agmatine formation from 2 mM [U-15N4]arginine was best fitted to a one-phase exponential curve with a production rate of approx. 29 pmol·min−1·(mg of protein)−1. Experiments with an increasing concentration (0– 40 mM) of [guanidino-15N2]arginine showed a Michaelis constant Km for arginine of 46 mM and a Vmax of 3.7 nmol·min−1·(mg of protein)−1 for flux through the ADC reaction. Experiments with broken mitochondria showed little changes in Vmax or Km values, suggesting that mitochondrial arginine uptake had little effect on the observed Vmax or Km values. Experiments with liver perfusion demonstrated that over 95% of the effluent agmatine was derived from perfusate [guanidino-15N2]arginine regardless of the experimental condition. However, the output of 15N-labelled agmatine (nmol·min−1·g−1) increased by approx. 2-fold (P<0.05) in perfusions with cAMP. The findings of the present study provide compelling evidence that mitochondrial ADC is present in the rat liver, and suggest that cAMP may stimulate flux through this pathway. PMID:15656789

Recent advances in targeting protein arginine methyltransferase enzymes in cancer therapy.

PubMed

Smith, Emily; Zhou, Wei; Shindiapina, Polina; Sif, Said; Li, Chenglong; Baiocchi, Robert A

2018-05-21

Exploration in the field of epigenetics has revealed the diverse roles of the protein arginine methyltransferase (PRMT) family of proteins in multiple disease states. These findings have led to the development of specific inhibitors and discovery of several new classes of drugs with potential to treat both benign and malignant conditions. Areas covered: We provide an overview on the role of PRMT enzymes in healthy and malignant cells, highlighting the role of arginine methylation in specific pathways relevant to cancer pathogenesis. Additionally, we describe structure and catalytic activity of PRMT and discuss the mechanisms of action of novel small molecule inhibitors of specific members of the arginine methyltransferase family. Expert opinion: As the field of PRMT biology advances, it's becoming clear that this class of enzymes is highly relevant to maintaining normal physiologic processes as well and disease pathogenesis. We discuss the potential impact of PRMT inhibitors as a broad class of drugs, including the pleiotropic effects, off target effects the need for more detailed PRMT-centric interactomes, and finally, the potential for targeting this class of enzymes in clinical development of experimental therapeutics for cancer.

Arginine, citrulline and nitric oxide metabolism in sepsis

USDA-ARS?s Scientific Manuscript database

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...

Ultrasonic assisted synthesis of adenosine triphosphate capped manganese-doped ZnS quantum dots for selective room temperature phosphorescence detection of arginine and methylated arginine in urine based on supramolecular Mg(2+)-adenosine triphosphate-arginine ternary system.

PubMed

Ren, Hu-Bo; Yan, Xiu-Ping

2012-08-15

An ultrasonic assisted approach was developed for rapid synthesis of highly water soluble phosphorescent adenosine triphosphate (ATP)-capped Mn-doped ZnS QDs. The prepared ATP-capped Mn-doped ZnS QDs allow selective phosphorescent detection of arginine and methylated arginine based on the specific recognition nature of supramolecular Mg(2+)-ATP-arginine ternary system in combination with the phosphorescence property of Mn-doped ZnS QDs. The developed QD based probe gives excellent selectivity and reproducibility (1.7% relative standard deviation for 11 replicate detections of 10 μM arginine) and low detection limit (3 s, 0.23 μM), and favors biological applications due to the effective elimination of interference from scattering light and autofluorescence. Copyright © 2012 Elsevier B.V. All rights reserved.

L-Arginine in the treatment of valproate overdose - five clinical cases.

PubMed

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.

Metabolism of arginine by aging and 7 day old pumpkin seedlings.

PubMed

Splittstoesser, W E

1969-03-01

The metabolism of arginine by etiolated pumpkin (Cucurbita moschata) seedlings was studied over various time and age intervals by injecting arginine-U-(14)C into the cotyledons. At most, 25% of the (14)C was transported from the cotyledon to the axis tissue and the amount of this transport decreased with increasing age of the seedlings. The cotyledons of 25 day old plants contained 60% of the administered (14)C as unmetabolized arginine. Little (14)C was in sugars and it appeared that arginine was the primary translocation product. Time course studies showed that arginine was extensively metabolized and the labeling patterns suggest that different pathways were in operation in the axis and cotyledons. The amount of arginine incorporated into cotyledonary protein show that synthesis and turnover were occurring at rapid rate. Only 25% of the label incorporated into protein by 1.5 hr remained after 96 hr. The label in protein was stable in the axis tissue. By 96 hr 50% of the administered label occurred as (14)CO(2) and it appeared that arginine was metabolized, through glutamate, by the citrio acid cycle in the cotyledons. The experiments showed that an extensive conversion of arginine carbon into other amino acids did not occur.

Altered brain arginine metabolism in schizophrenia

PubMed Central

Liu, P; Jing, Y; Collie, N D; Dean, B; Bilkey, D K; Zhang, H

2016-01-01

Previous research implicates altered metabolism of l-arginine, a versatile amino acid with a number of bioactive metabolites, in the pathogenesis of schizophrenia. The present study, for we believe the first time, systematically compared the metabolic profile of l-arginine in the frontal cortex (Brodmann's area 8) obtained post-mortem from schizophrenic individuals and age- and gender-matched non-psychiatric controls (n=20 per group). The enzyme assays revealed no change in total nitric oxide synthase (NOS) activity, but significantly increased arginase activity in the schizophrenia group. Western blot showed reduced endothelial NOS protein expression and increased arginase II protein level in the disease group. High-performance liquid chromatography and liquid chromatography/mass spectrometric assays confirmed significantly reduced levels of γ-aminobutyric acid (GABA), but increased agmatine concentration and glutamate/GABA ratio in the schizophrenia cases. Regression analysis indicated positive correlations between arginase activity and the age of disease onset and between l-ornithine level and the duration of illness. Moreover, cluster analyses revealed that l-arginine and its main metabolites l-citrulline, l-ornithine and agmatine formed distinct groups, which were altered in the schizophrenia group. The present study provides further evidence of altered brain arginine metabolism in schizophrenia, which enhances our understanding of the pathogenesis of schizophrenia and may lead to the future development of novel preventions and/or therapeutics for the disease. PMID:27529679

Altered brain arginine metabolism in schizophrenia.

PubMed

Liu, P; Jing, Y; Collie, N D; Dean, B; Bilkey, D K; Zhang, H

2016-08-16

Previous research implicates altered metabolism of l-arginine, a versatile amino acid with a number of bioactive metabolites, in the pathogenesis of schizophrenia. The present study, for we believe the first time, systematically compared the metabolic profile of l-arginine in the frontal cortex (Brodmann's area 8) obtained post-mortem from schizophrenic individuals and age- and gender-matched non-psychiatric controls (n=20 per group). The enzyme assays revealed no change in total nitric oxide synthase (NOS) activity, but significantly increased arginase activity in the schizophrenia group. Western blot showed reduced endothelial NOS protein expression and increased arginase II protein level in the disease group. High-performance liquid chromatography and liquid chromatography/mass spectrometric assays confirmed significantly reduced levels of γ-aminobutyric acid (GABA), but increased agmatine concentration and glutamate/GABA ratio in the schizophrenia cases. Regression analysis indicated positive correlations between arginase activity and the age of disease onset and between l-ornithine level and the duration of illness. Moreover, cluster analyses revealed that l-arginine and its main metabolites l-citrulline, l-ornithine and agmatine formed distinct groups, which were altered in the schizophrenia group. The present study provides further evidence of altered brain arginine metabolism in schizophrenia, which enhances our understanding of the pathogenesis of schizophrenia and may lead to the future development of novel preventions and/or therapeutics for the disease.

Receptor-mediated activation of nitric oxide synthesis by arginine in endothelial cells

PubMed Central

Joshi, Mahesh S.; Ferguson, T. Bruce; Johnson, Fruzsina K.; Johnson, Robert A.; Parthasarathy, Sampath; Lancaster, Jack R.

2007-01-01

Arginine contains the guanidinium group and thus has structural similarity to ligands of imidazoline and α-2 adrenoceptors (α-2 AR). Therefore, we investigated the possibility that exogenous arginine may act as a ligand for these receptors in human umbilical vein endothelial cells and activate intracellular nitric oxide (NO) synthesis. Idazoxan, a mixed antagonist of imidazoline and α-2 adrenoceptors, partly inhibited l-arginine-initiated NO formation as measured by a Griess reaction. Rauwolscine, a highly specific antagonist of α-2 AR, at very low concentrations completely inhibited NO formation. Like l-arginine, agmatine (decarboxylated arginine) also activated NO synthesis, however, at much lower concentrations. We found that dexmedetomidine, a specific agonist of α-2 AR was very potent in activating cellular NO, thus indicating a possible role for α-2 AR in l-arginine-mediated NO synthesis. d-arginine also activated NO production and could be inhibited by imidazoline and α-2 AR antagonists, thus indicating nonsubstrate actions of arginine. Pertussis toxin, an inhibitor of G proteins, attenuated l-arginine-mediated NO synthesis, thus indicating mediation via G proteins. l-type Ca2+ channel blocker nifedipine and phospholipase C inhibitor U73122 inhibited NO formation and thus implicated participation of a second messenger pathway. Finally, in isolated rat gracilis vessels, rauwolscine completely inhibited the l-arginine-initiated vessel relaxation. Taken together, these data provide evidence for binding of arginine to membrane receptor(s), leading to the activation of endothelial NO synthase (eNOS) NO production through a second messenger pathway. These findings provide a previously unrecognized mechanistic explanation for the beneficial effects of l-arginine in the cardiovascular system and thus provide new potential avenues for therapeutic development. PMID:17535904

Using oriented peptide array libraries to evaluate methylarginine-specific antibodies and arginine methyltransferase substrate motifs

PubMed Central

Gayatri, Sitaram; Cowles, Martis W.; Vemulapalli, Vidyasiri; Cheng, Donghang; Sun, Zu-Wen; Bedford, Mark T.

2016-01-01

Signal transduction in response to stimuli relies on the generation of cascades of posttranslational modifications that promote protein-protein interactions and facilitate the assembly of distinct signaling complexes. Arginine methylation is one such modification, which is catalyzed by a family of nine protein arginine methyltransferases, or PRMTs. Elucidating the substrate specificity of each PRMT will promote a better understanding of which signaling networks these enzymes contribute to. Although many PRMT substrates have been identified, and their methylation sites mapped, the optimal target motif for each of the nine PRMTs has not been systematically addressed. Here we describe the use of Oriented Peptide Array Libraries (OPALs) to methodically dissect the preferred methylation motifs for three of these enzymes – PRMT1, CARM1 and PRMT9. In parallel, we show that an OPAL platform with a fixed methylarginine residue can be used to validate the methyl-specific and sequence-specific properties of antibodies that have been generated against different PRMT substrates, and can also be used to confirm the pan nature of some methylarginine-specific antibodies. PMID:27338245

Altered expression of an RBP-associated arginine methyltransferase 7 in Leishmania major affects parasite infection.

PubMed

Ferreira, Tiago R; Alves-Ferreira, Eliza V C; Defina, Tania P A; Walrad, Pegine; Papadopoulou, Barbara; Cruz, Angela K

2014-10-08

Protein arginine methylation is a widely conserved post-translational modification performed by arginine methyltransferases (PRMTs). However, its functional role in parasitic protozoa is still under-explored. The Leishmania major genome encodes five PRMT homologs, including PRMT7. Here we show that LmjPRMT7 expression and arginine monomethylation are tightly regulated in a lifecycle stage-dependent manner. LmjPRMT7 levels are higher during the early promastigote logarithmic phase, negligible at stationary and late-stationary phases and rise once more post-differentiation to intracellular amastigotes. Immunofluorescence and co-immunoprecipitation studies demonstrate that LmjPRMT7 is a cytosolic protein associated with several RNA-binding proteins (RBPs) from which Alba20 is monomethylated only in LmjPRMT7-expressing promastigote stages. In addition, Alba20 protein levels are significantly altered in stationary promastigotes of the LmjPRMT7 knockout mutant. Considering RBPs are well-known mammalian PRMT substrates, our data suggest that arginine methylation via LmjPRMT7 may modulate RBP function during Leishmania spp. lifecycle progression. Importantly, genomic deletion of the LmjPRMT7 gene leads to an increase in parasite infectivity both in vitro and in vivo, while lesion progression is significantly reduced in LmjPRMT7-overexpressing parasites. This study is the first to describe a role of Leishmania protein arginine methylation in host-parasite interactions. © 2014 John Wiley & Sons Ltd.

Amine oxidation by d-arginine dehydrogenase in Pseudomonas aeruginosa.

PubMed

Ouedraogo, Daniel; Ball, Jacob; Iyer, Archana; Reis, Renata A G; Vodovoz, Maria; Gadda, Giovanni

2017-10-15

d-Arginine dehydrogenase from Pseudomonas aeruginosa (PaDADH) is a flavin-dependent oxidoreductase, which is part of a novel two-enzyme racemization system that functions to convert d-arginine to l-arginine. PaDADH contains a noncovalently linked FAD that shows the highest activity with d-arginine. The enzyme exhibits broad substrate specificity towards d-amino acids, particularly with cationic and hydrophobic d-amino acids. Biochemical studies have established the structure and the mechanistic properties of the enzyme. The enzyme is a true dehydrogenase because it displays no reactivity towards molecular oxygen. As established through solvent and multiple kinetic isotope studies, PaDADH catalyzes an asynchronous CH and NH bond cleavage via a hydride transfer mechanism. Steady-state kinetic studies with d-arginine and d-histidine are consistent with the enzyme following a ping-pong bi-bi mechanism. As shown by a combination of crystallography, kinetic and computational data, the shape and flexibility of loop L1 in the active site of PaDADH are important for substrate capture and broad substrate specificity. Copyright © 2017 Elsevier Inc. All rights reserved.

Unexpected Crosslinking and Diglycation as Advanced Glycation End-Products from Glyoxal

NASA Astrophysics Data System (ADS)

Lopez-Clavijo, Andrea F.; Duque-Daza, Carlos A.; Soulby, Andrew; Canelon, Isolda Romero; Barrow, Mark; O'Connor, Peter B.

2014-12-01

Glyoxal-derived advanced glycation end-products (AGEs) are formed in physiological systems affecting protein/peptide function and structure. These AGEs are generated during aging and chronic diseases such as diabetes and are considered arginine glycating agents. Thus, the study of glyoxal-derived AGEs in lysine residues and amino acid competition is addressed here using acetylated and non-acetylated undecapeptides, with one arginine and one lysine residue available for glycation. Tandem mass spectrometry results from a Fourier transform ion cyclotron resonance mass spectrometer showed glycated species at both the arginine and lysine residues. One species with the mass addition of 116.01096 Da is formed at the arginine residue. A possible structure is proposed to explain this finding (Nδ-[2-(dihydroxymethyl)-2H,3aH,4H,6aH-[1, 3]dioxolo[5,6-d]imidazolin-5-yl]-L-ornithine-derived AGE). The second species corresponded to intramolecular crosslink involving the lysine residue and its presence is checked with ion-mobility mass spectrometry.

Arginine methylation of translocated in liposarcoma (TLS) inhibits its binding to long noncoding RNA, abrogating TLS-mediated repression of CBP/p300 activity.

PubMed

Cui, Wei; Yoneda, Ryoma; Ueda, Naomi; Kurokawa, Riki

2018-05-21

Translocated in liposarcoma (TLS) is an RNA-binding protein and a transcription-regulatory sensor of DNA damage. TLS binds promoter-associated noncoding RNA (pncRNA) and inhibits histone acetyltransferase (HAT) activity of CREB-binding protein (CBP)/E1A-binding protein P300 (p300) on the cyclin D1 (CCND1) gene. Although post-translational modifications of TLS, such as arginine methylation, are known to regulate TLS's nucleocytoplasmic shuttling and assembly in stress granules, its interactions with RNAs remain poorly characterized. Herein, using various biochemical assays, we confirmed the earlier observations that TLS is methylated by protein arginine methyltransferase 1 (PRMT1) in vitro. The arginine methylation of TLS disrupted binding to pncRNA and also prevented binding of TLS to and inhibition of CBP/p300. This result indicated that arginine methylation of TLS abrogates both binding to pncRNA and TLS-mediated inhibition of CBP/p300 HAT activities. We also report that an arginine residue within the Arg-Gly-Gly domain of TLS, Arg-476, serves as the major determinant for binding to pncRNA. Either methylation or mutation of Arg-476 of TLS significantly decreased pncRNA binding and thereby prevented a pncRNA-induced allosteric alteration in TLS that is required for its interaction with CBP/p300. Moreover, unlike wildtype TLS, an R476A TLS mutant did not inhibit CCND1 promoter activity in luciferase reporter assays. Taken together, we propose the hypothesis that arginine methylation of TLS regulates both TLS-nucleic acid and TLS-protein interactions and thereby participates in transcriptional regulation. Published under license by The American Society for Biochemistry and Molecular Biology, Inc.

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

PubMed Central

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

2015-01-01

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. PMID:26132994

Acquired Amino Acid Deficiencies: A Focus on Arginine and Glutamine.

PubMed

Morris, Claudia R; Hamilton-Reeves, Jill; Martindale, Robert G; Sarav, Menaka; Ochoa Gautier, Juan B

2017-04-01

Nonessential amino acids are synthesized de novo and therefore not diet dependent. In contrast, essential amino acids must be obtained through nutrition since they cannot be synthesized internally. Several nonessential amino acids may become essential under conditions of stress and catabolic states when the capacity of endogenous amino acid synthesis is exceeded. Arginine and glutamine are 2 such conditionally essential amino acids and are the focus of this review. Low arginine bioavailability plays a pivotal role in the pathogenesis of a growing number of varied diseases, including sickle cell disease, thalassemia, malaria, acute asthma, cystic fibrosis, pulmonary hypertension, cardiovascular disease, certain cancers, and trauma, among others. Catabolism of arginine by arginase enzymes is the most common cause of an acquired arginine deficiency syndrome, frequently contributing to endothelial dysfunction and/or T-cell dysfunction, depending on the clinical scenario and disease state. Glutamine, an arginine precursor, is one of the most abundant amino acids in the body and, like arginine, becomes deficient in several conditions of stress, including critical illness, trauma, infection, cancer, and gastrointestinal disorders. At-risk populations are discussed together with therapeutic options that target these specific acquired amino acid deficiencies.

Crystallization of dicalcium phosphate dihydrate with presence of glutamic acid and arginine at 37 °C.

PubMed

Li, Chengfeng; Ge, Xiaolu; Li, Guochang; Bai, Jiahai; Ding, Rui

2014-08-01

The formations of non-metabolic stones, bones and teeth were seriously related to the morphology, size and surface reactivity of dicalcium phosphate dihydrate (DCPD). Herein, a facile biomimetic mineralization method with presence of glutamic acid and arginine was employed to fabricate DCPD with well-defined morphology and adjustable crystallite size. In reaction solution containing more arginine, crystallization of DCPD occurred with faster rate of nucleation and higher density of stacked layers due to the generation of more OH(-) ions after hydrolysis of arginine at 37 °C. With addition of fluorescein or acetone, the consumption of OH(-) ions or desolvation reaction of Ca(2+) ions was modulated, which resulted in the fabrication of DCPD with adjustable crystallite sizes and densities of stacked layers. In comparison with fluorescein-loading DCPD, dicalcium phosphate anhydrate was prepared with enhanced photoluminescence properties due to the reduction of self-quenching effect and regular arrangement of encapsulated fluorescein molecules. With addition of more acetone, DCPD was prepared with smaller crystallite size via antisolvent crystallization. The simulated process with addition of amino acids under 37 °C would shed light on the dynamic process of biomineralization for calcium phosphate compounds. Copyright © 2014 Elsevier B.V. All rights reserved.

Mechanistic basis for type 2 long QT syndrome caused by KCNH2 mutations that disrupt conserved arginine residues in the voltage sensor.

PubMed

McBride, Christie M; Smith, Ashley M; Smith, Jennifer L; Reloj, Allison R; Velasco, Ellyn J; Powell, Jonathan; Elayi, Claude S; Bartos, Daniel C; Burgess, Don E; Delisle, Brian P

2013-05-01

KCNH2 encodes the Kv11.1 channel, which conducts the rapidly activating delayed rectifier K+ current (I Kr) in the heart. KCNH2 mutations cause type 2 long QT syndrome (LQT2), which increases the risk for life-threatening ventricular arrhythmias. LQT2 mutations are predicted to prolong the cardiac action potential (AP) by reducing I Kr during repolarization. Kv11.1 contains several conserved basic amino acids in the fourth transmembrane segment (S4) of the voltage sensor that are important for normal channel trafficking and gating. This study sought to determine the mechanism(s) by which LQT2 mutations at conserved arginine residues in S4 (R531Q, R531W or R534L) alter Kv11.1 function. Western blot analyses of HEK293 cells transiently expressing R531Q, R531W or R534L suggested that only R534L inhibited Kv11.1 trafficking. Voltage-clamping experiments showed that R531Q or R531W dramatically altered Kv11.1 current (I Kv11.1) activation, inactivation, recovery from inactivation and deactivation. Coexpression of wild type (to mimic the patients' genotypes) mostly corrected the changes in I Kv11.1 activation and inactivation, but deactivation kinetics were still faster. Computational simulations using a human ventricular AP model showed that accelerating deactivation rates was sufficient to prolong the AP, but these effects were minimal compared to simply reducing I Kr. These are the first data to demonstrate that coexpressing wild type can correct activation and inactivation dysfunction caused by mutations at a critical voltage-sensing residue in Kv11.1. We conclude that some Kv11.1 mutations might accelerate deactivation to cause LQT2 but that the ventricular AP duration is much more sensitive to mutations that decrease I Kr. This likely explains why most LQT2 mutations are nonsense or trafficking-deficient.

Parenterally fed neonatal piglets have a low rate of endogenous arginine synthesis from circulating proline.

PubMed

Urschel, Kristine L; Evans, Amanda R; Wilkinson, Craig W; Pencharz, Paul B; Ball, Ronald O

2007-03-01

Parenterally fed neonatal piglets cannot synthesize sufficient arginine to maintain arginine status, presumably due to the intestinal atrophy that occurs with parenteral feeding. Parenteral feeding-induced atrophy can be reduced by the infusion of glucagon-like peptide 2 (GLP-2). GLP-2 infusion was hypothesized to increase the rate of endogenous arginine synthesis from proline, the major arginine precursor, in parenterally fed piglets receiving an arginine-deficient diet. Male piglets, fitted with jugular vein catheters for diet and isotope infusion, and femoral vein catheters for blood sampling (d 0), were allocated to a continuous infusion of either GLP-2 (n = 5; 10 nmol x kg(-1) x d(-1)) or saline (n = 5) for 7 d. Piglets received 2 d of a complete diet, followed by 5 d of an arginine-deficient [0.60 g x kg(-1) x d(-1)] diet. Piglets received primed, constant infusions of [guanido-(14)C]arginine to measure arginine flux (d 6) and [U-(14)C]proline (d 7) to measure proline conversion to arginine. Plasma arginine concentrations and arginine fluxes indicated a similar whole-body arginine status. Piglets receiving GLP-2 showed improvements in intestinal variables, including mucosal mass (P < 0.01) and villus height (P < 0.001), and a greater rate of arginine synthesis (micromol x kg(-1) x h(-1)) from proline (11.6 vs. 6.3) (P = 0.03). Mucosal mass (R(2) = 0.71; P = 0.002) and villus height were correlated (R(2) = 0.66; P = 0.004) with arginine synthesis. This study was the first to quantitate arginine synthesis in parenterally fed neonates and showed that although GLP-2 infusion increased arginine synthesis in a manner directly related to mucosal mass, this increased arginine synthesis was insufficient to improve whole-body arginine status in piglets receiving a low arginine diet.

Maximizing Selective Cleavages at Aspartic Acid and Proline Residues for the Identification of Intact Proteins

NASA Astrophysics Data System (ADS)

Foreman, David J.; Dziekonski, Eric T.; McLuckey, Scott A.

2018-04-01

A new approach for the identification of intact proteins has been developed that relies on the generation of relatively few abundant products from specific cleavage sites. This strategy is intended to complement standard approaches that seek to generate many fragments relatively non-selectively. Specifically, this strategy seeks to maximize selective cleavage at aspartic acid and proline residues via collisional activation of precursor ions formed via electrospray ionization (ESI) under denaturing conditions. A statistical analysis of the SWISS-PROT database was used to predict the number of arginine residues for a given intact protein mass and predict a m/z range where the protein carries a similar charge to the number of arginine residues thereby enhancing cleavage at aspartic acid residues by limiting proton mobility. Cleavage at aspartic acid residues is predicted to be most favorable in the m/z range of 1500-2500, a range higher than that normally generated by ESI at low pH. Gas-phase proton transfer ion/ion reactions are therefore used for precursor ion concentration from relatively high charge states followed by ion isolation and subsequent generation of precursor ions within the optimal m/z range via a second proton transfer reaction step. It is shown that the majority of product ion abundance is concentrated into cleavages C-terminal to aspartic acid residues and N-terminal to proline residues for ions generated by this process. Implementation of a scoring system that weights both ion fragment type and ion fragment area demonstrated identification of standard proteins, ranging in mass from 8.5 to 29.0 kDa. [Figure not available: see fulltext.

Maximizing Selective Cleavages at Aspartic Acid and Proline Residues for the Identification of Intact Proteins.

PubMed

Foreman, David J; Dziekonski, Eric T; McLuckey, Scott A

2018-04-30

A new approach for the identification of intact proteins has been developed that relies on the generation of relatively few abundant products from specific cleavage sites. This strategy is intended to complement standard approaches that seek to generate many fragments relatively non-selectively. Specifically, this strategy seeks to maximize selective cleavage at aspartic acid and proline residues via collisional activation of precursor ions formed via electrospray ionization (ESI) under denaturing conditions. A statistical analysis of the SWISS-PROT database was used to predict the number of arginine residues for a given intact protein mass and predict a m/z range where the protein carries a similar charge to the number of arginine residues thereby enhancing cleavage at aspartic acid residues by limiting proton mobility. Cleavage at aspartic acid residues is predicted to be most favorable in the m/z range of 1500-2500, a range higher than that normally generated by ESI at low pH. Gas-phase proton transfer ion/ion reactions are therefore used for precursor ion concentration from relatively high charge states followed by ion isolation and subsequent generation of precursor ions within the optimal m/z range via a second proton transfer reaction step. It is shown that the majority of product ion abundance is concentrated into cleavages C-terminal to aspartic acid residues and N-terminal to proline residues for ions generated by this process. Implementation of a scoring system that weights both ion fragment type and ion fragment area demonstrated identification of standard proteins, ranging in mass from 8.5 to 29.0 kDa. Graphical Abstract ᅟ.

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

PubMed Central

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

Restoration of impaired nitric oxide production in MELAS syndrome with citrulline and arginine supplementation

PubMed Central

El-Hattab, Ayman W.; Hsu, Jean W.; Emrick, Lisa T.; Wong, Lee-Jun C.; Craigen, William J.; Jahoor, Farook; Scaglia, Fernando

2014-01-01

Mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes (MELAS) syndrome is one of the most common mitochondrial disorders. Although the pathogenesis of stroke-like episodes remains unclear, it has been suggested that mitochondrial proliferation may result in endothelial dysfunction and decreased nitric oxide (NO) availability leading to cerebral ischemic events. This study aimed to assess NO production in subjects with MELAS syndrome and the effect of the NO precursors arginine and citrulline. Using stable isotope infusion techniques, we assessed arginine, citrulline, and NO metabolism in control subjects and subjects with MELAS syndrome before and after arginine or citrulline supplementation. The results showed that subjects with MELAS had lower NO synthesis rate associated with reduced citrulline flux, de novo arginine synthesis rate, and plasma arginine and citrulline concentrations, and higher plasma asymmetric dimethylarginine (ADMA) concentration and arginine clearance. We conclude that the observed impaired NO production is due to multiple factors including elevated ADMA, higher arginine clearance, and, most importantly, decreased de novo arginine synthesis secondary to decreased citrulline availability. Arginine and, to a greater extent, citrulline supplementation increased the de novo arginine synthesis rate, the plasma concentrations and flux of arginine and citrulline, and NO production. De novo arginine synthesis increased markedly with citrulline supplementation, explaining the superior efficacy of citrulline in increasing NO production. The improvement in NO production with arginine or citrulline supplementation supports their use in MELAS and suggests that citrulline may have a better therapeutic effect than arginine. These findings can have a broader relevance for other disorders marked by perturbations in NO metabolism. PMID:22325939

Arginine Metabolism in Bacterial Pathogenesis and Cancer Therapy

PubMed Central

Xiong, Lifeng; Teng, Jade L. L.; Botelho, Michael G.; Lo, Regina C.; Lau, Susanna K. P.; Woo, Patrick C. Y.

2016-01-01

Antibacterial resistance to infectious diseases is a significant global concern for health care organizations; along with aging populations and increasing cancer rates, it represents a great burden for government healthcare systems. Therefore, the development of therapies against bacterial infection and cancer is an important strategy for healthcare research. Pathogenic bacteria and cancer have developed a broad range of sophisticated strategies to survive or propagate inside a host and cause infection or spread disease. Bacteria can employ their own metabolism pathways to obtain nutrients from the host cells in order to survive. Similarly, cancer cells can dysregulate normal human cell metabolic pathways so that they can grow and spread. One common feature of the adaption and disruption of metabolic pathways observed in bacterial and cancer cell growth is amino acid pathways; these have recently been targeted as a novel approach to manage bacterial infections and cancer therapy. In particular, arginine metabolism has been illustrated to be important not only for bacterial pathogenesis but also for cancer therapy. Therefore, greater insights into arginine metabolism of pathogenic bacteria and cancer cells would provide possible targets for controlling of bacterial infection and cancer treatment. This review will summarize the recent progress on the relationship of arginine metabolism with bacterial pathogenesis and cancer therapy, with a particular focus on arginase and arginine deiminase pathways of arginine catabolism. PMID:26978353

Interaction of a novel peptoid enhancer--arginine oligomer with bovine submaxillary mucin.

PubMed

Liang, Wei; Davalian, Dariush; Torchilin, Vladimir P

2004-12-01

To determine the thermodynamics of binding reaction of arginine oligomer (R8) to bovine submaxillary mucin (BSM) in order to provide the foundation for understanding the influence of mucin on transport of macromolecules through mucosa mediated by arginine oligomer. Ultracentrifugation sedimentation was employed to investigate the interaction of BSM-R8. The mixtures of R8 with variable concentration and constant volume of BSM were placed on a shaker under oscillation at 25 degrees C to achieve equilibriums of binding reaction, and then centrifuged. The fluorescence intensity of the supernatant was measured by spectrofluorometer. The data were described by two types of binding sites model, the binding parameters of BSM-R8 were obtained by Scatchard plots. At the low pH values < or = 4.5 and ionic strength > or = 0.2 mol x L(-1), the BSM-R8 interaction was principally electrostatic interaction, the five primary binding sites (n1) predominantly were supplied by sulfate groups, the secondary binding sites apparently depended on pH, in that percent ionization of sialic acid residues (n2) in BSM. At the low ionic strength < or = 0.2 mol x L(-1) and pH 7.0, the BSM-R8 interaction was exceedingly complex, hydrogen bonds, hydrophobic interaction and electrostatic forces were involved in the interaction between R8 and BSM, the binding sites of BSM bound R8 were markedly increased. There existed evidence that R8 interacted with BSM. The pH and the ionic strength of the binding solution strongly affected the interaction of BSM with R8. The results suggested that the enhancing efficacy of the arginine oligomer for the transport of macromolecules through different site mucosa in body might be variable.

Consequences of Phosphate-Arginine Complexes in Voltage-Gated Ion Channels

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

Green, Michael E.

2008-11-01

There are two reasons for suspecting that phosphate complexes of arginine make it very difficult to derive gating charge in voltage gated potassium (and presumably sodium) channels from the motion of charged arginines. For one thing, the arginines should be complexed with phosphate, thereby neutralizing the charge, at least partially. Second, Li et al.(1) have shown that there is a large energy penalty for putting a charged arginine into a membrane. on channel gating current is generally attributed to S4 motion, in that the S4 segment of the voltage sensing domain (VSD) of these channels contains arginines, some of whichmore » are not (or at least not obviously) salt bridged, or otherwise charge compensated. There is, however, good reason to expect that there should be a complex of these arginines with phosphate, very probably from lipid headgroups. This has consequences for gating current; the complexed arginines, if they moved, would carry too much of the membrane along. This leads to the suggestion that an alternative to S4 physical motion, H+ transport, should be considered as a possible resolution of the apparent paradox. The consequences for a gating model that was proposed in our earlier work are discussed; there is one major difference in the model in the present form (a conformational change), but the proton cascade as gating current and the role of water in the closed state are reinforced.« less

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

PubMed

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.

The formation of argpyrimidine, a methylglyoxal-arginine adduct, in the nucleus of neural cells

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

Nakadate, Yusuke; Uchida, Koji; Shikata, Keiji

2009-01-09

Methylglyoxal (MG) is an endogenous metabolite in glycolysis and forms stable adducts primarily with arginine residues of intracellular proteins. The biological role of this modification in cell function is not known. In the present study, we found that a MG-detoxification enzyme glyoxalase I (GLO1) is mainly expressed in the ventricular zone (VZ) at embryonic day 16 which neural stem and progenitor cells localize. Moreover, immunohistochemical analysis revealed that argpyrimidine, a major MG-arginine adduct, is predominantly produced in cortical plate neurons not VZ during cerebral cortex development and is exclusively located in the nucleus. Immunoblotting experiment showed that the formation ofmore » argpyrimidine occurs on some nuclear proteins of cortical neurons. To our knowledge, this is first report of the argpyrimidine formation in the nucleus of neuron. These findings suggest that GLO1, which is dominantly expressed in the embryonic VZ, reduces the intracellular level of MG and suppresses the formation of argpyrimidine in neural stem and progenitor cells. Argpyrimidine may contribute to the neural differentiation and/or the maintenance of the differentiated state via the modification of nuclear proteins.« less

Variability in arginine content and yield components in Valencia peanut germplasm

USDA-ARS?s Scientific Manuscript database

Peanut seeds are rich in arginine, an amino acid that has several positive effects on human health. Establishing the genetic variability of arginine content in peanut will be useful for breeding programs that have high arginine as one of their goals. The objective of this study was to evaluate the...

Guanidinium Group Remains Protonated in a Strongly Basic Arginine Solution

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

Xu, Bo; Jacobs, Michael I.; Kostko, Oleg

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. Here, we use X-ray photoelectron spectroscopy to study unsupported, aqueousmore » 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.« less

Guanidinium Group Remains Protonated in a Strongly Basic Arginine Solution

DOE PAGES

Xu, Bo; Jacobs, Michael I.; Kostko, Oleg; ...

2017-05-16

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. Here, we use X-ray photoelectron spectroscopy to study unsupported, aqueousmore » 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.« less

Arginine kinase in Phytomonas, a trypanosomatid parasite of plants.

PubMed

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.

Roles of conserved arginines in ATP-binding domains of AAA+ chaperone ClpB from Thermus thermophilus.

PubMed

Yamasaki, Takashi; Nakazaki, Yosuke; Yoshida, Masasuke; Watanabe, Yo-hei

2011-07-01

ClpB, a member of the expanded superfamily of ATPases associated with diverse cellular activities (AAA+), forms a ring-shaped hexamer and cooperates with the DnaK chaperone system to reactivate aggregated proteins in an ATP-dependent manner. The ClpB protomer consists of an N-terminal domain, an AAA+ module (AAA-1), a middle domain, and a second AAA+ module (AAA-2). Each AAA+ module contains highly conserved WalkerA and WalkerB motifs, and two arginines (AAA-1) or one arginine (AAA-2). Here, we investigated the roles of these arginines (Arg322, Arg323, and Arg747) of ClpB from Thermus thermophilus in the ATPase cycle and chaperone function by alanine substitution. These mutations did not affect nucleotide binding, but did inhibit the hydrolysis of the bound ATP and slow the threading of the denatured protein through the central pore of the T. thermophilus ClpB ring, which severely impaired the chaperone functions. Previously, it was demonstrated that ATP binding to the AAA-1 module induced motion of the middle domain and stabilized the ClpB hexamer. However, the arginine mutations of the AAA-1 module destabilized the ClpB hexamer, even though ATP-induced motion of the middle domain was not affected. These results indicated that the three arginines are crucial for ATP hydrolysis and chaperone activity, but not for ATP binding. In addition, the two arginines in AAA-1 and the ATP-induced motion of the middle domain independently contribute to the stabilization of the hexamer. © 2011 The Authors Journal compilation © 2011 FEBS.

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

PubMed

Fulde, Marcus; Willenborg, Joerg; Huber, Claudia; Hitzmann, Angela; Willms, Daniela; Seitz, Maren; Eisenreich, Wolfgang; Valentin-Weigand, Peter; Goethe, Ralph

2014-01-01

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-(13)C6]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 in chemically defined media supplemented with arginine when compared to the WT strain, suggesting 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.

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

PubMed Central

Fulde, Marcus; Willenborg, Joerg; Huber, Claudia; Hitzmann, Angela; Willms, Daniela; Seitz, Maren; Eisenreich, Wolfgang; Valentin-Weigand, Peter; Goethe, Ralph

2014-01-01

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 in chemically defined media supplemented with arginine when compared to the WT strain, suggesting 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. PMID:25161959

New Insights into the Methodology of L-Arginine-Induced Acute Pancreatitis

PubMed Central

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

Arginine-Dependent Acid Resistance in Salmonella enterica Serovar Typhimurium

PubMed Central

Kieboom, Jasper; Abee, Tjakko

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 resistance (AR) provided the cells are grown under anoxic conditions and not under the microaerobic conditions used for assessment of AR in E. coli. The role of the arginine decarboxylase pathway in Salmonella AR was shown by the loss of AR in mutants lacking adiA, which encodes arginine decarboxylase; adiC, which encodes the arginine-agmatine antiporter; or adiY, which encodes an AraC-like regulator. Transcription of adiA and adiC was found to be dependent on AdiY, anaerobiosis, and acidic pH. PMID:16855258

The presence of African American race predicts improvement in coronary endothelial function after supplementary L-arginine.

PubMed

Houghton, Jan L; Philbin, Edward F; Strogatz, David S; Torosoff, Mikhail T; Fein, Steven A; Kuhner, Patricia A; Smith, Vivienne E; Carr, Albert A

2002-04-17

The purpose of our study was to determine if the presence of African American ethnicity modulates improvement in coronary vascular endothelial function after supplementary L-arginine. Endothelial dysfunction is an early stage in the development of coronary atherosclerosis and has been implicated in the pathogenesis of hypertension and cardiomyopathy. Amelioration of endothelial dysfunction has been demonstrated in patients with established coronary atherosclerosis or with risk factors in response to infusion of L-arginine, the precursor of nitric oxide. Racial and gender patterns in L-arginine responsiveness have not, heretofore, been studied. Invasive testing of coronary artery and microvascular reactivity in response to graded intracoronary infusions of acetylcholine (ACh) +/- L-arginine was carried out in 33 matched pairs of African American and white subjects with no angiographic coronary artery disease. Pairs were matched for age, gender, indexed left ventricular mass, body mass index and low-density lipoprotein cholesterol. In addition to the matching parameters, there were no significant differences in peak coronary blood flow (CBF) response to intracoronary adenosine or in the peak CBF response to ACh before L-arginine infusion. However, absolute percentile improvement in CBF response to ACh infusion after L-arginine, as compared with before, was significantly greater among African Americans as a group (45 +/- 10% vs. 4 +/- 6%, p = 0.0016) and after partitioning by gender. The mechanism of this increase was mediated through further reduction in coronary microvascular resistance. L-arginine infusion also resulted in greater epicardial dilator response after ACh among African Americans. We conclude that intracoronary infusion of L-arginine provides significantly greater augmentation of endothelium-dependent vascular relaxation in those of African American ethnicity when compared with matched white subjects drawn from a cohort electively referred for coronary

Effect of Polyhydroxybutyrate (PHB) storage on L-arginine production in recombinant Corynebacterium crenatum using coenzyme regulation.

PubMed

Xu, Meijuan; Qin, Jingru; Rao, Zhiming; You, Hengyi; Zhang, Xian; Yang, Taowei; Wang, Xiaoyuan; Xu, Zhenghong

2016-01-19

Corynebacterium crenatum SYPA 5 is the industrial strain for L-arginine production. Poly-β-hydroxybutyrate (PHB) is a kind of biopolymer stored as bacterial reserve materials for carbon and energy. The introduction of the PHB synthesis pathway into several strains can regulate the global metabolic pathway. In addition, both the pathways of PHB and L-arginine biosynthesis in the cells are NADPH-dependent. NAD kinase could upregulate the NADPH concentration in the bacteria. Thus, it is interesting to investigate how both PHB and NAD kinase affect the L-arginine biosynthesis in C. crenatum SYPA 5. C. crenatum P1 containing PHB synthesis pathway was constructed and cultivated in batch fermentation for 96 h. The enzyme activities of the key enzymes were enhanced comparing to the control strain C. crenatum SYPA 5. More PHB was found in C. crenatum P1, up to 12.7 % of the dry cell weight. Higher growth level and enhanced glucose consumptions were also observed in C. crenatum P1. With respect to the yield of L-arginine, it was 38.54 ± 0.81 g/L, increasing by 20.6 %, comparing to the control under the influence of PHB accumulation. For more NADPH supply, C. crenatum P2 was constructed with overexpression of NAD kinase based on C. crenatum P1. The NADPH concentration was increased in C. crenatum P2 comparing to the control. PHB content reached 15.7 % and 41.11 ± 1.21 g/L L-arginine was obtained in C. crenatum P2, increased by 28.6 %. The transcription levels of key L-arginine synthesis genes, argB, argC, argD and argJ in recombinant C. crenatum increased 1.9-3.0 times compared with the parent strain. Accumulation of PHB by introducing PHB synthesis pathway, together with up-regulation of coenzyme level by overexpressing NAD kinase, enables the recombinant C. crenatum to serve as high-efficiency cell factories in the long-time L-arginine fermentation. Furthermore, batch cultivation of the engineered C. crenatum revealed that it could accumulate both extracellular L-arginine

Stimulated Nitric Oxide Production and Arginine Deficiency in Cystic Fibrosis Children with Nutritional Failure

PubMed Central

Engelen, Mariëlle PKJ; Com, Gulnur; Luiking, Yvette C; Deutz, Nicolaas EP

2013-01-01

Objective Reduced nitric oxide (NO) concentrations are found in the airways of many patients with cystic fibrosis (CF) and are associated with increased airflow obstruction. We determined whether upregulated whole body de novo arginine synthesis and protein breakdown are present as a compensatory mechanism to meet the increased demand for arginine and nitric oxide production in pediatric patients with CF and nutritional failure. Study design In 16 children with CF, studied at the end of antibiotic treatment for a pulmonary exacerbation, and 17 healthy controls, whole body arginine, citrulline, and protein turnover were assessed by stable isotope methodology and de novo arginine synthesis, arginine clearance, NO synthesis, protein synthesis and breakdown, and net protein balance were calculated. The plasma isotopic enrichments and amino acid concentrations were measured by LC-MS/MS. Results Increased arginine clearance was found in patients with CF (p<0.001) whereas whole body NO production rate and plasma arginine levels were not different. Whole body arginine production (P<0.001), de novo arginine synthesis, and protein breakdown and synthesis (P<0.05) were increased in patients with CF, but net protein balance was comparable. Patients with CF with nutritional failure (n=7) had significantly higher NO production (P<0.05), de novo arginine synthesis, citrulline production (P<0.001), and plasma citrulline concentration (P<0.05) and lower plasma arginine concentration (P<0.05) than those without nutritional failure (n=9). Conclusions Nutritional failure in CF is associated with increased NO production. However, upregulation of de novo arginine synthesis and citrulline production was not sufficient to meet the increased arginine needs leading to arginine deficiency. PMID:23419590

Restoration of impaired nitric oxide production in MELAS syndrome with citrulline and arginine supplementation.

PubMed

El-Hattab, Ayman W; Hsu, Jean W; Emrick, Lisa T; Wong, Lee-Jun C; Craigen, William J; Jahoor, Farook; Scaglia, Fernando

2012-04-01

Mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes (MELAS) syndrome is one of the most common mitochondrial disorders. Although the pathogenesis of stroke-like episodes remains unclear, it has been suggested that mitochondrial proliferation may result in endothelial dysfunction and decreased nitric oxide (NO) availability leading to cerebral ischemic events. This study aimed to assess NO production in subjects with MELAS syndrome and the effect of the NO precursors arginine and citrulline. Using stable isotope infusion techniques, we assessed arginine, citrulline, and NO metabolism in control subjects and subjects with MELAS syndrome before and after arginine or citrulline supplementation. The results showed that subjects with MELAS had lower NO synthesis rate associated with reduced citrulline flux, de novo arginine synthesis rate, and plasma arginine and citrulline concentrations, and higher plasma asymmetric dimethylarginine (ADMA) concentration and arginine clearance. We conclude that the observed impaired NO production is due to multiple factors including elevated ADMA, higher arginine clearance, and, most importantly, decreased de novo arginine synthesis secondary to decreased citrulline availability. Arginine and, to a greater extent, citrulline supplementation increased the de novo arginine synthesis rate, the plasma concentrations and flux of arginine and citrulline, and NO production. De novo arginine synthesis increased markedly with citrulline supplementation, explaining the superior efficacy of citrulline in increasing NO production. The improvement in NO production with arginine or citrulline supplementation supports their use in MELAS and suggests that citrulline may have a better therapeutic effect than arginine. These findings can have a broader relevance for other disorders marked by perturbations in NO metabolism. Copyright © 2012 Elsevier Inc. All rights reserved.

Arginine Vasopressin selectively enhances recognition of sexual cues in male humans.

PubMed

Guastella, Adam J; Kenyon, Amanda R; Unkelbach, Christian; Alvares, Gail A; Hickie, Ian B

2011-02-01

Arginine Vasopressin modulates complex social and sexual behavior by enhancing social recognition, pair bonding, and aggression in non-human mammals. The influence of Arginine Vasopressin in human social and sexual behavior is, however, yet to be fully understood. We evaluated whether Arginine Vasopressin nasal spray facilitated recognition of positive and negative social and sexual stimuli over non-social stimuli. We used a recognition task that has already been shown to be sensitive to the influence of Oxytocin nasal spray (Unkelbach et al., 2008). In a double-blind, randomized, placebo-controlled, between-subjects design, 41 healthy male volunteers were administered Arginine Vasopressin (20 IU) or a placebo nasal spray after a 45 min wait period and then completed the recognition task. Results showed that the participants administered Arginine Vasopressin nasal spray were faster to detect sexual words over other types of words. This effect appeared for both positively and negatively valenced words. Results demonstrate for the first time that Arginine Vasopressin selectively enhances human cognition for sexual stimuli, regardless of valence. They further extend animal and human genetic studies linking Arginine Vasopressin to sexual behavior in males. Findings suggest an important cognitive mechanism that could enhance sexual behaviors in humans. Crown Copyright © 2010. Published by Elsevier Ltd. All rights reserved.

Synthesis, characterization and properties of L-arginine-passivated silver nanocolloids

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

Sunatkari, A. L., E-mail: ashok.sunatkari@rediffmail.com; Talwatkar, S. S.; Tamgadge, Y. S.

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.

The Nitric Oxide Synthase Inhibitor NG-Nitro-L-Arginine Methyl Ester Diminishes the Immunomodulatory Effects of Parental Arginine in Rats with Subacute Peritonitis

PubMed Central

Lo, Hui-Chen; Hung, Ching-Yi; Huang, Fu-Huan; Su, Tzu-Cheng; Lee, Chien-Hsing

2016-01-01

The combined treatment of parenteral arginine and the nitric oxide synthase inhibitor NG-nitro-L-arginine methyl ester (L-NAME) have been shown to improve liver function and systemic inflammation in subacute peritonitic rats. Here, we investigated the effects of single and combined parenteral arginine and L-NAME treatments on leukocyte and splenocyte immunity. Male Wistar rats were subjected to cecal punctures and were intravenously given total parenteral nutrition solutions with or without arginine and/or L-NAME supplementations for 7 days. Non-surgical and sham-operated rats with no cecal puncture were given a chow diet and parenteral nutrition, respectively. Parenteral feeding elevated the white blood cell numbers and subacute peritonitis augmented the parenteral nutrition-induced alterations in the loss of body weight gain, splenomegaly, and splenocyte decreases. Parenteral arginine significantly increased the B-leukocyte level, decreased the natural killer T (NKT)-leukocyte and splenocyte levels, alleviated the loss in body weight gain and total and cytotoxic T-splenocyte levels, and attenuated the increases in plasma nitrate/nitrite and interferon-gamma production by T-splenocytes. L-NAME infusion significantly decreased NKT-leukocyte level, tumor-necrosis factor (TNF)-alpha production by T-splenocytes and macrophages, and interferon-gamma production by T-leukocytes, monocytes, and T-splenocytes, as well as increased interleukin-6 production by T-leukocytes and monocytes and nitrate/nitrite production by T-leukocytes. Combined treatment significantly decreased plasma nitrate/nitrite, the NKT-leukocyte level, and TNF-alpha production by T-splenocytes. Parenteral arginine may attenuate immune impairment and L-NAME infusion may augment leukocyte proinflammatory response, eliminate splenocyte proinflammatory and T-helper 1 responses, and diminish arginine-induced immunomodulation in combined treatment in subacute peritonitic rats. PMID:27007815

The influence of gastric pentadecapeptide BPC 157 on acute and chronic ethanol administration in mice. The effect of N(G)-nitro-L-arginine methyl ester and L-arginine.

PubMed

Boban-Blagaic, Alenka; Blagaic, Vladimir; Romic, Zeljko; Jelovac, Nikola; Dodig, Goran; Rucman, Rudolf; Petek, Marijan; Turkovic, Branko; Seiwerth, Sven; Sikiric, Predrag

2006-01-01

Alcohol disturbances, NO stimulation (by the NO-precursor L-arginine), and/or NO-synthesis blockade (by N(G)-nitro-L-arginine methyl ester, i.e. L-NAME) were challenged with stable gastric pentadecapeptide BPC 157, which inhibits both acute alcohol intoxication and alcohol withdrawal symptoms. Mice received intraperitoneally (i.p.) BPC 157 (10 microg/kg), L-NAME (10 mg/kg), and L-arginine (400 mg/kg), alone or in combination, 5 minutes before or after acute ethanol (4 g/kg i.p.) intoxication or after 0, 3, or 7 hours of withdrawal after drinking 20% alcohol for 13 days. BPC 157 rapidly opposes the strongest disturbance presentations in acute intoxication (sustained ethanol anesthesia, complete loss of righting reflex, no reaction to external stimuli, hypothermia, 25% mortality) and withdrawal (prominent seizures). NO-agents: Aggravation of acute alcohol intoxication and opposition to withdrawal are common, but the later intervals affected by L-arginine and the action throughout the experiment by L-NAME are distinctive. Given together, L-arginine and L-NAME counteract each other, while either the "L-NAME presentation" (acute intoxication) or the "L-arginine presentation" (withdrawal) predominates. BPC157+NO-agent: In acute intoxication (L-NAME predominating in NO-system functioning to aggravate intoxication), both BPC157+L-NAME and BPC157+L-arginine follow the presentation of L-NAME, but without worsened mortality. In withdrawal (L-arginine predominating in NO-system functioning to oppose disturbance symptoms), BPC157+L-NAME follows the presentation of L-NAME, while BPC 157+L-arginine imitates that of L-arginine. The relationships among pentadecapeptide BPC 157, the NO-system, acute alcohol intoxication, and opposed withdrawal may be important, presenting pentadecapeptide BPC 157 as a suitable alcohol antagonist.

Hepatic Adaptation Compensates Inactivation of Intestinal Arginine Biosynthesis in Suckling Mice

PubMed Central

Marion, Vincent; Sankaranarayanan, Selvakumari; de Theije, Chiel; van Dijk, Paul; Hakvoort, Theo B. M.; Lamers, Wouter H.; Köhler, Eleonore S.

2013-01-01

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. PMID:23785515

Human recombinant arginase enzyme reduces plasma arginine in mouse models of arginase deficiency

PubMed Central

Burrage, Lindsay C.; Sun, Qin; Elsea, Sarah H.; Jiang, Ming-Ming; Nagamani, Sandesh C.S.; Frankel, Arthur E.; Stone, Everett; Alters, Susan E.; Johnson, Dale E.; Rowlinson, Scott W.; Georgiou, George; Lee, Brendan H.

2015-01-01

Arginase deficiency is caused by deficiency of arginase 1 (ARG1), a urea cycle enzyme that converts arginine to ornithine. Clinical features of arginase deficiency include elevated plasma arginine levels, spastic diplegia, intellectual disability, seizures and growth deficiency. Unlike other urea cycle disorders, recurrent hyperammonemia is typically less severe in this disorder. Normalization of plasma arginine levels is the consensus treatment goal, because elevations of arginine and its metabolites are suspected to contribute to the neurologic features. Using data from patients enrolled in a natural history study conducted by the Urea Cycle Disorders Consortium, we found that 97% of plasma arginine levels in subjects with arginase deficiency were above the normal range despite conventional treatment. Recently, arginine-degrading enzymes have been used to deplete arginine as a therapeutic strategy in cancer. We tested whether one of these enzymes, a pegylated human recombinant arginase 1 (AEB1102), reduces plasma arginine in murine models of arginase deficiency. In neonatal and adult mice with arginase deficiency, AEB1102 reduced the plasma arginine after single and repeated doses. However, survival did not improve likely, because this pegylated enzyme does not enter hepatocytes and does not improve hyperammonemia that accounts for lethality. Although murine models required dosing every 48 h, studies in cynomolgus monkeys indicate that less frequent dosing may be possible in patients. Given that elevated plasma arginine rather than hyperammonemia is the major treatment challenge, we propose that AEB1102 may have therapeutic potential as an arginine-reducing agent in patients with arginase deficiency. PMID:26358771

Plasma L-arginine levels distinguish pulmonary arterial hypertension from left ventricular systolic dysfunction.

PubMed

Sandqvist, Anna; Schneede, Jörn; Kylhammar, David; Henrohn, Dan; Lundgren, Jakob; Hedeland, Mikael; Bondesson, Ulf; Rådegran, Göran; Wikström, Gerhard

2018-03-01

Pulmonary arterial hypertension (PAH) is a life-threatening condition, characterized by an imbalance of vasoactive substances and remodeling of pulmonary vasculature. Nitric oxide, formed from L-arginine, is essential for homeostasis and smooth muscle cell relaxation in PAH. Our aim was to compare plasma concentrations of L-arginine, asymmetric dimethylarginine (ADMA), and symmetric dimethylarginine (SDMA) in PAH compared to left ventricular systolic dysfunction (LVSD) and healthy subjects. This was an observational, multicenter study comparing 21 patients with PAH to 14 patients with LVSD and 27 healthy subjects. Physical examinations were obtained and blood samples were collected. Plasma levels of ADMA, SDMA, L-arginine, L-ornithine, and L-citrulline were analyzed using liquid chromatography-tandem mass spectrometry (LC-MS/MS). Plasma levels of ADMA and SDMA were higher, whereas L-arginine and L-arginine/ADMA ratio were lower in PAH patients compared to healthy subjects (p < 0.001). Patients with PAH also had lower levels of L-arginine than patients with LVSD (p < 0.05). L-Arginine correlated to 6 min walking distance (6MWD) (r s  = 0.58, p = 0.006) and L-arginine/ADMA correlated to WHO functional class (r s  = -0.46, p = 0.043) in PAH. In conclusion, L-arginine levels were significantly lower in treatment naïve PAH patients compared to patients with LVSD. Furthermore, L-arginine correlated with 6MWD in PAH. L-arginine may provide useful information in differentiating PAH from LVSD.

The role of the arginine metabolome in pain: implications for sickle cell disease.

PubMed

Bakshi, Nitya; Morris, Claudia R

2016-01-01

Sickle cell disease (SCD) is the most common hemoglobinopathy in the US, affecting approximately 100,000 individuals in the US and millions worldwide. Pain is the hallmark of SCD, and a subset of patients experience pain virtually all of the time. Of interest, the arginine metabolome is associated with several pain mechanisms highlighted in this review. Since SCD is an arginine deficiency syndrome, the contribution of the arginine metabolome to acute and chronic pain in SCD is a topic in need of further attention. Normal arginine metabolism is impaired in SCD through various mechanisms that contribute to endothelial dysfunction, vaso-occlusion, pulmonary complications, risk of leg ulcers, and early mortality. Arginine is a semiessential amino acid that serves as a substrate for protein synthesis and is the precursor to nitric oxide (NO), polyamines, proline, glutamate, creatine, and agmatine. Since arginine is involved in multiple metabolic processes, a deficiency of this amino acid has the potential to disrupt many cellular and organ functions. NO is a potent vasodilator that is depleted in SCD and may contribute to vaso-occlusive pain. As the obligate substrate for NO production, arginine also plays a mechanistic role in SCD-related pain, although its contribution to pain pathways likely extends beyond NO. Low global arginine bioavailability is associated with pain severity in both adults and children with SCD as well as other non-SCD pain syndromes. Preliminary clinical studies of arginine therapy in SCD demonstrate efficacy in treating acute vaso-occlusive pain, as well as leg ulcers and pulmonary hypertension. Restoration of arginine bioavailability through exogenous supplementation of arginine is, therefore, a promising therapeutic target. Phase II clinical trials of arginine therapy for sickle-related pain are underway and a Phase III randomized controlled trial is anticipated in the near future.

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

PubMed

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.

Effects of N-acetylcysteine and L-arginine in the antioxidant system of C2C12 cells.

PubMed

Da Silva, E P; Lambertucci, R H

2015-06-01

The aim of this study was to evaluate the effects of N-acetylcysteine or L-arginine in the antioxidant system of skeletal muscle cells in culture. We used C2C12 cells which were supplemented or not with N-acetylcysteine or L-arginine at different time points. Antioxidant enzymes' activities and protein expression were evaluated. Additionally, superoxide production by cytochrome c reduction method was carried out. It was observed that the supplementation with either N-acetylcysteine or L-arginine was capable to acutely reduce superoxide production (after 30 and 60 minutes). Surprisingly, N-acetylcysteine supplementation also induced an increased production of superoxide during the period of 24 hours. Moreover, both supplements were capable to improve the activity and protein expression of some antioxidants enzymes. In conclusion, we have found new evidences showing that N-acetylcysteine or L-arginine supplementation can provide some benefits to the antioxidant system of skeletal muscle cells in culture. Further studies have to be carried out to evaluate if such benefits could also occur in an in vivo model, with possible benefits for athletes' health and performance.

L-arginine: a new opportunity in the management of clinical derangements in dialysis patients.

PubMed

Bellinghieri, Guido; Santoro, Domenico; Mallamace, Agostino; Di Giorgio, Rosa Maria; De Luca, Grazia; Savica, Vincenzo

2006-07-01

L-Arginine is an essential amino acid for infants and growing children, as well as for pregnant women. This amino acid is a substrate for at least 5 enzymes identified in mammals, including arginase, arginine-glycine transaminase, kyotorphine synthase, nitric oxide synthase, and arginine decarboxylase. L-arginine is essential for the synthesis of creatine, urea, polyamines, nitric oxide, and agmatine. Arginine may be considered an essential amino acid in sepsis, and its supplementation could be beneficial in this clinical setting by improving microcirculation and protein anabolism. Rats receiving arginine-supplemented parenteral nutrition showed an increased ability to synthesize acute phase proteins when challenged with sepsis. Finally, L-arginine exerts antihypertensive and antiproliferative effects on vascular smooth muscles. It has been shown to reduce systemic blood pressure in some forms of experimental hypertension. Endothelial dysfunction and reduced nitric oxide bioactivity are associated with increased incidence of cardiovascular diseases. A beneficial effect of acute and chronic L-arginine supplementation on endothelial derived nitric oxide production and endothelial function has been shown. In end-stage renal disease patients, the rate of de novo arginine synthesis seemed to be preserved. Our preliminary data on a group of dialysis patients showed that predialysis arginine levels were stable in a normal range during the dialysis session and that hypertensive patients had lower arginine-citrulline ratio than normotensive patients.

Arginine Methylation: The Coming of Age.

PubMed

Blanc, Roméo S; Richard, Stéphane

2017-01-05

Arginine methylation is a common post-translational modification functioning as an epigenetic regulator of transcription and playing key roles in pre-mRNA splicing, DNA damage signaling, mRNA translation, cell signaling, and cell fate decision. Recently, a wealth of studies using transgenic mouse models and selective PRMT inhibitors helped define physiological roles for protein arginine methyltransferases (PRMTs) linking them to diseases such as cancer and metabolic, neurodegenerative, and muscular disorders. This review describes the recent molecular advances that have been uncovered in normal and diseased mammalian cells. Copyright © 2017 Elsevier Inc. All rights reserved.

Does L-arginine induce intestinal adaptation by epithelial growth factor?

PubMed

Camli, Alparslan; Barlas, Meral; Yagmurlu, Aydin

2005-01-01

To evaluate whether L-Arginine has an effect on endogenous epidermal growth factor secretion and intestinal adaptation in massive small bowel resection an experimental study was performed. Fourteen albino Wistar rats weighing 250-300 g were used for the study. After performing 50% small bowel resection and anastomosis the rats were randomly divided into two groups. The first group received 500 mg/kg/day of L-Arginine intraperitoneally for 14 days just after the surgical procedure. The control group received isotonic saline instead. Body weight measurement was preformed daily. At the end of the second postoperative week all rats underwent relaparotomy. Small bowel was resected for histopathological examination. Levels of epidermal growth factor were measured by enzyme-linked immunosorbent assay in serum, saliva, and urine at the end of second postoperative week in both groups. The weight gain was higher in the L-Arginine treated group (P < 0.05). Serum, saliva and urinary epidermal growth factor levels were significantly higher at the end of the second week compared to the control group (P < 0.05). The villus height was higher on histopathological examination in L-Arginine treated group compared to the control group (P < 0.05). L-Arginine resulted in a better intestinal adaptation after massive bowel resection. The high levels of epidermal growth factor in body fluids of L-Arginine treated rats could be the explanation for this effect.

Stimulated nitric oxide production and arginine deficiency in children with cystic fibrosis with nutritional failure.

PubMed

Engelen, Mariëlle P K J; Com, Gulnur; Luiking, Yvette C; Deutz, Nicolaas E P

2013-08-01

To determine whether upregulated whole body de novo arginine synthesis and protein breakdown are present as a compensatory mechanism to meet the increased demand for arginine and nitric oxide (NO) production in pediatric patients with cystic fibrosis (CF) and nutritional failure. In 16 children with CF, studied at the end of antibiotic treatment for a pulmonary exacerbation, and 17 healthy controls, whole body arginine, citrulline (Cit), and protein turnover were assessed by stable isotope methodology and de novo arginine synthesis, arginine clearance, NO synthesis, protein synthesis and breakdown, and net protein balance were calculated. The plasma isotopic enrichments and amino acid concentrations were measured by liquid chromatography-tandem mass spectrometry. Increased arginine clearance was found in patients with CF (P < .001), whereas whole body NO production rate and plasma arginine levels were not different. Whole body arginine production (P < .001), de novo arginine synthesis, and protein breakdown and synthesis (P < .05) were increased in patients with CF, but net protein balance was comparable. Patients with CF with nutritional failure (n = 7) had significantly higher NO production (P < .05), de novo arginine synthesis, Cit production (P < .001), and plasma Cit concentration (P < .05) and lower plasma arginine concentration (P < .05) than those without nutritional failure (n = 9). Nutritional failure in CF is associated with increased NO production. However, up-regulation of de novo arginine synthesis and Cit production was not sufficient to meet the increased arginine needs leading to arginine deficiency. Copyright © 2013 Mosby, Inc. All rights reserved.

Importance of the Active Site "Canopy" Residues in an O2-Tolerant [NiFe]-Hydrogenase.

PubMed

Brooke, Emily J; Evans, Rhiannon M; Islam, Shams T A; Roberts, Gerri M; Wehlin, Sara A M; Carr, Stephen B; Phillips, Simon E V; Armstrong, Fraser A

2017-01-10

The active site of Hyd-1, an oxygen-tolerant membrane-bound [NiFe]-hydrogenase from Escherichia coli, contains four highly conserved residues that form a "canopy" above the bimetallic center, closest to the site at which exogenous agents CO and O 2 interact, substrate H 2 binds, and a hydrido intermediate is stabilized. Genetic modification of the Hyd-1 canopy has allowed the first systematic and detailed kinetic and structural investigation of the influence of the immediate outer coordination shell on H 2 activation. The central canopy residue, arginine 509, suspends a guanidine/guanidinium side chain at close range above the open coordination site lying between the Ni and Fe atoms (N-metal distance of 4.4 Å): its replacement with lysine lowers the H 2 oxidation rate by nearly 2 orders of magnitude and markedly decreases the H 2 /D 2 kinetic isotope effect. Importantly, this collapse in rate constant can now be ascribed to a very unfavorable activation entropy (easily overriding the more favorable activation enthalpy of the R509K variant). The second most important canopy residue for H 2 oxidation is aspartate 118, which forms a salt bridge to the arginine 509 headgroup: its mutation to alanine greatly decreases the H 2 oxidation efficiency, observed as a 10-fold increase in the potential-dependent Michaelis constant. Mutations of aspartate 574 (also salt-bridged to R509) to asparagine and proline 508 to alanine have much smaller effects on kinetic properties. None of the mutations significantly increase sensitivity to CO, but neutralizing the expected negative charges from D118 and D574 decreases O 2 tolerance by stabilizing the oxidized resting Ni III -OH state ("Ni-B"). An extensive model of the catalytic importance of residues close to the active site now emerges, whereby a conserved gas channel culminates in the arginine headgroup suspended above the Ni and Fe.

The phenotypic spectrum in patients with arginine to cysteine mutations in the COL2A1 gene

PubMed Central

Hoornaert, K P; Dewinter, C; Vereecke, I; Beemer, F A; Courtens, W; Fryer, A; Fryssira, H; Lees, M; Müllner‐Eidenböck, A; Rimoin, D L; Siderius, L; Superti‐Furga, A; Temple, K; Willems, P J; Zankl, A; Zweier, C; De Paepe, A; Coucke, P; Mortier, G R

2006-01-01

Background The majority of COL2A1 missense mutations are substitutions of obligatory glycine residues in the triple helical domain. Only a few non‐glycine missense mutations have been reported and among these, the arginine to cysteine substitutions predominate. Objective To investigate in more detail the phenotype resulting from arginine to cysteine mutations in the COL2A1 gene. Methods The clinical and radiographic phenotype of all patients in whom an arginine to cysteine mutation in the COL2A1 gene was identified in our laboratory, was studied and correlated with the abnormal genotype. The COL2A1 genotyping involved DHPLC analysis with subsequent sequencing of the abnormal fragments. Results Six different mutations (R75C, R365C, R519C, R704C, R789C, R1076C) were found in 11 unrelated probands. Each mutation resulted in a rather constant and site‐specific phenotype, but a perinatally lethal disorder was never observed. Spondyloarthropathy with normal stature and no ocular involvement were features of patients with the R75C, R519C, or R1076C mutation. Short third and/or fourth toes was a distinguishing feature of the R75C mutation and brachydactyly with enlarged finger joints a key feature of the R1076C substitution. Stickler dysplasia with brachydactyly was observed in patients with the R704C mutation. The R365C and R789C mutations resulted in classic Stickler dysplasia and spondyloepiphyseal dysplasia congenita (SEDC), respectively. Conclusions Arginine to cysteine mutations are rather infrequent COL2A1 mutations which cause a spectrum of phenotypes including classic SEDC and Stickler dysplasia, but also some unusual entities that have not yet been recognised and described as type II collagenopathies. PMID:16155195

Association of plasma arginine with breast cancer molecular subtypes in women of Liaoning province.

PubMed

Hu, Lu; Gao, Yu; Cao, Yunfeng; Zhang, Yinxu; Xu, Minghao; Wang, Yuanyuan; Jing, Yu; Guo, Shengnan; Jing, Fangyu; Hu, Xiaodan; Zhu, Zhitu

2016-12-01

Arginine is one of the human nonessential amino acids critical for the growth of human cancers. The aim of this study is to investigate the variation of arginine between breast cancer (BC) patients and benign mammary gland disease (control) patients to determine its value in predicting the risk of BC. We also explore the associations between arginine levels and breast cancer subtypes. Preoperative blood samples were obtained from 267 patients (102 BC and 165 controls) in 2015. Plasma arginine values were determined for all preoperative blood samples using liquid chromatography-tandem mass spectrometry (LC-MS/MS) to analyse differences in arginine levels between BC patients and control patients and the correlations between arginine and clinicopathologic parameters in BC. The arginine levels of BC patients were significantly lower than those of control patients (5.96 [3.76-12.47] vs. 12.54 [7.14-24.94], P = 0.000). The area under the curve (AUC) for arginine was 0.721 (95% CI, 0.660-0.782, P < 0.0001). The concentration of arginine was significantly different among different molecular BC subtypes (P = 0.030). Our results suggested that plasma arginine was associated with breast cancer molecular subtypes. © 2016 IUBMB Life, 68(12):980-984, 2016. © 2016 International Union of Biochemistry and Molecular Biology.

Lactic acid bacteria isolated from apples are able to catabolise arginine.

PubMed

Savino, María J; Sánchez, Leandro A; Saguir, Fabiana M; de Nadra, María C Manca

2012-03-01

We investigated the potentiality of lactic acid bacteria (LAB) isolated from two apples variety to utilize arginine at different initial pH values. Apples surface contained average levels of bacteria ranging from log 2.49 ± 0.53 to log 3.73 ± 0.48 cfu/ml for Red Delicious and Golden Delicious varieties, respectively. Thirty-one strains able to develop in presence of arginine at low pH were phenotypically and genotipically identified as belonging to Lactobacillus, Pediococcus and Leuconostoc genera. In general, they did not produce ammonia from arginine when cultivated in basal medium with arginine (BMA) at pH 4.5 or 5.2. When this metabolite was quantified only six strains belonging to Leuconostoc dextranicum, Lactobacillus brevis and Lactobacillus plantarum species formed higher ammonia amounts in BMA as compared to control. This was correlated with arginine utilization and it was more pronounced at pH 4.5 than 5.2. Analysis of citrulline production confirmed the arginine utilization in these bacteria by the arginine deiminase (ADI) pathway. Maxima citrulline production was observed for Lactobacillus brevis M15 at the two pH values. In this strain ammonia was formed at higher rate than citrulline, which was detected in concentration lower than 1 mM. Thus, main LAB species found on apple surfaces with abilities to degrade arginine by the ADI pathway under different conditions were reported here at the first time. The results suggested that the ADI pathway in apples LAB might not be mainly relevant for their survival in the acid natural environmental, despite leading to the ammonia formation, which may contribute to the increase in pH, coping the acid stress.

An Arginine Deprivation Response Pathway Is Induced in Leishmania during Macrophage Invasion

PubMed Central

Strasser, Rona; Zeituni-Molad, Michal; Bendelak, Keren; Rentsch, Doris; Ephros, Moshe; Wiese, Martin; Jardim, Armando; Myler, Peter J.; Zilberstein, Dan

2016-01-01

Amino acid sensing is an intracellular function that supports nutrient homeostasis, largely through controlled release of amino acids from lysosomal pools. The intracellular pathogen Leishmania resides and proliferates within human macrophage phagolysosomes. Here we describe a new pathway in Leishmania that specifically senses the extracellular levels of arginine, an amino acid that is essential for the parasite. During infection, the macrophage arginine pool is depleted due to its use to produce metabolites (NO and polyamines) that constitute part of the host defense response and its suppression, respectively. We found that parasites respond to this shortage of arginine by up-regulating expression and activity of the Leishmania arginine transporter (LdAAP3), as well as several other transporters. Our analysis indicates the parasite monitors arginine levels in the environment rather than the intracellular pools. Phosphoproteomics and genetic analysis indicates that the arginine-deprivation response is mediated through a mitogen-activated protein kinase-2-dependent signaling cascade. PMID:27043018

Discovery and mechanistic study of a class of protein arginine methylation inhibitors.

PubMed

Feng, You; Li, Mingyong; Wang, Binghe; Zheng, Yujun George

2010-08-26

Protein arginine methylation regulates multiple biological processes such as chromatin remodeling and RNA splicing. Malfunction of protein arginine methyltransferases (PRMTs) is correlated with many human diseases. Thus, small molecule inhibitors of protein arginine methylation are of great potential for therapeutic development. Herein, we report a type of compound that blocks PRMT1-mediated arginine methylation at micromolar potency through a unique mechanism. Most of the discovered compounds bear naphthalene and sulfonate groups and are structurally different from typical PRMT substrates, for example, histone H4 and glycine- and arginine-rich sequences. To elucidate the molecular basis of inhibition, we conducted a variety of kinetic and biophysical assays. The combined data reveal that this type of naphthyl-sulfo (NS) molecule directly targets the substrates but not PRMTs for the observed inhibition. We also found that suramin effectively inhibited PRMT1 activity. These findings about novel PRMT inhibitors and their unique inhibition mechanism provide a new way for chemical regulation of protein arginine methylation.

Mitochondrial dysfunction in brain cortex mitochondria of STZ-diabetic rats: effect of l-Arginine.

PubMed

Ortiz, M Del Carmen; Lores-Arnaiz, Silvia; Albertoni Borghese, M Florencia; Balonga, Sabrina; Lavagna, Agustina; Filipuzzi, Ana Laura; Cicerchia, Daniela; Majowicz, Monica; Bustamante, Juanita

2013-12-01

Mitochondrial dysfunction has been implicated in many diseases, including diabetes. It is well known that oxygen free radical species are produced endogenously by mitochondria, and also nitric oxide (NO) by nitric oxide synthases (NOS) associated to mitochondrial membranes, in consequence these organelles constitute main targets for oxidative damage. The aim of this study was to analyze mitochondrial physiology and NO production in brain cortex mitochondria of streptozotocin (STZ) diabetic rats in an early stage of diabetes and the potential effect of L-arginine administration. The diabetic condition was characterized by a clear hyperglycaemic state with loose of body weight after 4 days of STZ injection. This hyperglycaemic state was associated with mitochondrial dysfunction that was evident by an impairment of the respiratory activity, increased production of superoxide anion and a clear mitochondrial depolarization. In addition, the alteration in mitochondrial physiology was associated with a significant decrease in both NO production and nitric oxide synthase type I (NOS I) expression associated to the mitochondrial membranes. An increased level of thiobarbituric acid-reactive substances (TBARS) in brain cortex homogenates from STZ-diabetic rats indicated the presence of lipid peroxidation. L-arginine treatment to diabetic rats did not change blood glucose levels but significantly ameliorated the oxidative stress evidenced by lower TBARS and a lower level of superoxide anion. This effect was paralleled by improvement of mitochondrial respiratory function and a partial mitochondrial repolarization.In addition, the administration of L-arginine to diabetic rats prevented the decrease in NO production and NOSI expression. These results could indicate that exogenously administered L-arginine may have beneficial effects on mitochondrial function, oxidative stress and NO production in brain cortex mitochondria of STZ-diabetic rats.

Manipulation of arginase expression modulates abiotic stress tolerance in Arabidopsis: effect on arginine metabolism and ROS accumulation

PubMed Central

Chan, Zhulong

2013-01-01

Arginine is an important medium for the transport and storage of nitrogen, and arginase (also known as arginine amidohydrolase, ARGAH) is responsible for catalyse of arginine into ornithine and urea in plants. In this study, the impact of AtARGAHs on abiotic stress response was investigated by manipulating AtARGAHs expression. In the knockout mutants of AtARGAHs, enhanced tolerances were observed to multiple abiotic stresses including water deficit, salt, and freezing stresses, while AtARGAH1- and AtARGAH2-overexpressing lines exhibited reduced abiotic stress tolerances compared to the wild type. Consistently, the enhanced tolerances were confirmed by the changes of physiological parameters including electrolyte leakage, water loss rate, stomatal aperture, and survival rate. Interestingly, the direct downstream products of arginine catabolism including polyamines and nitric oxide (NO) concentrations significantly increased in the AtARGAHs-knockout lines, but decreased in overexpressing lines under control conditions. Additionally, the AtARGAHs-overexpressing and -knockout lines displayed significantly reduced relative arginine (% of total free amino acids) relative to the wild type. Similarly, reactive oxygen species accumulation was remarkably regulated by AtARGAHs under abiotic stress conditions, as shown from hydrogen peroxide (H2O2), superoxide radical () concentrations, and antioxidant enzyme activities. Taken together, this is the first report, as far as is known, to provide evidence that AtARGAHs negatively regulate many abiotic stress tolerances, at least partially, attribute to their roles in modulating arginine metabolism and reactive oxygen species accumulation. Biotechnological strategy based on manipulation of AtARGAHs expression will be valuable for future crop breeding. PMID:23378380

Effects of a chronic l-arginine supplementation on the arginase pathway in aged rats.

PubMed

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

Associating cooking additives with sodium hydroxide to pretreat bamboo residues for improving the enzymatic saccharification and monosaccharides production.

PubMed

Huang, Caoxing; He, Juan; Wang, Yan; Min, Douyong; Yong, Qiang

2015-10-01

Cooking additive pulping technique is used in kraft mill to increase delignification degree and pulp yield. In this work, cooking additives were firstly applied in the sodium hydroxide pretreatment for improving the bioconversion of bamboo residues to monosaccharides. Meanwhile, steam explosion and sulfuric acid pretreatments were also carried out on the sample to compare their impacts on monosaccharides production. Results indicated that associating anthraquinone with sodium hydroxide pretreatment showed the best performance in improving the original carbohydrates recovery, delignification, enzymatic saccharification, and monosaccharides production. After consecutive pretreatment and enzymatic saccharification process, 347.49 g, 307.48 g, 142.93 g, and 87.15 g of monosaccharides were released from 1000 g dry bamboo residues pretreated by sodium hydroxide associating with anthraquinone, sodium hydroxide, steam explosion and sulfuric acid, respectively. The results suggested that associating cooking additive with sodium hydroxide is an effective pretreatment for bamboo residues to enhance enzymatic saccharification for monosaccharides production. Copyright © 2015 Elsevier Ltd. All rights reserved.

The Topology of the l-Arginine Exporter ArgO Conforms to an Nin-Cout Configuration in Escherichia coli: Requirement for the Cytoplasmic N-Terminal Domain, Functional Helical Interactions, and an Aspartate Pair for ArgO Function.

PubMed

Pathania, Amit; Gupta, Arvind Kumar; Dubey, Swati; Gopal, Balasubramanian; Sardesai, Abhijit A

2016-12-01

ArgO and LysE are members of the LysE family of exporter proteins and ordinarily mediate the export of l-arginine (Arg) in Escherichia coli and l-lysine (Lys) and Arg in Corynebacterium glutamicum, respectively. Under certain conditions, ArgO also mediates Lys export. To delineate the arrangement of ArgO in the cytoplasmic membrane of E. coli, we have employed a combination of cysteine accessibility in situ, alkaline phosphatase fusion reporters, and protein modeling to arrive at a topological model of ArgO. Our studies indicate that ArgO assumes an N in -C out configuration, potentially forming a five-transmembrane helix bundle flanked by a cytoplasmic N-terminal domain (NTD) comprising roughly its first 38 to 43 amino acyl residues and a short periplasmic C-terminal region (CTR). Mutagenesis studies indicate that the CTR, but not the NTD, is dispensable for ArgO function in vivo and that a pair of conserved aspartate residues, located near the opposing edges of the cytoplasmic membrane, may play a pivotal role in facilitating transmembrane Arg flux. Additional studies on amino acid substitutions that impair ArgO function in vivo and their derivatives bearing compensatory amino acid alterations indicate a role for intramolecular interactions in the Arg export mechanism, and some interactions are corroborated by normal-mode analyses. Lastly, our studies suggest that ArgO may exist as a monomer in vivo, thus highlighting the requirement for intramolecular interactions in ArgO, as opposed to interactions across multiple ArgO monomers, in the formation of an Arg-translocating conduit. The orthologous proteins LysE of C. glutamicum and ArgO of E. coli function as exporters of the basic amino acids l-arginine and l-lysine and the basic amino acid l-arginine, respectively, and LysE can functionally substitute for ArgO when expressed in E. coli Notwithstanding this functional equivalence, studies reported here show that ArgO possesses a membrane topology that is distinct

The Topology of the l-Arginine Exporter ArgO Conforms to an Nin-Cout Configuration in Escherichia coli: Requirement for the Cytoplasmic N-Terminal Domain, Functional Helical Interactions, and an Aspartate Pair for ArgO Function

PubMed Central

Pathania, Amit; Gupta, Arvind Kumar; Dubey, Swati; Gopal, Balasubramanian

2016-01-01

ABSTRACT ArgO and LysE are members of the LysE family of exporter proteins and ordinarily mediate the export of l-arginine (Arg) in Escherichia coli and l-lysine (Lys) and Arg in Corynebacterium glutamicum, respectively. Under certain conditions, ArgO also mediates Lys export. To delineate the arrangement of ArgO in the cytoplasmic membrane of E. coli, we have employed a combination of cysteine accessibility in situ, alkaline phosphatase fusion reporters, and protein modeling to arrive at a topological model of ArgO. Our studies indicate that ArgO assumes an Nin-Cout configuration, potentially forming a five-transmembrane helix bundle flanked by a cytoplasmic N-terminal domain (NTD) comprising roughly its first 38 to 43 amino acyl residues and a short periplasmic C-terminal region (CTR). Mutagenesis studies indicate that the CTR, but not the NTD, is dispensable for ArgO function in vivo and that a pair of conserved aspartate residues, located near the opposing edges of the cytoplasmic membrane, may play a pivotal role in facilitating transmembrane Arg flux. Additional studies on amino acid substitutions that impair ArgO function in vivo and their derivatives bearing compensatory amino acid alterations indicate a role for intramolecular interactions in the Arg export mechanism, and some interactions are corroborated by normal-mode analyses. Lastly, our studies suggest that ArgO may exist as a monomer in vivo, thus highlighting the requirement for intramolecular interactions in ArgO, as opposed to interactions across multiple ArgO monomers, in the formation of an Arg-translocating conduit. IMPORTANCE The orthologous proteins LysE of C. glutamicum and ArgO of E. coli function as exporters of the basic amino acids l-arginine and l-lysine and the basic amino acid l-arginine, respectively, and LysE can functionally substitute for ArgO when expressed in E. coli. Notwithstanding this functional equivalence, studies reported here show that ArgO possesses a membrane topology

ORAL DELIVERY OF L-ARGININE STIMULATES PROSTAGLANDIN-DEPENDENT SECRETORY DIARRHEA IN C. PARVUM INFECTED NEONATAL PIGLETS

PubMed Central

Gookin, Jody L.; Foster, Derek M.; Coccaro, Maria R.; Stauffer, Stephen H.

2008-01-01

Objectives To determine if oral supplementation with L-arginine could augment nitric oxide (NO) synthesis and promote epithelial defense in neonatal piglets infected with C. parvum. Methods Neonatal piglets were fed a liquid milk replacer and on day 3 of age infected or not with 108 C. parvum oocysts and the milk replacer supplemented with L-arginine or L-alanine. Milk consumption, body weight, fecal consistency, and oocyst excretion were recorded daily. On day 3 post-infection, piglets were euthanized, and serum concentration of NO metabolites and histological severity of villous atrophy and epithelial infection were quantified. Sheets of ileal mucosa were mounted in Ussing chambers for measurement of barrier function (transepithelial resistance (TER) and permeability) and short-circuit current (Isc; an indirect measurement of Cl− secretion in this tissue). Results C. parvum infected piglets had large numbers of epithelial parasites, villous atrophy, decreased barrier function, severe watery diarrhea, and failure to gain weight. L-arginine promoted synthesis of NO by infected piglets which was unaccompanied by improvement in severity of infection but rather promoted epithelial chloride secretion and diarrhea. Epithelial secretion by infected mucosa from L-arginine supplemented piglets was fully inhibited by the cyclooxygenase inhibitor indomethacin, indicating that prostaglandin synthesis was responsible for this effect. Conclusions Results of these studies demonstrate that provision of additional NO substrate in the form of L-arginine incites prostaglandin-dependent secretory diarrhea and does not promote epithelial defense or barrier function of C. parvum infected neonatal ileum. PMID:18223372

Mechanism of arginine sensing by CASTOR1 upstream of mTORC1

PubMed Central

Saxton, Robert A.; Chantranupong, Lynne; Knockenhauer, Kevin E.; Schwartz, Thomas U.; Sabatini, David M.

2016-01-01

Summary The mechanistic Target of Rapamycin Complex 1 (mTORC1) is a major regulator of eukaryotic growth that coordinates anabolic and catabolic cellular processes with inputs such as growth factors and nutrients, including amino acids1–3. In mammals, arginine is particularly important and promotes diverse physiological effects including immune cell activation, insulin secretion, and muscle growth, largely through activation of mTORC14–7. Arginine activates mTORC1 upstream of the Rag GTPases8, through either the lysosomal amino acid transporter SLC38A9 or the GATOR2-interacting CASTOR1 (Cellular Arginine Sensor for mTORC1)9–12. However, the mechanism by which the mTORC1 pathway detects and transmits the arginine signal has been elusive. Here, we present the 1.8 Å crystal structure of arginine-bound CASTOR1. Homodimeric CASTOR1 binds arginine at the interface of two ACT domains, enabling allosteric control of the adjacent GATOR2-binding site to trigger dissociation from GATOR2 and the downstream activation of mTORC1. Our data reveal that CASTOR1 shares substantial structural homology with the lysine-binding regulatory domain of prokaryotic aspartate kinases, suggesting that the mTORC1 pathway exploited an ancient amino-acid-dependent allosteric mechanism to acquire arginine sensitivity. Together, these results establish a structural basis for arginine sensing by the mTORC1 pathway and provide insights into the evolution of a mammalian nutrient sensor. PMID:27487210

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

PubMed

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

2014-11-01

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 in humans via the intestinal-renal axis. Therefore, we hypothesized that parenteral glutamine supplementation may stimulate the interorgan pathway of arginine production. The objectives were to quantify arginine production from its precursor glutamine and to establish the contribution of the kidneys to de novo synthesis of arginine in patients receiving intravenous supplementation of glutamine dipeptide during major abdominal surgery. Whole-body and renal metabolism of glutamine, citrulline, and arginine was assessed by stable isotope techniques in 7 patients receiving a perioperative supplement of intravenous alanyl-glutamine (0.5 g · kg(-1) · d(-1)). Plasma glutamine, citrulline, and arginine concentrations increased significantly in patients receiving intravenous glutamine dipeptide. At whole-body level, 91% of total citrulline turnover was derived from glutamine, whereas 49% of whole-body citrulline turnover was used for de novo synthesis of arginine. The kidneys were responsible for 75% of whole-body arginine production from citrulline. Glutamine and citrulline are important sources for de novo arginine synthesis. The kidneys are the main production site for endogenous arginine. After comparison of these results with previous similar studies, our data suggest that an intravenous glutamine supplement doubles renal arginine production from citrulline. This trial was registered at www.trialregister.nl as NTR2914. © 2014 American Society for Nutrition.

Simultaneous ablation of prmt-1 and prmt-5 abolishes asymmetric and symmetric arginine dimethylations in Caenorhabditis elegans.

PubMed

Hirota, Keiko; Shigekawa, Chihiro; Araoi, Sho; Sha, Liang; Inagawa, Takayuki; Kanou, Akihiko; Kako, Koichiro; Daitoku, Hiroaki; Fukamizu, Akiyoshi

2017-06-01

Protein arginine methyltransferases (PRMTs) catalyze the transfer of a methyl group from S-adenosylmethionine to arginine residues and are classified into two types: type I producing asymmetric dimethylarginine (ADMA) and type II producing symmetric dimethylarginine (SDMA). PRMTs have been shown to regulate many cellular processes, including signal transduction, transcriptional regulation and RNA processing. Since the loss-of-function mutation of PRMT1 and PRMT5, each of which is the predominant type I and II, respectively, causes embryonic lethality in mice, their physiological significance at the whole-body level remains largely unknown. Here, we show the morphological and functional phenotypes of single or double null alleles of prmt-1 and prmt-5 in Caenorhabditis elegans. The prmt-1;prmt-5 double mutants are viable, and exhibit short body length and small brood size compared to N2 and each of the single mutants. The liquid chromatography-tandem mass spectrometry analysis demonstrated that the levels of ADMA and SDMA were abolished in the prmt-1;prmt-5 double mutants. Both prmt-1 and prmt-5 were required for resistance to heat and oxidative stresses, whereas prmt-5 is not involved in lifespan regulation even when prmt-1 is ablated. This mutant strain would be a useful model animal for investigating the role of asymmetric and symmetric arginine dimethylation in vivo. © The Authors 2017. Published by Oxford University Press on behalf of the Japanese Biochemical Society. All rights reserved.

Efficiency of cardioplegic solutions containing L-arginine and L-aspartic acid.

PubMed

Pisarenko, O I; Shul'zhenko, V S; Studneva, I M

2006-04-01

In experiments on rats we studied the effects of cardioplegic solutions with L-aspartic acid or L-arginine on functional recovery and metabolism of isolated working heart after 40-min normothermal global ischemia and 30-min reperfusion. After reperfusion of the hearts preventively protected with cardioplegic solution containing L-aspartic acid or L-arginine, coronary flow decreased in comparison with the initial values. As a component of cardioplegic solution, L-arginine was less efficient in recovery of contractility and cardiac output of the hearts in comparison with L-aspartic acid. In hearts protected with L-aspartic acid, the postischemic levels of ATP and phosphocreatine were significantly higher, and the level of lactate was significantly lower than in hearts protected with L-arginine. In comparison with L-arginine, L-aspartic acid is a more efficient component of cardioplegic solution in protection of the heart from metabolic and functional damages caused by global ischemia and reperfusion.

Supplementation with a combination of beta-hydroxy-beta-methylbutyrate (HMB), arginine, and glutamine is safe and could improve hematological parameters.

PubMed

Rathmacher, J A; Nissen, S; Panton, L; Clark, R H; Eubanks May, P; Barber, A E; D'Olimpio, J; Abumrad, N N

2004-01-01

Combining the amino acids arginine and glutamine with the leucine metabolite beta-hydroxy-beta-methylbutyrate (HMB) has been shown to reverse lean tissue loss in cancer and acquired immunodeficiency syndrome (AIDS) patients. Although each of these nutrients has been shown to be safe, the safety of this mixture has not been reported. Three double-blind studies examined the safety of the combination of HMB, arginine and glutamine on blood chemistries, hematology, emotional profile, and adverse events. Study 1 was conducted in healthy adult males (n = 34), study 2 was in HIV patients with AIDS-associated weight loss (n = 43), and study 3 was in cancer patients with wasting (n = 32). Volunteers were assigned to either a placebo or a mixture of 3 g HMB, 14 g arginine, and 14 g glutamine per day. Across the 3 studies, HMB, arginine, and glutamine supplementation was not associated with any adverse indicators of health. The only significant changes noted were positive indicators of health status. HMB, arginine, and glutamine supplementation was associated with an improvement in emotional profile (p = .05), a decreased feeling of weakness (p = .03), and increased red blood cells, hemoglobin, hematocrit, lymphocytes, and eosinophils (p < .05) when compared with placebo-supplemented subjects. Blood creatinine levels were not changed. However, blood urea nitrogen increased (p = .01) with HMB, arginine, and glutamine supplementation, which was possibly caused by the additional nitrogen consumed or to the fact that ureagenesis is influenced by arginine and glutamine supplementation. These results show that HMB, arginine, and glutamine can be safely used to treat muscle wasting associated with AIDS and cancer.

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

PubMed

Tharakan, John F; Yu, Yong M; Zurakowski, David; Roth, Rachel M; Young, Vernon R; Castillo, Leticia

2008-08-01

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 healthy subjects. Ten healthy adults received a complete amino acid diet for 1 week (control diet) and following a break period, six subjects received a 4-week arginine, proline, glutamate and aspartate-free diet (APF diet). The other four subjects continued for 4 weeks with the complete diet. On days 4 and 7 of the first week and days 25 and 28 of the 4-week period, the subjects received 24-h infusions of arginine, citrulline, leucine and urea tracers. During the 4-week APF, plasma arginine fluxes for the fed state, were significantly reduced. There were no significant differences for citrulline, leucine or urea fluxes. Arginine de novo synthesis was not affected by the APF intake. However, arginine oxidation was significantly decreased. In healthy adults, homeostasis of arginine under a long term arginine- and precursor-free intake is achieved by decreasing catabolic rates, while de novo arginine synthesis is maintained.

Inhibition of lytic infection of pseudorabies virus by arginine depletion

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

Wang, H.-C.; Kao, Y.-C.; Chang, T-J.

2005-08-26

Pseudorabies virus (PRV) is a member of Alphahepesviruses; it is an enveloped virus with a double-stranded DNA genome. Polyamines (such as spermine and spermidine) are ubiquitous in animal cells and participate in cellular proliferation and differentiation. Previous results of our laboratory showed that the PRV can accomplish lytic infection either in the presence of exogenous spermine (or spermidine) or depletion of cellular polyamines. The amino acid arginine is a precursor of polyamine biosynthesis. In this work, we investigated the role of arginine in PRV infection. It was found that the plaque formation of PRV was inhibited by arginase (enzyme catalyzingmore » the conversion of arginine into ornithine and urea) treatment whereas this inhibition can be reversed by exogenous arginine, suggesting that arginine is essential for PRV proliferation. Western blotting was conducted to study the effect of arginine depletion on the levels of structural proteins of PRV in virus-infected cells. Four PRV structural proteins (gB, gE, UL47, and UL48) were chosen for examination, and results revealed that the levels of viral proteins were obviously reduced in long time arginase treatment. However, the overall protein synthesis machinery was apparently not influenced by arginase treatment either in mock or PRV-infected cells. Analyzing with native gel, we found that arginase treatment affected the mobility of PRV structural proteins, suggesting the conformational change of viral proteins by arginine depletion. Heat shock proteins, acting as molecular chaperons, participate in protein folding and translocation. Our results demonstrated that long time arginase treatment could reduce the expression of cellular heat shock proteins 70 (hsc70 and hsp70), and transcriptional suppression of heat shock protein 70 gene promoter was one of the mechanisms involved in this reduced expression.« less

Reengineering of a Corynebacterium glutamicum L-arginine and L-citrulline producer.

PubMed

Ikeda, Masato; Mitsuhashi, Satoshi; Tanaka, Kenji; Hayashi, Mikiro

2009-03-01

Toward the creation of a robust and efficient producer of L-arginine and L-citrulline (arginine/citrulline), we have performed reengineering of a Corynebacterium glutamicum strain by using genetic information of three classical producers. Sequence analysis of their arg operons identified three point mutations (argR123, argG92(up), and argG45) in one producer and one point mutation (argB26 or argB31) in each of the other two producers. Reconstitution of the former three mutations or of each argB mutation on a wild-type genome led to no production. Combined introduction of argB26 or argB31 with argR123 into a wild type gave rise to arginine/citrulline production. When argR123 was replaced by an argR-deleted mutation (Delta argR), the production was further increased. The best mutation set, Delta argR and argB26, was used to screen for the highest productivity in the backgrounds of different wild-type strains of C. glutamicum. This yielded a robust producer, RB, but the production was still one-third of that of the best classical producer. Transcriptome analysis revealed that the arg operon of the classical producer was much more highly upregulated than that of strain RB. Introduction of leuC456, a mutation derived from a classical L-lysine producer and provoking global induction of the amino acid biosynthesis genes, including the arg operon, into strain RB led to increased production but incurred retarded fermentation. On the other hand, replacement of the chromosomal argB by heterologous Escherichia coli argB, natively insensitive to arginine, caused a threefold-increased production without retardation, revealing that the limitation in strain RB was the activity of the argB product. To overcome this, in addition to argB26, the argB31 mutation was introduced into strain RB, which caused higher deregulation of the enzyme and resulted in dramatically increased production, like the strain with E. coli argB. This reconstructed strain displayed an enhanced performance

L-arginine availability and arginase activity: Characterization of amino acid permease 3 in Leishmania amazonensis.

PubMed

Aoki, Juliana Ide; Muxel, Sandra Marcia; Zampieri, Ricardo Andrade; Acuña, Stephanie Maia; Fernandes, Juliane Cristina Ribeiro; Vanderlinde, Rubia Heloisa; Sales, Maria Carmen Oliveira de Pinho; Floeter-Winter, Lucile Maria

2017-10-01

Leishmania uses the amino acid L-arginine as a substrate for arginase, enzyme that produces urea and ornithine, last precursor of polyamine pathway. This pathway is used by the parasite to replicate and it is essential to establish the infection in the mammalian host. L-arginine is not synthesized by the parasite, so its uptake occurs through the amino acid permease 3 (AAP3). AAP3 is codified by two copies genes (5.1 and 4.7 copies), organized in tandem in the parasite genome. One copy presents the expression regulated by L-arginine availability. RNA-seq data revealed 14 amino acid transporters differentially expressed in the comparison of La-WT vs. La-arg- promastigotes and axenic amastigotes. The 5.1 and 4.7 aap3 transcripts were down-regulated in La-WT promastigotes vs. axenic amastigotes, and in La-WT vs. La-arg- promastigotes. In contrast, transcripts of other transporters were up-regulated in the same comparisons. The amount of 5.1 and 4.7 aap3 mRNA of intracellular amastigotes was also determined in sample preparations from macrophages, obtained from BALB/c and C57BL/6 mice and the human THP-1 lineage infected with La-WT or La-arg-, revealing that the genetic host background is also important. We also determined the aap3 mRNA and AAP3 protein amounts of promastigotes and axenic amastigotes in different environmental growth conditions, varying pH, temperature and L-arginine availability. Interestingly, the increase of temperature increased the AAP3 level in plasma membrane and consequently the L-arginine uptake, independently of pH and L-arginine availability. In addition, we demonstrated that besides the plasma membrane localization, AAP3 was also localized in the glycosome of L. amazonensis promastigotes and axenic amastigotes. In this report, we described the differential transcriptional profiling of amino acids transporters from La-WT and La-arg- promastigotes and axenic amastigotes. We also showed the increased AAP3 levels under amino acid starvation or

Role of L-arginine in the biological effects of blue light

NASA Astrophysics Data System (ADS)

Makela, Anu M.

2005-11-01

Arginine, a semi-essential amino acid, and metabolites of arginine exert multiple biological effects. It has been known that arginine causes the release of various hormones such as insulin, glucagon, growth hormone, prolactin, and adrenal catecholamines. Arginine infusion also produces vasodilation, and in the kidney increased plasma flow accompanied by increases in glomerular filtration rate (GFR). Recent studies have showed that blue and red light irradiation in vitro and in vivo can increase production of nitric oxide (NO), superoxide anion, and related reactive oxygen species (ROS). These then can modulate the production and secretion of several cytokines and other mediators and play an important role as regulatory mediators in signaling processes which can then modulate the production, mobilization and homing of stem cells. It is proposed that some of the therapeutic effects of light can be considered to be due to the changes in the metabolism of L-arginine. The regulation of L-arginine turnover by the use of light at blue wavelengths between 400nm and 510nm can be the explanation for some of the observed effects of blue light: lowering of blood pressure, pain killing effect, regulating insulin production, anti-inflammatory action, and possible effects on the release and homing of stem cells.

Vegephy: impact of vegetable oils used as extemporaneous additives on pesticide residues and their crop protection potential.

PubMed

Rousseau, G; Coutanceau, P; Lebeau, F; Pigeon, O; Ducat, N; De Vos, P

2013-01-01

Within the framework of the VEGEPHY project set up to assess the effect of refined oils used as extemporaneous additives, both alone and in combination with oligosaccharides (guar, xanthan and carboxymethyl cellulose), on the quality of plant protection treatments for wheat, a study was conducted on the effect of combinations of additives on the level of pesticide residues in wheat plants and grain and their impact on treatment efficiency. The use of some of these additives gave efficiency results that were comparable with those obtained with additives that are currently used but are not bio-based. The use of refined oils as extemporaneous additives, both alone and combined with oligosaccharides, led to better penetration by the pesticide as well as longer persistence of its activity. The experiments were conducted with fungicides, herbicides, plant growth regulators and various types of formulation (EC, SC and WG). The results obtained were conclusive, but they did depend on the physico-chemical properties of the active substance. The risk of exceeding the maximum residue levels (MRLs) of pesticides was also evaluated. Even where the MRLs had not been not exceeded, the experiments showed that in some cases the treatment with these additives could lead to pesticide residues up to two times higher than those measured for the treatment without additives. It would be necessary, therefore, to reduce the treatment dose associated with the additive and/or have a long enough pre-harvest interval to avoid exceeding the MRLs. The use of green additives could be a useful and easy way to attain the European Union (EU) goal of reducing pesticide use by improving the retention of active substances on the plant and reducing the number of treatments.

Involvement of l-arginine-nitric oxide pathway in anxiolytic-like effects of zinc chloride in rats.

PubMed

Navabi, Seyedeh Parisa; Eshagh Harooni, Hooman; Moazedi, Ahmad Ali; Khajepour, Lotfolah; Fathinia, Kosar

2016-10-01

Zinc is crucial for normal development of the brain, and Zinc deficiency has been shown to associate with neurological disorders (e.g. anxiety) through interactions with several neurotransmitter systems such as nitric oxide (NO). In this regard, our study aimed to evaluate the possible involvement of l-arginine NO pathway on anxiolytic effects of zinc in adult male rats. Zinc chloride at doses of 2.5 and 10mg/kg (intraperitoneal or ip) or saline (1ml/kg, ip) were injected 30min before the anxiety test. Zinc administrated rats (10mg/kg) were pre-treated with intra-CA1 microinjection of l-arginine in sub-effective dose of 1μg/rat (dorsal hippocampus, vehicle: saline1μl/rat). In addition, zinc chloride and NG-nitro-l-arginine methyl ester (l-NAME) were intraperitoneally co-administrated in sub-effective doses of 2.5mg/kg and 80mg/kg, respectively. The percentage of open arm time (OAT%), percentage of open arm entry (OAE%), as measures of anxiety, and total number of arm entries, as measures of locomotor activity, were recorded. Treatment with zinc (10mg/kg) markedly produced an increase in OAT% and OAE% in the Elevated plus maze test (EPM). A decrease of OAT% and OAE% was shown in groups which received zinc (10mg/kg) and l-arginine (1μg/rat) concomitantly as compared to the control group. Moreover, an increase of OAE% was revealed in the group exposed to Zinc (2.5mg/kg) and l-NAME (80mg/kg) co-administration. Although, Two-way ANOVA showed no significant differences of anxiety indices in rats received drug+zinc chloride in compare to the zinc pretreated with saline group. Anxiolytic- like effect of zinc reversed by nitric oxide precursor l-arginine. Additionally, the synergistic effects of l-NAME and ZnCl 2 were shown in the EPM. Thus our findings suggest that at least in part the anxiolytic effects of zinc can be mediated through the nitric oxide system. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

l-Arginine is a Radioprotector for Hematopoietic Progenitor Cells

PubMed Central

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

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

PubMed Central

Tharakan, John F.; Yu, Yong M.; Zurakowski, David; Roth, Rachel M.; Young, Vernon R.; Castillo, Leticia

2008-01-01

Summary Background & aims 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 healthy subjects. Methods Ten healthy adults received a complete amino acid diet for 1 week (control diet) and following a break period, six subjects received a 4-week arginine, proline, glutamate and aspartate-free diet (APF diet). The other four subjects continued for 4 weeks with the complete diet. On days 4 and 7 of the first week and days 25 and 28 of the 4-week period, the subjects received 24-h infusions of arginine, citrulline, leucine and urea tracers. Results During the 4-week APF, plasma arginine fluxes for the fed state, were significantly reduced. There were no significant differences for citrulline, leucine or urea fluxes. Arginine de novo synthesis was not affected by the APF intake. However, arginine oxidation was significantly decreased. Conclusions In healthy adults, homeostasis of arginine under a long term arginine- and precursor-free intake is achieved by decreasing catabolic rates, while de novo arginine synthesis is maintained. PMID:18590940

Dishevelled3 is a novel arginine methyl transferase substrate.

PubMed

Bikkavilli, Rama Kamesh; Avasarala, Sreedevi; Vanscoyk, Michelle; Sechler, Marybeth; Kelley, Nicole; Malbon, Craig C; Winn, Robert A

2012-01-01

Dishevelled, a phosphoprotein scaffold, is a central component in all the Wnt-sensitive signaling pathways. In the present study, we report that Dishevelled is post-translationally modified, both in vitro and in vivo, via arginine methylation. We also show protein arginine methyl transferases 1 and 7 as the key enzymes catalyzing Dishevelled methylation. Interestingly, Wnt3a stimulation of F9 teratocarcinoma cells results in reduced Dishevelled methylation. Similarly, the methylation-deficient mutant of Dishevelled, R271K, displayed spontaneous membrane localization and robust activation of Wnt signaling; suggesting that differential methylation of Dishevelled plays an important role in Wnt signaling. Thus arginine methylation is shown to be an important switch in regulation of Dishevelled function and Wnt signaling.

Tetrahydrobiopterin, l-Arginine and Vitamin C Act Synergistically to Decrease Oxidant Stress and Increase Nitric Oxide That Increases Blood Flow Recovery after Hindlimb Ischemia in the Rat

PubMed Central

Yan, Jinglian; Tie, Guodong; Messina, Louis M

2012-01-01

Nitric oxide (NO) derived from endothelial nitric oxide synthase (eNOS) is a potent vasodilator and signaling molecule that plays essential roles in neovascularization. During limb ischemia, decreased NO bioavailability occurs secondary to increased oxidant stress, decreased l-arginine and tetrahydrobiopterin. This study tested the hypothesis that dietary cosupplementation with tetrahydrobiopterin (BH4), l-arginine and vitamin C acts synergistically to decrease oxidant stress, increase NO and thereby increase blood flow recovery after hindlimb ischemia. Rats were fed normal chow, chow supplemented with BH4 or l-arginine (alone or in combination) or chow supplemented with BH4 + l-arginine + vitamin C for 1 wk before induction of hindlimb ischemia. In the is-chemic hindlimb, cosupplementation with BH4 + l-arginine resulted in greater eNOS and phospho-eNOS (P-eNOS) expression, Ca2+-dependent NOS activity and NO concentration in the ischemic calf region (gastrocnemius), as well as greater NO concentration in the region of collateral arteries (gracilis). Rats receiving cosupplementation of BH4 + l-arginine led to greater recovery of foot perfusion and greater collateral enlargement than did rats receiving either agent separately. The addition of vitamin C to the BH4 + l-arginine regimen further increased these dependent variables. In addition, rats given all three supplements showed significantly less Ca2+-independent activity, less nitrotyrosine accumulation, greater glutathione (GSH)–to–glutathione disulfide (GSSG) ratio and less gastrocnemius muscle necrosis, on both macroscopic and microscopic levels. In conclusion, co-supplementation with BH4 + l-arginine + vitamin C significantly increased blood flow recovery after hindlimb ischemia by reducing oxidant stress, increasing NO bioavailability, enlarging collateral arteries and reducing muscle necrosis. Oral cosupplementation of BH4, l-arginine and vitamin C holds promise as a biological therapy to induce

Purification and characterization of moschins, arginine-glutamate-rich proteins with translation-inhibiting activity from brown pumpkin (Cucurbita moschata) seeds.

PubMed

Ng, T B; Parkash, A; Tso, W W

2002-10-01

From fresh brown pumpkin seeds, two proteins with a molecular mass of 12kDa and an N-terminal sequence rich in arginine and glutamate residues were obtained. The protein designated alpha-moschin closely resembled the fruitfly programmed-cell death gene product and the protein designated beta-moschin demonstrated striking similarity to prepro 2S albumin in N-terminal sequence. alpha- and beta-moschins inhibited translation in the rabbit reticulocyte lysate system with an IC(50) of 17 microM and 300nM, respectively.

Residual tumor size and IGCCCG risk classification predict additional vascular procedures in patients with germ cell tumors and residual tumor resection: a multicenter analysis of the German Testicular Cancer Study Group.

PubMed

Winter, Christian; Pfister, David; Busch, Jonas; Bingöl, Cigdem; Ranft, Ulrich; Schrader, Mark; Dieckmann, Klaus-Peter; Heidenreich, Axel; Albers, Peter

2012-02-01

Residual tumor resection (RTR) after chemotherapy in patients with advanced germ cell tumors (GCT) is an important part of the multimodal treatment. To provide a complete resection of residual tumor, additional surgical procedures are sometimes necessary. In particular, additional vascular interventions are high-risk procedures that require multidisciplinary planning and adequate resources to optimize outcome. The aim was to identify parameters that predict additional vascular procedures during RTR in GCT patients. A retrospective analysis was performed in 402 GCT patients who underwent 414 RTRs in 9 German Testicular Cancer Study Group (GTCSG) centers. Overall, 339 of 414 RTRs were evaluable with complete perioperative data sets. The RTR database was queried for additional vascular procedures (inferior vena cava [IVC] interventions, aortic prosthesis) and correlated to International Germ Cell Cancer Collaborative Group (IGCCCG) classification and residual tumor volume. In 40 RTRs, major vascular procedures (23 IVC resections with or without prosthesis, 11 partial IVC resections, and 6 aortic prostheses) were performed. In univariate analysis, the necessity of IVC intervention was significantly correlated with IGCCCG (14.1% intermediate/poor vs 4.8% good; p=0.0047) and residual tumor size (3.7% size < 5 cm vs 17.9% size ≥ 5 cm; p < 0.0001). In multivariate analysis, IVC intervention was significantly associated with residual tumor size ≥ 5 cm (odds ratio [OR]: 4.61; p=0.0007). In a predictive model combining residual tumor size and IGCCCG classification, every fifth patient (20.4%) with a residual tumor size ≥ 5 cm and intermediate or poor prognosis needed an IVC intervention during RTR. The need for an aortic prosthesis showed no correlation to either IGCCCG (p=0.1811) or tumor size (p=0.0651). The necessity for IVC intervention during RTR is correlated to residual tumor size and initial IGCCCG classification. Patients with high-volume residual tumors and

Nitric oxide donor augments antineoplastic effects of arginine deprivation in human melanoma cells.

PubMed

Mayevska, Oksana; Chen, Oleh; Karatsai, Olena; Bobak, Yaroslav; Barska, Maryna; Lyniv, Liliana; Pavlyk, Iuliia; Rzhepetskyy, Yuriy; Igumentseva, Natalia; Redowicz, Maria Jolanta; Stasyk, Oleh

2017-06-15

Anticancer therapy based on recombinant arginine-degrading enzymes has been proposed for the treatment of several types of malignant cells deficient in arginine biosynthesis. One of the predicted side effects of such therapy is restricted bioavailability of nitric oxide as arginine catabolic product. Prolonged NO limitation may lead to unwanted disturbances in NO-dependent vasodilation, cardiovascular and immune systems. This problem can be overcome by co-supplementation with exogenous NO donor. However, NO may potentially counteract anticancer effects of therapy based on arginine deprivation. In this study, we evaluate for the first time the effects of an exogenous NO donor, sodium nitroprusside, on viability and metastatic properties of two human melanoma cell lines SK-MEL-28 and WM793 under arginine-deprived conditions. It was revealed that NO did not rescue melanoma cells from specific effects evoked by arginine deprivation, namely decreased viability and induction of apoptosis, dramatically reduced motility, invasiveness and clonogenic potential. Moreover, sodium nitroprusside co-treatment augmented several of these antineoplastic effects. We report that a combination of NO-donor and arginine deprivation strongly and specifically impaired metastatic behavior of melanoma cells. Thus, sodium nitroprusside can be considered as an adjuvant for the more efficient treatment of malignant melanoma and possibly other tumors with arginine-degrading enzymes. Copyright © 2017 Elsevier Inc. All rights reserved.

Effect of additives on the tensile performance and protein solubility of industrial oilseed residual based plastics.

PubMed

Newson, William R; Kuktaite, Ramune; Hedenqvist, Mikael S; Gällstedt, Mikael; Johansson, Eva

2014-07-16

Ten chemical additives were selected from the literature for their proposed modifying activity in protein-protein interactions. These consisted of acids, bases, reducing agents, and denaturants and were added to residual deoiled meals of Crambe abyssinica (crambe) and Brassica carinata (carinata) to modify the properties of plastics produced through hot compression molding at 130 °C. The films produced were examined for tensile properties, protein solubility, molecular weight distribution, and water absorption. Of the additives tested, NaOH had the greatest positive effect on tensile properties, with increases of 105% in maximum stress and 200% in strain at maximum stress for crambe and a 70% increase in strain at maximum stress for carinata. Stiffness was not increased by any of the applied additives. Changes in tensile strength and elongation for crambe and elongation for carinata were related to changes in protein solubility. Increased pH was the most successful in improving the protein aggregation and mechanical properties within the complex chemistry of residual oilseed meals.

Arginine for gestating sows and foetal development: A systematic review.

PubMed

Palencia, J Y P; Lemes, M A G; Garbossa, C A P; Abreu, M L T; Pereira, L J; Zangeronimo, M G

2018-02-01

The use of functional amino acids during pregnancy has been linked to improved reproduction in mammals. In this context, arginine is a precursor in the synthesis of numerous molecules, such as nitric oxide and polyamines, which play an important role during reproduction. However, contradictory studies are found in the literature, particularly regarding the amount of supplementation and the period of pregnancy in which it is used. The objective of this study was to evaluate the effects of dietary arginine supplementation for pregnant sows on foetal development via a systematic review. The search for papers was performed during the month of December 2015, in the databases ISI Web of Science, Science Direct, Scopus, and SciELO. From a total of 5675 returned studies, only 13 papers were selected after applying selection criteria. Most (47%) of the studies that evaluated the effects of dietary arginine supplementation on foetal development in pigs used 1% arginine. Supplementation was initiated in the first third of pregnancy in 47% of tests, including in both primiparous and multiparous sows. These studies showed positive results for embryo survival and foetal development, evidenced by the increase in placental weight and the number and weight of piglets born alive. Of all evaluated studies, 53% showed benefits on foetal development. It is concluded that supplementing dietary arginine in gestating sows can benefit embryo survival and foetal development. However, to establish a supplementation plan with this amino acid, aspects related to the period of pregnancy, supplementation levels, and source of arginine must be well defined. © 2017 Blackwell Verlag GmbH.

Celecoxib-induced gastrointestinal, liver and brain lesions in rats, counteraction by BPC 157 or L-arginine, aggravation by L-NAME

PubMed Central

Drmic, Domagoj; Kolenc, Danijela; Ilic, Spomenko; Bauk, Lara; Sever, Marko; Zenko Sever, Anita; Luetic, Kresimir; Suran, Jelena; Seiwerth, Sven; Sikiric, Predrag

2017-01-01

AIM To counteract/reveal celecoxib-induced toxicity and NO system involvement. METHODS Celecoxib (1 g/kg b.w. ip) was combined with therapy with stable gastric pentadecapeptide BPC 157 (known to inhibit these lesions, 10 μg/kg, 10 ng/kg, or 1 ng/kg ip) and L-arginine (100 mg/kg ip), as well as NOS blockade [N(G)-nitro-L-arginine methyl ester (L-NAME)] (5 mg/kg ip) given alone and/or combined immediately after celecoxib. Gastrointestinal, liver, and brain lesions and liver enzyme serum values in rats were assessed at 24 h and 48 h thereafter. RESULTS This high-dose celecoxib administration, as a result of NO system dysfunction, led to gastric, liver, and brain lesions and increased liver enzyme serum values. The L-NAME-induced aggravation of the lesions was notable for gastric lesions, while in liver and brain lesions the beneficial effect of L-arginine was blunted. L-arginine counteracted gastric, liver and brain lesions. These findings support the NO system mechanism(s), both NO system agonization (L-arginine) and NO system antagonization (L-NAME), that on the whole are behind all of these COX phenomena. An even more complete antagonization was identified with BPC 157 (at both 24 h and 48 h). A beneficial effect was evident on all the increasingly negative effects of celecoxib and L-NAME application and in all the BPC 157 groups (L-arginine + BPC 157; L-NAME + BPC 157; L-NAME + L-arginine + BPC 157). Thus, these findings demonstrated that BPC 157 may equally counteract both COX-2 inhibition (counteracting the noxious effects of celecoxib on all lesions) and additional NOS blockade (equally counteracting the noxious effects of celecoxib + L-NAME). CONCLUSION BPC 157 and L-arginine alleviate gastrointestinal, liver and brain lesions, redressing NSAIDs’ post-surgery application and NO system involvement. PMID:28839430

Celecoxib-induced gastrointestinal, liver and brain lesions in rats, counteraction by BPC 157 or L-arginine, aggravation by L-NAME.

PubMed

Drmic, Domagoj; Kolenc, Danijela; Ilic, Spomenko; Bauk, Lara; Sever, Marko; Zenko Sever, Anita; Luetic, Kresimir; Suran, Jelena; Seiwerth, Sven; Sikiric, Predrag

2017-08-07

To counteract/reveal celecoxib-induced toxicity and NO system involvement. Celecoxib (1 g/kg b.w. ip) was combined with therapy with stable gastric pentadecapeptide BPC 157 (known to inhibit these lesions, 10 μg/kg, 10 ng/kg, or 1 ng/kg ip) and L-arginine (100 mg/kg ip), as well as NOS blockade [N(G)-nitro-L-arginine methyl ester (L-NAME)] (5 mg/kg ip) given alone and/or combined immediately after celecoxib. Gastrointestinal, liver, and brain lesions and liver enzyme serum values in rats were assessed at 24 h and 48 h thereafter. This high-dose celecoxib administration, as a result of NO system dysfunction, led to gastric, liver, and brain lesions and increased liver enzyme serum values. The L-NAME-induced aggravation of the lesions was notable for gastric lesions, while in liver and brain lesions the beneficial effect of L-arginine was blunted. L-arginine counteracted gastric, liver and brain lesions. These findings support the NO system mechanism(s), both NO system agonization (L-arginine) and NO system antagonization (L-NAME), that on the whole are behind all of these COX phenomena. An even more complete antagonization was identified with BPC 157 (at both 24 h and 48 h). A beneficial effect was evident on all the increasingly negative effects of celecoxib and L-NAME application and in all the BPC 157 groups (L-arginine + BPC 157; L-NAME + BPC 157; L-NAME + L-arginine + BPC 157). Thus, these findings demonstrated that BPC 157 may equally counteract both COX-2 inhibition (counteracting the noxious effects of celecoxib on all lesions) and additional NOS blockade (equally counteracting the noxious effects of celecoxib + L-NAME). BPC 157 and L-arginine alleviate gastrointestinal, liver and brain lesions, redressing NSAIDs' post-surgery application and NO system involvement.

An arginine-aspartate network in the active site of bacterial TruB is critical for catalyzing pseudouridine formation.

PubMed

Friedt, Jenna; Leavens, Fern M V; Mercier, Evan; Wieden, Hans-Joachim; Kothe, Ute

2014-04-01

Pseudouridine synthases introduce the most common RNA modification and likely use the same catalytic mechanism. Besides a catalytic aspartate residue, the contributions of other residues for catalysis of pseudouridine formation are poorly understood. Here, we have tested the role of a conserved basic residue in the active site for catalysis using the bacterial pseudouridine synthase TruB targeting U55 in tRNAs. Substitution of arginine 181 with lysine results in a 2500-fold reduction of TruB's catalytic rate without affecting tRNA binding. Furthermore, we analyzed the function of a second-shell aspartate residue (D90) that is conserved in all TruB enzymes and interacts with C56 of tRNA. Site-directed mutagenesis, biochemical and kinetic studies reveal that this residue is not critical for substrate binding but influences catalysis significantly as replacement of D90 with glutamate or asparagine reduces the catalytic rate 30- and 50-fold, respectively. In agreement with molecular dynamics simulations of TruB wild type and TruB D90N, we propose an electrostatic network composed of the catalytic aspartate (D48), R181 and D90 that is important for catalysis by fine-tuning the D48-R181 interaction. Conserved, negatively charged residues similar to D90 are found in a number of pseudouridine synthases, suggesting that this might be a general mechanism.

An arginine-aspartate network in the active site of bacterial TruB is critical for catalyzing pseudouridine formation

PubMed Central

Friedt, Jenna; Leavens, Fern M. V.; Mercier, Evan; Wieden, Hans-Joachim; Kothe, Ute

2014-01-01

Pseudouridine synthases introduce the most common RNA modification and likely use the same catalytic mechanism. Besides a catalytic aspartate residue, the contributions of other residues for catalysis of pseudouridine formation are poorly understood. Here, we have tested the role of a conserved basic residue in the active site for catalysis using the bacterial pseudouridine synthase TruB targeting U55 in tRNAs. Substitution of arginine 181 with lysine results in a 2500-fold reduction of TruB’s catalytic rate without affecting tRNA binding. Furthermore, we analyzed the function of a second-shell aspartate residue (D90) that is conserved in all TruB enzymes and interacts with C56 of tRNA. Site-directed mutagenesis, biochemical and kinetic studies reveal that this residue is not critical for substrate binding but influences catalysis significantly as replacement of D90 with glutamate or asparagine reduces the catalytic rate 30- and 50-fold, respectively. In agreement with molecular dynamics simulations of TruB wild type and TruB D90N, we propose an electrostatic network composed of the catalytic aspartate (D48), R181 and D90 that is important for catalysis by fine-tuning the D48-R181 interaction. Conserved, negatively charged residues similar to D90 are found in a number of pseudouridine synthases, suggesting that this might be a general mechanism. PMID:24371284

High asymmetric dimethylarginine, symmetric dimethylarginine and L-arginine levels in migraine patients.

PubMed

Reyhani, Aylin; Celik, Yahya; Karadag, Hakan; Gunduz, Ozgur; Asil, Talip; Sut, Necdet

2017-07-01

Experimental and clinical data strongly suggests that nitric oxide (NO) plays a pivotal role in migraine. This is also supported by studies of migraine induced by substances that release NO. NO is synthesized from L-arginine by endothelial NO synthase (NOS). Asymmetric dimethylarginine (ADMA) is the major endogenous competitive inhibitor of NOS. Symmetric dimethylarginine (SDMA) is an inactive stereoisomer of ADMA. It may reduce NO production by competing with arginine for cellular uptake. The aim of this study was to measure the levels of ADMA, SDMA and L-arginine in migraine patients during the interictal period. One hundred migraine patients and 100 healthy volunteers were recruited. The patients were in the interictal period and classified into two groups as having migraine with aura and migraine without aura. Their serum ADMA, SDMA and L-arginine levels were measured by high-performance liquid chromotography (HPLC) method. ADMA, SDMA and L-arginine levels were significantly higher in migraine patients compared to the control group. But there was no difference between the patients with and without aura. These results suggest that NOS inhibitors and L-arginine/NO pathway plays an important role in migraine pathopysiology.

Arginine Promotes Slow Myosin Heavy Chain Expression via Akirin2 and the AMP-Activated Protein Kinase Signaling Pathway in Porcine Skeletal Muscle Satellite Cells.

PubMed

Chen, Xiaoling; Guo, Yafei; Jia, Gang; Zhao, Hua; Liu, Guangmang; Huang, Zhiqing

2018-05-09

This study aimed to investigate the effect of arginine on the expression of slow myosin heavy chain (MyHC) I and its underlying mechanism in porcine skeletal muscle satellite cells. Our results showed that arginine upregulated the mRNA (1.54 ± 0.08; p < 0.01) and protein (2.01 ± 0.01; p < 0.001) levels of MyHC I. We also showed that arginine upregulated the expression of Akirin2 (1.35 ± 0.1; p < 0.05) and increased the NO content (1.56 ± 0.04; p < 0.001). Akirin2 siRNA abolished arginine-induced upregulation of MyHC I and the increase of the NO content. In addition, arginine significantly increased the phospho-AMP-activated protein kinase (AMPK)/AMPK level (1.33 ± 0.06; p < 0.05), the AMPK content (79.55 ± 0.13; p < 0.001), and the AMPKα2 mRNA level (2.03 ± 0.20; p < 0.01). AMPKα2 silencing or AMPK inhibitor Compound C abolished arginine-induced upregulation of MyHC I. Our results provide, for the first time, evidence for the involvement of Akirin2 and the AMPK signaling pathway in arginine-induced MyHC I expression in porcine skeletal muscle satellite cells.

Arginine supplementation modulates pig plasma lipids, but not hepatic fatty acids, depending on dietary protein level with or without leucine.

PubMed

Madeira, Marta Sofia Morgado Dos Santos; Rolo, Eva Sofia Alves; Pires, Virgínia Maria Rico; Alfaia, Cristina Maria Riscado Pereira Mateus; Coelho, Diogo Francisco Maurício; Lopes, Paula Alexandra Antunes Brás; Martins, Susana Isabel Vargas; Pinto, Rui Manuel Amaro; Prates, José António Mestre

2017-05-30

In the present study, the effect of arginine and leucine supplementation, and dietary protein level, were investigated in commercial crossbred pigs to clarify their individual or combined impact on plasma metabolites, hepatic fatty acid composition and mRNA levels of lipid sensitive factors. The experiment was conducted on fifty-four entire male pigs (Duroc × Pietrain × Large White × Landrace crossbred) from 59 to 92 kg of live weight. Each pig was randomly assigned to one of six experimental treatments (n = 9). The treatments followed a 2 × 3 factorial arrangement, providing two levels of arginine supplementation (0 vs. 1%) and three levels of basal diet (normal protein diet, NPD; reduced protein diet, RPD; reduced protein diet with 2% of leucine, RPDL). Significant interactions between arginine supplementation and protein level were observed across plasma lipids. While dietary arginine increased total lipids, total cholesterol, HDL-cholesterol, LDL-cholesterol, VLDL-cholesterol and triacylglycerols in NPD, the inverse effect was observed in RPD. Overall, dietary treatments had a minor impact on hepatic fatty acid composition. RPD increased 18:1c9 fatty acid while the combination of leucine and RPD reduced 18:0 fatty acid. Arginine supplementation increased the gene expression of FABP1, which contributes for triacylglycerols synthesis without affecting hepatic fatty acids content. RPD, with or without leucine addition, upregulated the lipogenic gene CEBPA but downregulated the fat oxidation gene LPIN1. Arginine supplementation was responsible for a modulated effect on plasma lipids, which is dependent on dietary protein level. It consistently increased lipaemia in NPD, while reducing the correspondent metabolites in RPD. In contrast, arginine had no major impact, neither on hepatic fatty acids content nor on fatty acid composition. Likewise, leucine supplementation of RPD, regardless the presence of arginine, promoted no changes on total fatty acids in

Intestinal absorption of an arginine-containing peptide in cystinuria

PubMed Central

Asatoor, A. M.; Harrison, B. D. W.; Milne, M. D.; Prosser, D. I.

1972-01-01

Separate tolerance tests involving oral intake of the dipeptide, L-arginyl-L-aspartate, and of a corresponding free amino acid mixture, were carried out in a single type 2 cystinuric patient. Absorption of aspartate was within normal limits, whilst that of arginine was normal after the peptide but considerably reduced after the amino acid mixture. The results are compared with the increments of serum arginine found in eight normal subjects after the oral intake of the free amino acid mixture. Analyses of urinary pyrrolidine and of tetramethylenediamine in urine samples obtained after the two tolerance tests in the patient support the view that arginine absorption was subnormal after the amino acid mixture but within normal limits after the dipeptide. PMID:5045711

Reduced voltage sensitivity in a K+-channel voltage sensor by electric field remodeling

PubMed Central

González-Pérez, Vivian; Stack, Katherine; Boric, Katica; Naranjo, David

2010-01-01

Propagation of the nerve impulse relies on the extreme voltage sensitivity of Na+ and K+ channels. The transmembrane movement of four arginine residues, located at the fourth transmembrane segment (S4), in each of their four voltage-sensing domains is mostly responsible for the translocation of 12 to 13 eo across the transmembrane electric field. Inserting additional positively charged residues between the voltage-sensing arginines in S4 would, in principle, increase voltage sensitivity. Here we show that either positively or negatively charged residues added between the two most external sensing arginines of S4 decreased voltage sensitivity of a Shaker voltage-gated K+-channel by up to ≈50%. The replacement of Val363 with a charged residue displaced inwardly the external boundaries of the electric field by at least 6 Å, leaving the most external arginine of S4 constitutively exposed to the extracellular space and permanently excluded from the electric field. Both the physical trajectory of S4 and its electromechanical coupling to open the pore gate seemed unchanged. We propose that the separation between the first two sensing charges at resting is comparable to the thickness of the low dielectric transmembrane barrier they must cross. Thus, at most a single sensing arginine side chain could be found within the field. The conserved hydrophobic nature of the residues located between the voltage-sensing arginines in S4 may shape the electric field geometry for optimal voltage sensitivity in voltage-gated ion channels. PMID:20194763

Epigenetic control via allosteric regulation of mammalian protein arginine methyltransferases.

PubMed

Jain, Kanishk; Jin, Cyrus Y; Clarke, Steven G

2017-09-19

Arginine methylation on histones is a central player in epigenetics and in gene activation and repression. Protein arginine methyltransferase (PRMT) activity has been implicated in stem cell pluripotency, cancer metastasis, and tumorigenesis. The expression of one of the nine mammalian PRMTs, PRMT5, affects the levels of symmetric dimethylarginine (SDMA) at Arg-3 on histone H4, leading to the repression of genes which are related to disease progression in lymphoma and leukemia. Another PRMT, PRMT7, also affects SDMA levels at the same site despite its unique monomethylating activity and the lack of any evidence for PRMT7-catalyzed histone H4 Arg-3 methylation. We present evidence that PRMT7-mediated monomethylation of histone H4 Arg-17 regulates PRMT5 activity at Arg-3 in the same protein. We analyzed the kinetics of PRMT5 over a wide range of substrate concentrations. Significantly, we discovered that PRMT5 displays positive cooperativity in vitro, suggesting that this enzyme may be allosterically regulated in vivo as well. Most interestingly, monomethylation at Arg-17 in histone H4 not only raised the general activity of PRMT5 with this substrate, but also ameliorated the low activity of PRMT5 at low substrate concentrations. These kinetic studies suggest a biochemical explanation for the interplay between PRMT5- and PRMT7-mediated methylation of the same substrate at different residues and also suggest a general model for regulation of PRMTs. Elucidating the exact relationship between these two enzymes when they methylate two distinct sites of the same substrate may aid in developing therapeutics aimed at reducing PRMT5/7 activity in cancer and other diseases.

Epigenetic control via allosteric regulation of mammalian protein arginine methyltransferases

PubMed Central

Jin, Cyrus Y.; Clarke, Steven G.

2017-01-01

Arginine methylation on histones is a central player in epigenetics and in gene activation and repression. Protein arginine methyltransferase (PRMT) activity has been implicated in stem cell pluripotency, cancer metastasis, and tumorigenesis. The expression of one of the nine mammalian PRMTs, PRMT5, affects the levels of symmetric dimethylarginine (SDMA) at Arg-3 on histone H4, leading to the repression of genes which are related to disease progression in lymphoma and leukemia. Another PRMT, PRMT7, also affects SDMA levels at the same site despite its unique monomethylating activity and the lack of any evidence for PRMT7-catalyzed histone H4 Arg-3 methylation. We present evidence that PRMT7-mediated monomethylation of histone H4 Arg-17 regulates PRMT5 activity at Arg-3 in the same protein. We analyzed the kinetics of PRMT5 over a wide range of substrate concentrations. Significantly, we discovered that PRMT5 displays positive cooperativity in vitro, suggesting that this enzyme may be allosterically regulated in vivo as well. Most interestingly, monomethylation at Arg-17 in histone H4 not only raised the general activity of PRMT5 with this substrate, but also ameliorated the low activity of PRMT5 at low substrate concentrations. These kinetic studies suggest a biochemical explanation for the interplay between PRMT5- and PRMT7-mediated methylation of the same substrate at different residues and also suggest a general model for regulation of PRMTs. Elucidating the exact relationship between these two enzymes when they methylate two distinct sites of the same substrate may aid in developing therapeutics aimed at reducing PRMT5/7 activity in cancer and other diseases. PMID:28874563

Quantitative phosphoproteomics reveals the role of protein arginine phosphorylation in the bacterial stress response.

PubMed

Schmidt, Andreas; Trentini, Débora Broch; Spiess, Silvia; Fuhrmann, Jakob; Ammerer, Gustav; Mechtler, Karl; Clausen, Tim

2014-02-01

Arginine phosphorylation is an emerging protein modification implicated in the general stress response of Gram-positive bacteria. The modification is mediated by the arginine kinase McsB, which phosphorylates and inactivates the heat shock repressor CtsR. In this study, we developed a mass spectrometric approach accounting for the peculiar chemical properties of phosphoarginine. The improved methodology was used to analyze the dynamic changes in the Bacillus subtilis arginine phosphoproteome in response to different stress situations. Quantitative analysis showed that a B. subtilis mutant lacking the YwlE arginine phosphatase accumulated a strikingly large number of arginine phosphorylations (217 sites in 134 proteins), however only a minor fraction of these sites was increasingly modified during heat shock or oxidative stress. The main targets of McsB-mediated arginine phosphorylation comprise central factors of the stress response system including the CtsR and HrcA heat shock repressors, as well as major components of the protein quality control system such as the ClpCP protease and the GroEL chaperonine. These findings highlight the impact of arginine phosphorylation in orchestrating the bacterial stress response.

L-arginine and Arginase Products Potentiate Dexmedetomidine-induced Contractions in the Rat Aorta.

PubMed

Wong, Emily S W; Man, Ricky Y K; Ng, Kwok F J; Leung, Susan W S; Vanhoutte, Paul M

2018-03-01

The α2-adrenergic sedative/anesthetic agent dexmedetomidine exerts biphasic effects on isolated arteries, causing endothelium-dependent relaxations at concentrations at or below 30 nM, followed by contractions at higher concentrations. L-arginine is a common substrate of endothelial nitric oxide synthase and arginases. This study was designed to investigate the role of L-arginine in modulating the overall vascular response to dexmedetomidine. Isometric tension was measured in isolated aortic rings of Sprague Dawley rats. Cumulative concentrations of dexmedetomidine (10 nM to 10 μM) were added to quiescent rings (with and without endothelium) after previous incubation with vehicle, N-nitro-L-arginine methyl ester hydrochloride (L-NAME; nitric oxide synthase inhibitor), prazosin (α1-adrenergic antagonist), rauwolscine (α2-adrenergic antagonist), L-arginine, (S)-(2-boronethyl)-L-cysteine hydrochloride (arginase inhibitor), N-hydroxy-L-arginine (arginase inhibitor), urea and/or ornithine. In some preparations, immunofluorescent staining, immunoblotting, or measurement of urea content were performed. Dexmedetomidine did not contract control rings with endothelium but evoked concentration-dependent increases in tension in such rings treated with L-NAME (Emax 50 ± 4%) or after endothelium-removal (Emax 74 ± 5%; N = 7 to 12). Exogenous L-arginine augmented the dexmedetomidine-induced contractions in the presence of L-NAME (Emax 75 ± 3%). This potentiation was abolished by (S)-(2-boronethyl)-L-cysteine hydrochloride (Emax 16 ± 4%) and N-hydroxy-L-arginine (Emax 18 ± 4%). Either urea or ornithine, the downstream arginase products, had a similar potentiating effect as L-arginine. Immunoassay measurements demonstrated an upregulation of arginase I by L-arginine treatment in the presence of L-NAME (N = 4). These results suggest that when vascular nitric oxide homeostasis is impaired, the potentiation of the vasoconstrictor effect of

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

PubMed

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.

L-arginine availability and arginase activity: Characterization of amino acid permease 3 in Leishmania amazonensis

PubMed Central

Aoki, Juliana Ide; Muxel, Sandra Marcia; Zampieri, Ricardo Andrade; Acuña, Stephanie Maia; Fernandes, Juliane Cristina Ribeiro; Vanderlinde, Rubia Heloisa; Sales, Maria Carmen Oliveira de Pinho

2017-01-01

Background Leishmania uses the amino acid L-arginine as a substrate for arginase, enzyme that produces urea and ornithine, last precursor of polyamine pathway. This pathway is used by the parasite to replicate and it is essential to establish the infection in the mammalian host. L-arginine is not synthesized by the parasite, so its uptake occurs through the amino acid permease 3 (AAP3). AAP3 is codified by two copies genes (5.1 and 4.7 copies), organized in tandem in the parasite genome. One copy presents the expression regulated by L-arginine availability. Methodology/Principal findings RNA-seq data revealed 14 amino acid transporters differentially expressed in the comparison of La-WT vs. La-arg- promastigotes and axenic amastigotes. The 5.1 and 4.7 aap3 transcripts were down-regulated in La-WT promastigotes vs. axenic amastigotes, and in La-WT vs. La-arg- promastigotes. In contrast, transcripts of other transporters were up-regulated in the same comparisons. The amount of 5.1 and 4.7 aap3 mRNA of intracellular amastigotes was also determined in sample preparations from macrophages, obtained from BALB/c and C57BL/6 mice and the human THP-1 lineage infected with La-WT or La-arg-, revealing that the genetic host background is also important. We also determined the aap3 mRNA and AAP3 protein amounts of promastigotes and axenic amastigotes in different environmental growth conditions, varying pH, temperature and L-arginine availability. Interestingly, the increase of temperature increased the AAP3 level in plasma membrane and consequently the L-arginine uptake, independently of pH and L-arginine availability. In addition, we demonstrated that besides the plasma membrane localization, AAP3 was also localized in the glycosome of L. amazonensis promastigotes and axenic amastigotes. Conclusions/Significance In this report, we described the differential transcriptional profiling of amino acids transporters from La-WT and La-arg- promastigotes and axenic amastigotes. We

Supplemental dietary arginine accelerates intestinal mucosal regeneration and enhances bacterial clearance following radiation enteritis in rats.

PubMed

Gurbuz, A T; Kunzelman, J; Ratzer, E E

1998-02-01

Arginine is a dibasic amino acid with significant metabolic and immunologic, effects especially in trauma and stress situations. Arginine supplementation has been shown to promote wound healing and improve immune system. We designed a study to evaluate the effects of supplemental dietary arginine on intestinal mucosal recovery and bacterial translocation and bacterial clearance after induction of radiation injury in rats. Twenty-one male Sprague-Dawley rats were subjected to a single dose of 1100 rads of abdominal X radiation. Rats were divided into three groups; the first group received diet enriched with 2% arginine, the second group with 4% arginine, and the third group with isonitrogenous 4% glycine. Rats were sacrificed 7 days after the radiation. Blood was drawn for arginine levels and mesenteric lymph nodes were harvested for quantitative aerobic and anaerobic cultures. Segments of ileum and jejunum were evaluated for villous height, number of villi per centimeter of intestine, and the number of mucous cells per villous. Arginine is absorbed reliably from the gut following oral administration. Dietary 4% arginine supplementation enhanced bacterial clearance from mesenteric lymph nodes compared to 2% arginine and 4% glycine supplemented diet following radiation enteritis in rats. Four percent arginine resulted in clear improvement in intestinal mucosal recovery when compared to 2% arginine and 4% glycine after abdominal irradiation in rats.

Arginase treatment prevents the recovery of canine lymphoma and osteosarcoma cells resistant to the toxic effects of prolonged arginine deprivation.

PubMed

Wells, James W; Evans, Christopher H; Scott, Milcah C; Rütgen, Barbara C; O'Brien, Timothy D; Modiano, Jaime F; Cvetkovic, Goran; Tepic, Slobodan

2013-01-01

Rapidly growing tumor cells require a nutrient-rich environment in order to thrive, therefore, restricting access to certain key amino acids, such as arginine, often results in the death of malignant cells, which frequently display defective cell cycle check-point control. Healthy cells, by contrast, become quiescent and remain viable under arginine restriction, displaying full recovery upon return to arginine-rich conditions. The use of arginase therapy to restrict available arginine for selectively targeting malignant cells is currently under investigation in human clinical trials. However, the suitability of this approach for veterinary uses is unexplored. As a prelude to in vivo studies in canine malignancies, we examined the in vitro effects of arginine-deprivation on canine lymphoid and osteosarcoma cell lines. Two lymphoid and 2 osteosarcoma cell lines were unable to recover following 6 days of arginine deprivation, but all remaining cell lines displayed full recovery upon return to arginine-rich culture conditions. These remaining cell lines all proved susceptible to cell death following the addition of arginase to the cultures. The lymphoid lines were particularly sensitive to arginase, becoming unrecoverable after just 3 days of treatment. Two of the osteosarcoma lines were also susceptible over this time-frame; however the other 3 lines required 6-8 days of arginase treatment to prevent recovery. In contrast, adult progenitor cells from the bone marrow of a healthy dog were able to recover fully following 9 days of culture in arginase. Over 3 days in culture, arginase was more effective than asparaginase in inducing the death of lymphoid lines. These results strongly suggest that short-term arginase treatment warrants further investigation as a therapy for lymphoid malignancies and osteosarcomas in dogs.

The C. elegans PRMT-3 possesses a type III protein arginine methyltransferase activity.

PubMed

Takahashi, Yuta; Daitoku, Hiroaki; Yokoyama, Atsuko; Nakayama, Kimihiro; Kim, Jun-Dal; Fukamizu, Akiyoshi

2011-04-01

Protein arginine methylation is a common post-translational modification in eukaryotes that is catalyzed by a family of the protein arginine methyltransferases (PRMTs). PRMTs are classified into three types: type I and type II add asymmetrically and symmetrically dimethyl groups to arginine, respectively, while type III adds solely monomethyl group to arginine. However, although the enzymatic activity of type I and type II PRMTs have been reported, the substrate specificity and the methylation activity of type III PRMTs still remains unknown. Here, we report the characterization of Caenorhabditis elegans PRMT-2 and PRMT-3, both of which are highly homologous to human PRMT7. We find that these two PRMTs can bind to S-adenosyl methionine (SAM), but only PRMT-3 has methyltransferase activity for histone H2A depending on its SAM-binding domain. Importantly, thin-layer chromatographic analysis demonstrates that PRMT-3 catalyzes the formation of monomethylated, but not dimethylated arginine. Our study thus identifies the first type III PRMT in C. elegans and provides a means to elucidate the physiological significance of arginine monomethylation in multicellular organisms.

L-Arginine Modulates Glucose and Lipid Metabolism in Obesity and Diabetes.

PubMed

Hu, Shengdi; Han, Meng; Rezaei, Arash; Li, Defa; Wu, Guoyao; Ma, Xi

2017-01-01

Type 2 diabetes has become a global public health problem affecting approximately 380 million people throughout the world. It can cause many complications and lead to greater mortality. At present, there is no available medicine for effectively preventing diabetes. L-arginine, a functional amino acid, the precursor of nitric oxide, plays a crucial role in maintenance, reproduction, growth, anti-aging and immunity for animals. Growing clinical evidence indicates that dietary L-arginine supplementation can reduce obesity, decrease arterial blood pressure, resist oxidation and normalize endothelial dysfunction to bring about remission of type 2 diabetes. The potential molecular mechanism may play a role in modulating glucose homeostasis, promoting lipolysis, maintaining hormone levels, ameliorating insulin resistance, and fetal programing in early stages. The possible signaling pathway of the beneficial effects of L-arginine likely involves L-arginine-nitric oxide pathway through which cell signal protein can be activated. Accumulating studies have indicated that L-arginine may have potential to prevent and/or relieve type 2 diabetes via restoring insulin sensitivity in vivo. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

N-hydroxylamine is not an intermediate in the conversion of L-arginine to an activator of soluble guanylate cyclase in neuroblastoma N1E-115 cells.

PubMed Central

Pou, S; Pou, W S; Rosen, G M; el-Fakahany, E E

1991-01-01

This study evaluates the role of N-hydroxylamine (NH2OH) in activating soluble guanylate cyclase in the mouse neuroblastoma clone N1E-115. It has been proposed that NH2OH is a putative intermediate in the biochemical pathway for the generation of nitric oxide (NO)/endothelium-derived relaxing factor (EDRF) from L-arginine. NH2OH caused a time- and concentration-dependent increase in cyclic GMP formation in intact cells. This response was not dependent on Ca2+. In cytosol preparations the activation of guanylate cyclase by L-arginine was dose-dependent and required Ca2+ and NADPH. In contrast, NH2OH itself did not activate cytosolic guanylate cyclase but it inhibited the basal activity of this enzyme in a concentration-dependent manner. The formation of cyclic GMP in the cytosolic fractions in response to NH2OH required the addition of catalase and H2O2. On the other hand, catalase and/or H2O2 lead to a decrease in L-arginine-induced cyclic GMP formation. Furthermore, NH2OH inhibited L-arginine- and sodium nitroprusside-induced cyclic GMP formation in the cytosol. The inhibition of L-arginine-induced cyclic GMP formation in the cytosol by NH2OH was not reversed by the addition of superoxide dismutase. These data strongly suggest that NH2OH is not a putative intermediate in the metabolism of L-arginine to an activator of guanylate cyclase. PMID:1671745

Arginine-rich cross-linking peptides with different SV40 nuclear localization signal content as vectors for intranuclear DNA delivery.

PubMed

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.

Dietary arginine supplementation affects microvascular development in the small intestine of early-weaned pigs.

PubMed

Zhan, Zhenfeng; Ou, Deyuan; Piao, Xiangshu; Kim, Sung Woo; Liu, Yanhong; Wang, Junjun

2008-07-01

This study was conducted to evaluate the effects of dietary arginine levels on microvascular development of the small intestine in early-weaned pigs. Twenty-four crossbred pigs (5.0 +/- 0.3 kg body weight) were individually housed and randomly allotted to 1 of 3 diets supplemented with 0, 0.7, and 1.2% L-arginine (8 pigs per group). Pigs consumed the diets ad libitum for 10 d. We collected blood samples on d 3, 6, and 10. On d 10, 6 pigs from each group were randomly selected and killed for tissue sample collection. Compared with control pigs, dietary supplementation with 0.7% L-arginine increased (P < 0.05) jejunal concentrations of nitrite and nitrate (stable oxidation products of nitric oxide), intestinal villus height, as well as plasma proline and arginine concentrations on d 6 and 10. Dietary supplementation with 0.7% L-arginine also increased (P < 0.05) immunoreactive expression of CD34 in duodenal submucosa, ileal mucosa and submucosa, and expression of vascular endothelial growth factor (VEGF) in duodenal submucosa, jejunal mucosa and submucosa, and ileal mucosa compared with the control and 1.2% L-arginine supplementation. Dietary supplementation with 1.2% L-arginine increased (P < 0.05) the concentration of jejunal endothelin-1 compared with the control pigs. Immunoexpression of VEGF in duodenal mucosa and plasma lysine concentrations on d 6 and 10 were lower (P < 0.05) in pigs supplemented with 1.2% L-arginine than in unsupplemented pigs. Collectively, these findings indicate that the effects of L-arginine on microvascular development are beneficial at lower levels but have adverse effects at higher intakes. Dietary supplementation with 0.7% L-arginine may be a useful method to improve microvascular development in the small intestine of early-weaned pigs.

Poly-L-arginine: Enhancing Cytotoxicity and Cellular Uptake of Doxorubicin and Necrotic Cell Death.

PubMed

Movafegh, Bahareh; Jalal, Razieh; Mohammadi, Zobeideh; Aldaghi, Seyyede Araste

2018-04-11

Cell resistance to doxorubicin and its toxicity to healthy tissue reduce its efficiency. The use of cell penetrating peptides as drug delivery system along with doxorubicin is a strategy to reduce its side effects. In this study, the influence of poly-L-arginine on doxorubicin cytotoxicity, its cellular uptake and doxorubicin-induced apoptosis on human prostate cancer DU145 cells are assessed. The cytotoxicity of doxorubicin and poly-L-arginine, alone and in combination, in DU145 cells was evaluated at different exposure times using MTT assay. The influence of poly-L-arginine on doxorubicin delivery into cells was evaluated by fluorescence microscopy and ultraviolet spectroscopy. DAPI and ethidium bromide-acridine orange stainings, flow cytometry using annexin V/propidium iodide, western blot analysis with anti-p21 antibody and caspase-3 activity were used to examine the influence of poly-L-arginine on doxorubicin-induced cell death. Poly-L-arginine had no cytotoxicity at low concentrations and short exposure times. Poly-L-arginine increased the cytotoxic effect of doxorubicin in DU145 cells in a time-dependent manner. But no significant reduction was found in HFF cell viability. Poly-L-arginine seems to facilitate doxorubicin uptake and increase its intracellular concentration. 24 h combined treatment of cells with doxorubicin (0.5 μM) and poly-L-arginine (1 μg ml-1) caused a small increase in doxorubicin-induced apoptosis and significant elevated necrosis in DU145 cells as compared to each agent alone. Conlusion: Our results indicate that poly-L-arginine at lowest and highest concentrations act as proliferation-inducing and antiproliferative agents, respectively. Between these concentrations, poly-L-arginine increases the cellular uptake of doxorubicin and its cytotoxicity through induction of necrosis. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Pathogenesis of chronic cluster headache and bouts: role of tryptamine, arginine metabolism and α1-agonists.

PubMed

D'Andrea, G; Bussone, G; Di Fiore, P; Perini, F; Gucciardi, A; Bolner, A; Aguggia, M; Saracco, G; Galloni, E; Giordano, G; Leon, A

2017-05-01

The aim of this study was to explore the possible role of tryptamine in the pathogenesis of chronic cluster headache along with that of adrenaline and noradrenaline (α-agonists) together with arginine metabolism in the origin of cluster bouts. Plasma levels of tyramine, tryptamine, serotonin, 5-hydroxyindolacetic acid, noradrenalin, adrenalin and the markers of arginine metabolism such as arginine, homoarginine, citrulline, ADMA and NMMA, were measured in 23 chronic cluster headache patients (10 chronic cluster ab initio and 13 transformed from episodic cluster) and 28 control subjects. The plasma levels of tyramine, tryptamine, noradrenalin and adrenalin were found several times higher in chronic cluster headache patients compared to controls, whereas the plasma levels of arginine, homoarginine and citrulline were significantly lower. No differences were found in the plasma levels of serotonin, 5-hydroxyindolacetic, ADMA and NMMA between chronic cluster headache patients and control subjects. These results provide support for a role of tryptamine in the pathogenesis of chronic cluster headache and, in particular, in the duration of the cluster bouts. In addition, the low levels of the nitric oxide substrates together with the high levels of noradrenalin and adrenalin suggest an activation of endothelial TAAR1 receptors followed by the release of nitric oxide in the circulation that may constitute the final step of the physiopathology of cluster crisis.

Collision-Induced Dissociation of Deprotonated Peptides. Relative Abundance of Side-Chain Neutral Losses, Residue-Specific Product Ions, and Comparison with Protonated Peptides

NASA Astrophysics Data System (ADS)

Liang, Yuxue; Neta, Pedatsur; Yang, Xiaoyu; Stein, Stephen E.

2018-03-01

High-accuracy MS/MS spectra of deprotonated ions of 390 dipeptides and 137 peptides with three to six residues are studied. Many amino acid residues undergo neutral losses from their side chains. The most abundant is the loss of acetaldehyde from threonine. The abundance of losses from the side chains of other amino acids is estimated relative to that of threonine. While some amino acids lose the whole side chain, others lose only part of it, and some exhibit two or more different losses. Side-chain neutral losses are less abundant in the spectra of protonated peptides, being significant mainly for methionine and arginine. In addition to the neutral losses, many amino acid residues in deprotonated peptides produce specific negative ions after peptide bond cleavage. An expanded list of fragment ions from protonated peptides is also presented and compared with those of deprotonated peptides. Fragment ions are mostly different for these two cases. These lists of fragments are used to annotate peptide mass spectral libraries and to aid in the confirmation of specific amino acids in peptides. [Figure not available: see fulltext.

Collision-Induced Dissociation of Deprotonated Peptides. Relative Abundance of Side-Chain Neutral Losses, Residue-Specific Product Ions, and Comparison with Protonated Peptides.

PubMed

Liang, Yuxue; Neta, Pedatsur; Yang, Xiaoyu; Stein, Stephen E

2018-03-01

High-accuracy MS/MS spectra of deprotonated ions of 390 dipeptides and 137 peptides with three to six residues are studied. Many amino acid residues undergo neutral losses from their side chains. The most abundant is the loss of acetaldehyde from threonine. The abundance of losses from the side chains of other amino acids is estimated relative to that of threonine. While some amino acids lose the whole side chain, others lose only part of it, and some exhibit two or more different losses. Side-chain neutral losses are less abundant in the spectra of protonated peptides, being significant mainly for methionine and arginine. In addition to the neutral losses, many amino acid residues in deprotonated peptides produce specific negative ions after peptide bond cleavage. An expanded list of fragment ions from protonated peptides is also presented and compared with those of deprotonated peptides. Fragment ions are mostly different for these two cases. These lists of fragments are used to annotate peptide mass spectral libraries and to aid in the confirmation of specific amino acids in peptides. Graphical Abstract ᅟ.

Characterization and biocompatibility studies of new degradable poly(urea)urethanes prepared with arginine, glycine or aspartic acid as chain extenders.

PubMed

Chan-Chan, L H; Tkaczyk, C; Vargas-Coronado, R F; Cervantes-Uc, J M; Tabrizian, M; Cauich-Rodriguez, J V

2013-07-01

Polyurethanes are very often used in the cardiovascular field due to their tunable physicochemical properties and acceptable hemocompatibility although they suffer from poor endothelialization. With this in mind, we proposed the synthesis of a family of degradable segmented poly(urea)urethanes (SPUUs) using amino acids (L-arginine, glycine and L-aspartic acid) as chain extenders. These polymers degraded slowly in PBS (pH 7.4) after 24 weeks via a gradual decrease in molecular weight. In contrast, accelerated degradation showed higher mass loss under acidic, alkaline and oxidative media. MTT tests on polyurethanes with L-arginine as chain extenders showed no adverse effect on the metabolism of human umbilical vein endothelial cells (HUVECs) indicating the leachables did not provoke any toxic responses. In addition, SPUUs containing L-arginine promoted higher levels of HUVECs adhesion, spreading and viability after 7 days compared to the commonly used Tecoflex(®) polyurethane. The biodegradability and HUVEC proliferation on L-arginine-based SPUUs suggests that they can be used in the design of vascular grafts for tissue engineering.

Intestinal trophic effect of enteral arginine is independent of blood flow in neonatal piglets

USDA-ARS?s Scientific Manuscript database

Arginine is an indispensable amino acid in neonates. Arginine is synthesized by gut epithelial cells and may have a protective role in preventing necrotizing enterocolitis. We hypothesized our method included that enteral arginine is a stimulus for intestinal blood flow and subsequent mucosal growth...

Decreased Rate of Plasma Arginine Appearance in Murine Malaria May Explain Hypoargininemia in Children With Cerebral Malaria

PubMed Central

Alkaitis, Matthew S.; Wang, Honghui; Ikeda, Allison K.; Rowley, Carol A.; MacCormick, Ian J. C.; Chertow, Jessica H.; Billker, Oliver; Suffredini, Anthony F.; Roberts, David J.; Taylor, Terrie E.; Seydel, Karl B.; Ackerman, Hans C.

2016-01-01

Background. Plasmodium infection depletes arginine, the substrate for nitric oxide synthesis, and impairs endothelium-dependent vasodilation. Increased conversion of arginine to ornithine by parasites or host arginase is a proposed mechanism of arginine depletion. Methods. We used high-performance liquid chromatography to measure plasma arginine, ornithine, and citrulline levels in Malawian children with cerebral malaria and in mice infected with Plasmodium berghei ANKA with or without the arginase gene. Heavy isotope–labeled tracers measured by quadrupole time-of-flight liquid chromatography–mass spectrometry were used to quantify the in vivo rate of appearance and interconversion of plasma arginine, ornithine, and citrulline in infected mice. Results. Children with cerebral malaria and P. berghei–infected mice demonstrated depletion of plasma arginine, ornithine, and citrulline. Knock out of Plasmodium arginase did not alter arginine depletion in infected mice. Metabolic tracer analysis demonstrated that plasma arginase flux was unchanged by P. berghei infection. Instead, infected mice exhibited decreased rates of plasma arginine, ornithine, and citrulline appearance and decreased conversion of plasma citrulline to arginine. Notably, plasma arginine use by nitric oxide synthase was decreased in infected mice. Conclusions. Simultaneous arginine and ornithine depletion in malaria parasite–infected children cannot be fully explained by plasma arginase activity. Our mouse model studies suggest that plasma arginine depletion is driven primarily by a decreased rate of appearance. PMID:27923948

L-arginine supplementation enhances exhaled NO, breath condensate VEGF, and headache at 4,342 m.

PubMed

Mansoor, Jim K; Morrissey, Brian M; Walby, William F; Yoneda, Ken Y; Juarez, Maya; Kajekar, Radhika; Severinghaus, John W; Eldridge, Marlowe W; Schelegle, Edward S

2005-01-01

We examined the effect of dietary supplementation with L-arginine on breath condensate VEGF, exhaled nitric oxide (NO), plasma erythropoietin, symptoms of acute mountain sickness, and respiratory related sensations at 4,342 m through the course of 24 h in seven healthy male subjects. Serum L-arginine levels increased in treated subjects at time 0, 8, and 24 h compared with placebo, indicating the effectiveness of our treatment. L-arginine had no significant effect on overall Lake Louise scores compared with placebo. However, there was a significant increase in headache within the L-arginine treatment group at 12 h compared with time 0, a change not seen in the placebo condition between these two time points. There was a trend (p = 0.087) toward greater exhaled NO and significant increases in breath condensate VEGF with L-arginine treatment, but no L-arginine effect on serum EPO. These results suggest that L-arginine supplementation increases HIF-1 stabilization in the lung, possibly through a NO-dependent pathway. In total, our observations indicate that L-arginine supplementation is not beneficial in the prophylactic treatment of AMS.

Sided functions of an arginine-agmatine antiporter oriented in liposomes.

PubMed

Tsai, Ming-Feng; Fang, Yiling; Miller, Christopher

2012-02-28

The arginine-dependent extreme acid resistance system helps enteric bacteria survive the harsh gastric environment. At the center of this multiprotein system is an arginine-agmatine antiporter, AdiC. To maintain cytoplasmic pH, AdiC imports arginine and exports its decarboxylated product, agmatine, resulting in a net extrusion of one "virtual proton" in each turnover. The random orientation of AdiC in reconstituted liposomes throws up an obstacle to quantifying its transport mechanism. To overcome this problem, we introduced a mutation, S26C, near the substrate-binding site. This mutant exhibits substrate recognition and pH-dependent activity similar to those of the wild-type protein but loses function completely upon reaction with thiol reagents. The membrane-impermeant MTSES reagent can then be used as a cleanly sided inhibitor to silence those S26C-AdiC proteins whose extracellular portion projects from the external side of the liposome. Alternatively, the membrane-permeant MTSEA and membrane-impermeant reducing reagent, TCEP, can be used together to inhibit proteins in the opposite orientation. This approach allows steady-state kinetic analysis of AdiC in a sided fashion. Arginine and agmatine have similar Michaelis-Menten parameters for both sides of the protein, while the extracellular side selects arginine over argininamide, a mimic of the carboxylate-protonated form of arginine, more effectively than does the cytoplasmic side. Moreover, the two sides of AdiC have different pH sensitivities. AdiC activity increases to a plateau at pH 4 as the extracellular side is acidified, while the cytoplasmic side shows an optimal pH of 5.5, with further acidification inhibiting transport. This oriented system allows more precise analysis of AdiC-mediated substrate transport than has been previously available and permits comparison to the situation experienced by the bacterial membrane under acid stress.

Quantitative Phosphoproteomics Reveals the Role of Protein Arginine Phosphorylation in the Bacterial Stress Response*

PubMed Central

Schmidt, Andreas; Trentini, Débora Broch; Spiess, Silvia; Fuhrmann, Jakob; Ammerer, Gustav; Mechtler, Karl; Clausen, Tim

2014-01-01

Arginine phosphorylation is an emerging protein modification implicated in the general stress response of Gram-positive bacteria. The modification is mediated by the arginine kinase McsB, which phosphorylates and inactivates the heat shock repressor CtsR. In this study, we developed a mass spectrometric approach accounting for the peculiar chemical properties of phosphoarginine. The improved methodology was used to analyze the dynamic changes in the Bacillus subtilis arginine phosphoproteome in response to different stress situations. Quantitative analysis showed that a B. subtilis mutant lacking the YwlE arginine phosphatase accumulated a strikingly large number of arginine phosphorylations (217 sites in 134 proteins), however only a minor fraction of these sites was increasingly modified during heat shock or oxidative stress. The main targets of McsB-mediated arginine phosphorylation comprise central factors of the stress response system including the CtsR and HrcA heat shock repressors, as well as major components of the protein quality control system such as the ClpCP protease and the GroEL chaperonine. These findings highlight the impact of arginine phosphorylation in orchestrating the bacterial stress response. PMID:24263382

Use of Arginine Hydrochloride in the Treatment of Metabolic Alkalosis or Hypochloremia in Pediatric Patients

PubMed Central

Hernandez, Elvin A.; Parbuoni, Kristine A.

2018-01-01

OBJECTIVES Dosing of arginine for treatment of hypochloremia or metabolic alkalosis is laborious and has inherent variability in dose selection. The primary objective of this study was to determine the efficacy of arginine in the treatment of metabolic alkalosis and hypochloremia. Secondary objectives were to determine an optimal dose, route, and frequency for arginine administration in the treatment of these conditions. METHODS This single center, retrospective, descriptive study was conducted in children who received arginine for treatment of hypochloremia or metabolic alkalosis. Treatment success was assessed by measuring serum chloride and bicarbonate concentrations after arginine administration. RESULTS Of the 464 orders analyzed, 177 met inclusion criteria in 82 unique patients. Fifty percent (n = 81) of arginine administrations used to manage hypochloremia saw normalization of abnormal chloride levels, and 83% (n = 62) of arginine administrations used to treat metabolic alkalosis saw normalization of abnormal bicarbonate levels. Patients who received arginine to resolve hypochloremia were statistically significantly more likely to have their hypochloremia resolve if they used alternative dosing methods compared to established dosing methods (76 vs. 5, p = 0.001). However, this relationship was not seen for patients with metabolic alkalosis (11 vs. 51, p = 1.000). The median percentage of calculated daily dose of arginine needed for resolution of hypochloremia was 59% and was 35% for metabolic alkalosis. CONCLUSIONS Arginine is effective to improve metabolic alkalosis and hypochloremia. Established dosing methods are not more effective than other methods in resolving metabolic alkalosis or hypochloremia. Further prospective studies are warranted to validate these results. PMID:29720912

The effect of arginine supplementation on growth hormone release and intestinal mucosal growth after massive small bowel resection in growing rats.

PubMed

Hebiguchi, T; Kato, T; Yoshino, H; Mizuno, M; Koyama, K

1997-08-01

Four-week-old male Sprague-Dawley rats underwent a 90% small bowel resection. From the fourth day after surgery, they were divided into group 1 and 2, and pair-fed by elemental diets (0.8 kcal/mL, 50 mL/day) with L-arginine (n = 10) or L-glycine (n = 11) as an isonitrogenous and isoenergetic supplement for 3 weeks. They were compared with each other 3 weeks after surgery. A statistical analysis was performed using the unpaired Student's t test and the one-way factorial analysis of variance (ANOVA) using Bonferroni/Dunn multiple comparison test. A Pvalue of < .05 was considered significant. There were no significant differences between the two groups in food intake, body weight, tail length, residual ileal length, and plasma IGF-I level. However, the mean height of ileal villi in group 1 showed higher than that in group 2 (P < .01). Growth hormone-releasing hormone (GHRH) provocative tests (1 microg per rat, intravenously) showed the more significant elevation of growth hormone IGH) secretion in the arginine supplement group than that of glycine supplement group at 5 minutes (P < .05). There were no significant differences between basal levels of plasma rat GH in both groups. It is suggested that arginine has a possible significant role of GH secretion and intestinal mucosal growth after massive small bowel resection.

Arginine Transcriptional Response Does Not Require Inositol Phosphate Synthesis*

PubMed Central

Bosch, Daniel; Saiardi, Adolfo

2012-01-01

Inositol phosphates are key signaling molecules affecting a large variety of cellular processes. Inositol-polyphosphate multikinase (IPMK) is a central component of the inositol phosphate biosynthetic routes, playing essential roles during development. IPMK phosphorylates inositol 1,4,5-trisphosphate to inositol tetrakisphosphate and subsequently to inositol pentakisphosphate and has also been described to function as a lipid kinase. Recently, a catalytically inactive mammalian IPMK was reported to be involved in nutrient signaling by way of mammalian target of rapamycin and AMP-activated protein kinase. In yeast, the IPMK homologue, Arg82, is the sole inositol-trisphosphate kinase. Arg82 has been extensively studied as part of the transcriptional complex regulating nitrogen sensing, in particular arginine metabolism. Whether this role requires Arg82 catalytic activity has long been a matter of contention. In this study, we developed a novel method for the real time study of promoter strength in vivo and used it to demonstrate that catalytically inactive Arg82 fully restored the arginine-dependent transcriptional response. We also showed that expression in yeast of catalytically active, but structurally very different, mammalian or plant IPMK homologue failed to restore arginine regulation. Our work indicates that inositol phosphates do not regulate arginine-dependent gene expression. PMID:22992733

Malate and Aspartate Increase L-Arginine and Nitric Oxide and Attenuate Hypertension.

PubMed

Hou, Entai; Sun, Na; Zhang, Fuchang; Zhao, Chenyang; Usa, Kristie; Liang, Mingyu; Tian, Zhongmin

2017-05-23

Fumarase catalyzes the interconversion of fumarate and L-malate in the tricarboxylic acid cycle. The Dahl salt-sensitive (SS) rat, a model of salt-sensitive hypertension, exhibits fumarase insufficiencies. To investigate the mechanism mediating the effect of fumarase-related metabolites on hypertension, we considered the pathway in which L-malate can be converted to oxaloacetate, aspartate, argininosuccinate, and L-arginine, the substrate of nitric oxide (NO) synthase. The levels of aspartate, citrulline, L-arginine, and NO were significantly decreased in the kidneys of SS rats compared to salt-insensitive consomic SS.13 BN rats. Knockdown of fumarase in human kidney cells and vascular endothelial cells resulted in decreased levels of malate, aspartate, L-arginine, and NO. Supplementation of aspartate or malate increased renal levels of L-arginine and NO and attenuated hypertension in SS rats. These findings reveal a multi-step metabolic pathway important for hypertension in which malate and aspartate may modulate blood pressure by altering levels of L-arginine and NO. Copyright © 2017 The Author(s). Published by Elsevier Inc. All rights reserved.

Excess L-arginine restores endothelium-dependent relaxation impaired by monocrotaline pyrrole

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

Cheng Wei; Oike, Masahiro; Hirakawa, Masakazu

2005-09-15

The pyrrolizidine alkaloid plant toxin monocrotaline pyrrole (MCTP) causes pulmonary hypertension in experimental animals. The present study aimed to examine the effects of MCTP on the endothelium-dependent relaxation. We constructed an in vitro disease model of pulmonary hypertension by overlaying MCTP-treated bovine pulmonary artery endothelial cells (CPAEs) onto pulmonary artery smooth muscle cell-embedded collagen gel lattice. Acetylcholine (Ach) induced a relaxation of the control CPAEs-overlaid gels that were pre-contracted with noradrenaline, and the relaxation was inhibited by L-NAME, an inhibitor of NO synthase (NOS). In contrast, when MCTP-treated CPAEs were overlaid, the pre-contracted gels did not show a relaxation inmore » response to Ach in the presence of 0.5 mM L-arginine. Expression of endothelial NOS protein, Ach-induced Ca{sup 2+} transients and cellular uptake of L-[{sup 3}H]arginine were significantly smaller in MCTP-treated CPAEs than in control cells, indicating that these changes were responsible for the impaired NO production in MCTP-treated CPAEs. Since cellular uptake of L-[{sup 3}H]arginine linearly increased according to its extracellular concentration, we hypothesized that the excess concentration of extracellular L-arginine might restore NO production in MCTP-treated CPAEs. As expected, in the presence of 10 mM L-arginine, Ach showed a relaxation of the MCTP-treated CPAEs-overlaid gels. These results indicate that the impaired NO production in damaged endothelial cells can be reversed by supplying excess L-arginine.« less

Maternal Dietary L-Arginine and Adverse Birth Outcomes in Dar es Salaam, Tanzania.

PubMed

Darling, Anne Marie; McDonald, Chloe R; Urassa, Willy S; Kain, Kevin C; Mwiru, Ramadhani S; Fawzi, Wafaie W

2017-09-01

The amino acid arginine is a physiological precursor to nitric oxide, which is a key mediator of embryonic survival, fetal growth, and pregnancy maintenance. We evaluated the association between consumption of the amino acid arginine and the rate of adverse birth outcomes using data from a double-blind, randomized, placebo-controlled micronutrient supplementation trial among pregnant women in Dar es Salaam, Tanzania (2001-2004). Dietary intakes of arginine were assessed using repeated 24-hour recalls that were administered throughout pregnancy. Participants (n = 7,591) were monitored by research midwives throughout follow-up to assess pregnancy outcomes. Cubic-restricted splines and multivariable log-Poisson regression with empirical standard errors were used to estimate the continuous and categorical associations between arginine intake and adverse birth outcomes. Compared with women within the lowest quintile of arginine intake, those within the highest quintile had 0.79 times the risk of preterm birth before 37 weeks (95% confidence interval: 0.63, 1.00; P = 0.03). The continuous associations of arginine intake with preterm birth before 37 weeks and with preterm birth before 34 weeks were characterized by an initial rapid decrease in risk with increasing intake (P for nonlinearity < 0.01). Arginine intake was not associated with fetal loss or giving birth to infants who were born small for their gestational ages. This data suggest that the association between dietary arginine intake and preterm birth warrants further investigation. © The Author(s) 2017. Published by Oxford University Press on behalf of the Johns Hopkins Bloomberg School of Public Health. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Alterations in plasma L-arginine and methylarginines in heart failure and after heart transplantation.