Effects of dietary lysine and methionine supplementation on ross 708 male broilers from 21 to 42 days of age (III): serum metabolites, hormones, and their relationship with growth performance

USDA-ARS?s Scientific Manuscript database

A previous study has shown that a limited increase of lysine (Lys) and methionine (Met) in broiler diets may improve feed conversion ratio (FCR), BW, carcass yield, and breast meat yield. This study was conducted to determine the effects of dietary Lys and Met supplementation on various blood serum ...

Effects of supplements of folic acid, vitamin B12, and rumen-protected methionine on whole body metabolism of methionine and glucose in lactating dairy cows.

PubMed

Preynat, A; Lapierre, H; Thivierge, M C; Palin, M F; Matte, J J; Desrochers, A; Girard, C L

2009-02-01

The present experiment was undertaken to determine the effects of dietary supplements of rumen-protected methionine and intramuscular injections of folic acid and vitamin B(12), given 3 wk before to 16 wk after calving, on glucose and methionine metabolism of lactating dairy cows. Twenty-four multiparous Holstein cows were assigned to 6 blocks of 4 cows each according to their previous milk production. Within each block, 2 cows were fed a diet estimated to supply methionine as 1.83% metabolizable protein, equivalent to 76% of methionine requirement, whereas the 2 other cows were fed the same diet supplemented daily with 18 g of rumen-protected methionine. Within each diet, the cows were administrated either no vitamin supplement or weekly intramuscular injections of 160 mg of folic acid plus 10 mg of vitamin B(12.) To investigate metabolic changes at 12 wk of lactation, glucose and methionine kinetics were measured by isotope dilution using infusions of 3[U-(13)C]glucose, [(13)C]NaHCO(3) and 3[1-(13)C,(2)H(3)] methionine. Milk and plasma concentrations of folic acid and vitamin B(12) increased with vitamin injections. Supplementary B-vitamins increased milk production from 34.7 to 38.9 +/- 1.0 kg/d and increased milk lactose, protein, and total solids yields. Whole-body glucose flux tended to increase with vitamin supplementation with a similar quantitative magnitude as the milk lactose yield increase. Vitamin supplementation increased methionine utilization for protein synthesis through increased protein turnover when methionine was deficient and through decreased methionine oxidation when rumen-protected methionine was fed. Vitamin supplementation decreased plasma concentrations of homocysteine independently of rumen-protected methionine feeding, although no effect of vitamin supplementation was measured on methionine remethylation, but this could be due to the limitation of the technique used. Therefore, the effects of these B-vitamins on lactation performance

Overexpression of Wild-Type Aspartokinase Increases l-Lysine Production in the Thermotolerant Methylotrophic Bacterium Bacillus methanolicus▿

PubMed Central

Jakobsen, Øyvind M.; Brautaset, Trygve; Degnes, Kristin F.; Heggeset, Tonje M. B.; Balzer, Simone; Flickinger, Michael C.; Valla, Svein; Ellingsen, Trond E.

2009-01-01

Aspartokinase (AK) controls the carbon flow into the aspartate pathway for the biosynthesis of the amino acids l-methionine, l-threonine, l-isoleucine, and l-lysine. We report here the cloning of four genes (asd, encoding aspartate semialdehyde dehydrogenase; dapA, encoding dihydrodipicolinate synthase; dapG, encoding AKI; and yclM, encoding AKIII) of the aspartate pathway in Bacillus methanolicus MGA3. Together with the known AKII gene lysC, dapG and yclM form a set of three AK genes in this organism. Overexpression of dapG, lysC, and yclM increased l-lysine production in wild-type B. methanolicus strain MGA3 2-, 10-, and 60-fold (corresponding to 11 g/liter), respectively, without negatively affecting the specific growth rate. The production levels of l-methionine (less than 0.5 g/liter) and l-threonine (less than 0.1 g/liter) were low in all recombinant strains. The AK proteins were purified, and biochemical analyses demonstrated that they have similar Vmax values (between 47 and 58 μmol/min/mg protein) and Km values for l-aspartate (between 1.9 and 5.0 mM). AKI and AKII were allosterically inhibited by meso-diaminopimelate (50% inhibitory concentration [IC50], 0.1 mM) and by l-lysine (IC50, 0.3 mM), respectively. AKIII was inhibited by l-threonine (IC50, 4 mM) and by l-lysine (IC50, 5 mM), and this enzyme was synergistically inhibited in the presence of both of these amino acids at low concentrations. The correlation between the impact on l-lysine production in vivo and the biochemical properties in vitro of the individual AK proteins is discussed. This is the first example of improving l-lysine production by metabolic engineering of B. methanolicus and also the first documentation of considerably increasing l-lysine production by overexpression of a wild-type AK. PMID:19060158

Overexpression of wild-type aspartokinase increases L-lysine production in the thermotolerant methylotrophic bacterium Bacillus methanolicus.

PubMed

Jakobsen, Oyvind M; Brautaset, Trygve; Degnes, Kristin F; Heggeset, Tonje M B; Balzer, Simone; Flickinger, Michael C; Valla, Svein; Ellingsen, Trond E

2009-02-01

Aspartokinase (AK) controls the carbon flow into the aspartate pathway for the biosynthesis of the amino acids l-methionine, l-threonine, l-isoleucine, and l-lysine. We report here the cloning of four genes (asd, encoding aspartate semialdehyde dehydrogenase; dapA, encoding dihydrodipicolinate synthase; dapG, encoding AKI; and yclM, encoding AKIII) of the aspartate pathway in Bacillus methanolicus MGA3. Together with the known AKII gene lysC, dapG and yclM form a set of three AK genes in this organism. Overexpression of dapG, lysC, and yclM increased l-lysine production in wild-type B. methanolicus strain MGA3 2-, 10-, and 60-fold (corresponding to 11 g/liter), respectively, without negatively affecting the specific growth rate. The production levels of l-methionine (less than 0.5 g/liter) and l-threonine (less than 0.1 g/liter) were low in all recombinant strains. The AK proteins were purified, and biochemical analyses demonstrated that they have similar V(max) values (between 47 and 58 micromol/min/mg protein) and K(m) values for l-aspartate (between 1.9 and 5.0 mM). AKI and AKII were allosterically inhibited by meso-diaminopimelate (50% inhibitory concentration [IC(50)], 0.1 mM) and by l-lysine (IC(50), 0.3 mM), respectively. AKIII was inhibited by l-threonine (IC(50), 4 mM) and by l-lysine (IC(50), 5 mM), and this enzyme was synergistically inhibited in the presence of both of these amino acids at low concentrations. The correlation between the impact on l-lysine production in vivo and the biochemical properties in vitro of the individual AK proteins is discussed. This is the first example of improving l-lysine production by metabolic engineering of B. methanolicus and also the first documentation of considerably increasing l-lysine production by overexpression of a wild-type AK.

Synthesis of the sulfur amino acids: cysteine and methionine.

PubMed

Wirtz, Markus; Droux, Michel

2005-12-01

This review will assess new features reported for the molecular and biochemical aspects of cysteine and methionine biosynthesis in Arabidopsis thaliana with regards to early published data from other taxa including crop plants and bacteria (Escherichia coli as a model). By contrast to bacteria and fungi, plant cells present a complex organization, in which the sulfur network takes place in multiple sites. Particularly, the impact of sulfur amino-acid biosynthesis compartmentalization will be addressed in respect to localization of sulfur reduction. To this end, the review will focus on regulation of sulfate reduction by synthesis of cysteine through the cysteine synthase complex and the synthesis of methionine and its derivatives. Finally, regulatory aspects of sulfur amino-acid biosynthesis will be explored with regards to interlacing processes such as photosynthesis, carbon and nitrogen assimilation.

Energetics and dynamics of the fragmentation reactions of protonated peptides containing methionine sulfoxide or aspartic acid via energy- and time-resolved surface induced dissociation.

PubMed

Lioe, Hadi; Laskin, Julia; Reid, Gavin E; O'Hair, Richard A J

2007-10-25

The surface-induced dissociation (SID) of six model peptides containing either methionine sulfoxide or aspartic acid (GAILM(O)GAILR, GAILM(O)GAILK, GAILM(O)GAILA, GAILDGAILR, GAILDGAILK, and GAILDGAILA) have been studied using a specially configured Fourier transform ion-cyclotron resonance mass spectrometer (FT-ICR MS). In particular, we have investigated the energetics and dynamics associated with (i) preferential cleavage of the methionine sulfoxide side chain via the loss of CH3SOH (64 Da), and (ii) preferential cleavage of the amide bond C-terminal to aspartic acid. The role of proton mobility in these selective bond cleavage reactions was examined by changing the C-terminal residue of the peptide from arginine (nonmobile proton conditions) to lysine (partially mobile proton conditions) to alanine (mobile proton conditions). Time- and energy-resolved fragmentation efficiency curves (TFECs) reveal that selective cleavages due to the methionine sulfoxide and aspartic acid residues are characterized by slow fragmentation kinetics. RRKM modeling of the experimental data suggests that the slow kinetics is associated with large negative entropy effects and these may be due to the presence of rearrangements prior to fragmentation. It was found that the Arrhenius pre-exponential factor (A) for peptide fragmentations occurring via selective bond cleavages are 1-2 orders of magnitude lower than nonselective peptide fragmentation reactions, while the dissociation threshold (E0) is relatively invariant. This means that selective bond cleavage is kinetically disfavored compared to nonselective amide bond cleavage. It was also found that the energetics and dynamics for the preferential loss of CH3SOH from peptide ions containing methionine sulfoxide are very similar to selective C-terminal amide bond cleavage at the aspartic acid residue. These results suggest that while preferential cleavage can compete with amide bond cleavage energetically, dynamically, these processes

Structural Basis for Recognition of L-lysine, L-ornithine, and L-2,4-diamino Butyric Acid by Lysine Cyclodeaminase.

PubMed

Min, Kyungjin; Yoon, Hye-Jin; Matsuura, Atsushi; Kim, Yong Hwan; Lee, Hyung Ho

2018-04-30

L-pipecolic acid is a non-protein amino acid commonly found in plants, animals, and microorganisms. It is a well-known precursor to numerous microbial secondary metabolites and pharmaceuticals, including anticancer agents, immunosuppressants, and several antibiotics. Lysine cyclodeaminase (LCD) catalyzes β-deamination of L-lysine into L-pipecolic acid using β-nicotinamide adenine dinucleotide as a cofactor. Expression of a human homolog of LCD, μ-crystallin, is elevated in prostate cancer patients. To understand the structural features and catalytic mechanisms of LCD, we determined the crystal structures of Streptomyces pristinaespiralis LCD (SpLCD) in (i) a binary complex with NAD + , (ii) a ternary complex with NAD + and L-pipecolic acid, (iii) a ternary complex with NAD + and L-proline, and (iv) a ternary complex with NAD + and L-2,4-diamino butyric acid. The overall structure of SpLCD was similar to that of ornithine cyclodeaminase from Pseudomonas putida . In addition, SpLCD recognized L-lysine, L-ornithine, and L-2,4-diamino butyric acid despite differences in the active site, including differences in hydrogen bonding by Asp236, which corresponds with Asp228 from Pseudomonas putida ornithine cyclodeaminase. The substrate binding pocket of SpLCD allowed substrates smaller than lysine to bind, thus enabling binding to ornithine and L-2,4-diamino butyric acid. Our structural and biochemical data facilitate a detailed understanding of substrate and product recognition, thus providing evidence for a reaction mechanism for SpLCD. The proposed mechanism is unusual in that NAD + is initially converted into NADH and then reverted back into NAD + at a late stage of the reaction.

Hypochlorite-induced damage to proteins: formation of nitrogen-centred radicals from lysine residues and their role in protein fragmentation.

PubMed Central

Hawkins, C L; Davies, M J

1998-01-01

Stimulated monocytes and neutrophils generate hypochlorite (HOCl) via the release of the enzyme myeloperoxidase and hydrogen peroxide. HOCl damages proteins by reaction with amino acid side-chains or backbone cleavage. Little information is available about the mechanisms and intermediates involved in these reactions. EPR spin trapping has been employed to identify radicals on proteins, peptides and amino acids after treatment with HOCl. Reaction with HOCl gives both high- and low-molecular-mass nitrogen-centred, protein-derived radicals; the yield of the latter increases with both higher HOCl:protein ratios and enzymic digestion. These radicals, which arise from lysine side-chain amino groups, react with ascorbate, glutathione and Trolox. Reaction of HOCl-treated proteins with excess methionine eliminates radical formation, which is consistent with lysine-derived chloramines (via homolysis of N-Cl bonds) being the radical source. Incubation of HOCl-treated proteins, after removal of excess oxidant, gives rise to both nitrogen-centred radicals, over a period of hours, and time-dependent fragmentation of the protein. Treatment with excess methionine or antioxidants (Trolox, ascorbate, glutathione) protects against fragmentation; urate and bilirubin do not. Chloramine formation and nitrogen-centred radicals are therefore key species in HOCl-induced protein fragmentation. PMID:9620862

Histidine-lysine peptides as carriers of nucleic acids.

PubMed

Leng, Qixin; Goldgeier, Lisa; Zhu, Jingsong; Cambell, Patricia; Ambulos, Nicholas; Mixson, A James

2007-03-01

With their biodegradability and diversity of permutations, peptides have significant potential as carriers of nucleic acids. This review will focus on the sequence and branching patterns of peptide carriers composed primarily of histidines and lysines. While lysines within peptides are important for binding to the negatively charged phosphates, histidines are critical for endosomal lysis enabling nucleic acids to reach the cytosol. Histidine-lysine (HK) polymers by either covalent or ionic bonds with liposomes augment transfection compared to liposome carriers alone. More recently, we have examined peptides as sole carriers of nucleic acids because of their intrinsic advantages compared to the bipartite HK/liposome carriers. With a protocol change and addition of a histidine-rich tail, HK peptides as sole carriers were more effective than liposomes alone in several cell lines. While four-branched polymers with a primary repeating sequence pattern of -HHK- were more effective as carriers of plasmids, eight-branched polymers with a sequence pattern of -HHHK- were more effective as carriers of siRNA. Compared to polyethylenimine, HK carriers of siRNA and plasmids had reduced toxicity. When injected intravenously, HK polymers in complex with plasmids encoding antiangiogenic proteins significantly decreased tumor growth. Furthermore, modification of HK polymers with polyethylene glycol and vascular-specific ligands increased specificity of the polyplex to the tumor by more than 40-fold. Together with further development and insight on the structure of HK polyplexes, HK peptides may prove to be useful as carriers of different forms of nucleic acids both in vitro and in vivo.

Voluntary wheel running is beneficial to the amino acid profile of lysine-deficient rats.

PubMed

Nagao, Kenji; Bannai, Makoto; Seki, Shinobu; Kawai, Nobuhiro; Mori, Masato; Takahashi, Michio

2010-06-01

Rats voluntarily run up to a dozen kilometers per night when their cages are equipped with a running wheel. Daily voluntary running is generally thought to enhance protein turnover. Thus, we sought to determine whether running worsens or improves protein degradation caused by a lysine-deficient diet and whether it changes the utilization of free amino acids released by proteolysis. Rats were fed a lysine-deficient diet and were given free access to a running wheel or remained sedentary (control) for 4 wk. Amino acid levels in plasma, muscle, and liver were measured together with plasma insulin levels and tissue weight. The lysine-deficient diet induced anorexia, skeletal muscle loss, and serine and threonine aminoacidemia, and it depleted plasma insulin and essential amino acids in skeletal muscle. Allowing rats to run voluntarily improved these symptoms; thus, voluntary wheel running made the rats less susceptible to dietary lysine deficiency. Amelioration of the declines in muscular leucine and plasma insulin observed in running rats could contribute to protein synthesis together with the enhanced availability of lysine and other essential amino acids in skeletal muscle. These results indicate that voluntary wheel running under lysine-deficient conditions does not enhance protein catabolism; on the contrary, it accelerates protein synthesis and contributes to the maintenance of muscle mass. The intense nocturnal voluntary running that characterizes rodents might be an adaptation of lysine-deficient grain eaters that allows them to maximize opportunities for food acquisition.

Expanding lysine industry: industrial biomanufacturing of lysine and its derivatives.

PubMed

Cheng, Jie; Chen, Peng; Song, Andong; Wang, Dan; Wang, Qinhong

2018-04-13

L-Lysine is widely used as a nutrition supplement in feed, food, and beverage industries as well as a chemical intermediate. At present, great efforts are made to further decrease the cost of lysine to make it more competitive in the markets. Furthermore, lysine also shows potential as a feedstock to produce other high-value chemicals for active pharmaceutical ingredients, drugs, or materials. In this review, the current biomanufacturing of lysine is first presented. Second, the production of novel derivatives from lysine is discussed. Some chemicals like L-pipecolic acid, cadaverine, and 5-aminovalerate already have been obtained at a lab scale. Others like 6-aminocaproic acid, valerolactam, and caprolactam could be produced through a biological and chemical coupling pathway or be synthesized by a hypothetical pathway. This review demonstrates an active and expansive lysine industry, and these green biomanufacturing strategies could also be applied to enhance the competitiveness of other amino acid industry.

Analysis and Manipulation of Aspartate Pathway Genes for l-Lysine Overproduction from Methanol by Bacillus methanolicus▿

PubMed Central

Nærdal, Ingemar; Netzer, Roman; Ellingsen, Trond E.; Brautaset, Trygve

2011-01-01

We investigated the regulation and roles of six aspartate pathway genes in l-lysine overproduction in Bacillus methanolicus: dapG, encoding aspartokinase I (AKI); lysC, encoding AKII; yclM, encoding AKIII; asd, encoding aspartate semialdehyde dehydrogenase; dapA, encoding dihydrodipicolinate synthase; and lysA, encoding meso-diaminopimelate decarboxylase. Analysis of the wild-type strain revealed that in vivo lysC transcription was repressed 5-fold by l-lysine and induced 2-fold by dl-methionine added to the growth medium. Surprisingly, yclM transcription was repressed 5-fold by dl-methionine, while the dapG, asd, dapA, and lysA genes were not significantly repressed by any of the aspartate pathway amino acids. We show that the l-lysine-overproducing classical B. methanolicus mutant NOA2#13A52-8A66 has—in addition to a hom-1 mutation—chromosomal mutations in the dapG coding region and in the lysA promoter region. No mutations were found in its dapA, lysC, asd, and yclM genes. The mutant dapG gene product had abolished feedback inhibition by meso-diaminopimelate in vitro, and the lysA mutation was accompanied by an elevated (6-fold) lysA transcription level in vivo. Moreover, yclM transcription was increased 16-fold in mutant strain NOA2#13A52-8A66 compared to the wild-type strain. Overexpression of wild-type and mutant aspartate pathway genes demonstrated that all six genes are important for l-lysine overproduction as tested in shake flasks, and the effects were dependent on the genetic background tested. Coupled overexpression of up to three genes resulted in additive (above 80-fold) increased l-lysine production levels. PMID:21724876

Analysis and manipulation of aspartate pathway genes for L-lysine overproduction from methanol by Bacillus methanolicus.

PubMed

Nærdal, Ingemar; Netzer, Roman; Ellingsen, Trond E; Brautaset, Trygve

2011-09-01

We investigated the regulation and roles of six aspartate pathway genes in L-lysine overproduction in Bacillus methanolicus: dapG, encoding aspartokinase I (AKI); lysC, encoding AKII; yclM, encoding AKIII; asd, encoding aspartate semialdehyde dehydrogenase; dapA, encoding dihydrodipicolinate synthase; and lysA, encoding meso-diaminopimelate decarboxylase. Analysis of the wild-type strain revealed that in vivo lysC transcription was repressed 5-fold by L-lysine and induced 2-fold by dl-methionine added to the growth medium. Surprisingly, yclM transcription was repressed 5-fold by dl-methionine, while the dapG, asd, dapA, and lysA genes were not significantly repressed by any of the aspartate pathway amino acids. We show that the L-lysine-overproducing classical B. methanolicus mutant NOA2#13A52-8A66 has-in addition to a hom-1 mutation-chromosomal mutations in the dapG coding region and in the lysA promoter region. No mutations were found in its dapA, lysC, asd, and yclM genes. The mutant dapG gene product had abolished feedback inhibition by meso-diaminopimelate in vitro, and the lysA mutation was accompanied by an elevated (6-fold) lysA transcription level in vivo. Moreover, yclM transcription was increased 16-fold in mutant strain NOA2#13A52-8A66 compared to the wild-type strain. Overexpression of wild-type and mutant aspartate pathway genes demonstrated that all six genes are important for L-lysine overproduction as tested in shake flasks, and the effects were dependent on the genetic background tested. Coupled overexpression of up to three genes resulted in additive (above 80-fold) increased L-lysine production levels.

L-Methionine Production.

PubMed

Shim, Jihyun; Shin, Yonguk; Lee, Imsang; Kim, So Young

L-Methionine has been used in various industrial applications such as the production of feed and food additives and has been used as a raw material for medical supplies and drugs. It functions not only as an essential amino acid but also as a physiological effector, for example, by inhibiting fat accumulation and enhancing immune response. Producing methionine from fermentation is beneficial in that microorganisms can produce L-methionine selectively using eco-sustainable processes. Nevertheless, the fermentative method has not been used on an industrial scale because it is not competitive economically compared with chemical synthesis methods. Presented are efforts to develop suitable strains, engineered enzymes, and alternative process of producing L-methionine that overcomes problems of conventional fermentation methods. One of the alternative processes is a two-step process in which the L-methionine precursor is produced by fermentation and then converted to L-methionine by enzymes. Directed efforts toward strain development and enhanced enzyme engineering will advance industrial production of L-methionine based on fermentation.

Echinococcus granulosus: specificity of amino acid transport systems in protoscoleces.

PubMed

Jeffs, S A; Arme, C

1987-08-01

Protoscoleces of Echinococcus granulosus absorb the L-amino acids proline, methionine, leucine, alanine, serine, phenylalanine, lysine and glutamic acid by a combination of mediated transport and diffusion. All eight amino acids were accumulated against a concentration gradient. Comparison of Kt and Vmax values suggests that a low affinity for a particular compound is compensated for by a relatively larger number of transport sites for that compound. Four systems serve for the transport of the eight substrates studied: 2 for neutral (EgN1, EgN2) and 1 each for acidic (EgA) and basic (EgB) amino acids. All eight amino acids are incorporated into protein to varying degrees and substantial portions of absorbed L-alanine and L-methionine are metabolized into other compounds.

Selective control of toxic Microcystis water blooms using lysine and malonic acid: an enclosure experiment.

PubMed

Kaya, Kunimitsu; Liu, Yong-Ding; Shen, Yin-Wu; Xiao, Bang-Ding; Sano, Tomoharu

2005-04-01

Three enclosures (10 x 10 x 1.5-1.3 m in depth) were set beside Dianch Lake, Kunming, People's Republic of China, for the period from July 28 to August 26, 2002. The enclosures were filled with cyanobacterial (Microcystis aeruginosa) water bloom-containing lake water. Lake sediment that contained macrophytes and water chestnut seeds was spread over the entire bottom of each enclosure. Initially, 10 g/m(2) of lysine was sprayed in Enclosure B, and 10 g/m(2) each of lysine and malonic acid were sprayed together in Enclosure C. Enclosure A remained untreated and was used as a control. The concentrations of lysine, malonic acid, chlorophyll a, and microcystin as well as the cell numbers of phytoplankton such as cyanobacteria, diatom, and euglena were monitored. On day 1 of the treatment, formation of cyanobacterial blooms almost ceased in Enclosures B and C, although Microcystis cells in the control still formed blooms. On day 7 Microcystis cells in Enclosure B that had been treated with lysine started growing again, whereas growth was not observed in Microcystis cells in Enclosure C, which had been treated with lysine and malonic acid. On day 28 the surface of Enclosure B was covered with water chestnut (Trapa spp.) and the Microcystis blooms again increased. In contrast, growth of macrophytes (Myriophllum spicatum and Potamogeton crispus) was observed in Enclosure C; however, no cyanobacterial blooms were observed. Lysine and malonic acid had completely decomposed. The microcystin concentration on day 28 decreased to 25% of the initial value, and the pH shifted from the initial value of 9.2 to 7.8. We concluded that combined treatment with lysine and malonic acid selectively controlled toxic Microcystis water blooms and induced the growth of macrophytes.

Degradation of Amino Acids and Structure in Model Proteins and Bacteriophage MS2 by Chlorine, Bromine, and Ozone.

PubMed

Choe, Jong Kwon; Richards, David H; Wilson, Corey J; Mitch, William A

2015-11-17

Proteins are important targets of chemical disinfectants. To improve the understanding of disinfectant-protein reactions, this study characterized the disinfectant:protein molar ratios at which 50% degradation of oxidizable amino acids (i.e., Met, Tyr, Trp, His, Lys) and structure were observed during HOCl, HOBr, and O3 treatment of three well-characterized model proteins and bacteriophage MS2. A critical question is the extent to which the targeting of amino acids is driven by their disinfectant rate constants rather than their geometrical arrangement. Across the model proteins and bacteriophage MS2 (coat protein), differing widely in structure, methionine was preferentially targeted, forming predominantly methionine sulfoxide. This targeting concurs with its high disinfectant rate constants and supports its hypothesized role as a sacrificial antioxidant. Despite higher HOCl and HOBr rate constants with histidine and lysine than for tyrosine, tyrosine generally was degraded in preference to histidine, and to a lesser extent, lysine. These results concur with the prevalence of geometrical motifs featuring histidines or lysines near tyrosines, facilitating histidine and lysine regeneration upon Cl[+1] transfer from their chloramines to tyrosines. Lysine nitrile formation occurred at or above oxidant doses where 3,5-dihalotyrosine products began to degrade. For O3, which lacks a similar oxidant transfer pathway, histidine, tyrosine, and lysine degradation followed their relative O3 rate constants. Except for its low reactivity with lysine, the O3 doses required to degrade amino acids were as low as or lower than for HOCl or HOBr, indicating its oxidative efficiency. Loss of structure did not correlate with loss of particular amino acids, suggesting the need to characterize the oxidation of specific geometric motifs to understand structural degradation.

A common transport system for methionine, L-methionine-DL-sulfoximine (MSX), and phosphinothricin (PPT) in the diazotrophic cyanobacterium Nostoc muscorum.

PubMed

Singh, Arvind Kumar; Syiem, Mayashree B; Singh, Rajkumar S; Adhikari, Samrat; Rai, Amar Nath

2008-05-01

We present evidence, for the first time, of the occurrence of a transport system common for amino acid methionine, and methionine/glutamate analogues L-methionine-DL-sulfoximine (MSX) and phosphinothricin (PPT) in cyanobacterium Nostoc muscorum. Methionine, which is toxic to cyanobacterium, enhanced its nitrogenase activity at lower concentrations. The cyanobacterium showed a biphasic pattern of methionine uptake activity that was competitively inhibited by the amino acids alanine, isoleucine, leucine, phenylalanine, proline, valine, glutamine, and asparagine. The methionine/glutamate analogue-resistant N. muscorum strains (MSX-R and PPT-R strains) also showed methionine-resistant phenotype accompanied by a drastic decrease in 35S methionine uptake activity. Treatment of protein extracts from these mutant strains with MSX and PPT reduced biosynthetic glutamine synthetase (GS) activity only in vitro and not in vivo. This finding implicated that MSX- and PPT-R phenotypes may have arisen due to a defect in their MSX and PPT transport activity. The simultaneous decrease in methionine uptake activity and in vitro sensitivity toward MSX and PPT of GS protein in MSX- and PPT-R strains indicated that methionine, MSX, and PPT have a common transport system that is shared by other amino acids as well in N. muscorum. Such information can become useful for isolation of methionine-producing cyanobacterial strains.

Effect of methionine and lactic acid bacteria as aflatoxin binder on broiler performance

NASA Astrophysics Data System (ADS)

Istiqomah, Lusty; Damayanti, Ema; Julendra, Hardi; Suryani, Ade Erma; Sakti, Awistaros Angger; Anggraeni, Ayu Septi

2017-06-01

The use of aflatoxin binder product based amino acids, lacic acid bacteria, and natural product gived the opportunity to be an alternative biological decontamination of aflatoxins. A study was conducted to determine the efficacy of aflatoxin binder administration (amino acid methionine and lactic acid bacteria (Lactobacillus plantarum G7)) as feed additive on broiler performance. In this study, 75 Lohmann unsexed day old chicks were distributed randomly into 5 units of cages, each filled with 15 broilers. Five cages were assigned into 5 treatments groups and fed with feed contained aflatoxin. The treatments as follow: P1 (aflatoxin feed without aflatoxin binder), P3 (aflatoxin feed + 0.8% of methionine + 1% of LAB), P4 (aflatoxin feed + 1.2% of methionine + 1% of LAB), P5 (aflatoxin feed + 1% of LAB), and K0 (commercial feed). The measurement of aflatoxin content in feed was performed by Enzyme Linked Immunosorbent Assay method using AgraQuant® Total Aflatoxin Assay Romer Labs procedure. The experimental period was 35 days with feeding and drinking ad libitum. LAB was administered into drinking water, while methionine into feed. Vaccination program of Newcastle Disease (ND) was using active vaccine at 4 and 18 day old, while Infectious Bursal Disease (IBD) was given at 8 day old. Parameter of body weight was observed weekly, while feed consumption noted daily. The result showed that aflatoxin in feed for 35 days period did not significantly affect the body weight gain and feed conversion. The lowest percentage of organ damage at 21 day old was found in P5 treatment (55%), while at 35day old was found in P4 treatment (64%). It could be concluded that technological process of detoxifying aflatoxin could be applied in an attempt to reduce the effect on the toxicity of aflatoxin in poultry feed.

Hydrolysis of proteins with methanesulfonic acid for improved HPLC-ICP-MS determination of seleno-methionine in yeast and nuts.

PubMed

Wrobel, Katarzyna; Kannamkumarath, Sasi S; Wrobel, Kazimierz; Caruso, Joseph A

2003-01-01

In this work, the use of methanesulfonic acid for protein hydrolysis is proposed for evaluation of Se-methionine in yeast, Brazil nuts, and possibly other selenium-rich biological samples. The hydrolysis was carried out by heating the sample with 4 mol L(-1) acid at reflux for 8 h. Two chromatographic techniques (size-exclusion and ion-pairing) coupled with ICP-MS detection were used to compare the release of Se-methionine from proteins by enzymatic (proteinase K, protease XIV) and acid hydrolyses. A more efficient liberation of Se-methionine was observed by acid hydrolysis. For quantification, the sample extracts were introduced onto a C8 Alltima column, and the separation was achieved with a mobile phase containing 5 mmol L(-1) hexanesulfonic acid in citrate buffer (pH 4.5)/methanol (95:5). The results obtained by standard addition showed 816+/-17 micro g g(-1) and 36.2+/-1.5 micro g g(-1) of selenium in the form of Se-methionine in yeast and nuts, respectively (65% and 75% of total selenium).

Sulfur amino acid deficiency upregulates intestinal methionine cycle activity and suppresses epithelial growth in neonatal pigs

PubMed Central

Bauchart-Thevret, Caroline; Stoll, Barbara; Chacko, Shaji; Burrin, Douglas G.

2009-01-01

We recently showed that the developing gut is a significant site of methionine transmethylation to homocysteine and transsulfuration to cysteine. We hypothesized that sulfur amino acid (SAA) deficiency would preferentially reduce mucosal growth and antioxidant function in neonatal pigs. Neonatal pigs were enterally fed a control or an SAA-free diet for 7 days, and then whole body methionine and cysteine kinetics were measured using an intravenous infusion of [1-13C;methyl-2H3]methionine and [15N]cysteine. Body weight gain and plasma methionine, cysteine, homocysteine, and taurine and total erythrocyte glutathione concentrations were markedly decreased (−46% to −85%) in SAA-free compared with control pigs. Whole body methionine and cysteine fluxes were reduced, yet methionine utilization for protein synthesis and methionine remethylation were relatively preserved at the expense of methionine transsulfuration, in response to SAA deficiency. Intestinal tissue concentrations of methionine and cysteine were markedly reduced and hepatic levels were maintained in SAA-free compared with control pigs. SAA deficiency increased the activity of methionine metabolic enzymes, i.e., methionine adenosyltransferase, methionine synthase, and cystathionine β-synthase, and S-adenosylmethionine concentration in the jejunum, whereas methionine synthase activity increased and S-adenosylmethionine level decreased in the liver. Small intestine weight and protein and DNA mass were lower, whereas liver weight and DNA mass were unchanged, in SAA-free compared with control pigs. Dietary SAA deficiency induced small intestinal villus atrophy, lower goblet cell numbers, and Ki-67-positive proliferative crypt cells in association with lower tissue glutathione, especially in the jejunum. We conclude that SAA deficiency upregulates intestinal methionine cycle activity and suppresses epithelial growth in neonatal pigs. PMID:19293331

Insight into the collagen assembly in the presence of lysine and glutamic acid: An in vitro study.

PubMed

Liu, Xinhua; Dan, Nianhua; Dan, Weihua

2017-01-01

The aim of this study is to evaluate the effects of two different charged amino acids in collagen chains, lysine and glutamic acid, on the fibrillogenesis process of collagen molecules. The turbidity, zeta potential, and fiber diameter analysis suggest that introducing the positively charged lysine into collagen might improve the sizes or amounts of the self-assembled collagen fibrils significantly. Conversely, the negatively charged glutamic acid might restrict the self-assembly of collagen building blocks into a higher order structure. Meanwhile, the optimal fibrillogenesis condition is achieved when the concentration of lysine reaches to 1mM. Both scanning electron microscopy (SEM) and atomic force microscope (AFM) analysis indicates that compared to pure collagen fibrils, the reconstructed collagen-lysine co-fibrils exhibit a higher degree of inter-fiber entanglements with more straight and longer fibrils. Noted that the specific D-period patterns of the reconstructed collagen fibrils could be clearly discernible and the width of D-banding increases steadily after introducing lysine. Besides, the kinetic and thermodynamic collagen self-assembly analysis confirms that the rate constants of both the first and second assembly phase decrease after introducing lysine, and lysine could promote the process of collagen fibrillogenesis obeying the laws of thermodynamics. Copyright © 2016 Elsevier B.V. All rights reserved.

Piezoelectric and pyroelectric properties of DL-alanine and L-lysine amino-acid polymer nanofibres

NASA Astrophysics Data System (ADS)

de Matos Gomes, Etelvina; Viseu, Teresa; Belsley, Michael; Almeida, Bernardo; Costa, Maria Margarida R.; Rodrigues, Vitor H.; Isakov, Dmitry

2018-04-01

The piezoelectric and pyroelectric properties of electrospun polyethylene oxide nanofibres embedded with polar amino acids DL-alanine and L-lysine hemihydrate are reported. A high pyroelectric coefficient of 150 μC m‑2 K‑1 was measured for L-lysine hemihydrate and piezoelectric current densities up to 7 μA m‑2 were obtained for the nanofibres. The study reveals a potential for polymer amino-acid nanofibres to be used as biocompatible energy harvesters for autonomous circuit applications like in implantable electronics.

Factors influencing methionine toxicity in young bobwhite quail

USGS Publications Warehouse

Serafin, J.A.

1981-01-01

Young Bobwhite quail (Colinus virginianus) were fed low and adequate protein purified diets with and without excess methionine to evaluate factors affecting methionine toxicity. Growth of quail fed an adequate protein (27%) diet, without supplemental glycine, was depressed by 1.75% and 2.25% excess methionine. Supplemental glycine (.3%) alleviated growth depression caused by 2.25% excess methionine. Quail fed 1.75% and 2.25% excess methionine developed signs of toxicity characterized by weakness, a lowered, outstretched neck when moving, and ataxia. In addition, quail would fall on their sides when disturbed and spin with their heads retracted. These conditions were transient in nature. Growth of quail fed a low protein (18.9%) diet was depressed by 1% and 1.5% excess methionine and DL-homocystine. Quail fed 1% and 1.5% excess methionine in this diet also developed signs of toxicity, the incidence of which was greater and the duration longer than occurred with quail fed adequate protein. Supplementing a low protein (20.15%) diet with .3% or .6% glycine or threonine or a combination of these amino acids did not alleviate growth depression caused by 1.5% excess methionine; however, 2% and 3% supplemental glycine were somewhat effective. Supplements of glycine (2%, 3%) and threonine (1%) completely reversed growth depression from 1% excess methionine but did not influence growth of controls, indicating that both amino acids counteract methionine toxicity. Both glycine and threonine alone improved growth by about the same extent in diets with 1% or 1.5% excess methionine; however, these amino acids alleviated less than 30% of the growth depression resulting from 1.5% excess methionine. The effectiveness of glycine in alleviating methionine toxicity in a low protein diet was decreased, and hemoglobin levels were depressed with 1.5% excess methionine compared to less amounts.

Metabolism of 5-methylthioribose to methionine

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

Miyazaki, J.H.; Yang, S.F.

1987-06-01

During ethylene biosynthesis, the H/sub 3/CS-group of S-adenosylmethionine is released as 5'-methylthioadenosine, which is recycled to methionine via 5-methylthioribose (MTR). In mungbean hypocotyls and cell-free extracts of avocado, (/sup 14/C)MTR was converted into labeled methionine via 2-keto-4-methylthiobutyric acid (KMB) and 2-hydroxy-4-methylthiobutyric acid (HMB), as intermediates. Incubation of (ribose-U-/sup 14/C)MTR with avocado extract resulted in the production of (/sup 14/C)formate, indicating the conversion of MTR to KMB involves a loss of formate, presumably from C-1 of MTR. Tracer studies showed that KMB was converted readily in vivo and in vitro to methionine, while HMB was converted much more slowly. The conversionmore » of KMB to methionine by dialyzed avocado extract requires an amino donor. Among several potential donors examined, L-glutamine was the most efficient. Anaerobiosis inhibited only partially the oxidation of MTR to formate, KMB/HMB, and methionine by avocado extract. The role of O/sub 2/ in the conversion of MTR to methionine is discussed.« less

Lysine and Glutamic Acids as the End Products of Multi-response of Optimized Fermented Medium by Mucor mucedo KP736529.

PubMed

El-Hersh, Mohammed S; Saber, WesamEldin I A; El-Fadaly, Husain A; Mahmoud, Mohammed K

Amino acids are important for living organisms, they acting as crucial for metabolic activities and energy generation, wherein the deficiency in these amino acids cause various physiological defects. The aim of this study is to investigate the effect of some nutritional factors on the amino acids production by Mucor mucedo KP736529 during fermentation intervals. Mucor mucedo KP736529 was selected according to proteolytic activity. Corn steep liquor and olive cake were used in the fermented medium during Placket-Burman and central composite design to maximize the production of lysine and glutamic acids. During the screening by Plackett-Burman design, olive cake and Corn Steep Liquor (CSL) had potential importance for the higher production of amino acids. The individual fractionation of total amino acids showed both lysine and glutamic as the major amino acids associated with the fermentation process. Moreover, the Central Composite Design (CCD) has been adopted to explain the interaction between olive cake and CSL on the production of lysine and glutamic acids. The model recorded significant F-value, with high values of R 2, adjusted R 2 and predicted R 2 for both lysine and glutamic, indicating the validity of the data. Solving equation for maximum production of lysine recorded theoretical levels of olive cake and CSL, being 2.58 and 1.83 g L -1, respectively, with predicting value of lysine at 1.470 μg mL -1, whereas the predicting value of glutamic acid reached 0.805 mg mL -1 at levels of 2.49 and 1.93 g L -1 from olive cake and CSL, respectively. The desirability function (D) showed the actual responses being 1.473±0.009 and 0.801±0.004 μg mL -1 for lysine and glutamic acids, respectively. The model showed adequate validity to be applied in a large-scale production of both lysine and glutamic acids.

Molecular control mechanisms of lysine and threonine biosynthesis in amino acid-producing corynebacteria: redirecting carbon flow.

PubMed

Malumbres, M; Martín, J F

1996-10-01

Threonine and lysine are two of the economically most important essential amino acids. They are produced industrially by species of the genera Corynebacterium and Brevibacterium. The branched biosynthetic pathway of these amino acids in corynebacteria is unusual in gene organization and in the control of key enzymatic steps with respect to other microorganisms. This article reviews the molecular control mechanisms of the biosynthetic pathways leading to threonine and lysine in corynebacteria, and their implications in the production of these amino acids. Carbon flux can be redirected at branch points by gene disruption of the competing pathways for lysine or threonine. Removal of bottlenecks has been achieved by amplification of genes which encode feedback resistant aspartokinase and homoserine dehydrogenase (obtained by in vitro directed mutagenesis).

Investigation of Amino Acids As Herbicides for Control of Orobanche minor Parasitism in Red Clover.

PubMed

Fernández-Aparicio, Mónica; Bernard, Alexandre; Falchetto, Laurent; Marget, Pascal; Chauvel, Bruno; Steinberg, Christian; Morris, Cindy E; Gibot-Leclerc, Stephanie; Boari, Angela; Vurro, Maurizio; Bohan, David A; Sands, David C; Reboud, Xavier

2017-01-01

Certain amino acids induce inhibitory effects in plant growth due to feedback inhibition of metabolic pathways. The inhibition patterns depend on plant species and the plant developmental stage. Those amino acids with inhibitory action on specific weeds could be utilized as herbicides, however, their use for weed control has not been put into practice. Orobanche minor is a weed that parasitizes red clover. O. minor germination is stimulated by clover root exudates. The subsequent seedling is an obligated parasite that must attach quickly to the clover root to withdraw its nutrients. Early development of O. minor is vulnerable to amino acid inhibition and therefore, a series of in vitro , rhizotron, and field experiments were conducted to investigate the potential of amino acids to inhibit O. minor parasitism. In in vitro experiments it was found that among a collection of 20 protein amino acids, lysine, methionine and tryptophan strongly interfere with O. minor early development. Field research confirmed their inhibitory effect but revealed that methionine was more effective than lysine and tryptophan, and that two successive methionine applications at 308 and 543 growing degree days inhibited O. minor emergence in red clover up to 67%. We investigated additional effects with potential to influence the practical use of amino acids against broomrape weeds, whether the herbicidal effect may be reversible by other amino acids exuded by host plants or may be amplified by inducing host resistance barriers against O. minor penetration. This paper suggests that amino acids may have the potential to be integrated into biorational programs of broomrape management.

Investigation of Amino Acids As Herbicides for Control of Orobanche minor Parasitism in Red Clover

PubMed Central

Fernández-Aparicio, Mónica; Bernard, Alexandre; Falchetto, Laurent; Marget, Pascal; Chauvel, Bruno; Steinberg, Christian; Morris, Cindy E.; Gibot-Leclerc, Stephanie; Boari, Angela; Vurro, Maurizio; Bohan, David A.; Sands, David C.; Reboud, Xavier

2017-01-01

Certain amino acids induce inhibitory effects in plant growth due to feedback inhibition of metabolic pathways. The inhibition patterns depend on plant species and the plant developmental stage. Those amino acids with inhibitory action on specific weeds could be utilized as herbicides, however, their use for weed control has not been put into practice. Orobanche minor is a weed that parasitizes red clover. O. minor germination is stimulated by clover root exudates. The subsequent seedling is an obligated parasite that must attach quickly to the clover root to withdraw its nutrients. Early development of O. minor is vulnerable to amino acid inhibition and therefore, a series of in vitro, rhizotron, and field experiments were conducted to investigate the potential of amino acids to inhibit O. minor parasitism. In in vitro experiments it was found that among a collection of 20 protein amino acids, lysine, methionine and tryptophan strongly interfere with O. minor early development. Field research confirmed their inhibitory effect but revealed that methionine was more effective than lysine and tryptophan, and that two successive methionine applications at 308 and 543 growing degree days inhibited O. minor emergence in red clover up to 67%. We investigated additional effects with potential to influence the practical use of amino acids against broomrape weeds, whether the herbicidal effect may be reversible by other amino acids exuded by host plants or may be amplified by inducing host resistance barriers against O. minor penetration. This paper suggests that amino acids may have the potential to be integrated into biorational programs of broomrape management. PMID:28588599

Transcriptomic and biochemical evidence for the role of lysine biosynthesis against linoleic acid hydroperoxide-induced stress in Saccharomyces cerevisiae.

PubMed

O'Doherty, P J; Lyons, V; Tun, N M; Rogers, P J; Bailey, T D; Wu, M J

2014-12-01

Amino acid biosynthesis forms part of an integrated stress response against oxidants in Saccharomyces cerevisiae and higher eukaryotes. Here we show an essential protective role of the l-lysine biosynthesis pathway in response to the oxidative stress condition induced by the lipid oxidant-linoleic acid hydroperoxide (LoaOOH), by means of transcriptomic profiling and phenotypic analysis, and using the deletion mutant dal80∆ and lysine auxotroph lys1∆. A comprehensive up-regulation of lysine biosynthetic genes (LYS1, LYS2, LYS4, LYS9, LYS12, LYS20 and LYS21) was revealed in dal80Δ following the oxidant challenge. The lysine auxotroph (lys1∆) exhibited a significant decrease in growth compared with that of BY4743 upon exposure to LoaOOH, albeit with the sufficient provision of lysine in the medium. Furthermore, the growth of wild type BY4743 exposed to LoaOOH was also greatly reduced in lysine-deficient conditions, despite a full complement of lysine biosynthetic genes. Amino acid analysis of LoaOOH-treated yeast showed that the level of cellular lysine remained unchanged throughout oxidant challenge, suggesting that the induced lysine biosynthesis leads to a steady-state metabolism as compared to the untreated yeast cells. Together, these findings demonstrate that lysine availability and its biosynthesis pathway play an important role in protecting the cell from lipid peroxide-induced oxidative stress, which is directly related to understanding environmental stress and industrial yeast management in brewing, wine making and baking.

Methionine toxicity in chicks and poults.

PubMed

Hafez, Y S; Chavez, E; Vohra, P; Kratzer, F H

1978-05-01

In feeding experiments with poults, 2% DL-methionine caused a marked growth depression which could be alleviated by the addition of glycine. Homocystine at an equimolar level depressed growth to a lesser degree than methionine, and this growth depression could be alleviated by glycine. Betaine could alleviate the growth depression of homocystine but not that of methionine. Methionine-fed poults developed a cervical paralysis similar to that of a folic acid deficiency, but the addition of this vitamin at several times the requirement was ineffective in counteracting the toxicity of methionine in either chicks or poults.

Interactions among the branched-chain amino acids and their effects on methionine utilization in growing pigs: effects on plasma amino- and keto-acid concentrations and branched-chain keto-acid dehydrogenase activity.

PubMed

Langer, S; Scislowski, P W; Brown, D S; Dewey, P; Fuller, M F

2000-01-01

The present experiment was designed to elucidate the mechanism of the methionine-sparing effect of excess branched-chain amino acids (BCAA) reported in the previous paper (Langer & Fuller, 2000). Twelve growing gilts (30-35 kg) were prepared with arterial catheters. After recovery, they received for 7 d a semipurified diet with a balanced amino acid pattern. On the 7th day blood samples were taken before (16 h postabsorptive) and after the morning meal (4 h postprandial). The animals were then divided into three groups and received for a further 7 d a methionine-limiting diet (80% of requirement) (1) without any amino acid excess; (2) with excess leucine (50% over requirement); or (3) with excesses of all three BCAA (leucine, isoleucine, valine, each 50% over the requirement). On the 7th day blood samples were taken as in the first period, after which the animals were killed and liver and muscle samples taken. Plasma amino acid and branched-chain keto acid (BCKA) concentrations in the blood and branched-chain keto-acid dehydrogenase (BCKDH; EC 1.2.4.4) activity in liver and muscle homogenates were determined. Compared with those on the balanced diet, pigs fed on methionine-limiting diets had significantly lower (P < 0.05) plasma methionine concentrations in the postprandial but not in the postabsorptive state. There was no effect of either leucine or a mixture of all three BCAA fed in excess on plasma methionine concentrations. Excess dietary leucine reduced (P < 0.05) the plasma concentrations of isoleucine and valine in both the postprandial and postabsorptive states. Plasma concentrations of the BCKA reflected the changes in the corresponding amino acids. Basal BCKDH activity in the liver and total BCKDH activity in the biceps femoris muscle were significantly (P < 0.05) increased by excesses of leucine or all BCAA.

Response of rainbow trout to source and level of supplemental dietary methionine

USGS Publications Warehouse

Poston, H.A.

1986-01-01

1. Methionine and total sulfur amino acid (TSAA) requirements of rainbow trout (Salmo gairdneri) were investigated by feeding graded isosulfurous levels of l- and dl-methionine, l-cystine, and the free acid and calcium forms of methionine hydroxy analog (MHA).2. Added cystine did not promote growth, survival or prevent cataracts.3. l-methionine produced fastest growth, followed by dl-methionine, CaMHA and free acid MHA.4. Trout fed CaMHA gained 85.7 and 92.3% as much as those fed l-methionine and dl-methionine.5. Within each experiment, the level of L-methionine isomer that prevented cataracts was constant (1.86 g/100g protein in experiment (1), 1.45 in experiment (2) and was lower than for maximum growth (2.89 and 2.15 g) regardless of methionine source.

Enzymatic preparation of. cap alpha. - and. beta. -deuterated or tritiated amino acids with l-methionine. gamma. -lyase

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

Esaki, N.; Sawada, S.; Tanaka, H.

L-Methionine ..gamma..-lyase catalyzes the exchange of ..cap alpha..- and ..beta..-hydrogens of L-methionine and S-methyl-L-cysteine with deuterium or tritium of solvents. The rate of ..cap alpha..-hydrogen exchange with deuterium was about 40 times faster than that of the elimination reactions. The deuterium and tritium were exchanged also with the ..cap alpha..- and ..beta..-hydrogens of the straight-chain amino acids which do not undergo the elimination: L-alanine, L-..cap alpha..-aminobutyrate, L-norvaline, and L-norleucine. No exchange occurs for the D-isomers, acidic L-amino acids, basic L-amino acids, and branched-chain L-amino acids, although ..cap alpha..-hydrogen of glycine, L-trypotophan, and L-phenylalanine is exchanged slowly. These enzymatic hydrogen-exchange reactionsmore » facilitate specific labeling of the L-amino acids with deuterium and tritium.« less

The effect of amino acids on the intestinal absorption of immunoglobulins in the neonatal rat

PubMed Central

Bamford, D. R.; Donnelly, H.

1974-01-01

An in vitro preparation of 10-day-old rat intestine was used to examine the absorption of a number of amino acids and immunoglobulins. Evidence was obtained for the active absorption of alanine, leucine, methionine, histidine and lysine, but not for aspartic acid. A selective absorption of the homologous molecule was found in experiments where 131I-labelled rat and bovine IgG were presented to the ileum in 10-minute incubations. The greater uptake of rat IgG was unrelated to the relative rates of catabolism of the two molecules. Although the uptake of rat IgG was unaffected by 100 mM concentrations of neutral and acidic amino acids, the basic amino acids arginine and lysine significantly stimulated uptake. PMID:4854740

Biofortification of rice with the essential amino acid lysine: molecular characterization, nutritional evaluation, and field performance

PubMed Central

Yang, Qing-qing; Zhang, Chang-quan; Chan, Man-ling; Zhao, Dong-sheng; Chen, Jin-zhu; Wang, Qing; Li, Qian-feng; Yu, Heng-xiu; Gu, Ming-hong; Sun, Samuel Sai-ming; Liu, Qiao-quan

2016-01-01

Rice (Oryza sativa L.), a major staple crop worldwide, has limited levels of the essential amino acid lysine. We previously produced engineered rice with increased lysine content by expressing bacterial aspartate kinase and dihydrodipicolinate synthase and inhibiting rice lysine ketoglutarate reductase/saccharopine dehydrogenase activity. However, the grain quality, field performance, and integration patterns of the transgenes in these lysine-enriched lines remain unclear. In the present study, we selected several elite transgenic lines with endosperm-specific or constitutive regulation of the above key enzymes but lacking the selectable marker gene. All target transgenes were integrated into the intragenic region in the rice genome. Two pyramid transgenic lines (High Free Lysine; HFL1 and HFL2) with free lysine levels in seeds up to 25-fold that of wild type were obtained via a combination of the above two transgenic events. We observed a dramatic increase in total free amino acids and a slight increase in total protein content in both pyramid lines. Moreover, the general physicochemical properties were improved in pyramid transgenic rice, but the starch composition was not affected. Field trials indicated that the growth of HFL transgenic rice was normal, except for a slight difference in plant height and grain colour. Taken together, these findings will be useful for the potential commercialization of high-lysine transgenic rice. PMID:27252467

Acetylome Profiling Reveals Extensive Lysine Acetylation of the Fatty Acid Metabolism Pathway in the Diatom Phaeodactylum tricornutum.

PubMed

Chen, Zhuo; Luo, Ling; Chen, Runfa; Hu, Hanhua; Pan, Yufang; Jiang, Haibo; Wan, Xia; Jin, Hu; Gong, Yangmin

2018-03-01

N ε -lysine acetylation represents a highly dynamic and reversibly regulated post-translational modification widespread in almost all organisms, and plays important roles for regulation of protein function in diverse metabolic pathways. However, little is known about the role of lysine acetylation in photosynthetic eukaryotic microalgae. We integrated proteomic approaches to comprehensively characterize the lysine acetylome in the model diatom Phaeodactylum tricornutum In total, 2324 acetylation sites from 1220 acetylated proteins were identified, representing the largest data set of the lysine acetylome in plants to date. Almost all enzymes involved in fatty acid synthesis were found to be lysine acetylated. Six putative lysine acetylation sites were identified in a plastid-localized long-chain acyl-CoA synthetase. Site-directed mutagenesis and site-specific incorporation of N-acetyllysine in acyl-CoA synthetase show that acetylation at K407 and K425 increases its enzyme activity. Moreover, the nonenzymatically catalyzed overall hyperacetylation of acyl-CoA synthetase by acetyl-phosphate can be effectively deacetylated and reversed by a sirtuin-type NAD + -dependent deacetylase with subcellular localization of both the plastid and nucleus in Phaeodactylum This work indicates the regulation of acyl-CoA synthetase activity by site-specific lysine acetylation and highlights the potential regulation of fatty acid metabolism by lysine actetylation in the plastid of the diatom Phaeodactylum . © 2018 by The American Society for Biochemistry and Molecular Biology, Inc.

Amino acid levels in nascent metabolic syndrome: A contributor to the pro-inflammatory burden.

PubMed

Reddy, Priya; Leong, Joseph; Jialal, Ishwarlal

2018-05-01

Metabolic Syndrome (MetS) is a cluster of cardio-metabolic risk factors characterized by low-grade inflammation which confers an increased risk for type 2 diabetes mellitus (T2DM) and cardiovascular disease (CVD). Prior studies have linked elevated branched chain amino acids (BCAA) and aromatic amino acids (AAA) with T2DM and CVD. Due to the paucity of data in MetS, the aim of this study was to investigate the status of amino acids as early biomarkers of nascent MetS patients without T2DM and CVD or smoking. Healthy controls (n = 20) and MetS (n = 29) patients were recruited for the study. MetS was defined by criteria of National Cholesterol Education Program Adult Treatment Panel III of having at least 3 risk factors. Urinary amino acids were quantified by gas chromatography time-of-flight mass spectrometry at the Western NIH Metabolomics Center as expressed to urinary creatinine. Tyrosine and Isoleucine levels were significantly elevated in MetS patients. Isoleucine positively correlated with salient cardio-metabolic features and inflammatory biomarkers. Lysine and Methionine levels were decreased in MetS patients. Lysine correlated negatively with cardio-metabolic features and inflammatory bimarkers. Methionine also correlated negatively with blood pressure and certain inflammatory biomarkers. Our novel results suggest that with regards to the cardio-metabolic risk factors and pro-inflammatory features of MetS, isoleucine (BCAA) demonstrated a positive correlation while lysine demonstrated a negative correlation. Thus, increased levels of isoleucine and decreased levels of lysine could be potential early biomarkers of MetS. Copyright © 2018. Published by Elsevier Inc.

Influence of methionine/valine-depleted enteral nutrition on nucleic acid and protein metabolism in tumor-bearing rats

PubMed Central

He, Yin-Cheng; Cao, Jun; Chen, Ji-Wei; Pan, Ding-Yu; Zhou, Ya-Kui

2003-01-01

AIM: To investigate the effects of methionine/valine-depleted enteral nutrition (EN) on RNA, DNA and protein metabolism in tumor-bearing (TB) rats. METHODS: Sprague-Dawlley (SD) rats underwent jejunostomy for nutritional support. A suspension of Walker-256 carcinosarcoma cells was subcutaneously inoculated. 48 TB rats were randomly divided in 4 groups: A, B, C and D. The TB rats had respectively received jejunal feedings supplemented with balanced amino acids, methionine-depleted, balanced amino acids and valine-depleted for 6 d before injection of 740 KBq 3H- methionine/valine via jejunum. The 3H incorporation rate of the radioactivity into RNA, DNA and proteins in tumor tissues at 0.5, 1, 2, 4 h postinjection of tracers was assessed with liquid scintillation counter. RESULTS: Incorporation of 3H into proteins in groups B and D was (0.500 ± 0.020)% to (3.670 ± 0.110)% and (0.708 ± 0.019)% to (3.813 ± 0.076)% respectively, lower than in groups A [(0.659 ± 0.055)% to (4.492 ± 0.108)%] and C [(0.805 ± 0.098)% to (4.180 ± 0.018)%]. Incorporation of 3H into RNA, DNA in group B was (0.237 ± 0.075)% and (0.231 ± 0.052)% respectively, lower than in group A (P < 0.01). There was no significant difference in uptake of 3H by RNA and DNA between group C and D (P > 0.05). CONCLUSION: Protein synthesis was inhibited by methionine/valine starvation in TB rats and nucleic acid synthesis was reduced after methionine depletion, thus resulting in suppression of tumor growth. PMID:12679929

Accumulation, selection and covariation of amino acids in sieve tube sap of tansy (Tanacetum vulgare) and castor bean (Ricinus communis): evidence for the function of a basic amino acid transporter and the absence of a γ-amino butyric acid transporter.

PubMed

Bauer, Susanne N; Nowak, Heike; Keller, Frank; Kallarackal, Jose; Hajirezaei, Mohamad-Reza; Komor, Ewald

2014-09-01

Sieve tube sap was obtained from Tanacetum by aphid stylectomy and from Ricinus after apical bud decapitation. The amino acids in sieve tube sap were analyzed and compared with those from leaves. Arginine and lysine accumulated in the sieve tube sap of Tanacetum more than 10-fold compared to the leaf extracts and they were, together with asparagine and serine, preferably selected into the sieve tube sap, whereas glycine, methionine/tryptophan and γ-amino butyric acid were partially or completely excluded. The two basic amino acids also showed a close covariation in sieve tube sap. The acidic amino acids also grouped together, but antagonistic to the other amino acids. The accumulation ratios between sieve tube sap and leaf extracts were smaller in Ricinus than in Tanacetum. Arginine, histidine, lysine and glutamine were enriched and preferentially loaded into the phloem, together with isoleucine and valine. In contrast, glycine and methionine/tryptophan were partially and γ-amino butyric acid almost completely excluded from sieve tube sap. The covariation analysis grouped arginine together with several neutral amino acids. The acidic amino acids were loaded under competition with neutral amino acids. It is concluded from comparison with the substrate specificities of already characterized plant amino acid transporters, that an AtCAT1-like transporter functions in phloem loading of basic amino acids, whereas a transporter like AtGAT1 is absent in phloem. Although Tanacetum and Ricinus have different minor vein architecture, their phloem loading specificities for amino acids are relatively similar. © 2014 Scandinavian Plant Physiology Society.

Lysine Fermentation: History and Genome Breeding.

PubMed

Ikeda, Masato

Lysine fermentation by Corynebacterium glutamicum was developed in 1958 by Kyowa Hakko Kogyo Co. Ltd. (current Kyowa Hakko Bio Co. Ltd.) and is the second oldest amino acid fermentation process after glutamate fermentation. The fundamental mechanism of lysine production, discovered in the early stages of the process's history, gave birth to the concept known as "metabolic regulatory fermentation," which is now widely applied to metabolite production. After the development of rational metabolic engineering, research on lysine production first highlighted the need for engineering of the central metabolism from the viewpoints of precursor supply and NADPH regeneration. Furthermore, the existence of active export systems for amino acids was first demonstrated for lysine in C. glutamicum, and this discovery has resulted in the current recognition of such exporters as an important consideration in metabolite production. Lysine fermentation is also notable as the first process to which genomics was successfully applied to improve amino acid production. The first global "genome breeding" strategy was developed using a lysine producer as a model; this has since led to new lysine producers that are more efficient than classical industrial producers. These advances in strain development technology, combined with recent systems-level approaches, have almost achieved the optimization of entire cellular systems as cell factories for lysine production. In parallel, the continuous improvement of the process has resulted not only in fermentation processes with reduced load on downstream processing but also in commercialization of various product forms according to their intended uses. Nowadays lysine fermentation underpins a giant lysine demand of more than 2 million metric tons per year.

Protein recycling in growing rabbits: contribution of microbial lysine to amino acid metabolism.

PubMed

Belenguer, Alvaro; Balcells, Joaquim; Guada, Jose A; Decoux, Marc; Milne, Eric

2005-11-01

To study the absorption of microbial lysine in growing rabbits, a labelled diet (supplemented with (15)NH4Cl) was administered to six animals (group ISOT); a control group (CTRL, four rabbits) received a similar, but unlabelled, diet. Diets were administered for 30 d. An additional group of six animals were fed the unlabelled diet for 20 d and then the labelled diet for 10 d while wearing a neck collar to avoid caecotrophy (group COLL), in order to discriminate it from direct intestinal absorption. At day 30 animals were slaughtered and caecal bacteria and liver samples taken. The (15)N enrichment in amino acids of caecal bacteria and liver were determined by GC-combustion/isotope ratio MS. Lysine showed a higher enrichment in caecal microflora (0.925 atom% excess, APE) than liver (0.215 APE) in group ISOT animals, confirming the double origin of body lysine: microbial and dietary. The COLL group showed a much lower enrichment in tissue lysine (0.007 (se 0.0029) APE for liver). Any enrichment in the latter animals was due to direct absorption of microbial lysine along the digestive tract, since recycling of microbial protein (caecotrophy) was avoided. In such conditions liver enrichment was low, indicating a small direct intestinal absorption. From the ratio of [(15)N]lysine enrichment between liver and bacteria the contribution of microbes to body lysine was estimated at 23 %, with 97 % of this arising through caecotrophy. Absorption of microbial lysine through caecotrophy was 119 (se 4.0) mg/d, compared with 406 (se 1.8) mg/d available from the diet. This study confirms the importance of caecotrophy in rabbit nutrition (15 % of total protein intake).

Photooxidation of Methionine

ERIC Educational Resources Information Center

Lewis, Catherine; Scouten, William H.

1976-01-01

Describes an experiment in which the photooxidation of methionine using free methylene blue as the sensitizer is applied to the isolated amino acid or to the methionyl residues of a complex polypeptide. (MLH)

Synthesis and characterization of arginine-glycine-aspartic peptides conjugated poly(lactic acid-co-L-lysine) diblock copolymer.

PubMed

Yu, Hui; Guo, Xiaojuan; Qi, Xueliang; Liu, Peifeng; Shen, Xinyuan; Duan, Yourong

2008-03-01

A biodegradable Copolymer of poly(lactic acid-co-lysine)(PLA-PLL) was synthesized by a modified method and novel Arginine-Glycine-Aspartic (RGD) peptides were chemical conjugated to the primary epsilon-amine groups of lysine components in four steps: I to prepare the monomer of 3-(Nepsilon-benzoxycarbonyl-L-lysine)-6-L-methyl-2,5-morpholinedione; II to prepare diblock copolymer poly(lactic acid-co-(Z)-L-lysine) (PLA-PLL(Z)) by ring-opening polymerization of monomer and L,L-lactide with stannous octoate as initiator; III to prepare diblock copolymer PLA-PLL by deprotected the copolymer PLA-PLL(Z) in HBr/HoAc solution; IV the reaction between RGD and the primary epsilon-amine groups of the PLA-PLL. The structure of PLA-PLL-RGD and its precursors were conformed by FTIR-Raman and 1H NMR. Low weight average molecular weight (9,200 g/mol) of the PLA-PLL was obtained and its PDI is 1.33 determined by GPC. The PLA-PLL contained 2.1 mol% lysine groups as determined by 1H NMR using the lysine protecting group's phenyl protons. Therefore, the novel RGD-grafted diblock copolymer is expected to find application in drug carriers for tumor therapy or non-viral DNA carriers for gene therapy.

New developments in uses of "cereals and pulses," traditionally a basic food ingredient in the East

USDA-ARS?s Scientific Manuscript database

‘Cereals and pulses’ are very popular in the developing world. They provide a harmonious balance of amino acids, as pulses are high in lysine and low in methionine, while cereals are low in lysine and not in methionine. Over the years, a number of studies have been reported on improved nutritional ...

Methionine and serine synergistically suppress hyperhomocysteinemia induced by choline deficiency, but not by guanidinoacetic acid, in rats fed a low casein diet.

PubMed

Liu, Yi-qun; Liu, Ying; Morita, Tatsuya; Sugiyama, Kimio

2011-01-01

The effects of dietary supplementation with 0.5% methionine, 2.5% serine, or both on hyperhomocysteinemia induced by deprivation of dietary choline or by dietary addition of 0.5% guanidinoacetic acid (GAA) were investigated in rats fed a 10% casein diet. Hyperhomocysteinemia induced by choline deprivation was not suppressed by methionine alone and was only partially suppressed by serine alone, whereas it was completely suppressed by a combination of methionine and serine, suggesting a synergistic effect of methionine and serine. Fatty liver was also completely prevented by the combination of methionine and serine. Compared with methionine alone, the combination of methionine and serine decreased hepatic S-adenosylhomocysteine and homocysteine concentrations and increased hepatic betaine and serine concentrations and betaine-homocysteine S-methyltransferase activity. GAA-induced hyperhomocysteinemia was partially suppressed by methionine alone, but no interacting effect of methionine and serine was detected. In contrast, GAA-induced fatty liver was completely prevented by the combination of methionine and serine. These results indicate that a combination of methionine and serine is effective in suppressing both hyperhomocysteinemia and fatty liver induced by choline deprivation, and that methionine alone is effective in suppressing GAA-induced hyperhomocysteinemia partially.

Study on mutual interactions and electronic structures of hyaluronan with Lysine, 6-Aminocaproic acid and Arginine.

PubMed

Chytil, Martin; Trojan, Martin; Kovalenko, Alexander

2016-05-20

Interactions between polyelectrolytes and oppositely charged surfactants have been in a great interest for several decades, yet the conventional surfactants may cause a problem in medical applications. Interactivity between polysaccharide hyaluronan (HA) and amino acids Lysine, 6-Aminocaproic acid (6-AcA), and Arginine as an alternative system is reported. The interactions were investigated by means of rheology and electric conductance and the electronic structures were explored by the density functional theory (DFT). Lysine exhibits the strongest interaction of all, which was manifested, e.g. by nearly 6-time drop of the initial viscosity comparing with only 1.3-time lower value in the case of 6-AcA. Arginine interaction with HA was surprisingly weaker in terms of viscosity than that of Lysine due to a lower and delocalized charge density on its guanidine group. According to the DFT calculations, the binding of Lysine to HA was found to be more flexible, while Arginine creates more rigid structure with HA. Copyright © 2016 Elsevier Ltd. All rights reserved.

Anaerobic degradation of amino acids generated from the hydrolysis of sewage sludge.

PubMed

Park, Junghoon; Park, Seyong; Kim, Moonil

2014-01-01

The anaerobic degradation of each amino acid that could be generated through the hydrolysis of sewage sludge was evaluated. Stickland reaction as an intermediate reaction between two kinds of amino acids was restricted in order to evaluate each amino acid. Changes in the chemical oxygen demand (COD), T-N, NH4(+)-N, biogas, and CH4 were analysed for the anaerobic digestion process. The initial nitrogen concentration of all amino acids is adjusted as 1000 mg/L. The degradation rate of the amino acids was determined based on the ammonia form of nitrogen, which is generated by the deamination of amino acids. Among all amino acids, such as alpha-alanine, beta-alanine, lysine, arginine, glycine, histidine, cysteine, methionine, and leucine, deamination rates of cysteine, leucine, and methionine were just 61.55%, 54.59%, and 46.61%, respectively, and they had low removal rates of organic matter and showed very low methane production rates of 13.55, 71.04, and 80.77 mL CH4/g CODin, respectively. Especially for cysteine, the methane content was maintained at approximately 7% during the experiment. If wastewater contains high levels of cysteine, leucine, and methionine and Stickland reaction is not prepared, these amino acids may reduce the efficiency of the anaerobic digestion.

PubMed Central

Carbonneau, Roch; Demers, Jean-Marie

1965-01-01

The object of this experiment was to study the influence of essential amino acids on the growth, fatty infiltration of liver and cholesterol level of the serum in ducklings. A 11 per cent protein basal diet, deficient in many essential amino acids, given to ducklings, resulted in poor growth, fatty infiltration of liver and high cholesterol level of the serum. In our experimental design, three amino acids, lysine, methionine and threonine were promoting growth whereas lysine and threonine were preventing fatty infiltration of liver but methionine failed to do so. Rather than a deficiency in lysine alone, simultaneous deficiencies in valine, arginine and lysine resulted in better growth for ducklings. This protective effect of deficiency in valine and arginine together with one in lysine was not effective against fatty infiltration of liver. The cholesterolemia found for the ducklings given basal diet or diets with deficiency in many essential amino acids was higher than that found for the ducklings given diets without essential amino acids deficiency. PMID:4220644

Methionine metabolism in Yucatan miniature swine.

PubMed

McBreairty, Laura E

2016-06-01

Methionine is an essential amino acid which when not incorporated into protein, can be converted to S-adenosylmethionine, the universal methyl donor in over 200 transmethylation reactions, which include creatine and phosphatidylcholine (PC) synthesis, as well as deoxyribonucleic acid (DNA) methylation. Following transmethylation, homocysteine is formed, which can be converted to cysteine via transsulfuration or remethylated to methionine by receiving a methyl group from folate or betaine. Changes to methyl group availability in utero can lead to permanent changes in epigenetic patterns of DNA methylation, which has been implicated in "fetal programming", a phenomenon associated with poor nutrition during fetal development that results in low birth weight and disease in later life. It has been shown that programming can also occur in the neonate. Our global objective was to understand how the variability of nutrients involved in methionine metabolism can affect methionine and methyl group availability. We hypothesize that nutrients that converge on methionine metabolism can affect methionine availability for its various functions. In this thesis, we used intrauterine growth restricted (IUGR) piglets to investigate whether a global nutritional insult in utero can lead to a perturbed methionine metabolism. Our results demonstrate that IUGR piglets have a lower capacity to dispose of homocysteine via both transsulfuration and remethylation pathways, as well as a lower incorporation of methyl groups into PC. The second objective of this thesis was to determine whether variation in methionine supply and demand can affect methionine availability. We demonstrated that stimulating either acute or chronic creatine synthesis leads to lower methyl incorporation into protein and PC in pigs. Furthermore, when methionine is limiting, supplementation with either folate or betaine leads to higher methionine availability for protein synthesis. Finally, because creatine is

Metabolic Availability of the Limiting Amino Acids Lysine and Tryptophan in Cooked White African Cornmeal Assessed in Healthy Young Men Using the Indicator Amino Acid Oxidation Technique.

PubMed

Rafii, Mahroukh; Elango, Rajavel; Ball, Ronald O; Pencharz, Paul B; Courtney-Martin, Glenda

2018-06-01

Maize is a staple food in many regions of the world, particularly in Africa and Latin America. However, maize protein is limiting in the indispensable amino acids lysine and tryptophan, making its protein of poor quality. The main objective of this study was to determine the protein quality of white African cornmeal by determining the metabolic availability (MA) of lysine and tryptophan. To determine the MA of lysine, 4 amounts of l-lysine (10, 13, 16, and 18 mg · kg-1 · d-1 totaling 28.6%, 37.1%, 45.7%, and 51.4% of the mean lysine requirement of 35 mg · kg-1 · d-1, respectively) were studied in 6 healthy young men in a repeated-measures design. To determine the MA of tryptophan, 4 amounts of l-tryptophan (0.5, 1, 1.5, and 2 mg · kg-1 · d-1 totaling 12.5%, 25.0%, 37.5%, and 50.0% of the mean tryptophan requirement of 4 mg · kg-1 · d-1, respectively) were studied in 7 healthy young men in a repeated-measures design. The MAs of lysine and tryptophan were estimated by comparing the indicator amino acid oxidation (IAAO) response with varying intakes of lysine and tryptophan in cooked white cornmeal compared with the IAAO response to l-lysine and l-tryptophan intakes in the reference protein (crystalline amino acid mixture patterned after egg protein) with the use of the slope ratio method. The MAs of lysine and tryptophan from African cooked white cornmeal were 71% and 80%, respectively. Our study provides a robust estimate of the availability of lysine and tryptophan in African white maize to healthy young men. This estimate provides a basis for postproduction fortification or supplementation of maize-based diets. This trial was registered at www.clinicaltrials.gov as NCT02402179.

Methionine transport in the malaria parasite Plasmodium falciparum.

PubMed

Cobbold, Simon A; Martin, Rowena E; Kirk, Kiaran

2011-01-01

The intraerythrocytic malaria parasite, Plasmodium falciparum, derives amino acids from the digestion of host cell haemoglobin. However, it also takes up amino acids from the extracellular medium. Isoleucine is absent from adult human haemoglobin and an exogenous source of isoleucine is essential for parasite growth. An extracellular source of methionine is also important for the normal growth of at least some parasite strains. In this study we have characterised the uptake of methionine by P. falciparum-infected human erythrocytes, and by parasites functionally isolated from their host cells by saponin-permeabilization of the erythrocyte membrane. Infected erythrocytes take up methionine much faster than uninfected erythrocytes, with the increase attributable to the flux of this amino acid via the New Permeability Pathways induced by the parasite in the erythrocyte membrane. Having entered the infected cell, methionine is taken up by the intracellular parasite via a saturable, temperature-dependent process that is independent of ATP, Na(+) and H(+). Substrate competition studies, and comparison of the transport of methionine with that of isoleucine and leucine, yielded results consistent with the hypothesis that the parasite has at its surface one or more transporters which mediate the flux into and out of the parasite of a broad range of neutral amino acids. These transporters function most efficiently when exchanging one neutral amino acid for another, thus providing a mechanism whereby the parasite is able to import important exogenous amino acids in exchange for surplus neutral amino acids liberated from the digestion of host cell haemoglobin. Copyright © 2010 Australian Society for Parasitology Inc. Published by Elsevier Ltd. All rights reserved.

Concurrent Overexpression of Arabidopsis thaliana Cystathionine γ-Synthase and Silencing of Endogenous Methionine γ-Lyase Enhance Tuber Methionine Content in Solanum tuberosum.

PubMed

Kumar, Pavan; Jander, Georg

2017-04-05

Potatoes (Solanum tuberosum) are deficient in methionine, an essential amino acid in human and animal diets. Higher methionine levels increase the nutritional quality and promote the typically pleasant aroma associated with baked and fried potatoes. Several attempts have been made to elevate tuber methionine levels by genetic engineering of methionine biosynthesis and catabolism. Overexpressing Arabidopsis thaliana cystathionine γ-synthase (AtCGS) in S. tuberosum up-regulates a rate-limiting step of methionine biosynthesis and increases tuber methionine levels. Alternatively, silencing S. tuberosum methionine γ-lyase (StMGL), which causes decreased degradation of methionine into 2-ketobutyrate, also increases methionine levels. Concurrently enhancing biosynthesis and reducing degradation were predicted to provide further increases in tuber methionine content. Here we report that S. tuberosum cv. Désirée plants with AtCGS overexpression and StMGL silenced by RNA interference are morphologically normal and accumulate higher free methionine levels than either single-transgenic line.

Effect of l-lysine-assisted surface grafting for nano-hydroxyapatite on mechanical properties and in vitro bioactivity of poly(lactic acid-co-glycolic acid).

PubMed

Liuyun, Jiang; Lixin, Jiang; Chengdong, Xiong; Lijuan, Xu; Ye, Li

2016-01-01

It is promising and challenging to study surface modification for nano-hydroxyapatite to improve the dispersion and enhance the mechanical properties and bioactivity of poly(lactic acid-co-glycolic acid). In this paper, we designed an effective new surface grafting with the assist of l-lysine for nano-hydroxyapatite, and the nano-hydroxyapatite surface grafted with the assist of l-lysine (g-nano-hydroxyapatite) was incorporated into poly(lactic acid-co-glycolic acid) to develop a series of g-nano-hydroxyapatite/poly(lactic acid-co-glycolic acid) nano-composites. The surface modification reaction for nano-hydroxyapatite, the mechanical properties, and in vitro human osteoblast-like cell (MG-63) response were characterized and investigated by Fourier transformation infrared, thermal gravimetric analysis, dispersion test, electromechanical universal tester, differential scanning calorimeter measurements, and in vitro cells culture experiment. The results showed that the grafting amount on the surface of nano-hydroxyapatite was enhanced with the increase of l-lysine, and the dispersion of nano-hydroxyapatite was improved more, so that it brought about better promotion crystallization and more excellent mechanical enhancement effect for poly(lactic acid-co-glycolic acid), comparing with the unmodified nano-hydroxyapatite. Moreover, the cells' attachment and proliferation results confirmed that the incorporation of the g-nano-hydroxyapatite into poly(lactic acid-co-glycolic acid) exhibited better biocompatibility than poly(lactic acid-co-glycolic acid). The above results indicated that the new surface grafting with the assist of l-lysine for nano-hydroxyapatite was an ideal novel surface modification method, which brought about better mechanical enhancement effect and in vitro bioactivity for poly(lactic acid-co-glycolic acid) with adding higher g-nano-hydroxyapatite content, suggesting it had a great potential to be used as bone fracture internal fixation materials

The use of feed-grade amino acids in lactating sow diets.

PubMed

Greiner, Laura; Srichana, Pairat; Usry, James L; Neill, Casey; Allee, Gary L; Connor, Joseph; Touchette, Kevin J; Knight, Christopher D

2018-01-01

The use of feed grade amino acids can reduce the cost of lactation feed. With changing genetics, increasing feed costs, and higher number of pigs weaned with heavier wean weights further evaluation of higher inclusion levels of feed-grade amino acid in lactation diets than previously published is warranted. Two experiments (Exp.) were conducted to determine the optimal inclusion level of L -lysine HCl to be included in swine lactation diets while digestible lysine levels remain constant across dietary treatments and allowing feed grade amino acids to be added to the diet to maintain dietary ratios relative to lysine to maximize litter growth rate and sow reproductive performance. Furthermore, the studies were to evaluate minimal amino acid ratios relative to lysine that allows for optimal litter growth rate and sow reproductive performance. Exp. 1: Increasing L -lysine HCl resulted in similar gilt feed intake, litter, and reproductive performance. Average litter gain from birth to weaning was 2.51, 2.49, 2.59, 2.43, and 2.65 kg/d when gilts were fed 0.00, 0.075, 0.150, 0.225, and 0.30% L -lysine HCl, respectively. Exp. 2: The average litter gain from birth to weaning was 2.68, 2.73, 2.67, 2.70, and 2.64 kg/d ( P  < 0.70) when sows were fed 0.1, 0.2, 0.3, 0.4, and 0.4% L -lysine HCl plus valine, respectively. No other differences among dietary treatments were observed. Collectively, these studies demonstrate corn-soybean meal based lactation diets formulated with a constant SID lysine content for all parities containing up to 0.40% L -lysine HCl with only supplemental feed grade threonine and a methionine source have no detrimental effect on litter growth rate and subsequent total born.

A review of methionine dependency and the role of methionine restriction in cancer growth control and life-span extension.

PubMed

Cavuoto, Paul; Fenech, Michael F

2012-10-01

Methionine is an essential amino acid with many key roles in mammalian metabolism such as protein synthesis, methylation of DNA and polyamine synthesis. Restriction of methionine may be an important strategy in cancer growth control particularly in cancers that exhibit dependence on methionine for survival and proliferation. Methionine dependence in cancer may be due to one or a combination of deletions, polymorphisms or alterations in expression of genes in the methionine de novo and salvage pathways. Cancer cells with these defects are unable to regenerate methionine via these pathways. Defects in the metabolism of folate may also contribute to the methionine dependence phenotype in cancer. Selective killing of methionine dependent cancer cells in co-culture with normal cells has been demonstrated using culture media deficient in methionine. Several animal studies utilizing a methionine restricted diet have reported inhibition of cancer growth and extension of a healthy life-span. In humans, vegan diets, which can be low in methionine, may prove to be a useful nutritional strategy in cancer growth control. The development of methioninase which depletes circulating levels of methionine may be another useful strategy in limiting cancer growth. The application of nutritional methionine restriction and methioninase in combination with chemotherapeutic regimens is the current focus of clinical studies. Copyright © 2012 Elsevier Ltd. All rights reserved.

Influence of Threonine Metabolism on S-adenosyl-methionine and Histone Methylation

PubMed Central

Shyh-Chang, Ng; Locasale, Jason W.; Lyssiotis, Costas A.; Zheng, Yuxiang; Teo, Ren Yi; Ratanasirintrawoot, Sutheera; Zhang, Jin; Onder, Tamer; Unternaehrer, Juli J.; Zhu, Hao; Asara, John M.; Daley, George Q.; Cantley, Lewis C.

2013-01-01

Threonine is the only amino acid critically required for the pluripotency of mouse embryonic stem cells (mESCs) but the detailed mechanism remains unclear. We found that threonine (Thr) and S-adenosyl-methionine (SAM) metabolism are coupled in pluripotent stem cells, resulting in regulation of histone methylation. Isotope labeling of mESCs revealed that Thr provides a substantial fraction of both the cellular glycine (Gly) and the acetyl-coenzyme A (CoA) needed for SAM synthesis. Depletion of Thr from the culture medium or threonine dehydrogenase (Tdh) from mESCs decreased accumulation of SAM and decreased tri-methylation of histone H3 lysine-4 (H3K4me3), leading to slowed growth, and increased differentiation. Thus abundance of SAM appears to influence H3K4me3, providing a possible mechanism by which modulation of a metabolic pathway might influence stem cell fate. PMID:23118012

Amino acid metabolism in the human fetus at term: leucine, valine, and methionine kinetics.

PubMed

van den Akker, Chris H P; Schierbeek, Henk; Minderman, Gardi; Vermes, Andras; Schoonderwaldt, Ernst M; Duvekot, Johannes J; Steegers, Eric A P; van Goudoever, Johannes B

2011-12-01

Human fetal metabolism is largely unexplored. Understanding how a healthy fetus achieves its fast growth rates could eventually play a pivotal role in improving future nutritional strategies for premature infants. To quantify specific fetal amino acid kinetics, eight healthy pregnant women received before elective cesarean section at term, continuous stable isotope infusions of the essential amino acids [1-13C,15N]leucine, [U-13C5]valine, and [1-13C]methionine. Umbilical blood was collected after birth and analyzed for enrichments and concentrations using mass spectrometry techniques. Fetuses showed considerable leucine, valine, and methionine uptake and high turnover rates. α-Ketoisocaproate, but not α-ketoisovalerate (the leucine and valine ketoacids, respectively), was transported at net rate from the fetus to the placenta. Especially, leucine and valine data suggested high oxidation rates, up to half of net uptake. This was supported by relatively low α-ketoisocaproate reamination rates to leucine. Our data suggest high protein breakdown and synthesis rates, comparable with, or even slightly higher than in premature infants. The relatively large uptakes of total leucine and valine carbon also suggest high fetal oxidation rates of these essential branched chain amino acids.

Impact of food supplementation and methionine on high densities of cotton rats: Support of the amino-acid-quality hypothesis?

USGS Publications Warehouse

Webb, R.E.; Leslie, David M.; Lochmiller, R.L.; Masters, R.E.

2005-01-01

Considerable research supports the tenet that quantity and quality of food limit vertebrate populations. We evaluated predictions that increased availabilities of food and the essential amino acid methionine were related to population limitation of the hispid cotton rat (Sigmodon hispidus). Effects of supplemental food and methionine on density, survival, and reproductive parameters of wild cotton rats were assessed in north-central Oklahoma in 1998-1999. Twelve enclosed groups of 16 adult cotton rats each (8 male, 8 female) were randomly assigned to either no supplementation (control), supplementation with a mixed ration that had methionine at slightly below maintenance levels (0.20%), or a methionine-enhanced mixed ration (1.20%). In general, densities of cotton rats were twice as high and were sustained longer with dietary supplementation, and methionine-supplemented populations maintained the highest densities. Treatment effects on survival depended on time of year, with higher survival in supplemented enclosures in October and November. Per capita recruitment was highest with methionine-enhanced food. Treatment effects on proportions of overall and female cotton rats in reproductive condition depended on sampling date, but males were most reproductively active with methionine supplementation. Methionine supplementation resulted in an earlier and longer reproductive season. Density-dependent and density-independent factors no doubt interplay to determine population dynamics of cotton rats, but our results suggest that methionine plays a role in the population dynamics of wild cotton rats, apparently by enhancing overall density, recruitment, and reproductive activity of males.

Effects of transgenic expression of Brevibacterium linens methionine gamma lyase (MGL) on accumulation of Tylenchulus semipenetrans and key aminoacid contents in Carrizo citrange.

PubMed

Castillo, Elenor; Martinelli, Federico; Zakharov-Negre, Florence; Ebeler, Susan E; Buzo, Tom R; McKenry, Michael V; Dandekar, Abhaya M

2017-11-01

Carrizo transgenic plants overexpressing methionine-gamma-lyase produced dimethyl sulfide. The transgenic plants displayed more resistance to nematode attacks (Tylenculus semipenetrans) and may represent an innovative strategy for nematode control. Tylenchulus semipenetrans is a nematode pest of many citrus varieties that causes extensive damage to commercial crops worldwide. Carrizo citrange vr. (Citrus sinensis L. Usb × Poncirus trifoliate L. Raf) plants overexpressing Brevibacterium linens methionine-gamma-lyase (BlMGL) produced the sulfur volatile compound dimethyl sulfide (DMS). The aim of this work was to determine if transgenic citrus plants expressing BlMGL showed increased tolerance to T. semipenetrans infestation and to determine the effect on the content of key amino acids. While transgenic lines emitted dimethyl sulfide from leaves and roots, no sulfur-containing volatiles were detectable in wild-type Carrizo in the same tissues. Significant changes detected some key amino acids from leaves of transgenic plants such as aspartate, lysine, glycine, leucine and threonine with no changes in the amounts of methionine and α-ketobutyrate. In roots only glycine showed significant changes across all transgenic lines in comparison to wild-type plants. Transgenic plants expressing BlMGL and emitting DMS had less T. semipenetrans aggregation and more biomass than infected WT control plants, indicating that they may represent an innovative management alternative to pesticide/nematicide-based remedies.

Effects of single oral doses of lysine clonixinate and acetylsalicylic acid on platelet functions in man.

PubMed

Pallapies, D; Muhs, A; Bertram, L; Rohleder, G; Nagyiványi, P; Peskar, B A

1996-01-01

Lysine clonixinate is an analgesic drug with a so far unknown mechanism of action. We have determined its effect on platelet cyclooxygenase in man. Biosynthesis of thromboxane (TX)B2 and prostaglandin (PG)F2 alpha in clotting whole blood ex vivo as well as collagen-induced platelet aggregation measured before and at various time points after oral administration of 125 mg lysine clonixinate were compared to results obtained with 500 mg acetylsalicylic acid (ASA). While biosynthesis of both TXB2 and PGF2 alpha measured radioimmunologically was inhibited significantly 2.5 h, but not 6 h, after administration of lysine clonixinate, inhibition by ASA was much greater and still highly significant after 48 h. Similarly, collagen-induced aggregation of platelet-rich plasma was inhibited for a longer period and to a greater extent after administration of ASA than after lysine clonixinate. Our results indicate that lysine clonixinate is a cyclooxygenase inhibitor of moderate potency. It remains to be investigated whether mechanisms other than inhibition of cyclooxygenase contribute to the analgesic activity of lysine clonixinate.

Determination of the methionine requirement of male and female broiler chicks using an indirect amino acid oxidation method.

PubMed

Chamruspollert, M; Pesti, G M; Bakalli, R I

2002-07-01

The methionine requirement of 250-to-300-g broiler chicks was estimated from the oxidation of L-[1-14C] phenylalanine of chicks given meals containing graded levels of DL-methionine. L-[1-14C] phenylalanine was used as an indicator amino acid for amino acid oxidation and, indirectly, protein synthesis. Four experiments were conducted using an incomplete block design with three replications each. Chicks were crop intubated with semifluid diets at a ratio of 1 g of diet per 45 g of bird weight. Two feedings 2 h apart were used to reduce variability, and the sample collection period was 3 h after the second feeding. Regression analysis of 14CO2 release from L-[1-14C] phenylalanine was used to estimate the methionine requirement. The model was as follows: response = max + rc x (req - x) x I, where max = plateau, rc = rate constant, req = requirement, and I = 1 when x < req, otherwise I = 0. The methionine requirements of Ross x Ross chicks were 0.57 +/- 0.03% and 0.52 +/- 0.08% for male and female chicks, respectively in Experiment 1 and 0.55 +/- 0.05% and 0.52 +/- 0.04%, respectively, in Experiment 2. In the third experiment (Arbor Acre High-Yield), phenylalanine oxidation stabilized at a low rate when dietary methionine levels reached 0.54 +/- 0.03% and 0.53 +/- 0.04% for males and females, respectively. In a growth trial covering a longer period (Experiment 4), the methionine requirements of male and female Ross x Ross chicks, based on feed conversion, were 0.52 +/- 0.05% and 0.45 +/- 0.02%, respectively, and based on body gain were 0.54 +/0.09% and 0.48 +/- 0.04%, respectively. The results suggested that the methionine requirement of male chicks tended to be higher than that of females in both strains. However, differences were small and not significant.

Hypochlorous Acid Reacts with the N-Terminal Methionines of Proteins to Give Dehydromethionine, a Potential Biomarker for Neutrophil-Induced Oxidative Stress†

PubMed Central

Beal, Jennifer L.; Foster, Steven B.; Ashby, Michael T.

2009-01-01

Electrophilic halogenating agents, including hypohalous acids and haloamines, oxidize free methionine and the N-terminal methionines of peptides and proteins (e.g., Met-1 of anti-inflammatory peptide 1 and ubiquitin) to produce dehydromethionine (a five-membered isothiazolidinium heterocycle). Amide derivatives of methionine are oxidized to the corresponding sulfoxide derivatives under the same reaction conditions (e.g., Met-3 of anti-inflammatory peptide 1). Other biological oxidants, including hydrogen peroxide and peroxynitrite, also only produce the corresponding sulfoxides. Hypothiocyanite does not react with methionine residues. It is suggested that dehydromethionine may be a useful biomarker for the myeloperoxidase-induced oxidative stress associated with many inflammatory diseases. PMID:19839600

Effects of castration age, protein level and lysine/methionine ratio in the diet on colour, lipid oxidation and meat acceptability of intensively reared Friesian steers.

PubMed

Prado, I N; Campo, M M; Muela, E; Valero, M V; Catalan, O; Olleta, J L; Sañudo, C

2015-08-01

A total of 64 intensively reared Friesian steers were used in a 2×2×2 design to study the effects of age of castration (15 days old v. 5 months old), dietary protein level (14.6% v. 16.8%; DM basis) and lysine/methionine (lys/met) ratio (3.0 v. 3.4) on meat quality. The lys/met ratio of 3.0 was reached with supplementation of protected methionine. Animals were slaughtered at a live weight of 443.5 ± 26.2 kg at around 12 months of age. Colour and lipid oxidation were measured in the longissimus thoracis muscle throughout the 14 days of display under modified atmospheric and commercial display conditions. A panel of 17 consumers assessed daily the visual acceptability of the meat on display. A consumer acceptability eating test was also performed with 120 consumers in meat aged for 7 days under vacuum conditions. Lipid oxidation was not influenced by castration age and the protein level in the diet. Castration age did not affect meat colour, but meat from the low protein level diet and the low lys/met ratio showed higher redness (a*) from 3 days of display onwards. Nevertheless, from 6 days onwards, consumer visual acceptability was below the level of acceptance in all treatments, and even from 5 days onwards in those animals that underwent early castration and were fed either a high protein diet or a combination diet low in protein content and high in lys/met ratio. The best accepted treatments throughout the display period were those from late castrated animals fed a low protein diet, probably related to other visual aspects. However, the best accepted meat after consumption was that from late castrated animals fed high protein and high lys/met. The addition of protected methionine to reach lys/met levels of 3.0 did not improve beef acceptability, with the high protein diet being preferred by consumers in terms of palatability in late castrated animals.

The structure, vibrational spectra and nonlinear optical properties of the L-lysine × tartaric acid complex—Theoretical studies

NASA Astrophysics Data System (ADS)

Drozd, M.; Marchewka, M. K.

2006-05-01

The room temperature X-ray studies of L-lysine × tartaric acid complex are not unambiguous. The disorder of three atoms of carbon in L-lysine molecule is observed. These X-ray studies are ambiguous. The theoretical geometry study performed by DFT methods explain the most doubts which are connected with crystallographic measurements. The theoretical vibrational frequencies and potential energy distribution (PED) of L-lysine × tartaric acid were calculated by B3LYP method. The calculated frequencies were compared with experimental measured IR spectra. The complete assignment of the bands has been made on the basis of the calculated PED. The restricted Hartee-Fock (RHF) methods were used for calculation of the hyperpolarizability for investigated compound. The theoretical results are compared with experimental value of β.

Reactions of aqueous L-methionine, L-phenylalanine, L-methionyl-L-phenylalanine, L-phenylalanyl-L-methionine and their mixtures with H atoms during steady radiolysis at pH 6. 5. [Gamma radiation

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

Mee, L.K.; Adelstein, S.J.; Steinhart, C.M.

Phenylalanine, methionine, and their mixtures, methionyl phenylalanine, phenylalnyl methionine, and mixtures of each dipeptide with phenylalanine were reacted with radiolytically generated H atoms in aqueous solution at pH 6.5. When methionine is irradiated alone, G(-methionine) = 2.0; the principal amino acid product is ..cap alpha..-amino-n-butyric acid. The initial destruction of phenylalanine, irradiated alone, is very low, G(-phenylalanine) approximately 0.15, and it decreases with dose. In mixtures of phenylalanine and methionine, radiolytic destruction of phenylalanine is potentiated, with a maximum potentiation at a phenylalanine:methionine ratio of 2 : 1. Repair reactions are postulated to account for the low initial yield ofmore » phenylalanine, its decrease with dose, and potentiation of destruction in mixtures with methionine. The destruction of the phenylalanyl and methionyl residues in the irradiated dipeptides is similar to that found for the loss of phenylalanine and methionine in 1 : 1 mixtures of the free amino acids; the destruction of residues in 1 : 1 mixtures of either dipeptide with phenylalanine is similar to that found in mixtures of phenylalanine:methionine at a ratio of 2 : 1. Thus, it is apparent already in simple mixtures of the divalent sulfur-containing methionine and the aromatic phenylalanine that kinetic interactions occur between these two kinds of amino acids which are not revealed by irradiation of these residues separately. The behavior of the dipeptides does not provide any evidence for intramolecular transfer of radical site.« less

Short peptides containing L-lysine and epsilon-aminocaproic acid as potential plasmin inhibitors.

PubMed

Purwin, M; Bruzgo, I; Markowska, A; Midura-Nowaczek, K

2009-11-01

Eight short peptides containing L-lysine and epsilon-aminocaproic acid were obtained and their effect on the amidolytic activities of plasmin, thrombin and trypsin was examined. Tripeptide amide Boc-EACA-L-Lys-EACA-NH2 was the most effective and specific plasmin inhibitor.

Effects of single amino acid deficiency on mRNA translation are markedly different for methionine versus leucine.

PubMed

Mazor, Kevin M; Dong, Leiming; Mao, Yuanhui; Swanda, Robert V; Qian, Shu-Bing; Stipanuk, Martha H

2018-05-24

Although amino acids are known regulators of translation, the unique contributions of specific amino acids are not well understood. We compared effects of culturing HEK293T cells in medium lacking either leucine, methionine, histidine, or arginine on eIF2 and 4EBP1 phosphorylation and measures of mRNA translation. Methionine starvation caused the most drastic decrease in translation as assessed by polysome formation, ribosome profiling, and a measure of protein synthesis (puromycin-labeled polypeptides) but had no significant effect on eIF2 phosphorylation, 4EBP1 hyperphosphorylation or 4EBP1 binding to eIF4E. Leucine starvation suppressed polysome formation and was the only tested condition that caused a significant decrease in 4EBP1 phosphorylation or increase in 4EBP1 binding to eIF4E, but effects of leucine starvation were not replicated by overexpressing nonphosphorylatable 4EBP1. This suggests the binding of 4EBP1 to eIF4E may not by itself explain the suppression of mRNA translation under conditions of leucine starvation. Ribosome profiling suggested that leucine deprivation may primarily inhibit ribosome loading, whereas methionine deprivation may primarily impair start site recognition. These data underscore our lack of a full understanding of how mRNA translation is regulated and point to a unique regulatory role of methionine status on translation initiation that is not dependent upon eIF2 phosphorylation.

Antioxidant activity of amino acids in soybean oil at frying temperature: Structural effects and synergism with tocopherols.

PubMed

Hwang, Hong-Sik; Winkler-Moser, Jill K

2017-04-15

The purpose of this study was to evaluate amino acids as natural antioxidants for frying. Twenty amino acids were added to soybean oil heated to 180°C, and the effects of amino acid structure on the antioxidant activity were investigated. Amino acids containing a thiol, a thioether, or an extra amine group such as arginine, cysteine, lysine, methionine, and tryptophan had the strongest antioxidant activities. At 5.5mM, these amino acids had stronger antioxidant activities than 0.02% (1.1mM) tert-butylhydroquinone (TBHQ). A functional group such as an amide, carboxylic acid, imidazole, or phenol appeared to negatively affect amino acid antioxidant activity. Synergism between amino acids and tocopherols was demonstrated, and we found that this synergistic interaction may be mostly responsible for the antioxidant activity that was observed. In a frying study with potato cubes, 5.5mM l-methionine had significantly stronger antioxidant activity than 0.02% TBHQ. Published by Elsevier Ltd.

Betaine is as effective as folate at re-synthesizing methionine for protein synthesis during moderate methionine deficiency in piglets.

PubMed

McBreairty, Laura E; Robinson, Jason L; Harding, Scott V; Randell, Edward W; Brunton, Janet A; Bertolo, Robert F

2016-12-01

Both folate and betaine (synthesized from choline) are nutrients used to methylate homocysteine to reform the amino acid methionine following donation of its methyl group; however, it is unclear whether both remethylation pathways are of equal importance during the neonatal period when remethylation rates are high. Methionine is an indispensable amino acid that is in high demand in neonates not only for protein synthesis, but is also particularly important for transmethylation reactions, such as creatine and phosphatidylcholine synthesis. The objective of this study was to determine whether supplementation with folate, betaine, or a combination of both can equally re-synthesize methionine for protein synthesis when dietary methionine is limiting. Piglets were fed a low methionine diet devoid of folate, choline, and betaine, and on day 6, piglets were supplemented with either folate, betaine, or folate + betaine (n = 6 per treatment) until day 10. [1- 13 C]-phenylalanine oxidation was measured as an indicator of methionine availability for protein synthesis both before and after 2 days of supplementation. Prior to supplementation, piglets had lower concentrations of plasma folate, betaine, and choline compared to baseline with no change in homocysteine. Post-supplementation, phenylalanine oxidation levels were 20-46 % lower with any methyl donor supplementation (P = 0.006) with no difference among different supplementation groups. Furthermore, both methyl donors led to similarly lower concentrations of homocysteine following supplementation (P < 0.05). These data demonstrate an equal capacity for betaine and folate to remethylate methionine for protein synthesis, as indicated by lower phenylalanine oxidation.

An economically and environmentally acceptable synthesis of chiral drug intermediate L-pipecolic acid from biomass-derived lysine via artificially engineered microbes.

PubMed

Cheng, Jie; Huang, Yuding; Mi, Le; Chen, Wujiu; Wang, Dan; Wang, Qinhong

2018-05-10

Deficiency in petroleum resources and increasing environmental concerns have pushed a bio-based economy to be built, employing a highly reproducible, metal contaminant free, sustainable and green biomanufacturing method. Here, a chiral drug intermediate L-pipecolic acid has been synthesized from biomass-derived lysine. This artificial bioconversion system involves the coexpression of four functional genes, which encode L-lysine α-oxidase from Scomber japonicus, glucose dehydrogenase from Bacillus subtilis, Δ 1 -piperideine-2-carboxylase reductase from Pseudomonas putida, and lysine permease from Escherichia coli. Besides, a lysine degradation enzyme has been knocked out to strengthen the process in this microbe. The overexpression of LysP improved the L-pipecolic acid titer about 1.6-folds compared to the control. This engineered microbial factory showed the highest L-pipecolic acid production of 46.7 g/L reported to date and a higher productivity of 2.41 g/L h and a yield of 0.89 g/g. This biotechnological L-pipecolic acid production is a simple, economic, and green technology to replace the presently used chemical synthesis.

Novel α-Oxoamide Advanced-Glycation Endproducts within the N6-Carboxymethyl Lysine and N6-Carboxyethyl Lysine Reaction Cascades.

PubMed

Baldensperger, Tim; Jost, Tobias; Zipprich, Alexander; Glomb, Marcus A

2018-02-28

The highly reactive α-dicarbonyl compounds glyoxal and methylglyoxal are major precursors of posttranslational protein modifications in vivo. Model incubations of N 2 -t-Boc-lysine and either glyoxal or methylglyoxal were used to further elucidate the underlying mechanisms of the N 6 -carboxymethyl lysine and N 6 -carboxyethyl lysine reaction cascades. After independent synthesis of the authentic reference standards, we were able to detect N 6 -glyoxylyl lysine and N 6 -pyruvoyl lysine for the first time by HPLC-MS 2 analyses. These two novel amide advanced-glycation endproducts were exclusively formed under aerated conditions, suggesting that they were potent markers for oxidative stress. Analogous to the well-known Strecker degradation pathway, leading from amino acids to Strecker acids, the oxidation of an enaminol intermediate is suggested to be the key mechanistic step. A highly sensitive workup for the determination of AGEs in tissues was developed. In support of our hypothesis, the levels of N 6 -glyoxylyl lysine and N 6 -pyruvoyl lysine in rat livers indeed correlated with liver cirrhosis and aging.

Effects of Glycine, Water, Ammonia, and Ammonium Bicarbonate on the Oligomerization of Methionine

NASA Astrophysics Data System (ADS)

Huang, Rui; Furukawa, Yoshihiro; Otake, Tsubasa; Kakegawa, Takeshi

2017-06-01

The abiotic oligomerization of amino acids may have created primordial, protein-like biological catalysts on the early Earth. Previous studies have proposed and evaluated the potential of diagenesis for the amino acid oligomerization, simulating the formation of peptides that include glycine, alanine, and valine, separately. However, whether such conditions can promote the formation of peptides composed of multiple amino acids remains unclear. Furthermore, the chemistry of pore water in sediments should affect the oligomerization and degradation of amino acids and oligomers, but these effects have not been studied extensively. In this study, we investigated the effects of water, ammonia, ammonium bicarbonate, pH, and glycine on the oligomerization and degradation of methionine under high pressure (150 MPa) and high temperature conditions (175 °C) for 96 h. Methionine is more difficult to oligomerize than glycine and methionine dimer was formed in the incubation of dry powder of methionine. Methionine oligomers as long as trimers, as well as methionylglycine and glycylmethionine, were formed under every condition with these additional compounds. Among the compounds tested, the oligomerization reaction rate was accelerated by the presence of water and by an increase in pH. Ammonia also increased the oligomerization rate but consumed methionine by side reactions and resulted in the rapid degradation of methionine and its peptides. Similarly, glycine accelerated the oligomerization rate of methionine and the degradation of methionine, producing water, ammonia, and bicarbonate through its decomposition. With Gly, heterogeneous dimers (methionylglycine and glycylmethionine) were formed in greater amounts than with other additional compounds although smaller amount of these heterogeneous dimers were formed with other additional compounds. These results suggest that accelerated reaction rates induced by water and co-existing reactive compounds promote the oligomerization

Oxidation of Methionine Residues in Polypeptide Ions via Gas-Phase Ion/Ion Chemistry

PubMed Central

Pilo, Alice L.; McLuckey, Scott A.

2014-01-01

The gas-phase oxidation of methionine residues is demonstrated here using ion/ion reactions with periodate anions. Periodate anions are observed to attach to varying degrees to all polypeptide ions irrespective of amino acid composition. Direct proton transfer yielding a charge reduced peptide ion is also observed. In the case of methionine and, to a much lesser degree, tryptophan containing peptide ions, collisional activation of the complex ion generated by periodate attachment yields an oxidized peptide product (i.e., [M+H+O]+), in addition to periodic acid detachment. Detachment of periodic acid takes place exclusively for peptides that do not contain either a methionine or tryptophan side-chain. In the case of methionine containing peptides, the [M+H+O]+ product is observed at a much greater abundance than the proton transfer product (viz., [M+H]+). Collisional activation of oxidized Met-containing peptides yields a signature loss of 64 Da from the precursor and/or product ions. This unique loss corresponds to the ejection of methanesulfenic acid from the oxidized methionine side chain and is commonly used in solution-phase proteomics studies to determine the presence of oxidized methionine residues. The present work shows that periodate anions can be used to ‘label’ methionine residues in polypeptides in the gas-phase. The selectivity of the periodate anion for the methionine side chain suggests several applications including identification and location of methionine residues in sequencing applications. PMID:24671696

Boosting Anaplerotic Reactions by Pyruvate Kinase Gene Deletion and Phosphoenolpyruvate Carboxylase Desensitization for Glutamic Acid and Lysine Production in Corynebacterium glutamicum.

PubMed

Yokota, Atsushi; Sawada, Kazunori; Wada, Masaru

In the 1980s, Shiio and coworkers demonstrated using random mutagenesis that the following three phenotypes were effective for boosting lysine production by Corynebacterium glutamicum: (1) low-activity-level citrate synthase (CS L ), (2) phosphoenolpyruvate carboxylase (PEPC) resistant to feedback inhibition by aspartic acid (PEPC R ), and (3) pyruvate kinase (PYK) deficiency. Here, we reevaluated these phenotypes and their interrelationship in lysine production using recombinant DNA techniques.The pyk deletion and PEPC R (D299N in ppc) independently showed marginal effects on lysine production, but both phenotypes synergistically increased lysine yield, demonstrating the importance of PEPC as an anaplerotic enzyme in lysine production. Similar effects were also found for glutamic acid production. CS L (S252C in gltA) further increased lysine yield. Thus, using molecular techniques, the combination of these three phenotypes was reconfirmed to be effective for lysine production. However, a simple CS L mutant showed instabilities in growth and lysine yield.Surprisingly, the pyk deletion was found to increase biomass production in wild-type C. glutamicum ATCC13032 under biotin-sufficient conditions. The mutant showed a 37% increase in growth (based on OD 660 ) compared with the ATCC13032 strain in a complex medium containing 100 g/L glucose. Metabolome analysis revealed the intracellular accumulation of excess precursor metabolites. Thus, their conversion into biomass was considered to relieve the metabolic distortion in the pyk-deleted mutant. Detailed physiological studies of various pyk-deleted mutants also suggested that malate:quinone oxidoreductase (MQO) is important to control both the intracellular oxaloacetic acid (OAA) level and respiration rate. These findings may facilitate the rational use of C. glutamicum in fermentation industries.

Dry-extrusion of asian carp to supplement natural methionine in organic poultry production

USDA-ARS?s Scientific Manuscript database

Methionine, a sulfur containing amino acid, is essential for healthy poultry production. Synthetic methionine is commonly used as a supplement in conventional poultry. However, for organic poultry, a natural, cost effective source of methionine that can replace synthetic methionine is unavailable. I...

Topological dispositions of lysine. alpha. 380 and lysine. gamma. 486 in the acetylcholine receptor from Torpedo californica

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

Dwyer, B.P.

1991-04-23

The locations have been determined, with respect to the plasma membrane, of lysine {alpha}380 and lysine {gamma}486 in the {alpha} subunit and the {gamma} subunit, respectively, of the nicotinic acetylcholine receptor from Torpedo californica. Immunoadsorbents were constructed that recognize the carboxy terminus of the peptide GVKYIAE released by proteolytic digestion from positions 378-384 in the amino acid sequence of the {alpha} subunit of the acetylcholine receptor and the carboxy terminus of the peptide KYVP released by proteolytic digestion from positions 486-489 in the amino acid sequence of the {gamma} subunit. They were used to isolate these peptides from proteolytic digestsmore » of polypeptides from the acetylcholine receptor. Sealed vesicles containing the native acetylcholine receptor were labeled with pyridoxal phosphate and sodium ({sup 3}H)-borohydride. The effect of saponin on the incorporation of pyridoxamine phosphate into lysine {alpha}380 and lysine {gamma}486 from the acetylcholine receptor in these vesicles was assessed with the immunoadsorbents. The conclusions that follow from these results are that lysine {alpha}380 is on the inside surface of a vesicle and lysine {gamma}486 is on the outside surface. Because a majority (85%) of the total binding sites for {alpha}-bungarotoxin bind the toxin in the absence of saponin, the majority of the vesicles are right side out with the inside of the vesicle corresponding to the cytoplasmic surface and the outside of the vesicle corresponding to the extracytoplasmic, synaptic surface. Because lysine {alpha}380 and lysine {gamma}486 lie on opposite sides of the membrane, a membrane-spanning segment must be located between the two positions occupied by these two amino acids in the common sequence of a polypeptide of the acetylcholine receptor.« less

Quantitation of Cellular Metabolic Fluxes of Methionine

PubMed Central

Shlomi, Tomer; Fan, Jing; Tang, Baiqing; Kruger, Warren D.; Rabinowitz, Joshua D.

2014-01-01

Methionine is an essential proteogenic amino acid. In addition, it is a methyl donor for DNA and protein methylation and a propylamine donor for polyamine biosyn-thesis. Both the methyl and propylamine donation pathways involve metabolic cycles, and methods are needed to quantitate these cycles. Here, we describe an analytical approach for quantifying methionine metabolic fluxes that accounts for the mixing of intracellular and extracellular methionine pools. We observe that such mixing prevents isotope tracing experiments from reaching the steady state due to the large size of the media pools and hence precludes the use of standard stationary metabolic flux analysis. Our approach is based on feeding cells with 13C methionine and measuring the isotope-labeling kinetics of both intracellular and extracellular methionine by liquid chromatography−mass spectrometry (LC-MS). We apply this method to quantify methionine metabolism in a human fibrosarcoma cell line and study how methionine salvage pathway enzyme methylthioadenosine phosphorylase (MTAP), frequently deleted in cancer, affects methionine metabolism. We find that both transmethylation and propylamine transfer fluxes amount to roughly 15% of the net methionine uptake, with no major changes due to MTAP deletion. Our method further enables the quantification of flux through the pro-tumorigenic enzyme ornithine decarboxylase, and this flux increases 2-fold following MTAP deletion. The analytical approach used to quantify methionine metabolic fluxes is applicable for other metabolic systems affected by mixing of intracellular and extracellular metabolite pools. PMID:24397525

Effect of varying dietary concentrations of lysine on growth performance of the Pearl Grey guinea fowl.

PubMed

Bhogoju, S; Nahashon, S N; Donkor, J; Kimathi, B; Johnson, D; Khwatenge, C; Bowden-Taylor, T

2017-05-01

Lysine is the second limiting essential amino acid in poultry nutrition after methionine. Understanding the lysine requirement of poultry is necessary in guiding formulation of least cost diets that effectively meet the nutritional needs of individual birds. The lysine requirement of the Pearl Grey guinea fowl (PGGF) is not known. Therefore, the objective of this study was to assess the appropriate lysine levels required for optimal growth attributes of the PGGF. In a 12-week study, 512 one-day-old Pearl Grey guinea keets were weighed individually and randomly assigned to electrically heated battery brooders. Each battery contained 12 compartments housing 15 birds each. Eight diets fed to the experimental birds consisted of corn-soybean meal and contained 0.80 to 1.22 digestible lysine in 0.06% increments. Feed and water were provided at free choice and the diets were replicated twice. Experimental diets contained 3,100 Kcal metabolizable energy (ME)/kg diet and 23% crude protein (CP), 3,150 ME Kcal ME/kg diet and 21% CP, and 3,100 ME/kg and 17% CP, at zero to 4, 5 to 10, and 11 to 12 weeks of age (WOA), respectively. Birds were provided water ad libitum and a 23:1 and 8:16-hr (light:dark) regimen at zero to 8 and 9 to 12 WOA, respectively. Birds were weighed weekly, and body weight gain, feed consumption, and feed conversions were determined. Data were analyzed using the General Linear Model (GLM) procedures of SAS (2002) with dietary lysine as treatment effect. Females responded better to diets containing 1.04 and 0.8% lysine from hatch to 4 and 5 to 12 WOA, respectively. Males responded better to diets containing 1.10 and 0.8% lysine at hatch to 4 WOA and 5 to 12 WOA, respectively. Therefore, we recommend that PGGF females and males be fed diets containing 1.04 and 1.10%, respectively, at hatch to 4 WOA and 0.80% lysine at 5 to 12 WOA. The diets should be supplied in phases. © 2016 Poultry Science Association Inc.

Methionine restriction inhibits chemically-induced malignant transformation in the BALB/c 3T3 cell transformation assay.

PubMed

Nicken, Petra; Empl, Michael T; Gerhard, Daniel; Hausmann, Julia; Steinberg, Pablo

2016-09-01

High consumption of red meat entails a higher risk of developing colorectal cancer. Methionine, which is more frequently a component of animal proteins, and folic acid are members of the one carbon cycle and as such important players in DNA methylation and cancer development. Therefore, dietary modifications involving altered methionine and folic acid content might inhibit colon cancer development. In the present study, the BALB/c 3T3 cell transformation assay was used to investigate whether methionine and folic acid are able to influence the malignant transformation of mouse fibroblasts after treatment with the known tumour initiator 3-methylcholanthrene. Three different methionine concentrations (representing a -40%, a "normal" and a +40% cell culture medium concentration, respectively) and two different folic acid concentrations (6 and 20 μM) were thereby investigated. Methionine restriction led to a decrease of type III foci, while enhancement of both methionine and folic acid did not significantly increase the cell transformation rate. Interestingly, the focus-lowering effect of methionine was only significant in conjunction with an elevated folic acid concentration. In summary, we conclude that the malignant transformation of mouse fibroblasts is influenced by methionine levels and that methionine restriction could be a possible approach to reduce cancer development. Copyright © 2016 Elsevier Ltd. All rights reserved.

X-ray studies on crystalline complexes involving amino acids and peptides. XXXII. Effect of chirality on ionisation state, stoichiometry and aggregation in the complexes of oxalic acid with DL- and L-lysine.

PubMed

Venkatraman, J; Prabu, M M; Vijayan, M

1997-08-01

Crystals of the oxalic acid complex of DL-lysine (triclinic P1; a = 5.540(1), b = 10.764(2), c = 12.056(2) A, alpha = 77.8(1), beta = 80.6(1), gamma = 75.6(1).; R = 4.7% for 2023 observed reflections) contain lysine and semioxalate ions in the 1:1 ratio, whereas the ratio of lysine and semioxalate/oxalate ions is 2:3 in the crystals of the L-lysine complex (monoclinic P2(1); alpha = 4.906(1), b = 20.145(4), c = 12.455(1) A, beta = 92.5(1).; R = 4.4% for 1494 observed reflections). The amino acid molecule in the L-lysine complex has an unusual ionisation state with positively charged alpha- and side-chain amino groups and a neutral carboxyl group. The unlike molecules aggregate into separate alternating layers in the DL-lysine complex in a manner similar to that observed in several of the amino acid complexes. The L-lysine complex exhibits a new aggregation pattern which cannot be easily explained in terms of planar features, thus emphasizing the fundamental dependence of aggregation on molecular characteristics. Despite the differences in stoichiometry, ionisation state and long-range aggregation patterns, the basic element of aggregation in the two complexes exhibits considerable similarity.

Advanced glycation end-products and methionine sulphoxide in skin collagen of patients with type 1 diabetes.

PubMed

Yu, Y; Thorpe, S R; Jenkins, A J; Shaw, J N; Sochaski, M A; McGee, D; Aston, C E; Orchard, T J; Silvers, N; Peng, Y G; McKnight, J A; Baynes, J W; Lyons, T J

2006-10-01

We determined whether oxidative damage in collagen is increased in (1) patients with diabetes; (2) patients with diabetic complications; and (3) subjects from the Diabetes Control and Complications Trial (DCCT)/Epidemiology of Diabetes Interventions and Complications (EDIC) study, with comparison of subjects from the former standard vs intensive treatment groups 4 years after DCCT completion. We quantified the early glycation product fructose-lysine, the two AGEs N (epsilon)-(carboxymethyl)lysine (CML) and pentosidine, and the oxidised amino acid methionine sulphoxide (MetSO) in skin collagen from 96 patients with type 1 diabetes (taken from three groups: DCCT/EDIC patients and clinic patients from South Carolina and Scotland) and from 78 healthy subjects. Fructose-lysine was increased in diabetic patients (p<0.0001), both with or without complications (p<0.0001). Controlling for HbA(1c), rates of accumulation of AGEs were higher in diabetic patients than control subjects, regardless of whether the former had complications (CML and pentosidine given as log(e)[pentosidine]) or not (CML only) (all p<0.0001). MetSO (log(e)[MetSO]) also accumulated more rapidly in diabetic patients with complications than in controls (p<0.0001), but rates were similar in patients without complications and controls. For all three products, rates of accumulation with age were significantly higher in diabetic patients with complications than in those without (all p<0.0001). At 4 years after the end of the DCCT, no differences were found between the previous DCCT management groups for fructose-lysine, AGEs or MetSO. The findings suggest that in type 1 diabetic patients enhanced oxidative damage to collagen is associated with the presence of vascular complications.

Effects of fortified lysine on the amino acid profile and sensory qualities of deep-fried and dried noodles.

PubMed

Polpuech, C; Chavasit, V; Srichakwal, P; Paniangvait, P

2011-08-01

Lysine fortification of wheat flour has been used toward reducing protein energy malnutrition in developing countries. The feasibility of fortifying instant noodles with lysine was evaluated based on sensory qualities and the residual lysine content. Fifty grams of deep-fried and dried instant noodles were fortified with 0.23 and 0.21 g lysine, respectively. The production temperatures used for deep-frying were 165-175 degrees C and for drying, 80-105 degrees C; these are the temperatures used in the industrial production of both kinds of noodles. Lysine fortification was then performed at the local factories using the commercial production lines and packaging for both types of instant noodles. Both fortified and unfortified deep-fried and dried instant noodles were stored at 50 degrees C under fluorescent light for 2 and 4 months, respectively. The fortified products were tested for residual lysine content and sensory qualities as compared with unfortified noodles. The results show fortified products from the tested processing temperatures were all accepted. After storage, significant losses of lysine were not found in both types of noodles analysed. The lysine-fortified noodles had amino acid scores of 102% and 122%, respectively. After 2 months, the sensory quality of fortified deep-fried noodles was still acceptable; however, the dried noodles turned to an unacceptable dark colour. This study shows that it is feasible to fortify deep-fried instant noodles with lysine, though lysine fortification exhibited an undesirable colour in the dried instant noodles after storage.

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

Methionine kinetics in adult men: effects of dietary betaine on L-(2H3-methyl-1-13C)methionine

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

Storch, K.J.; Wagner, D.A.; Young, V.R.

1991-08-01

The effects of a daily 3-g supplement of betaine on kinetic aspects of L-(2H3-methyl-1-13C)methionine (MET) metabolism in healthy young adult men were explored. Four groups of four subjects each were given a control diet, based on an L-amino acid mixture supplying 29.5 and 21.9 mg.kg-1.d-1 of L-methionine and L-cystine for 4 d before the tracer study, conducted on day 5 during the fed state. Two groups received the control diet and two groups received the betaine supplement. Tracer was given intravenously (iv) or orally. The transmethylation rate of MET (TM), homocysteine remethylation (RM), and oxidation of methionine were estimated frommore » plasma methionine labeling and 13C enrichment of expired air. RM tended to increase (P = 0.14) but the TM and methionine oxidation were significantly (P less than 0.05) higher after betaine supplementation when estimated with the oral tracer. No differences were detected with the intravenous tracer. Methionine concentration in plasma obtained from blood taken from subjects in the fed state was higher (P less than 0.01) with betaine supplementation. These results suggest that excess methyl-group intake may increase the dietary requirement for methionine.« less

Dry-extrusion of Asian Carp to supplement natural methionine for organic poultry production

USDA-ARS?s Scientific Manuscript database

Methionine, a sulfur containing amino acid, is essential for healthy poultry production. Synthetic methionine is commonly used as a supplement in conventional poultry. However, for organic poultry in the United States, a natural, cost effective source of methionine that can replace synthetic methion...

Effects of dietary valine:lysine ratio on the performance, amino acid composition of tissues and mRNA expression of genes involved in branched-chain amino acid metabolism of weaned piglets

PubMed Central

Xu, Ye Tong; Ma, Xiao Kang; Wang, Chun Lin; Yuan, Ming Feng; Piao, Xiang Shu

2018-01-01

Objective The goal of this study was to investigate the effects of dietary standard ileal digestible (SID) valine:lysine ratios on performance, intestinal morphology, amino acids of liver and muscle, plasma indices and mRNA expression of branched-chain amino acid (BCAA) metabolism enzymes. Methods A total of 144 crossbred pigs (Duroc×Landrace×Large White) weaned at 28±4 days of age (8.79±0.02 kg body weight) were randomly allotted to 1 of 4 diets formulated to provide SID valine:lysine ratios of 50%, 60%, 70%, or 80%. Each diet was fed to 6 pens of pigs with 6 pigs per pen (3 gilts and 3 barrows) for 28 days. Results Average daily gain increased quadratically (p<0.05), the villous height of the duodenum, jejunum and ileum increased linearly (p<0.05) as the SID valine:lysine ratio increased. The concentrations of plasma α-keto isovaleric and valine increased linearly (p<0.05), plasma aspartate, asparagine and cysteine decreased (p<0.05) as the SID valine:lysine ratio increased. An increase in SID lysine:valine levels increased mRNA expression levels of mitochondrial BCAA transaminase and branched-chain α-keto acid dehydrogenase in the longissimus dorsi muscle (p<0.05). Conclusion Using a quadratic model, a SID valine:lysine ratio of 68% was shown to maximize the growth of weaned pigs which is slightly higher than the level recommended by the National Research Council [6]. PMID:28728397

Comparison of volatile sulphur compound production by cheese-ripening yeasts from methionine and methionine-cysteine mixtures.

PubMed

López Del Castillo-Lozano, M; Delile, A; Spinnler, H E; Bonnarme, P; Landaud, S

2007-07-01

Production of volatile sulphur compounds (VSC) was assessed in culture media supplemented with L-methionine or L-methionine/L-cysteine mixtures, using five cheese-ripening yeasts: Debaryomyces hansenii DH47(8), Kluyveromyces lactis KL640, Geotrichum candidum GC77, Yarrowia lipolytica YL200 and Saccharomyces cerevisiae SC45(3). All five yeasts produced VSC with L-methionine or L-methionine/L-cysteine, but different VSC profiles were found. GC77 and YL200 produced dimethyldisulphide and trace levels of dimethyltrisulphide while DH47(8), KL640 and SC45(3) produced mainly methionol and low levels of methional. S-methylthioacetate was produced by all the yeasts but at different concentrations. DH47(8), KL640 and SC45(3) also produced other minor VSC including 3-methylthiopropyl acetate, ethyl-3-methylthiopropanoate, a thiophenone, and an oxathiane. However, VSC production diminished in a strain-dependent behaviour when L-cysteine was supplemented, even at a low concentration (0.2 g l(-1)). This effect was due mainly to a significant decrease in L-methionine consumption in all the yeasts except YL200. Hydrogen sulphide produced by L-cysteine catabolism did not seem to contribute to VSC generation at the acid pH of yeast cultures. The significance of such results in the cheese-ripening context is discussed.

The low-methionine content of vegan diets may make methionine restriction feasible as a life extension strategy.

PubMed

McCarty, Mark F; Barroso-Aranda, Jorge; Contreras, Francisco

2009-02-01

Recent studies confirm that dietary methionine restriction increases both mean and maximal lifespan in rats and mice, achieving "aging retardant" effects very similar to those of caloric restriction, including a suppression of mitochondrial superoxide generation. Although voluntary caloric restriction is never likely to gain much popularity as a pro-longevity strategy for humans, it may be more feasible to achieve moderate methionine restriction, in light of the fact that vegan diets tend to be relatively low in this amino acid. Plant proteins - especially those derived from legumes or nuts - tend to be lower in methionine than animal proteins. Furthermore, the total protein content of vegan diets, as a function of calorie content, tends to be lower than that of omnivore diets, and plant protein has somewhat lower bioavailability than animal protein. Whole-food vegan diets that moderate bean and soy intake, while including ample amounts of fruit and wine or beer, can be quite low in methionine, while supplying abundant nutrition for health (assuming concurrent B12 supplementation). Furthermore, low-fat vegan diets, coupled with exercise training, can be expected to promote longevity by decreasing systemic levels of insulin and free IGF-I; the latter effect would be amplified by methionine restriction - though it is not clear whether IGF-I down-regulation is the sole basis for the impact of low-methionine diets on longevity in rodents.

Studies on the biochemical composition, energetics and essential amino acids of three mudskippers in Xiamen Harbour

NASA Astrophysics Data System (ADS)

Wang, Jun; Su, Yong-Quan

1995-12-01

Measurements were made on the contents of protein, lipid, glycogen (PLG) and water, and on caloric values and amino acids, in muscle of three mudskippers Periophthalmus cantonensis, Scarteiaos viridis and Boleophthalmus pectinirostris collected from Haicang, Xiamen. The essential amino acids (EAA) for these fishes were also studied with radioisotopic trace method. The results showed: (1) The content of each component in tested fish muscles differed slightly, and protein was the most important component making up from 6.685% to 9.891% of the wet weight (about 44.21% 50.45% of dry weight); (2) Energy calculated from the sum of protein, lipid and glycogen in wet muscle was low (<4.3kJ/g) in these fishes, especially in B. pectinirostris (<3.1 kJ/g); the ratios of energy to protein content ( E/P) also were low (<39.873 45.535kJ/g); (3) Seventeen amino acids were determined in these three fishes. The content of the same amino acid (among the seventeen) tested in different species and sexes varied slightly. The amounts of methionine, phenylalanine lysine, arginine, histidine, threonine isoleucine and leucine which are indispensable for the needs of human beings and animals were relatively high, accounting for 47.35% 48.06% of the total amino acid content. (4) Leucine, isoleucine, arginine, lysine, phenylalanine, tryptophan, methionine, histidine, threonine, and valine, are essential in the diet of the three mudskippers as the radioisotopic trace method using D-[U-14C]-glucose showed little or no radioactivity was incorporated into these ten amino acids.

Studies on the biochemical composition, energetics and essential amino acids of three mudskippers in Xiamen Harbour

NASA Astrophysics Data System (ADS)

Jun, Wang; Yong-Quan, Su

1995-12-01

Measurements were made on the contents of protein, lipid, glycogen (PLG) and water, and on caloric values and amino acids, in muscle of three mudskippers Periophthalmus cantonensis, Scarteiaos viridis and Boleophthalmus pectinirostris collected from Haicang, Xiamen. The essential amino acids (EAA) for these fishes were also studied with radioisotopic trace method. The results showed: (1) The content of each component in tested fish muscles differed slightly, and protein was the most important component making up from 6.685% to 9.891% of the wet weight (about 44.21%-50.45% of dry weight); (2) Energy calculated from the sum of protein, lipid and glycogen in wet muscle was low (<4.3kJ/g) in these fishes, especially in B. pectinirostris (<3.1 kJ/g); the ratios of energy to protein content ( E/P) also were low (<39.873-45.535kJ/g); (3) Seventeen amino acids were determined in these three fishes. The content of the same amino acid (among the seventeen) tested in different species and sexes varied slightly. The amounts of methionine, phenylalanine lysine, arginine, histidine, threonine isoleucine and leucine which are indispensable for the needs of human beings and animals were relatively high, accounting for 47.35%-48.06% of the total amino acid content. (4) Leucine, isoleucine, arginine, lysine, phenylalanine, tryptophan, methionine, histidine, threonine, and valine, are essential in the diet of the three mudskippers as the radioisotopic trace method using D-[U-14C]-glucose showed little or no radioactivity was incorporated into these ten amino acids.

Regulation of cell function by methionine oxidation and reduction

PubMed Central

Hoshi, Toshinori; Heinemann, Stefan H

2001-01-01

Reactive oxygen species (ROS) are generated during normal cellular activity and may exist in excess in some pathophysiological conditions, such as inflammation or reperfusion injury. These molecules oxidize a variety of cellular constituents, but sulfur-containing amino acid residues are especially susceptible. While reversible cysteine oxidation and reduction is part of well-established signalling systems, the oxidation and the enzymatically catalysed reduction of methionine is just emerging as a novel molecular mechanism for cellular regulation. Here we discuss how the oxidation of methionine to methionine sulfoxide in signalling proteins such as ion channels affects the function of these target proteins. Methionine sulfoxide reductase, which reduces methionine sulfoxide to methionine in a thioredoxin-dependent manner, is therefore not only an enzyme important for the repair of age- or degenerative disease-related protein modifications. It is also a potential missing link in the post-translational modification cycle involved in the specific oxidation and reduction of methionine residues in cellular signalling proteins, which may give rise to activity-dependent plastic changes in cellular excitability. PMID:11179387

Effects of supplementary folic acid and vitamin B(12) on hepatic metabolism of dairy cows according to methionine supply.

PubMed

Preynat, A; Lapierre, H; Thivierge, M C; Palin, M F; Cardinault, N; Matte, J J; Desrochers, A; Girard, C L

2010-05-01

The present experiment was undertaken to study the interactions between dietary supplements of rumen-protected methionine (RPM) and intramuscular injections of folic acid and vitamin B(12), given from 3 wk before calving to 16 wk of lactation, on hepatic metabolism of lactating dairy cows. Sixty multiparous Holstein cows were assigned to 10 blocks of 6 cows each according to their previous milk production. Within each block, 3 cows were fed a diet calculated to supply Met as 1.83% of metabolizable protein, whereas the 3 other cows were fed the same diet supplemented with 18g of RPM calculated to provide Met as 2.23% of metabolizable protein. Within each level of Met, the cows received no vitamin supplement or weekly intramuscular injections of 160mg of folic acid alone or combined with 10mg of vitamin B(12). Liver biopsies were taken at 2, 4, 8, and 16 wk of lactation. Liver concentrations of folates and vitamin B(12) were increased by their respective supplements but this response to vitamin supplements was altered by methionine supply. Concentrations of total lipids and triglycerides increased in livers of cows fed RPM, whereas concentrations of cholesterol ester, cholesterol, diglycerides, phosphatidylethanolamine, and phosphatidylcholine were not affected. Folic acid, alone or combined with vitamin B(12), tended to increase the ratio of phosphatidylcholine to phosphatidylethanolamine. Gene expression of 5,10-methylene-tetrahydrofolate reductase, microsomal transfer protein, and phosphatidylethanolamine methyltransferase were higher in liver of cows fed RPM supplements. The relative mRNA abundance of 5,10-methylene-tetrahydrofolate reductase and methylmalonyl-CoA mutase were increased by the combined injections of folic acid and vitamin B(12), whereas those of methionine synthase and methionine synthase reductase were not affected by treatments. These results suggest that increasing supply of methyl groups, as preformed labile methyl groups or through

Role of L-lysine-alpha-ketoglutarate aminotransferase in catabolism of lysine as a nitrogen source for Rhodotorula glutinis.

PubMed Central

Kinzel, J J; Winston, M K; Bhattacharjee, J K

1983-01-01

Wild-type and saccharopine dehydrogenaseless mutant strains of Rhodotorula glutinis grew in minimal medium containing lysine as the sole nitrogen source and simultaneously accumulated, in the culture supernatant, large amounts of a product identified as alpha-aminoadipic-delta-semialdehyde. The saccharopine dehydrogenase and pipecolic acid oxidase levels remained unchanged in wild-type cells grown in the presence of ammonium or lysine as the nitrogen source. Lysine-alpha-ketoglutarate aminotransferase activity was demonstrated in ammonium-grown cells. This activity was depressed in cells grown in the presence of lysine as the sole source of nitrogen. PMID:6408065

Effect of L-methionine supplementation on plasma homocysteine and other free amino acids: a placebo-controlled double-blind cross-over study.

PubMed

Ditscheid, B; Fünfstück, R; Busch, M; Schubert, R; Gerth, J; Jahreis, G

2005-06-01

The essential amino acid L-methionine is a potential compound in the prophylaxis of recurrent or relapsing urinary tract infection due to acidification of urine. As an intermediate of L-methionine metabolism, homocysteine is formed. The objective was to study the metabolism of L-methionine and homocysteine, and to assess whether there are differences between patients with chronic urinary tract infection and healthy control subjects. A randomized placebo-controlled double-blind intervention study with cross-over design. Department of Nutritional Physiology, Institute of Nutrition in cooperation with the Department of Internal Medicine III, Friedrich Schiller University of Jena, Germany. Eight female patients with chronic urinary tract infection and 12 healthy women (controls). After a methionine-loading test, the volunteers received 500 mg L-methionine or a placebo three times daily for 4 weeks. Serum and urinary concentrations of methionine, homocysteine, cystathionine, cystine, serine, glycine and serum concentrations of vitamin B12, B6 and the state of folate. Homocysteine plasma concentrations increased from 9.4+/-2.7 micromol/l (patients) and 8.9+/-1.8 micromol/l (controls) in the placebo period to 11.2+/-4.1 micromol/l (P=0.031) and 11.0+/-2.3 micromol/l (P=0.000), respectively, during L-methionine supplementation. There were significant increases in serum methionine (53.6+/-22.0 micromol/l; P=0.003; n=20) and cystathionine (0.62+/-0.30 micromol/l; P=0.000; n=20) concentrations compared with the placebo period (33.0+/-12.0 and 0.30+/-0.10 micromol/l; n=20). Simultaneously, renal excretion of methionine and homocysteine was significantly higher during L-methionine intake. Despite an adequate vitamin status, the supplementation of 1500 mg of L-methionine daily significantly increases homocysteine plasma concentrations by an average of 2.0 micromol/l in patients and in control subjects. An optimal vitamin supplementation, especially with folate, might prevent

AMINO ACID COMPOSITION OF HIGHLY PURIFIED VIRAL PARTICLES OF INFLUENZA A AND B

PubMed Central

Knight, C. A.

1947-01-01

Microbiological assays for amino acids were made on hydrolysates of four to five highly purified preparations each of influenza A virus (PR8 strain) and influenza B virus (Lee strain). The results of the assays indicated that these strains of influenza virus contain approximately the same amounts of alanine, aspartic acid, glycine, histidine, isoleucine, leucine, methionine, phenylalanine, proline, serine, threonine, and valine. However, significant differences were found in the values for arginine, glutamic acid, lysine, tryptophane, and tyrosine. It is believed that these differences may provide, at least in part, a chemical explanation for some of the differing properties of the PR8 and Lee strains of influenza viruses. PMID:19871660

Formation of S-(carboxymethyl)-cysteine in rat liver mitochondrial proteins: effects of caloric and methionine restriction.

PubMed

Naudí, Alba; Jové, Mariona; Cacabelos, Daniel; Ayala, Victoria; Cabre, Rosanna; Caro, Pilar; Gomez, José; Portero-Otín, Manuel; Barja, Gustavo; Pamplona, Reinald

2013-02-01

Maillard reaction contributes to the chemical modification and cross-linking of proteins. This process plays a significant role in the aging process and determination of animal longevity. Oxidative conditions promote the Maillard reaction. Mitochondria are the primary site of oxidants due to the reactive molecular species production. Mitochondrial proteome cysteine residues are targets of oxidative attack due to their specific chemistry and localization. Their chemical, non-enzymatic modification leads to dysfunctional proteins, which entail cellular senescence and organismal aging. Previous studies have consistently shown that caloric and methionine restrictions, nutritional interventions that increase longevity, decrease the rate of mitochondrial oxidant production and the physiological steady-state levels of markers of oxidative damage to macromolecules. In this scenario, we have detected S-(carboxymethyl)-cysteine (CMC) as a new irreversible chemical modification in mitochondrial proteins. CMC content in mitochondrial proteins significantly correlated with that of the lysine-derived analog N (ε)-(carboxymethyl)-lysine. The concentration of CMC is, however, one order of magnitude lower compared with CML likely due in part to the lower content of cysteine with respect to lysine of the mitochondrial proteome. CMC concentrations decreases in liver mitochondrial proteins of rats subjected to 8.5 and 25 % caloric restriction, as well as in 40 and 80 % methionine restriction. This is associated with a concomitant and significant increase in the protein content of sulfhydryl groups. Data presented here evidence that CMC, a marker of Cys-AGE formation, could be candidate as a biomarker of mitochondrial damage during aging.

Response of growing goslings to dietary supplementation with methionine and betaine.

PubMed

Yang, Z; Wang, Z Y; Yang, H M; Zhao, F Z; Kong, L L

2016-12-01

An experiment with a 2 × 3 factorial design with two concentrations of dietary betaine (0 and 600 mg/kg) and three dietary concentrations of methionine (0, 600 and 1200 mg/kg) was conducted using goslings to estimate growth, nutrient utilisation and digestibility of amino acids from 21 to 70 d of age. Three hundred geese were randomised at 18 d of age into 6 groups with 5 replicates per treatment and 10 geese per replicate. Increasing dietary concentrations of methionine gave a linear increase in body weight and average daily gain. The coefficient of crude fat retention increased as dietary methionine increased and there was a significant non-linear response to increasing dietary methionine. Similarly, increasing supplemental methionine gave linear increases in the digestibility of methionine and cysteine. The results of this study indicated that optimal dietary supplementation of methionine could increase growth performance and methionine and cysteine utilisation in growing goslings. Betaine supplementation had no apparent sparing effect on methionine needs for growth performance, but did improve the apparent cysteine digestibility.

Age-dependent increase in ortho-tyrosine and methionine sulfoxide in human skin collagen is not accelerated in diabetes. Evidence against a generalized increase in oxidative stress in diabetes.

PubMed Central

Wells-Knecht, M C; Lyons, T J; McCance, D R; Thorpe, S R; Baynes, J W

1997-01-01

The glycoxidation products Nepsilon-(carboxymethyl)lysine and pentosidine increase in skin collagen with age and at an accelerated rate in diabetes. Their age-adjusted concentrations in skin collagen are correlated with the severity of diabetic complications. To determine the relative roles of increased glycation and/or oxidation in the accelerated formation of glycoxidation products in diabetes, we measured levels of amino acid oxidation products, distinct from glycoxidative modifications of amino acids, as independent indicators of oxidative stress and damage to collagen in aging and diabetes. We show that ortho-tyrosine and methionine sulfoxide are formed in concert with Nepsilon-(carboxymethyl)lysine and pentosidine during glycoxidation of collagen in vitro, and that they also increase with age in human skin collagen. The age-adjusted levels of these oxidized amino acids in collagen was the same in diabetic and nondiabetic subjects, arguing that diabetes per se does not cause an increase in oxidative stress or damage to extracellular matrix proteins. These results provide evidence for an age-dependent increase in oxidative damage to collagen and support previous conclusions that the increase in glycoxidation products in skin collagen in diabetes can be explained by the increase in glycemia alone, without invoking a generalized, diabetes-dependent increase in oxidative stress. PMID:9259583

Transmethylation of homocysteine to methionine: efficiency in the rat and chick.

PubMed

Baker, D H; Czarnecki, G L

1985-10-01

Experiments were conducted with young chicks and rats to quantify the efficacy of L-homocysteine as a methionine precursor. Linear growth responses were obtained to both L-methionine and L-homocysteine when added to a methionine-deficient intact-protein diet containing a plethora of cystine. Slope-ratio multiple regression methodology indicated L-homocysteine to be 64.5% as efficacious as L-methionine in rats and 62.5% as efficacious in chicks. Plasma-free methionine also increased linearly as graded levels of either L-methionine or L-homocysteine were added to the diet of rats. At higher dosages of L-homocysteine, betaine, but not choline, showed some efficacy in enhancing the conversion of homocysteine to methionine. In the linear response surface of the growth curve, however, supplemental betaine was without effect on L-homocysteine bioefficacy, as was also the case for supplemental sarcosine and N5-methyltetrahydrofolic acid.

Synthesis of pro-prodrugs L-lysine based for 5-aminosalicylic acid and 6-mercaptopurine colon specific release.

PubMed

Trombino, Sonia; Cassano, Roberta; Cilea, Alessia; Ferrarelli, Teresa; Muzzalupo, Rita; Picci, Nevio

2011-11-28

The aim of this work is to design, prepare and characterize L-lysine based prodrugs capable of targeting 6-mercaptopurine to the colon, an anti-tumor and immunosuppressant drug, and 5-aminosalicylic acid (5-ASA), drug of choice for inflammatory bowel disease (IBD). More specifically, Nɛ-feruloyl-S-(6-purinyl)-L-lysine and Nɛ-acryloyl-S-(6-purinyl)-L-lysine were synthesized and then characterized by FT-IR, (1)H-NMR and GC/MS spectroscopies. The ability of feruloyl derivative in inhibiting lipid peroxidation in rat liver microsomal membranes, induced in vitro by tert-butyl hydroperoxide as source of free radicals, was evaluated. Moreover, Nɛ-acryloyl-S-(6-purinyl)-L-lysine, polymerizable prodrug, was used to microspheres realization for 5-ASA release. These lasts, obtained by emulsion inverse technique, were characterized by light scattering and scanning electron microscopy (SEM) analysis. The microspheres equilibrium swelling degree was evaluated and showed good swelling behaviour in simulating colonic fluids. Results confirm the possibility that the application range of L-lysine prodrug can be extended to the treatment of intestinal diseases whose conventional therapy envisages medications with serious side effects that, thanks to this new strategy, can be minimized in an optimal way. Copyright © 2011 Elsevier B.V. All rights reserved.

Free amino acid profiling in the giant puffball mushroom (Calvatia gigantea) using UPLC-MS/MS.

PubMed

Kıvrak, İbrahim; Kıvrak, Şeyda; Harmandar, Mansur

2014-09-01

Wild edible and medicinal mushroom, Calvatia gigantea, was quantitatively analyzed for the determination of its free amino acids using ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). The concentrations of total free amino acids, essential and non-essential amino acids were 199.65 mg/100 g, 113.69 mg/100 g, and 85.96 mg/100 g in C. gigantea, respectively. This study showed that C. gigantea, so called a giant puffball mushroom, has free amino acids content. The essential amino acids: tryptophan, isoleucine, valine, phenylalanine, leucine, threonine, lysine, histidine, methionine, and the non-essential amino acids: tyrosine, 4-hyrdroxy proline, arginine, proline, glycine, serine, alanine, glutamine, glutamic acid, aspargine, aspartic acid were detected. Copyright © 2014 Elsevier Ltd. All rights reserved.

A GC-ECD method for estimation of free and bound amino acids, gamma-aminobutyric acid, salicylic acid, and acetyl salicylic acid from Solanum lycopersicum (L.).

PubMed

Meher, Hari Charan; Gajbhiye, Vijay T; Singh, Ghanendra

2011-01-01

A gas chromatograph with electron capture detection method for estimation of selected metabolites--amino acids (free and bound), gamma-aminobutyric acid (GABA), salicylic acid (SA), and acetyl salicylic acid (ASA) from tomato--is reported. The method is based on nitrophenylation of the metabolites by 1-fluoro-2, 4-dinitrobenzene under aqueous alkaline conditions to form dinitophenyl derivatives. The derivatives were stable under the operating conditions of GC. Analysis of bound amino acids comprised perchloric acid precipitation of protein, alkylation (carboxymethylation) with iodoacetic acid, vapor-phase hydrolysis, and derivatization with 1-fluoro-2,4-dinitrobenzene in that order. The metabolites were resolved in 35 min, using a temperature-programmed run. The method is rapid, sensitive, and precise. It easily measured the typical amino acids (aspartate, asparagine, glutamate, glutamine, alanine, leucine, lysine, and phenylalanine) used for identification and quantification of a protein, resolved amino acids of the same mass (leucine and isoleucine), satisfactorily measured sulfur amino acid (methionine, cystine, and cysteine), and quantified GABA, SA, and ASA, as well. The developed method was validated for specificity, linearity, and precision. It has been applied and recommended for estimation of 25 metabolites from Solanum lycopersicum (L.).

Reconstruction of Cysteine Biosynthesis Using Engineered Cysteine-Free and Methionine-Free Enzymes

NASA Technical Reports Server (NTRS)

Wang, Kendrick; Fujishima, Kosuke; Abe, Nozomi; Nakahigashi, Kenji; Endy, Drew; Rothschild, Lynn J.

2016-01-01

Ten of the proteinogenic amino acids can be generated abiotically while the remaining thirteen require biology for their synthesis. Paradoxically, the biosynthesis pathways observed in nature require enzymes that are made with the amino acids they produce. For example, Escherichia coli produces cysteine from serine via two enzymes that contain cysteine. Here, we substituted alternate amino acids for cysteine and also methionine, which is biosynthesized from cysteine, in serine acetyl transferase (CysE) and O-acetylserine sulfhydrylase (CysM). CysE function was rescued by cysteine-and-methionine-free enzymes and CysM function was rescued by cysteine-free enzymes. Structural modeling suggests that methionine stabilizes CysM and is present in the active site of CysM. Cysteine is not conserved among CysE and CysM protein orthologs, suggesting that cysteine is not functionally important for its own synthesis. Engineering biosynthetic enzymes that lack the amino acids being synthesized provides insights into the evolution of amino acid biosynthesis and pathways for bioengineering.

Methionine biosynthesis is essential for infection in the rice blast fungus Magnaporthe oryzae.

PubMed

Saint-Macary, Marie Emmanuelle; Barbisan, Crystel; Gagey, Marie Josèphe; Frelin, Océane; Beffa, Roland; Lebrun, Marc Henri; Droux, Michel

2015-01-01

Methionine is a sulfur amino acid standing at the crossroads of several biosynthetic pathways. In fungi, the last step of methionine biosynthesis is catalyzed by a cobalamine-independent methionine synthase (Met6, EC 2.1.1.14). In the present work, we studied the role of Met6 in the infection process of the rice blast fungus, Magnaporthe oryzae. To this end MET6 null mutants were obtained by targeted gene replacement. On minimum medium, MET6 null mutants were auxotrophic for methionine. Even when grown in presence of excess methionine, these mutants displayed developmental defects, such as reduced mycelium pigmentation, aerial hypha formation and sporulation. They also displayed characteristic metabolic signatures such as increased levels of cysteine, cystathionine, homocysteine, S-adenosylmethionine, S-adenosylhomocysteine while methionine and glutathione levels remained unchanged. These metabolic perturbations were associated with the over-expression of MgCBS1 involved in the reversed transsulfuration pathway that metabolizes homocysteine into cysteine and MgSAM1 and MgSAHH1 involved in the methyl cycle. This suggests a physiological adaptation of M. oryzae to metabolic defects induced by the loss of Met6, in particular an increase in homocysteine levels. Pathogenicity assays showed that MET6 null mutants were non-pathogenic on both barley and rice leaves. These mutants were defective in appressorium-mediated penetration and invasive infectious growth. These pathogenicity defects were rescued by addition of exogenous methionine and S-methylmethionine. These results show that M. oryzae cannot assimilate sufficient methionine from plant tissues and must synthesize this amino acid de novo to fulfill its sulfur amino acid requirement during infection.

Methionine Biosynthesis is Essential for Infection in the Rice Blast Fungus Magnaporthe oryzae

PubMed Central

Gagey, Marie Josèphe; Frelin, Océane; Beffa, Roland; Lebrun, Marc Henri; Droux, Michel

2015-01-01

Methionine is a sulfur amino acid standing at the crossroads of several biosynthetic pathways. In fungi, the last step of methionine biosynthesis is catalyzed by a cobalamine-independent methionine synthase (Met6, EC 2.1.1.14). In the present work, we studied the role of Met6 in the infection process of the rice blast fungus, Magnaporthe oryzae. To this end MET6 null mutants were obtained by targeted gene replacement. On minimum medium, MET6 null mutants were auxotrophic for methionine. Even when grown in presence of excess methionine, these mutants displayed developmental defects, such as reduced mycelium pigmentation, aerial hypha formation and sporulation. They also displayed characteristic metabolic signatures such as increased levels of cysteine, cystathionine, homocysteine, S-adenosylmethionine, S-adenosylhomocysteine while methionine and glutathione levels remained unchanged. These metabolic perturbations were associated with the over-expression of MgCBS1 involved in the reversed transsulfuration pathway that metabolizes homocysteine into cysteine and MgSAM1 and MgSAHH1 involved in the methyl cycle. This suggests a physiological adaptation of M. oryzae to metabolic defects induced by the loss of Met6, in particular an increase in homocysteine levels. Pathogenicity assays showed that MET6 null mutants were non-pathogenic on both barley and rice leaves. These mutants were defective in appressorium-mediated penetration and invasive infectious growth. These pathogenicity defects were rescued by addition of exogenous methionine and S-methylmethionine. These results show that M. oryzae cannot assimilate sufficient methionine from plant tissues and must synthesize this amino acid de novo to fulfill its sulfur amino acid requirement during infection. PMID:25856162

Synthesis of peptides from amino acids and ATP with lysine-rich proteinoid

NASA Technical Reports Server (NTRS)

Nakashima, T.; Fox, S. W.

1980-01-01

The paper examines the synthesis of peptides from aminoacids and ATP with a lysine-rich protenoid. The latter in aqueous solution catalyzes the formation of peptides from free amino acids and ATP; this catalytic activity is not found in acidic protenoids, even though the latter contain a basic aminoacid. The pH optimum for the synthesis is about 11, but it is appreciable below 8 and above 13. Temperature data indicate an optimum at 20 C or above, with little increase in rate up to 60 C. Pyrophosphate can be used instead of ATP, but the yields are lower. The ATP-aided syntheses of peptides in aqueous solution occur with several types of proteinous aminoacids.

Effect of Dietary Combination of Methionine and Fish Oil on Cellular Immunity and Plasma Fatty Acids in Infectious Bursal Disease Challenged Chickens

PubMed Central

Kasim, Azhar; Yong Meng, Goh; Teck Chwen, Loh; Kamalidehghan, Behnam; Soleimani Farjam, Abdoreza

2013-01-01

This study was carried out to investigate the modulatory effects of dietary methionine and fish oil on immune response, plasma fatty acid profile, and blood parameters of infectious bursal disease (IBD) challenged broiler chickens. A total of 300 one-day-old male broiler chicks were assigned to one of six dietary treatment groups in a 3 × 2 factorial arrangement. There were three levels of fish oil (0, 2.5 and 5.5%), and two levels of methionine (NRC recommendation and twice NRC recommendation). The results showed that the birds fed with 5.5% fish oil had higher total protein, white blood cell count, and IL-2 concentration than those of other groups at 7 days after IBD challenge. Inclusion of fish oil in diet had no effect on IFN-γ concentration. However, supplementation of methionine twice the recommendation enhanced the serum IFN-γ and globulin concentration. Neither of fish oil nor methionine supplementation affected the liver enzymes concentration. It can be suggested that a balance of moderate level of fish oil (2.5%) and methionine level (twice NRC recommendation) might enhance immune response in IBD challenged broiler chickens. PMID:24198724

Methionine catabolism and production of volatile sulphur compounds by OEnococcus oeni.

PubMed

Pripis-Nicolau, L; de Revel, G; Bertrand, A; Lonvaud-Funel, A

2004-01-01

During malolactic fermentation (MLF), the secondary metabolisms of lactic acid bacteria (LAB) contribute to the organoleptic modification of wine. To understand the contribution of MLF, we evaluated the capacity of various wine LAB to metabolize methionine. Using gas chromatography (GC) coupled either with mass spectrometry (MS) or a flame photometry detector in sulphur mode (FPD), we studied this metabolism in laboratory media and wine. In laboratory media, several LAB isolated from wine were able to metabolize methionine. They formed methanethiol, dimethyl disulphide, 3-(methylsulphanyl)propan-1-ol and 3-(methylsulphanyl)propionic acid. These are known to have powerful characteristic odours and play a role in the aromatic complexity of wine. In various red wines, after MLF only the 3-(methylsulphanyl)propionic acid concentration increased significantly, as verified with several commercial starter cultures. This compound, which is characterized by chocolate and roasted odours, could contribute to the aromatic complexity produced by MLF. This study shows that LAB isolated from wine, especially OEnococcus oeni strains, the major species in MLF, are able to metabolize methionine to form volatile sulphur compounds. This is the first study to demonstrate the capacity of wine LAB to metabolize methionine.

L-leucine, L-methionine, and L-phenylalanine share a Na(+)/K (+)-dependent amino acid transporter in shrimp hepatopancreas.

PubMed

Duka, Ada; Ahearn, Gregory A

2013-08-01

Hepatopancreatic brush border membrane vesicles (BBMV), made from Atlantic White shrimp (Litopenaeus setiferus), were used to characterize the transport properties of (3)H-L-leucine influx by these membrane systems and how other essential amino acids and the cations, sodium and potassium, interact with this transport system. (3)H-L-leucine uptake by BBMV was pH-sensitive and occurred against transient transmembrane concentration gradients in both Na(+)- and K(+)-containing incubation media, suggesting that either cation was capable of providing a driving force for amino acid accumulation. (3)H-L-leucine uptake in NaCl or KCl media were each three times greater in acidic pH (pH 5.5) than in alkaline pH (pH 8.5). The essential amino acid, L-methionine, at 20 mM significantly (p < 0.0001) inhibited the 2-min uptakes of 1 mM (3)H-L-leucine in both Na(+)- and K(+)-containing incubation media. The residual (3)H-L-leucine uptake in the two media were significantly greater than zero (p < 0.001), but not significantly different from each other (p > 0.05) and may represent an L-methionine- and cation-independent transport system. (3)H-L-leucine influxes in both NaCl and KCl incubation media were hyperbolic functions of [L-leucine], following the carrier-mediated Michaelis-Menten equation. In NaCl, (3)H-L-leucine influx displayed a low apparent K M (high affinity) and low apparent J max, while in KCl the transport exhibited a high apparent K M (low affinity) and high apparent J max. L-methionine or L-phenylalanine (7 and 20 mM) were competitive inhibitors of (3)H-L-leucine influxes in both NaCl and KCl media, producing a significant (p < 0.01) increase in (3)H-L-leucine influx K M, but no significant response in (3)H-L-leucine influx J max. Potassium was a competitive inhibitor of sodium co-transport with (3)H-L-leucine, significantly (p < 0.01) increasing (3)H-L-leucine influx K M in the presence of sodium, but having negligible effect on (3)H-L-leucine influx J

Methionine peptide formation under primordial earth conditions.

PubMed

Li, Feng; Fitz, Daniel; Fraser, Donald G; Rode, Bernd M

2008-01-01

According to recent research on the origin of life it seems more and more likely that amino acids and peptides were among the first biomolecules formed on earth and that a peptide/protein world was thus a key starting point in evolution towards life. Salt-induced Peptide Formation (SIPF) has repeatedly been shown to be the most universal and plausible peptide-forming reaction currently known under prebiotic conditions and forms peptides from amino acids with the help of copper ions and sodium chloride. In this paper we present experimental results for salt-induced peptide formation from methionine. This is the first time that a sulphur-containing amino acid was investigated in this reaction. The possible catalytic effects of glycine and L-histidine in this reaction were also investigated and a possible distinction between the L- and D-forms of methionine was studied as well.

Involvement of histone methylation in macrophage apoptosis and unstable plaque formation in methionine-induced hyperhomocysteinemic ApoE-/- mice.

PubMed

Cong, Guangzhi; Yan, Ru; Huang, Hui; Wang, Kai; Yan, Ning; Jin, Ping; Zhang, Na; Hou, Jianjun; Chen, Dapeng; Jia, Shaobin

2017-03-15

Hyperhomocysteinemia (Hhcy) is an independent risk factor of atherosclerosis and promotes unstable plaque formation. Epigenetic mechanisms play an important role in the pathogenesis of atherosclerosis induced by Hhcy. However, the exact mechanism is still undefined. Lesional apoptotic cells and necrotic core formation contribute greatly to the progression of plaque. The present study sought to determine whether modification of histone methylation is involved in macrophage apoptosis and unstable plaque formation in the condition of Hhcy. The unstable plaque formation, lesional apoptotic cells and status of histone methylation were monitored in the aortas of Hhcy ApoE -/- mice induced by a high-methionine (HM) diet for 20weeks. Involvement of histone methylation in macrophage apoptosis and foam cell formation were assessed in macrophage Raw 264.7 cells after being challenged with homocysteine alone or in combination with the histone methylation inhibitor BIX 01294. The unstable plaque formation and lesion apoptotic cells are increased in ApoE -/ - mice supplemented with high-methionine (HM), accompanied with a decreased expression of histone H3 lysine 9 dimethylation. Hhcy increases the apoptosis of macrophages and inhibits the histone H3 lysine 9 dimethylation, as well as the expression of histone methyltransferase G9a in vitro. Inhibition of histone methylation by BIX01294 enhances macrophage apoptosis and foam cell formation in vitro. Our data suggest that Hhcy promotes the progression of atherosclerosis via macrophage apoptosis. Histone methylation might be involved in macrophage apoptosis and unstable plaque formation in methionine induced hyperhomocysteinemic ApoE -/- mice. Copyright © 2017 Elsevier Inc. All rights reserved.

Free amino acids hydroxyproline, lysine, and glycine promote differentiation of retinal pericytes to adipocytes: A protective role against proliferative diabetic retinopathy.

PubMed

Vidhya, S; Ramya, R; Coral, K; Sulochana, K N; Bharathidevi, S R

2018-05-10

This study was conducted to estimate the aminoacid levels in the vitreous of patients with proliferative diabetic retinopathy, and to correlate it with the adiponectin levels. Secondly to test if these amino acids can alter or induce adiponectin levels and its related factors in retinal cells like pericyte as an in vitro model. All human studies were done as per declaration of Helsinki with institutional approval and after obtaining consent from participating individuals. The vitreous amino acids were estimated in PDR (Proliferative diabetic retinopathy) and MH (Macular Hole) as disease control using HPLC. Bovine retinal pericytes (BRP) were cultured in DMEM/F12 medium and treated with 0.5 mM of any one of the individual amino acids (proline, hydroxyproline, phenylalanine, alanine, serine, glycine, lysine, isoleucine or valine) along with 100 nM insulin for 14 days in high glucose (25 mM) condition. The mRNA expression profile of adipogenic markers (such as Pref1, APN, ZAG and PPARγ), angiogenic markers (VEGF, MMP-2 and MMP-9, TGF-β) and antioxidant markers (Nrf2 and UCP-2) were evaluated by qPCR. Adipogenesis was further confirmed by adipogenesis assay, secretion of adiponectin in medium and triglyceride accumulation by Oil red O staining in Bovine retinal pericytes. Amino acids valine (p < 0.004), isoleucine (p < 0.0007), leucine (p < 0.022), serine (p < 0.0007), glycine (p < 0.001), alanine (p < 0.017), phenylalanine (p < 0.013), and lysine (p < 0.001) were significantly elevated in the vitreous of PDR group (n = 30) when compared to macular hole (n = 20). There was a significant positive correlation between serine (p < 0.021), alanine (p < 0.00016), phenylalanine (p < 0.04), isoleucine (p < 0.023), leucine (p < 0.043), and lysine (p < 0.026) with adiponectin level in the vitreous. The amino acids hydroxyproline, proline, lysine, glycine and alanine induced the triglyceride accumulation and

Aspartokinase in Lemna minor L

PubMed Central

Wong, Kwan F.; Dennis, David T.

1973-01-01

The growth of Lemna minor was followed by means of frond number, fresh weight, and dry weight measurements in the presence of various amino acids at a concentration 0.25 mm. Lysine inhibited growth but not to the same extent as threonine and homoserine. Isoleucine was also an inhibitor of growth. In the presence of methionine there was some growth for 2 to 3 days, but by 5 days most of the plants appeared to be dead. When lysine and threonine were added together, there was no growth at all, and the plants were dead after 5 days. This effect of lysine + threonine could be reversed by adding methionine or homoserine to the growth medium. The isolated aspartokinase from Lemna showed inhibition by lysine and higher concentrations of threonine. When these amino acids were added together at low concentrations, there was a concerted inhibition of the aspartokinase. It is suggested that some effects of amino acids on the growth of L. minor can be explained on the basis of a concerted feedback control of aspartokinase. Images PMID:16658324

l-lysine production by Bacillus methanolicus: Genome-based mutational analysis and l-lysine secretion engineering.

PubMed

Nærdal, Ingemar; Netzer, Roman; Irla, Marta; Krog, Anne; Heggeset, Tonje Marita Bjerkan; Wendisch, Volker F; Brautaset, Trygve

2017-02-20

Bacillus methanolicus is a methylotrophic bacterium with an increasing interest in academic research and for biotechnological applications. This bacterium was previously applied for methanol-based production of l-glutamate, l-lysine and the five-carbon diamine cadaverine by wild type, classical mutant and recombinant strains. The genomes of two different l-lysine secreting B. methanolicus classical mutant strains, NOA2#13A52-8A66 and M168-20, were sequenced. We focused on mutational mapping in genes present in l-lysine and other relevant amino acid biosynthetic pathways, as well as in the primary cell metabolism important for precursor supply. In addition to mutations in the aspartate pathway genes dapG, lysA and hom-1, new mutational target genes like alr, proA, proB1, leuC, odhA and pdhD were identified. Surprisingly, no mutations were found in the putative l-lysine transporter gene lysE MGA3 . Inspection of the wild type B. methanolicus strain PB1 genome sequence identified two homologous putative l-lysine transporter genes, lysE PB1 and lysE2 PB1 . The biological role of these putative l-lysine transporter genes, together with the heterologous l-lysine exporter gene lysE Cg from Corynebacterium glutamicum, were therefore investigated. Our results demonstrated that the titer of secreted l-lysine in B. methanolicus was significantly increased by overexpression of lysE Cg while overexpression of lysE MGA3 , lysE PB1 and lysE2 PB1 had no measurable effect. Copyright © 2017 Elsevier B.V. All rights reserved.

Light-activated amino acid transport in Halobacterium halobium envelope vesicles

NASA Technical Reports Server (NTRS)

Macdonald, R. E.; Lanyi, J. K.

1977-01-01

Vesicles prepared from Halobacterium halobium cell envelopes accumulate amino acids in response to light-induced electrical and chemical gradients. Nineteen of 20 commonly occurring amino acids have been shown to be actively accumulated by these vesicles in response to illumination or in response to an artificially created Na+ gradient. On the basis of shared common carriers the transport systems can be divided into eight classes, each responsible for the transport of one or several amino acids: arginine, lysine, histidine; asparagine, glutamine; alanine, glycine, threonine, serine; leucine, valine, isoleucine, methionine; phenylalanine, tyrosine, tryptophan; aspartate; glutamate; proline. Available evidence suggests that these carriers are symmetrical in that amino acids can be transported equally well in both directions across the vesicle membranes. A tentative working model to account for these observations is presented.

Complementary dietary treatment using lysine-free, arginine-fortified amino acid supplements in glutaric aciduria type I - A decade of experience.

PubMed

Kölker, Stefan; Boy, S P Nikolas; Heringer, Jana; Müller, Edith; Maier, Esther M; Ensenauer, Regina; Mühlhausen, Chris; Schlune, Andrea; Greenberg, Cheryl R; Koeller, David M; Hoffmann, Georg F; Haege, Gisela; Burgard, Peter

2012-09-01

The cerebral formation and entrapment of neurotoxic dicarboxylic metabolites (glutaryl-CoA, glutaric and 3-hydroxyglutaric acid) are considered to be important pathomechanisms of striatal injury in glutaric aciduria type I (GA-I). The quantitatively most important precursor of these metabolites is lysine. Recommended therapeutic interventions aim to reduce lysine oxidation (low lysine diet, emergency treatment to minimize catabolism) and to enhance physiologic detoxification of glutaryl-CoA via formation of glutarylcarnitine (carnitine supplementation). It has been recently shown in Gcdh(-/-) mice that cerebral lysine influx and oxidation can be modulated by arginine which competes with lysine for transport at the blood-brain barrier and the inner mitochondrial membrane [Sauer et al., Brain 134 (2011) 157-170]. Furthermore, short-term outcome of 12 children receiving arginine-fortified diet showed very promising results [Strauss et al., Mol. Genet. Metab. 104 (2011) 93-106]. Since lysine-free, arginine-fortified amino acid supplements (AAS) are commercially available and used in Germany for more than a decade, we evaluated the effect of arginine supplementation in a cohort of 34 neonatally diagnosed GA-I patients (median age, 7.43 years; cumulative follow-up period, 221.6 patient years) who received metabolic treatment according to a published guideline [Kölker et al., J. Inherit. Metab. Dis. 30 (2007) 5-22]. Patients used one of two AAS product lines during the first year of life, resulting in differences in arginine consumption [group 1 (Milupa Metabolics): mean=111 mg arginine/kg; group 2 (Nutricia): mean=145 mg arginine/kg; p<0.001]. However, in both groups the daily arginine intake was increased (mean, 137 mg/kg body weight) and the dietary lysine-to-arginine ratio was decreased (mean, 0.7) compared to infants receiving human milk and other natural foods only. All other dietary parameters were in the same range. Despite significantly different arginine intake

Potential for Development of an Escherichia coli—Based Biosensor for Assessing Bioavailable Methionine: A Review

PubMed Central

Chalova, Vesela I.; Froelich, Clifford A.; Ricke, Steven C.

2010-01-01

Methionine is an essential amino acid for animals and is typically considered one of the first limiting amino acids in animal feed formulations. Methionine deficiency or excess in animal diets can lead to sub-optimal animal performance and increased environmental pollution, which necessitates its accurate quantification and proper dosage in animal rations. Animal bioassays are the current industry standard to quantify methionine bioavailability. However, animal-based assays are not only time consuming, but expensive and are becoming more scrutinized by governmental regulations. In addition, a variety of artifacts can hinder the variability and time efficacy of these assays. Microbiological assays, which are based on a microbial response to external supplementation of a particular nutrient such as methionine, appear to be attractive potential alternatives to the already established standards. They are rapid and inexpensive in vitro assays which are characterized with relatively accurate and consistent estimation of digestible methionine in feeds and feed ingredients. The current review discusses the potential to develop Escherichia coli-based microbial biosensors for methionine bioavailability quantification. Methionine biosynthesis and regulation pathways are overviewed in relation to genetic manipulation required for the generation of a respective methionine auxotroph that could be practical for a routine bioassay. A prospective utilization of Escherichia coli methionine biosensor would allow for inexpensive and rapid methionine quantification and ultimately enable timely assessment of nutritional profiles of feedstuffs. PMID:22319312

Effects of methionine and betaine supplementation on growth performance, carcase composition and metabolism of lipids in male broilers.

PubMed

Zhan, X A; Li, J X; Xu, Z R; Zhao, R Q

2006-10-01

1. This study was conducted to investigate the effects of methionine and betaine supplementation on growth performance, carcase composition and lipid metabolism in growing broilers. 2. A total of 450 commercial broilers, 22 d of age, were randomly allocated to three groups, each of which included three replicates (50 birds per replicate). The groups received the same methionine-deficient diet supplemented with 0 or 1 g/kg methionine, or 0.5 g/kg betaine, respectively. 3. Methionine and betaine supplementation significantly improved weight gain and feed conversion. Supplemental methionine and betaine also significantly increased breast muscle yield and decreased abdominal fat content. Meanwhile, addition of methionine and betaine significantly increased the contents of creatine and free carnitine in liver, the activity of hormone-sensitive lipase in abdominal fat and the concentration of free fatty acid in serum, whereas uric acid concentration in serum was significantly decreased. 4. The results of this study suggest that betaine can spare methionine in its function as an essential amino acid and is as effective as methionine in improving performance and carcase quality of growing broilers if the diet is moderately deficient in methionine. The decrease in abdominal fat may be due to the increased carnitine synthesis in liver and hormone-sensitive lipase activity in abdominal fat.

Effects of thyrotrophin-releasing hormone, and methionine-enkephalin on gastric acid and pepsin secretion in the cat.

PubMed

Gascoigne, A D; Hirst, B H; Reed, J D; Shaw, B

1980-07-01

1 The effect of intravenous administration of thyrotrophin-releasing hormone (TRH) and methionine-enkephalin on gastric acid and pepsin secretions was investigated in conscious cats prepared with chronic gastric fistulae.2 TRH, 20 mug kg(-1) h(-1), did not influence unstimulated gastric acid secretion, nor gastric acid secretion stimulated by submaximal doses of pentagastrin or histamine. Pepsin secretion stimulated by pentagastrin was not influenced by TRH.3 TRH, 20 mug kg(-1) h(-1), significantly reduced the gastric acid and pepsin responses to intravenous infusion of insulin. TRH also significantly reduced the degree of hypoglycaemia seen in response to insulin. TRH, 20 mug kg(-1) h(-1), but not 5 mug kg(-1) h(-1), infused alone resulted in a significant hyperglycaemia.4 It is concluded that the reduction of insulin-stimulated gastric secretion by TRH is not dependent on the hyperglycaemic action of the peptide. The mechanism of action of TRH on insulin-stimulated secretion is discussed with respect to its site of action.5 Methionine-enkephalin or the potent analogue, D-Ala(2), Met-enkephalinamide were without effect on unstimulated gastric secretion, or secretion stimulated by pentagastrin, histamine, and insulin. The opiate receptor antagonist, naloxone, did not significantly alter the gastric acid or pepsin response to insulin.6 It is concluded that there is no evidence that opiates stimulate oxyntic glands directly, nor that the oxyntic cells may possess high affinity binding sites for opiates, nor that endogenous opiates are involved in the control of gastric secretion.

Sensitivity of breeding values for carcass traits of meat-type quail to changes in dietary (methionine + cystine):lysine ratio using reaction norm models.

PubMed

Miranda, J A; Pires, A V; Abreu, L R A; Mota, L F M; Silva, M A; Bonafé, C M; Lima, H J D; Martins, P G M A

2016-12-01

Our objective was to evaluate changes in breeding values for carcass traits of two meat-type quail (Coturnix coturnix) strains (LF1 and LF2) to changes in the dietary (methionine + cystine):lysine ([Met + Cys]:Lys) ratio due to genotype by environment (G × E) interaction via reaction norm. A total of 7000 records of carcass weight and yield were used for analyses. During the initial phase (from hatching to day 21), five diets with increasing (Met + Cys):Lys ratios (0.61, 0.66, 0.71, 0.76 and 0.81), containing 26.1% crude protein and 2900 kcal ME/kg, were evaluated. Analyses were performed using random regression models that included linear functions of sex (fixed effect) and breeding value (random effect) for carcass weight and yield, without and with heterogeneous residual variance adjustment. Both fixed and random effects were modelled using Legendre polynomials of second order. Genetic variance and heritability estimates were affected by both (Met + Cys):Lys ratio and strain. We observed that a G × E interaction was present, with changes in the breeding value ranking. Therefore, genetic evaluation for carcass traits should be performed under the same (Met + Cys):Lys ratio in which quails are raised. © 2016 Blackwell Verlag GmbH.

Pharmacokinetic investigations in adult humans after parenteral administration of the lysine salt of acetyl-salicylic acid.

PubMed

von Voss, H; Göbel, U; Petrich, C; Pütter, J

1978-11-15

The lysine salt of acetylsalicylic acid was administered intravenously to four volunteers and intramuscularly to three of them. The drug was tolerated without any observed side effects. Immediately after intravenous application most of the plasma salicylate was acetylsalicylic acid. The highest concentration of acetylsalicylic acid was found after 2 minutes, highest levels of salicylic acid after 60 minutes. Elimination of acetylsalicylic acid was relatively quick within the first period after intravenous administration according to a half-life of 8 minutes. Half-life of salicylic acid was determined to be 3 hours. Intramuscular application results in a constant blood level for a longer period. Bioavailability of acetylsalicylic acid was slightly lower after intramuscular application than after intravenous administration.

Separation and detection of amino acid metabolites of Escherichia coli in microbial fuel cell with CE.

PubMed

Wang, Wei; Ma, Lihong; Lin, Ping; Xu, Kaixuan

2016-07-01

In this work, CE-LIF was employed to investigate the amino acid metabolites produced by Escherichia coli (E. coli) in microbial fuel cell (MFC). Two peptides, l-carnosine and l-alanyl-glycine, together with six amino acids, cystine, alanine, lysine, methionine, tyrosine, arginine were separated and detected in advance by a CE-LIF system coupled with a homemade spontaneous injection device. The injection device was devised to alleviate the effect of electrical discrimination for analytes during sample injection. All analytes could be completely separated within 8 min with detection limits of 20-300 nmol/L. Then this method was applied to analyze the substrate solution containing amino acid metabolites produced by E. coli. l-carnosine, l-alanyl-glycine, and cystine were used as the carbon, nitrogen, and sulfur source for the E. coli culture in the MFC to investigate the amino acid metabolites during metabolism. Two MFCs were used to compare the activity of metabolism of the bacteria. In the sample collected at the running time 200 h of MFC, the amino acid methionine was discovered as the metabolite with the concentrations 23.3 μg/L. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Global Profiling of Protein Lysine Malonylation in Escherichia coli Reveals Its Role in Energy Metabolism.

PubMed

Qian, Lili; Nie, Litong; Chen, Ming; Liu, Ping; Zhu, Jun; Zhai, Linhui; Tao, Sheng-Ce; Cheng, Zhongyi; Zhao, Yingming; Tan, Minjia

2016-06-03

Protein lysine malonylation is a recently identified post-translational modification (PTM), which is evolutionarily conserved from bacteria to mammals. Although analysis of lysine malonylome in mammalians suggested that this modification was related to energy metabolism, the substrates and biological roles of malonylation in prokaryotes are still poorly understood. In this study, we performed qualitative and quantitative analyses to globally identify lysine malonylation substrates in Escherichia coli. We identified 1745 malonylation sites in 594 proteins in E. coli, representing the first and largest malonylome data set in prokaryotes up to date. Bioinformatic analyses showed that lysine malonylation was significantly enriched in protein translation, energy metabolism pathways and fatty acid biosynthesis, implying the potential roles of protein malonylation in bacterial physiology. Quantitative proteomics by fatty acid synthase inhibition in both auxotrophic and prototrophic E. coli strains revealed that lysine malonylation is closely associated with E. coli fatty acid metabolism. Protein structural analysis and mutagenesis experiment suggested malonylation could impact enzymatic activity of citrate synthase, a key enzyme in citric acid (TCA) cycle. Further comparative analysis among lysine malonylome, succinylome and acetylome data showed that these three modifications could participate in some similar enriched metabolism pathways, but they could also possibly play distinct roles such as in fatty acid synthesis. These data expanded our knowledge of lysine malonylation in prokaryotes, providing a resource for functional study of lysine malonylation in bacteria.

Dietary L-lysine prevents arterial calcification in adenine-induced uremic rats.

PubMed

Shimomura, Akihiro; Matsui, Isao; Hamano, Takayuki; Ishimoto, Takuya; Katou, Yumiko; Takehana, Kenji; Inoue, Kazunori; Kusunoki, Yasuo; Mori, Daisuke; Nakano, Chikako; Obi, Yoshitsugu; Fujii, Naohiko; Takabatake, Yoshitsugu; Nakano, Takayoshi; Tsubakihara, Yoshiharu; Isaka, Yoshitaka; Rakugi, Hiromi

2014-09-01

Vascular calcification (VC) is a life-threatening complication of CKD. Severe protein restriction causes a shortage of essential amino acids, and exacerbates VC in rats. Therefore, we investigated the effects of dietary l-lysine, the first-limiting amino acid of cereal grains, on VC. Male Sprague-Dawley rats at age 13 weeks were divided randomly into four groups: low-protein (LP) diet (group LP), LP diet+adenine (group Ade), LP diet+adenine+glycine (group Gly) as a control amino acid group, and LP diet+adenine+l-lysine·HCl (group Lys). At age 18 weeks, group LP had no VC, whereas groups Ade and Gly had comparable levels of severe VC. l-Lysine supplementation almost completely ameliorated VC. Physical parameters and serum creatinine, urea nitrogen, and phosphate did not differ among groups Ade, Gly, and Lys. Notably, serum calcium in group Lys was slightly but significantly higher than in groups Ade and Gly. Dietary l-lysine strongly suppressed plasma intact parathyroid hormone in adenine rats and supported a proper bone-vascular axis. The conserved orientation of the femoral apatite in group Lys also evidenced the bone-protective effects of l-lysine. Dietary l-lysine elevated plasma alanine, proline, arginine, and homoarginine but not lysine. Analyses in vitro demonstrated that alanine and proline inhibit apoptosis of cultured vascular smooth muscle cells, and that arginine and homoarginine attenuate mineral precipitations in a supersaturated calcium/phosphate solution. In conclusion, dietary supplementation of l-lysine ameliorated VC by modifying key pathways that exacerbate VC. Copyright © 2014 by the American Society of Nephrology.

Dietary l-Lysine Prevents Arterial Calcification in Adenine-Induced Uremic Rats

PubMed Central

Shimomura, Akihiro; Matsui, Isao; Hamano, Takayuki; Ishimoto, Takuya; Katou, Yumiko; Takehana, Kenji; Inoue, Kazunori; Kusunoki, Yasuo; Mori, Daisuke; Nakano, Chikako; Obi, Yoshitsugu; Fujii, Naohiko; Takabatake, Yoshitsugu; Nakano, Takayoshi; Tsubakihara, Yoshiharu; Rakugi, Hiromi

2014-01-01

Vascular calcification (VC) is a life-threatening complication of CKD. Severe protein restriction causes a shortage of essential amino acids, and exacerbates VC in rats. Therefore, we investigated the effects of dietary l-lysine, the first-limiting amino acid of cereal grains, on VC. Male Sprague-Dawley rats at age 13 weeks were divided randomly into four groups: low-protein (LP) diet (group LP), LP diet+adenine (group Ade), LP diet+adenine+glycine (group Gly) as a control amino acid group, and LP diet+adenine+l-lysine·HCl (group Lys). At age 18 weeks, group LP had no VC, whereas groups Ade and Gly had comparable levels of severe VC. l-Lysine supplementation almost completely ameliorated VC. Physical parameters and serum creatinine, urea nitrogen, and phosphate did not differ among groups Ade, Gly, and Lys. Notably, serum calcium in group Lys was slightly but significantly higher than in groups Ade and Gly. Dietary l-lysine strongly suppressed plasma intact parathyroid hormone in adenine rats and supported a proper bone-vascular axis. The conserved orientation of the femoral apatite in group Lys also evidenced the bone-protective effects of l-lysine. Dietary l-lysine elevated plasma alanine, proline, arginine, and homoarginine but not lysine. Analyses in vitro demonstrated that alanine and proline inhibit apoptosis of cultured vascular smooth muscle cells, and that arginine and homoarginine attenuate mineral precipitations in a supersaturated calcium/phosphate solution. In conclusion, dietary supplementation of l-lysine ameliorated VC by modifying key pathways that exacerbate VC. PMID:24652795

Plasma concentrations and intakes of amino acids in male meat-eaters, fish-eaters, vegetarians and vegans: a cross-sectional analysis in the EPIC-Oxford cohort.

PubMed

Schmidt, J A; Rinaldi, S; Scalbert, A; Ferrari, P; Achaintre, D; Gunter, M J; Appleby, P N; Key, T J; Travis, R C

2016-03-01

We aimed to investigate the differences in plasma concentrations and in intakes of amino acids between male meat-eaters, fish-eaters, vegetarians and vegans in the Oxford arm of the European Prospective Investigation into Cancer and Nutrition. This cross-sectional analysis included 392 men, aged 30-49 years. Plasma amino acid concentrations were measured with a targeted metabolomic approach using mass spectrometry, and dietary intake was assessed using a food frequency questionnaire. Differences between diet groups in mean plasma concentrations and intakes of amino acids were examined using analysis of variance, controlling for potential confounding factors and multiple testing. In plasma, concentrations of 6 out of 21 amino acids varied significantly by diet group, with differences of -13% to +16% between meat-eaters and vegans. Concentrations of methionine, tryptophan and tyrosine were highest in fish-eaters and vegetarians, followed by meat-eaters, and lowest in vegans. A broadly similar pattern was seen for lysine, whereas alanine concentration was highest in fish-eaters and lowest in meat-eaters. For glycine, vegans had the highest concentration and meat-eaters the lowest. Intakes of all 18 dietary amino acids differed by diet group; for the majority of these, intake was highest in meat-eaters followed by fish-eaters, then vegetarians and lowest in vegans (up to 47% lower than in meat-eaters). Men belonging to different habitual diet groups have significantly different plasma concentrations of lysine, methionine, tryptophan, alanine, glycine and tyrosine. However, the differences in plasma concentrations were less marked than and did not necessarily mirror those seen for amino acid intakes.

Placentome Nutrient Transporters and Mammalian Target of Rapamycin Signaling Proteins Are Altered by the Methionine Supply during Late Gestation in Dairy Cows and Are Associated with Newborn Birth Weight.

PubMed

Batistel, Fernanda; Alharthi, Abdulrahman Sm; Wang, Ling; Parys, Claudia; Pan, Yuan-Xiang; Cardoso, Felipe C; Loor, Juan J

2017-09-01

Background: To our knowledge, most research demonstrating a link between maternal nutrition and both fetal growth and offspring development after birth has been performed with nonruminants. Whether such relationships exist in large ruminants is largely unknown. Objective: We aimed to investigate whether increasing the methionine supply during late pregnancy would alter uteroplacental tissue nutrient transporters and mammalian target of rapamycin (mTOR) and their relation with newborn body weight. Methods: Multiparous Holstein cows were used in a randomized complete block design experiment. During the last 28 d of pregnancy, cows were fed a control diet or the control diet plus ethylcellulose rumen-protected methionine (0.9 g/kg dry matter intake) (Mepron; Evonik Nutrition & Care GmbH) to achieve a 2.8:1 ratio of lysine to methionine in the metabolizable protein reaching the small intestine. We collected placentome samples at parturition and used them to assess mRNA and protein expression and the phosphorylation status of mTOR pathway proteins. Results: Newborn body weight was greater in the methionine group than in the control group (44.1 kg and 41.8 kg, respectively; P ≤ 0.05). Increasing the methionine supply also resulted in greater feed intake (15.8 kg/d and 14.6 kg/d), plasma methionine (11.9 μM and 15.3 μM), and plasma insulin (1.16 μg/L and 0.81 μg/L) in cows during late pregnancy. As a result, mRNA expression of genes involved in neutral amino acid transport [solute carrier (SLC) family members SLC3A2 , SLC7A5 , SLC38A1 , and SLC38A10 ], glucose transport [ SLC2A1 , SLC2A3 , and SLC2A4 ], and the mTOR pathway [mechanistic target of rapamycin and ribosomal protein S6 kinase B1] were upregulated ( P ≤ 0.07) in methionine-supplemented cows. Among 6 proteins in the mTOR pathway, increasing the methionine supply led to greater ( P ≤ 0.09) protein expression of α serine-threonine kinase (AKT), phosphorylated (p)-AKT, p-eukaryotic elongation factor 2

Lysine-Grafted MCM-41 Silica as an Antibacterial Biomaterial.

PubMed

Villegas, María F; Garcia-Uriostegui, Lorena; Rodríguez, Ofelia; Izquierdo-Barba, Isabel; Salinas, Antonio J; Toriz, Guillermo; Vallet-Regí, María; Delgado, Ezequiel

2017-09-26

This paper proposes a facile strategy for the zwitterionization of bioceramics that is based on the direct incorporation of l-lysine amino acid via the ε-amino group onto mesoporous MCM-41 materials. Fourier transform infrared (FTIR) studies of lysine-grafted MCM-41 (MCM-LYS) simultaneously showed bands at 3080 and 1540 cm -1 and bands at 1625 and 1415 cm -1 corresponding to -NH 3+ /COO - pairs, which demonstrate the incorporation of the amino acid on the material surface keeping its zwitterionic character. Both elemental and thermogravimetric analyses showed that the amount of grafted lysine was 8 wt. % based on the bioceramic total weight. Moreover, MCM-LYS exhibited a reduction of adhesion of S. aureus and E. coli bacteria in 33% and 50%, respectively at physiological pH, as compared with pristine MCM-41. Biofilm studies onto surfaces showed that lysine functionalization elicited a reduction of the area covered by S. aureus biofilm from 42% to only 5% (88%). This research shows a simple and effective approach to chemically modify bioceramics using single amino acids that provides zwitterionic functionality, which is useful to develop new biomaterials that are able to resist bacterial adhesion.

Lysine-Grafted MCM-41 Silica as an Antibacterial Biomaterial

PubMed Central

Villegas, María F.; Garcia-Uriostegui, Lorena; Rodríguez, Ofelia; Izquierdo-Barba, Isabel; Salinas, Antonio J.; Toriz, Guillermo; Vallet-Regí, María; Delgado, Ezequiel

2017-01-01

This paper proposes a facile strategy for the zwitterionization of bioceramics that is based on the direct incorporation of l-lysine amino acid via the ε-amino group onto mesoporous MCM-41 materials. Fourier transform infrared (FTIR) studies of lysine-grafted MCM-41 (MCM-LYS) simultaneously showed bands at 3080 and 1540 cm−1 and bands at 1625 and 1415 cm−1 corresponding to -NH3+/COO− pairs, which demonstrate the incorporation of the amino acid on the material surface keeping its zwitterionic character. Both elemental and thermogravimetric analyses showed that the amount of grafted lysine was 8 wt. % based on the bioceramic total weight. Moreover, MCM-LYS exhibited a reduction of adhesion of S. aureus and E. coli bacteria in 33% and 50%, respectively at physiological pH, as compared with pristine MCM-41. Biofilm studies onto surfaces showed that lysine functionalization elicited a reduction of the area covered by S. aureus biofilm from 42% to only 5% (88%). This research shows a simple and effective approach to chemically modify bioceramics using single amino acids that provides zwitterionic functionality, which is useful to develop new biomaterials that are able to resist bacterial adhesion. PMID:28952559

Optimization of L: -methionine feeding strategy for improving S-adenosyl-L: -methionine production by methionine adenosyltransferase overexpressed Pichia pastoris.

PubMed

Hu, Hui; Qian, Jiangchao; Chu, Ju; Wang, Yonghong; Zhuang, Yingping; Zhang, Siliang

2009-07-01

The recombinant Pichia pastoris harboring an improved methionine adenosyltransferase (MAT) shuffled gene was employed to biosynthesize S-adenosyl-L: -methionine (SAM). Two L: -methionine (L: -Met) addition strategies were used to supply the precursor: the batch addition strategy (L: -Met was added separately at three time points) and the continuous feeding strategies (L: -Met was fed continuously at the rate of 0.1, 0.2, and 0.5 g l(-1) h(-1), respectively). SAM accumulation, L: -Met conversion rate, and SAM productivity with the continuous feeding strategies were all improved over the batch addition strategy, which reached 8.46 +/- 0.31 g l(-1), 41.7 +/- 1.4%, and 0.18 +/- 0.01 g l(-1) h(-1) with the best continuous feeding strategy (0.2 g l(-1) h(-1)), respectively. The bottleneck for SAM production with the low L: -Met feeding rate (0.1 g L(-1) h(-1)) was the insufficient L: -Met supply. The analysis of the key enzyme activities indicated that the tricarboxylic acid cycle and glycolytic pathway were reduced with the increasing L: -Met feeding rate, which decreased the adenosine triphosphate (ATP) synthesis. The MAT activity also decreased as the L: -Met feeding rate rose. The reduced ATP synthesis and MAT activity were probably the reason for the low SAM accumulation when the L: -Met feeding rate reached 0.5 g l(-1) h(-1).

Application of PCDA/SPH/CHO/Lysine vesicles to detect pathogenic bacteria in chicken.

PubMed

de Oliveira, Taíla V; Soares, Nilda de F F; de Andrade, Nélio J; Silva, Deusanilde J; Medeiros, Eber Antônio A; Badaró, Amanda T

2015-04-01

During the course of infection, Salmonella must successively survive the harsh acid stress of the stomach and multiply into a mild acidic compartment within macrophages. Inducible amino acid decarboxylases are known to promote adaptation to acidic environments, as lysine decarboxylation to cadaverine. The idea of Salmonella defenses responses could be employed in systems as polydiacetylene (PDA) to detect this pathogen so important to public health system. Beside that PDA is an important substance because of the unique optical property; that undergoes a colorimetric transitions by various external stimuli. Therefore 10,12-pentacosadyinoic acid (PCDA)/Sphingomyelin(SPH)/Cholesterol(CHO)/Lysine system was tested to determine the colorimetric response induced by Salmonella choleraesuis. PCDA/SPH/CHO/Lysine vesicles showed a colour change even in low S. choleraesuis concentration present in laboratory conditions and in chicken meat. Thus, this work showed a PCDA/SPH/CHO/Lysine vesicle application to simplify routine analyses in food industry, as chicken meat industry. Copyright © 2014 Elsevier Ltd. All rights reserved.

Optical resolution of phenylthiohydantoin-amino acids by capillary electrophoresis and identification of the phenylthiohydantoin-D-amino acid residue of [D-Ala2]-methionine enkephalin.

PubMed

Kurosu, Y; Murayama, K; Shindo, N; Shisa, Y; Ishioka, N

1996-11-01

This is an initial report to propose a protein sequence analysis system with DL differentiation using capillary electrophoresis (CE). This system consists of a protein sequencer and a CE system. After fractionation of phenyl-thiohydantoin (PTH)-amino acids using a protein sequencer, optical resolution for each PTH-amino acid is performed by CE using some chiral selectors such as digitonin, beta-escin and others. As a model peptide, [D-Ala2]-methionine enkephalin (L-Tyr-D-Ala-Gly-L-Phe-L-Met), was used and the sequence with DL differentiation was determined, with the exception of the fourth amino acid, L-Phe, using our proposed system.

Synthesis of stereoarray isotope labeled (SAIL) lysine via the "head-to-tail" conversion of SAIL glutamic acid.

PubMed

Terauchi, Tsutomu; Kamikawai, Tomoe; Vinogradov, Maxim G; Starodubtseva, Eugenia V; Takeda, Mitsuhiro; Kainosho, Masatsune

2011-01-07

A stereoarray isotope labeled (SAIL) lysine, (2S,3R,4R,5S,6R)-[3,4,5,6-(2)H(4);1,2,3,4,5,6-(13)C(6);2,6-(15)N(2)]lysine, was synthesized by the "head-to-tail" conversion of SAIL-Glu, (2S,3S,4R)-[3,4-(2)H(2);1,2,3,4,5-(13)C(5);2-(15)N]glutamic acid, with high stereospecificities for all five chiral centers. With the SAIL-Lys in hand, the unambiguous simultaneous stereospecific assignments were able to be established for each of the prochiral protons within the four methylene groups of the Lys side chains in proteins.

The Role of Rumen-Protected Methionine on Amino Acid Metabolism in Late Gestation Beef Heifers in the Northern Great Plains

USDA-ARS?s Scientific Manuscript database

This study evaluated changes in plasma amino acids in late-gestating (beginning 58 ± 1.02 d prior to calving), primiparous, winter-grazing range heifers receiving a wheat middling based supplement without (CON) or with rumen-protected methionine (MET). Plasma was collected on d -2 and d 0 (start of ...

Antioxidative Categorization of Twenty Amino Acids Based on Experimental Evaluation.

PubMed

Xu, Naijin; Chen, Guanqun; Liu, Hui

2017-11-27

In view of the great importance bestowed on amino acids as antioxidants in oxidation resistance, we attempted two common redox titration methods in this report, including micro-potassium permanganate titration and iodometric titration, to measure the antioxidative capacity of 20 amino acids, which are the construction units of proteins in living organisms. Based on the relative intensities of the antioxidative capacity, we further conducted a quantitative comparison and found out that the product of experimental values obtained from the two methods was proven to be a better indicator for evaluating the relative antioxidative capacity of amino acids. The experimental results were largely in accordance with structural analysis made on amino acids. On the whole, the 20 amino acids concerned could be divided into two categories according to their antioxidative capacity. Seven amino acids, including tryptophan, methionine, histidine, lysine, cysteine, arginine and tyrosine, were greater in total antioxidative capacity compared with the other 13 amino acids.

Methionine as a safe and effective novel biorational mosquito larvicide.

PubMed

Weeks, Emma N I; Baniszewski, Julie; Gezan, Salvador A; Allan, Sandra A; Cuda, James P; Stevens, Bruce R

2018-06-11

Mosquito larvicides provide a source-reduction strategy to diminish adult females that bite and potentially spread pathogens. Demands are mounting for new and innovative effective biorational larvicides, due to the development of resistance to some currently utilized mosquito larvicides, undesirable non-target effects, and U.S. Environmental Protection Agency (EPA) restrictions. Methionine is a human nutrient essential amino acid that unexpectedly has been shown to be a valuable safe pest management tool against select insect pests that possess alkaline gut physiology. The present study evaluated larvicidal toxicity of methionine in several pestiferous mosquito (Diptera: Culicidae) genera. Concentration-dependent DL-methionine kinetics assays of survival and pupation were conducted in larvae of Aedes albopictus Skuse, Anopheles quadrimaculatus Say, and Culex tarsalis Coquillett in glass jars. Higher concentrations of DL-methionine yielded 100% mortality for all test species and prevented pupation at a rate equivalent to Bacillus thuringiensis israelensis (Bti) treatments. Concentration kinetics indicated that An. quadrimaculatus was 10-fold more sensitive to DL-methionine than Ae. albopictus and Cx. tarsalis. EPA regulations currently exempt methionine in pesticide formulations applied to agricultural crops. This study demonstrates that methionine is a highly effective mosquito larvicide that can provide a beneficial new biorational, environmentally sustainable tool to control pestiferous mosquitoes. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

The Pediatric Methionine Requirement Should Incorporate Remethylation Potential and Transmethylation Demands.

PubMed

Robinson, Jason L; Bertolo, Robert F

2016-05-01

The metabolic demand for methionine is great in neonates. Indeed, methionine is the only indispensable sulfur amino acid and is required not only for protein synthesis and growth but is also partitioned to a greater extent to transsulfuration for cysteine and taurine synthesis and to >50 transmethylation reactions that serve to methylate DNA and synthesize metabolites, including creatine and phosphatidylcholine. Therefore, the pediatric methionine requirement must accommodate the demands of rapid protein turnover as well as vast nonprotein demands. Because cysteine spares the methionine requirement, it is likely that the dietary provision of transmethylation products can also feasibly spare methionine. However, understanding the requirement of methionine is further complicated because demethylated methionine can be remethylated by the dietary methyl donors folate and betaine (derived from choline). Intakes of dietary methyl donors are highly variable, which is of particular concern for newborns. It has been demonstrated that many populations have enhanced requirements for these nutrients, and nutrient fortification may exacerbate this phenomenon by selecting phenotypes that increase methyl requirements. Moreover, higher transmethylation rates can limit methyl supply and affect other transmethylation reactions as well as protein synthesis. Therefore, careful investigations are needed to determine how remethylation and transmethylation contribute to the methionine requirement. The purpose of this review is to support our hypothesis that dietary methyl donors and consumers can drive methionine availability for protein synthesis and transmethylation reactions. We argue that nutritional strategies in neonates need to ensure that methionine is available to meet requirements for growth as well as for transmethylation products. © 2016 American Society for Nutrition.

In Salmonella enterica, the Gcn5-Related Acetyltransferase MddA (Formerly YncA) Acetylates Methionine Sulfoximine and Methionine Sulfone, Blocking Their Toxic Effects

PubMed Central

Hentchel, Kristy L.

2014-01-01

Protein and small-molecule acylation reactions are widespread in nature. Many of the enzymes catalyzing acylation reactions belong to the Gcn5-related N-acetyltransferase (GNAT; PF00583) family, named after the yeast Gcn5 protein. The genome of Salmonella enterica serovar Typhimurium LT2 encodes 26 GNATs, 11 of which have no known physiological role. Here, we provide in vivo and in vitro evidence for the role of the MddA (methionine derivative detoxifier; formerly YncA) GNAT in the detoxification of oxidized forms of methionine, including methionine sulfoximine (MSX) and methionine sulfone (MSO). MSX and MSO inhibited the growth of an S. enterica ΔmddA strain unless glutamine or methionine was present in the medium. We used an in vitro spectrophotometric assay and mass spectrometry to show that MddA acetylated MSX and MSO. An mddA+ strain displayed biphasic growth kinetics in the presence of MSX and glutamine. Deletion of two amino acid transporters (GlnHPQ and MetNIQ) in a ΔmddA strain restored growth in the presence of MSX. Notably, MSO was transported by GlnHPQ but not by MetNIQ. In summary, MddA is the mechanism used by S. enterica to respond to oxidized forms of methionine, which MddA detoxifies by acetyl coenzyme A-dependent acetylation. PMID:25368301

Rhizobitoxine-induced Chlorosis Occurs in Coincidence with Methionine Deficiency in Soybeans

PubMed Central

Okazaki, Shin; Sugawara, Masayuki; Yuhashi, Ken-Ichi; Minamisawa, Kiwamu

2007-01-01

Background and Aims Rhizobitoxine, produced by the legume symbiont Bradyrhizobium elkanii, inhibits cystathionine-β-lyase (EC 4·4·1·8) in methionine biosynthesis and 1-aminocyclopropane-1-carboxylate synthase (ACC) in ethylene biosynthesis. Rhizobitoxine production by B. elkanii enhances nodulation of host legumes via the inhibition of ethylene synthesis, but causes foliar chlorosis in susceptible soybeans, though how it does so remains to be investigated. The aim of this study was to examine the physiological basis of rhizobitoxine-induced chlorosis in soybeans. Methods Wild-type B. elkanii and a rhizobitoxine-deficient mutant were inoculated in Glycine max ‘Lee’. Thirty days after inoculation, the upper parts of soybean shoots were analysed for amino acid contents. Chlorotic soybeans inoculated with wild-type B. elkanii were treated with methionine and ACC to assess the effects of the chemicals on the chlorosis. Key Results Chlorotic upper shoots of soybeans inoculated with wild-type B. elkanii had a lower methionine content and higher accumulation of the methionine precursors than those with the rhizobitoxine-deficient mutant. In addition, the foliar chlorosis was alleviated by the application of methionine. Conclusions Rhizobitoxine-induced chlorosis occurs in coincidence with methionine deficiency as a result of cystathione-β-lyase inhibition during methionine biosynthesis. PMID:17525098

Ecological genomics of Boechera stricta: identification of a QTL controlling the allocation of methionine- vs branched-chain amino acid-derived glucosinolates and levels of insect herbivory.

PubMed

Schranz, M E; Manzaneda, A J; Windsor, A J; Clauss, M J; Mitchell-Olds, T

2009-05-01

In the Brassicaceae, glucosinolates influence the feeding, reproduction and development of many insect herbivores. Glucosinolate production and effects on herbivore feeding have been extensively studied in the model species, Arabidopsis thaliana and Brassica crops, both of which constitutively produce leaf glucosinolates mostly derived from the amino acid, methionine. Much less is known about the regulation or role in defense of glucosinolates derived from other aliphatic amino acids, such as the branched-chain amino acids (BCAA), valine and isoleucine. We have identified a glucosinolate polymorphism in Boechera stricta controlling the allocation to BCAA- vs methionine-derived glucosinolates in both leaves and seeds. B. stricta is a perennial species that grows in mostly undisturbed habitats of western North America. We have measured glucosinolate profiles and concentrations in 192 F(2) lines that have earlier been used for genetic map construction. We also performed herbivory assays on six F(3) replicates per F(2) line using the generalist lepidopteran, Trichoplusia ni. Quantitative trait locus (QTL) analysis identified a single locus controlling both glucosinolate profile and levels of herbivory, the branched chain-methionine allocation or BCMA QTL. We have delimited this QTL to a small genomic region with a 1.0 LOD confidence interval just 1.9 cm wide, which, in A. thaliana, contains approximately 100 genes. We also found that methionine-derived glucosinolates provided significantly greater defense than the BCAA-derived glucosinolates against feeding by this generalist insect herbivore. The future positional cloning of this locus will allow for testing various adaptive explanations.

Effects of rumen-protected methionine on plasma amino acid concentrations during a period of weight loss for late gestating beef heifers

USDA-ARS?s Scientific Manuscript database

This study determined changes in plasma amino acid concentration in late-gestating (beginning 58 ± 1.02 d prior to calving), primiparous, winter-grazing range heifers receiving wheat middling based supplement without (CON) or with rumen-protected methionine (MET) to provide 15 g DL- MET each day. Pl...

Biosynthesis of Ethylene from Methionine in Aminoethoxyvinylglycine-Resistant Avocado Tissue

PubMed Central

Baker, James E.; Anderson, James D.; Adams, Douglas O.; Apelbaum, Akiva; Lieberman, Morris

1982-01-01

This study was conducted to determine if aminoethoxyvinylglycine (AVG) insensitivity in avocado (Persea americana Mill., Lula, Haas, and Bacon) tissue was due to an alternate pathway of ethylene biosynthesis from methionine. AVG, at 0.1 millimolar, had little or no inhibitory effect on either total ethylene production or [14C] ethylene production from [14C]methionine in avocado tissue at various stages of ripening. However, aminoxyacetic acid (AOA), which inhibits 1-aminocyclopropane-1-carboxylic acid (ACC) synthase (the AVG-sensitive enzyme of ethylene biosynthesis), inhibited ethylene production in avocado tissue. Total ethylene production was stimulated, and [14C]ethylene production from [14C]methionine was lowered by treating avocado tissue with 1 millimolar ACC. An inhibitor of methionine adenosyltransferase (EC 2.5.1.6), l-2-amino-4-hexynoic acid (AHA), at 1.5 millimolar, effectively inhibited [14C]ethylene production from [14C]methionine in avocado tissue but had no effect on total ethylene production during a 2-hour incubation. Rates of [14C]AVG uptake by avocado and apple (Malus domestica Borkh., Golden Delicious) tissues were similar, and [14C]AVG was the only radioactive compound in alcohol-soluble fractions of the tissues. Hence, AVG-insensitivity in avocado tissue does not appear to be due to lack of uptake or to metabolism of AVG by avocado tissue. ACC synthase activity in extracts of avocado tissue was strongly inhibited (about 60%) by 10 micromolar AVG. Insensitivity of ethylene production in avocado tissue to AVG may be due to inaccessibility of ACC synthase to AVG. AVG-resistance in the avocado system is, therefore, different from that of early climacteric apple tissue, in which AVG-insensitivity of total ethylene production appears to be due to a high level of endogenous ACC relative to its rate of conversion to ethylene. However, the sensitivity of the avocado system to AOA and AHA, dilution of labeled ethylene production by ACC, and stimulation

Coacervate-like microspheres from lysine-rich proteinoid

NASA Technical Reports Server (NTRS)

Rohlfing, D. L.

1975-01-01

Microspheres form isothermally from lysine-rich proteinoid when the ionic strength of the solution is increased with NaCl or other salts. Studies with different monovalent anions and with polymers of different amino acid composition indicate that charge neutralization and hydrophobic bonding contribute to microsphere formation. The particles also form in sea water, especially if heated or made slightly alkaline. The microspheres differ from those made from acidic proteinoid but resemble coacervate droplets in some ways (isothermal formation, limited stability, stabilization by quinone, uptake of dyes). Because the constituent lysine-rich proteinoid is of simulated prebiotic origin, the study is interpreted to add emphasis to and suggest an evolutionary continuity for coacervation phenomena.

Quantitative detection of crystalline lysine supplementation in poultry feeds using a rapid bacterial bioluminescence assay.

PubMed

Zabala Díaz, I B; Ricke, S C

2003-08-01

Lysine is an essential amino acid for both humans and animals; and it is usually the first or second limiting amino acid in most formulated diets. In order to estimate the lysine content in feeds and feed sources, rapid amino acid bioassays have been developed. The objective of this work is to assess a rapid assay for lysine supplementation in chicken feeds, using a luminescent Escherichia coli lysine-auxotrophic strain, to avoid prior thermal sterilization. An E. coli lysine auxotroph carrying a plasmid with lux genes was used as the test organism. The lysine assay was conducted using depleted auxotrophic cells in lysine samples. Luminescence was measured with a Dynex MLX luminometer after addition of the aldehyde substrate. Growth response (monitored as optical density at 600 nm) and light emission response of the assay E. coli strain were monitored to generate standard curves. Bioluminescent analysis of feed samples indicated that the method works well in the presence of a complex feed matrix. Comparison of both optical density and luminescent-based methods indicated that, when the assay takes place under optimal conditions, both methodologies correlated well ( r(2)=0.99). Except for the 0.64% lysine-supplemented feed, estimates for lysine based on the bacterial assay were over 80% (82-97%) of the theoretical values. Animal data showed that the bacterial bioluminescent method correlated well with the chick bioassay when diets with different levels of lysine supplementation were assayed for lysine bioavailability ( r(2)=0.97). Luminescent methodology coupled with a bacterial growth assay is a promising technique to assess lysine availability in supplemented animal feeds.

Plasma concentrations and intakes of amino acids in male meat-eaters, fish-eaters, vegetarians and vegans: a cross-sectional analysis in the EPIC-Oxford cohort

PubMed Central

Schmidt, J A; Rinaldi, S; Scalbert, A; Ferrari, P; Achaintre, D; Gunter, M J; Appleby, P N; Key, T J; Travis, R C

2016-01-01

Background/Objectives: We aimed to investigate the differences in plasma concentrations and in intakes of amino acids between male meat-eaters, fish-eaters, vegetarians and vegans in the Oxford arm of the European Prospective Investigation into Cancer and Nutrition. Subjects/Methods: This cross-sectional analysis included 392 men, aged 30–49 years. Plasma amino acid concentrations were measured with a targeted metabolomic approach using mass spectrometry, and dietary intake was assessed using a food frequency questionnaire. Differences between diet groups in mean plasma concentrations and intakes of amino acids were examined using analysis of variance, controlling for potential confounding factors and multiple testing. Results: In plasma, concentrations of 6 out of 21 amino acids varied significantly by diet group, with differences of −13% to +16% between meat-eaters and vegans. Concentrations of methionine, tryptophan and tyrosine were highest in fish-eaters and vegetarians, followed by meat-eaters, and lowest in vegans. A broadly similar pattern was seen for lysine, whereas alanine concentration was highest in fish-eaters and lowest in meat-eaters. For glycine, vegans had the highest concentration and meat-eaters the lowest. Intakes of all 18 dietary amino acids differed by diet group; for the majority of these, intake was highest in meat-eaters followed by fish-eaters, then vegetarians and lowest in vegans (up to 47% lower than in meat-eaters). Conclusions: Men belonging to different habitual diet groups have significantly different plasma concentrations of lysine, methionine, tryptophan, alanine, glycine and tyrosine. However, the differences in plasma concentrations were less marked than and did not necessarily mirror those seen for amino acid intakes. PMID:26395436

Effects of adding liquid DL-methionine hydroxy analogue-free acid to drinking water on growth performance and small intestinal morphology of nursery pigs.

PubMed

Kaewtapee, C; Krutthai, N; Poosuwan, K; Poeikhampha, T; Koonawootrittriron, S; Bunchasak, C

2010-06-01

This study was conducted to evaluate the effect of adding liquid DL-methionine hydroxy analogue free acid (LMA) to drinking water on growth performance, small intestinal morphology and volatile fatty acids in the caecum of nursery pigs. Twenty-four crossbred pigs (Large White x Landrace, BW approximately 18 kg) were divided into three groups with four replications of two piglets each. The piglets received drinking water without (control), with 0.05 or 0.10% LMA. The results indicated that adding LMA at 0.10% to drinking water significantly increased their weight gain, average daily feed intake (p < 0.05) and tended to improve the feed conversion ratio. Adding LMA to drinking water significantly increased their water intake and significantly reduced the pH of drinking water (p < 0.01), thus total plate count (p < 0.01) and Escherichia coli in drinking water was reduced (p < 0.05), while the total number of bacteria in the caecum was not significantly affected. Liquid DL-methionine hydroxy analogue free acid supplementation in drinking water tended to decrease pH in the stomach, duodenum, jejunum, colon and rectum. Furthermore, adding LMA at 0.10% significantly increased villous height in the duodenum, jejunum and ileum (p < 0.05), and the villous height:crypt depth ratio in the jejunum and ileum (p < 0.01) was higher, whereas acetic acid concentration in the caecum was significantly lower than in the control group. It could be concluded that adding LMA to drinking water improved growth performance of the nursery pigs because of high water quality and high nutrient utilization caused by an improvement of small intestinal morphology (not from nutritional effect of methionine source).

Methionine-Mediated Repression in Saccharomyces cerevisiae: a Pleiotropic Regulatory System Involving Methionyl Transfer Ribonucleic Acid and the Product of Gene eth2

PubMed Central

Cherest, H.; Surdin-Kerjan, Y.; De Robichon-Szulmajster, H.

1971-01-01

Detailed study of methionine-mediated repression of enzymes involved in methionine biosynthesis in Saccharomyces cerevisiae led to classification of these enzymes into two distinct regulatory groups. Group I comprises four enzymes specifically involved in different parts of methionine biosynthesis, namely, homoserine-O-transacetylase, homocysteine synthetase, adenosine triphosphate sulfurylase, and sulfite reductase. Repressibility of these enzymes is greatly decreased in strains carrying a genetically impaired methionyl-transfer ribonucleic acid (tRNA) synthetase (mutation ts− 296). Conditions leading to absence of repression in the mutant strain have been correlated with a sharp decrease in bulk tRNAmet charging, whereas conditions which restore repressibility of group I enzymes also restore tRNAmet charging. These findings implicate methionyl-tRNA in the regulatory process. However, the absence of a correlation in the wild type between methionyl-tRNA charging and the levels of methionine group I enzymes suggests that only a minor iso accepting species of tRNAmet may be devoted with a regulatory function. Repressibility of the same four enzymes (group I) was also decreased in strains carrying the regulatory mutation eth2r. Although structural genes coding for two of these enzymes, as well as mutations ts− 296 and eth2r segregate independently to each other, synthesis of group I enzymes is coordinated. The pleiotropic regulatory system involved seems then to comprise beside a “regulatory methionyl tRNAmet,” another element, product of gene eth2, which might correspond either to an aporepressor protein or to the “regulatory tRNAmet” itself. Regulation of group II enzymes is defined by response to exogenous methionine, absence of response to either mutations ts− 296 and eth2r, and absence of coordinacy with group I enzymes. However, the two enzymes which belong to this group and are both involved in threonine and methionine biosynthesis undergo

The Pediatric Methionine Requirement Should Incorporate Remethylation Potential and Transmethylation Demands12

PubMed Central

2016-01-01

The metabolic demand for methionine is great in neonates. Indeed, methionine is the only indispensable sulfur amino acid and is required not only for protein synthesis and growth but is also partitioned to a greater extent to transsulfuration for cysteine and taurine synthesis and to >50 transmethylation reactions that serve to methylate DNA and synthesize metabolites, including creatine and phosphatidylcholine. Therefore, the pediatric methionine requirement must accommodate the demands of rapid protein turnover as well as vast nonprotein demands. Because cysteine spares the methionine requirement, it is likely that the dietary provision of transmethylation products can also feasibly spare methionine. However, understanding the requirement of methionine is further complicated because demethylated methionine can be remethylated by the dietary methyl donors folate and betaine (derived from choline). Intakes of dietary methyl donors are highly variable, which is of particular concern for newborns. It has been demonstrated that many populations have enhanced requirements for these nutrients, and nutrient fortification may exacerbate this phenomenon by selecting phenotypes that increase methyl requirements. Moreover, higher transmethylation rates can limit methyl supply and affect other transmethylation reactions as well as protein synthesis. Therefore, careful investigations are needed to determine how remethylation and transmethylation contribute to the methionine requirement. The purpose of this review is to support our hypothesis that dietary methyl donors and consumers can drive methionine availability for protein synthesis and transmethylation reactions. We argue that nutritional strategies in neonates need to ensure that methionine is available to meet requirements for growth as well as for transmethylation products. PMID:27184279

Replacement value of betaine for DL-methionine in male broiler chicks.

PubMed

Schutte, J B; De Jong, J; Smink, W; Pack, M

1997-02-01

The effect of DL-methionine and betaine supplementation on growth performance of 2,400 male broilers in the age period of 1 to 38 d, and on carcass composition of a subsample of 384 birds was examined. Three dose levels of DL-methionine (0, 0.05, and 0.10%) and two doses of betaine (0 and 0.04%) were supplemented in different combinations to methioninedeficient diets. Two types of diets were fed as starters and growers: either corn-soybean diets or practical diets typical for the Dutch broiler industry. All diets were fortified with 220 ppm choline in order to avoid a deficiency in methyl groups. Increasing DL-methionine supplementation significantly improved daily weight gain and feed conversion efficiency. Supplemental betaine did not affect bird growth. Betaine slightly improved feed conversion in diets without supplemental DL-methionine, but did not affect this parameter in diets with added DL-methionine. Breast meat yield was significantly increased by about 1.5 percentage points by the addition of 0.05% DL-methionine, whereas 0.04% betaine only tended to increase breast meat yield in the range of 0.3 to 0.6 percentage points. The type of diet did not have any effect on the responses obtained. In summary, there was no evidence for betaine to spare DL-methionine as an essential amino acid supplement in broiler diets.

Structural Insight into Amino Group-carrier Protein-mediated Lysine Biosynthesis

PubMed Central

Yoshida, Ayako; Tomita, Takeo; Fujimura, Tsutomu; Nishiyama, Chiharu; Kuzuyama, Tomohisa; Nishiyama, Makoto

2015-01-01

In the biosynthesis of lysine by Thermus thermophilus, the metabolite α-ketoglutarate is converted to the intermediate α-aminoadipate (AAA), which is protected by the 54-amino acid acidic protein LysW. In this study, we determined the crystal structure of LysZ from T. thermophilus (TtLysZ), an amino acid kinase that catalyzes the second step in the AAA to lysine conversion, which was in a complex with LysW at a resolution of 1.85 Å. A crystal analysis coupled with isothermal titration calorimetry of the TtLysZ mutants for TtLysW revealed tight interactions between LysZ and the globular and C-terminal extension domains of the LysW protein, which were mainly attributed to electrostatic forces. These results provided structural evidence for LysW acting as a protecting molecule for the α-amino group of AAA and also as a carrier protein to guarantee better recognition by biosynthetic enzymes for the efficient biosynthesis of lysine. PMID:25392000

Global profiling of lysine reactivity and ligandability in the human proteome

NASA Astrophysics Data System (ADS)

Hacker, Stephan M.; Backus, Keriann M.; Lazear, Michael R.; Forli, Stefano; Correia, Bruno E.; Cravatt, Benjamin F.

2017-12-01

Nucleophilic amino acids make important contributions to protein function, including performing key roles in catalysis and serving as sites for post-translational modification. Electrophilic groups that target amino-acid nucleophiles have been used to create covalent ligands and drugs, but have, so far, been mainly limited to cysteine and serine. Here, we report a chemical proteomic platform for the global and quantitative analysis of lysine residues in native biological systems. We have quantified, in total, more than 9,000 lysines in human cell proteomes and have identified several hundred residues with heightened reactivity that are enriched at protein functional sites and can frequently be targeted by electrophilic small molecules. We have also discovered lysine-reactive fragment electrophiles that inhibit enzymes by active site and allosteric mechanisms, as well as disrupt protein-protein interactions in transcriptional regulatory complexes, emphasizing the broad potential and diverse functional consequences of liganding lysine residues throughout the human proteome.

Global profiling of lysine reactivity and ligandability in the human proteome.

PubMed

Hacker, Stephan M; Backus, Keriann M; Lazear, Michael R; Forli, Stefano; Correia, Bruno E; Cravatt, Benjamin F

2017-12-01

Nucleophilic amino acids make important contributions to protein function, including performing key roles in catalysis and serving as sites for post-translational modification. Electrophilic groups that target amino-acid nucleophiles have been used to create covalent ligands and drugs, but have, so far, been mainly limited to cysteine and serine. Here, we report a chemical proteomic platform for the global and quantitative analysis of lysine residues in native biological systems. We have quantified, in total, more than 9,000 lysines in human cell proteomes and have identified several hundred residues with heightened reactivity that are enriched at protein functional sites and can frequently be targeted by electrophilic small molecules. We have also discovered lysine-reactive fragment electrophiles that inhibit enzymes by active site and allosteric mechanisms, as well as disrupt protein-protein interactions in transcriptional regulatory complexes, emphasizing the broad potential and diverse functional consequences of liganding lysine residues throughout the human proteome.

Poly (ethylenimine)-grafted-poly [(aspartic acid)-co-lysine], a potential non-viral vector for DNA delivery.

PubMed

Tang, Gu Ping; Yang, Zhi; Zhou, Jun

2006-01-01

A potential non-viral gene-transfer vector, poly(ethylenimine)-grafted-poly[(aspartic acid)-co-lysine] (PSL), has been developed by thermal polycondensation of aspartic acid and lysine under reduced pressure. Low-molecular-mass branch poly(ethylenimine) (PEI600) was conjugated to the backbone. The chemical structure of the resulting co-polymer was identified by 1H-NMR, FT-IR, TGA and X-ray diffraction. The results of the MTT assay showed that at concentration up to 4000 nmol/l of the vector cell viability was over 80% and showed low toxicity. Electrophoretic retardation and ethidum bromide assay showed that at N/P ratios 12-15 (w/w) the DNA could be condensed and neutralized. Using the zeta potential assay we discovered that it had a high positive charge on its surface of the particle (over 30 mV). The particle sizes of the co-polymer/DNA complexes were 150-170 nm, as measured by DLS and AFM. Compared with PEI600, co-polymer/DNA complexes showed a significant enhancement of transfection activity in the absence and presence of serum in NT2 and COS7 cell lines. This means that the PEI600-PSL co-polymer is a promising candidate for gene delivery.

Correlation Between Gastric Emptying and Gastric Adaptive Relaxation Influenced by Amino Acids

PubMed Central

Uchida, Masayuki; Kobayashi, Orie; Saito, Chizuru

2017-01-01

Background/Aims Amino acids have many physiological activities. We report the correlation between gastric emptying and gastric adaptive relaxation using tryptophan and amino acids with a straight alkyl chain, hydroxylated chain, and branched chain. Here we sought to further clarify the correlation between gastric emptying and gastric adaptive relaxation by using other amino acids. Methods In Sprague-Dawley rats, gastric emptying was evaluated by a breath test using [1-13C] acetic acid. The expired 13CO2 pattern, Tmax, Cmax, and AUC120min values were used as evaluation items. Gastric adaptive relaxation was evaluated in a barostat experiment. Individual amino acids (1 g/kg) were administered orally 30 minutes before each breath test or barostat test. Results L-phenylalanine and L-tyrosine did not influence gastric emptying. All other amino acids, ie, L-proline, L-histidine, L-cysteine, L-methionine, L-aspartic acid, L-glutamic acid, L-asparagine, L-arginine, L-glutamine, and L-lysine significantly delayed and inhibited gastric emptying. L-Cysteine and L-aspartic acid significantly enhanced and L-methionine and L-glutamine significantly inhibited gastric adaptive relaxation. L-Phenylalanine moved the balloon toward the antrum, suggesting strong contraction of the fundus. Tmax showed a significant positive correlation (r = 0.709), and Cmax and AUC120min each showed negative correlations (r = 0.613 and 0.667, respectively) with gastric adaptive relaxation. Conclusion From the above findings, it was found that a close correlation exists between gastric emptying and adaptive relaxation, suggesting that enhanced gastric adaptive relaxation inhibits gastric emptying. PMID:28335103

Lysine-functionalized nanodiamonds: synthesis, physiochemical characterization, and nucleic acid binding studies

PubMed Central

Kaur, Randeep; Chitanda, Jackson M; Michel, Deborah; Maley, Jason; Borondics, Ferenc; Yang, Peng; Verrall, Ronald E; Badea, Ildiko

2012-01-01

Purpose: Detonation nanodiamonds (NDs) are carbon-based nanomaterials that, because of their size (4–5 nm), stable inert core, alterable surface chemistry, fluorescence, and biocompatibility, are emerging as bioimaging agents and promising tools for the delivery of biochemical molecules into cellular systems. However, diamond particles possess a strong propensity to aggregate in liquid formulation media, restricting their applicability in biomedical sciences. Here, the authors describe the covalent functionalization of NDs with lysine in an attempt to develop nanoparticles able to act as suitable nonviral vectors for transferring genetic materials across cellular membranes. Methods: NDs were oxidized and functionalized by binding lysine moieties attached to a three-carbon-length linker (1,3-diaminopropane) to their surfaces through amide bonds. Raman and Fourier transform infrared spectroscopy, zeta potential measurement, dynamic light scattering, atomic force microscopic imaging, and thermogravimetric analysis were used to characterize the lysine-functionalized NDs. Finally, the ability of the functionalized diamonds to bind plasmid DNA and small interfering RNA was investigated by gel electrophoresis assay and through size and zeta potential measurements. Results: NDs were successfully functionalized with the lysine linker, producing surface loading of 1.7 mmol g−1 of ND. These modified NDs formed highly stable aqueous dispersions with a zeta potential of 49 mV and particle size of approximately 20 nm. The functionalized NDs were found to be able to bind plasmid DNA and small interfering RNA by forming nanosized “diamoplexes”. Conclusion: The lysine-substituted ND particles generated in this study exhibit stable aqueous formulations and show potential for use as carriers for genetic materials. PMID:22904623

Effect of different postharvest temperatures on the accumulation of sugars, organic acids, and amino acids in the juice sacs of Satsuma mandarin (Citrus unshiu Marc.) fruit.

PubMed

Matsumoto, Hikaru; Ikoma, Yoshinori

2012-10-03

To elucidate the effect of different postharvest temperatures on the accumulation of sugars, organic acids, and amino acids and to determine the best temperature to minimize their postharvest change, their content after harvest was investigated at 5, 10, 20, and 30 °C for 14 days in the juice sacs of Satsuma mandarin (Citrus unshiu Marc. cv. Aoshima-unshiu) fruit. In all sugars, the changes were negligible at all temperatures. Organic acids decreased slightly at all temperatures, with the exception of malic acid at 30 °C, which increased slightly. Two amino acids, ornithine and glutamine, increased at 5 °C, but they did not increase at other temperatures. In 11 amino acids (phenylalanine, tryptophan, tyrosine, isoleucine, leucine, valine, threonine, lysine, methionine, histidine, and γ-amino butyric acid), the content was higher at 20 and 30 °C than at other temperatures. Thus, the content of amino acids was more variable than that of sugars and organic acids in response to temperatures. Moreover, amino acids responded to temperature differently: two amino acids were cold responsive, and 11 were heat-responsive. The best temperature to minimize the postharvest changes in amino acid profiles in the juice sacs of Aoshima-unshiu was 10 °C. The responsiveness to temperatures in two cold-responsive (ornithine and glutamine) and five heat-responsive (phenylalanine, tryptophan, valine, lysine, and histidine) amino acids was conserved among three different Satsuma mandarin cultivars, Aoshima-unshiu (late-maturing cultivar), Silverhill (midmaturing cultivar), and Miyagawa-wase (early-maturing cultivar). The metabolic responsiveness to temperature stress was discussed on the basis of the changes in the amino acid profile.

Regulated methionine oxidation by monooxygenases

PubMed Central

Manta, Bruno; Gladyshev, Vadim N.

2017-01-01

Protein function can be regulated via post-translational modifications by numerous enzymatic and non-enzymatic mechanisms, including oxidation of cysteine and methionine residues. Redox-dependent regulatory mechanisms have been identified for nearly every cellular process, but the major paradigm has been that cellular components are oxidized (damaged) by reactive oxygen species (ROS) in a relatively unspecific way, and then reduced (repaired) by designated reductases. While this scheme may work with cysteine, it cannot be ascribed to other residues, such as methionine, whose reaction with ROS is too slow to be biologically relevant. However, methionine is clearly oxidized in vivo and enzymes for its stereoselective reduction are present in all three domains of life. Here, we revisit the chemistry and biology of methionine oxidation, with emphasis on its generation by enzymes from the monooxygenase family. Particular attention is placed on MICALs, a recently discovered family of proteins that harbor an unusual flavin-monooxygenase domain with an NADPH-dependent methionine sulfoxidase activity. Based on the structural and kinetic information we provide a rational framework to explain MICAL mechanism, inhibition, and regulation. Methionine residues that are targeted by MICALs are reduced back by methionine sulfoxide reductases, suggesting that reversible methionine oxidation may be a general mechanism analogous to the regulation by phosphorylation by kinases/phosphatases. The identification of new enzymes that catalyze the oxidation of methionine will open a new area of research at the forefront of redox signaling. PMID:28229915

Effect of methyl jasmonate application to grapevine leaves on grape amino acid content.

PubMed

Garde-Cerdán, Teresa; Portu, Javier; López, Rosa; Santamaría, Pilar

2016-07-15

Over the last few years, considerable attention has been paid to the application of elicitors to vineyard. However, research about the effect of elicitors on grape amino acid content is scarce. Therefore, the aim of this study was to evaluate the influence of foliar application of methyl jasmonate on must amino acid content. Results revealed that total amino acid content was not modified by the application of methyl jasmonate. However, the individual content of certain amino acids was increased as consequence of methyl jasmonate foliar application, i.e., histidine, serine, tryptophan, phenylalanine, tyrosine, asparagine, methionine, and lysine. Among them, phenylalanine content was considerably increased; this amino acid is precursor of phenolic and aromatic compounds. In conclusion, foliar application of methyl jasmonate improved must nitrogen composition. This finding suggests that methyl jasmonate treatment might be conducive to obtain wines of higher quality since must amino acid composition could affect the wine volatile composition and the fermentation kinetics. Copyright © 2016 Elsevier Ltd. All rights reserved.

The Crucial Role of Early Mitochondrial Injury in L-Lysine-Induced Acute Pancreatitis

PubMed Central

Biczó, György; Hegyi, Péter; Dósa, Sándor; Shalbuyeva, Natalia; Berczi, Sándor; Sinervirta, Riitta; Hracskó, Zsuzsanna; Siska, Andrea; Kukor, Zoltán; Jármay, Katalin; Venglovecz, Viktória; Varga, Ilona S.; Iványi, Béla; Alhonen, Leena; Wittmann, Tibor; Gukovskaya, Anna; Takács, Tamás

2011-01-01

Abstract Aims Large doses of intraperitoneally injected basic amino acids, L-arginine, or L-ornithine, induce acute pancreatitis in rodents, although the mechanisms mediating pancreatic toxicity remain unknown. Another basic amino acid, L-lysine, was also shown to cause pancreatic acinar cell injury. The aim of the study was to get insight into the mechanisms through which L-lysine damages the rat exocrine pancreas, in particular to characterize the kinetics of L-lysine-induced mitochondrial injury, as well as the pathologic responses (including alteration of antioxidant systems) characteristic of acute pancreatitis. Results We showed that intraperitoneal administration of 2 g/kg L-lysine induced severe acute necrotizing pancreatitis. L-lysine administration caused early pancreatic mitochondrial damage that preceded the activation of trypsinogen and the proinflammatory transcription factor nuclear factor-κB (NF-κB), which are commonly thought to play an important role in the development of acute pancreatitis. Our data demonstrate that L-lysine impairs adenosine triphosphate synthase activity of isolated pancreatic, but not liver, mitochondria. Innovation and Conclusion Taken together, early mitochondrial injury caused by large doses of L-lysine may lead to the development of acute pancreatitis independently of pancreatic trypsinogen and NF-κB activation. PMID:21644850

Gene expression differences in the methionine remethylation and transsulphuration pathways under methionine restriction and recovery with D,L-methionine or D,L-HMTBA in meat-type chickens.

PubMed

Aggrey, S E; González-Cerón, F; Rekaya, R; Mercier, Y

2018-02-01

This study examined the molecular mechanisms of methionine pathways in meat-type chickens where birds were provided with a diet deficient in methionine from 3 to 5 weeks of age. The birds on the deficient diet were then provided with a diet supplemented with either D,L-methionine or D,L-HMTBA from 5 to 7 weeks. The diet of the control birds was supplemented with L-methionine from hatch till 7 weeks of age. We studied the mRNA expression of methionine adenosyltransferase 1, alpha, methionine adenosyltransferase 1, beta, 5-methyltetrahydrofolate-homocysteine methyltransferase, 5-methyltetrahydrofolate-homocysteine methyltransferase reductase, betaine-homocysteine S-methyltransferase, glycine N-methyltransferase, S-adenosyl-L-homocysteine hydrolase and cystathionine beta synthase genes in the liver, duodenum, Pectoralis (P.) major and the gastrocnemius muscle at 5 and 7 weeks. Feeding a diet deficient in dietary methionine affected body composition. Birds that were fed a methionine-deficient diet expressed genes that indicated that remethylation occurred via the one-carbon pathway in the liver and duodenum; however, in the P. major and the gastrocnemius muscles, gene expression levels suggested that homocysteine received methyl from both folate and betaine for remethylation. Birds who were switched from a methionine deficiency diet to one supplemented with either D,L-methionine or D,L-HMTBA showed a downregulation of all the genes studied in the liver. However, depending on the tissue or methionine form, either folate or betaine was elicited for remethylation. Thus, mRNA expressions show that genes in the remethylation and transsulphuration pathways were regulated according to tissue need, and there were some differences in the methionine form. © 2017 Blackwell Verlag GmbH.

A Novel Concept of Amino Acid Supplementation to Improve the Growth of Young Malnourished Male Rats.

PubMed

Furuta, Chie; Murakami, Hitoshi

2018-01-01

This study was aimed at understanding the relationship between plasma amino acids and protein malnutrition and at determining whether amino acid supplementation associated with malnutrition and growth improves linear growth in growing rats. Body length and plasma amino acids were measured in young male rats that were fed the following diet for 3 weeks, mimicking a low and imbalanced protein diets based on maize, a major staple consumed in developing countries: a 70% calorically restricted cornmeal-based diet (C), C + micronutrients (CM), CM + casein (CMC), CM + soy protein (CMS) or CMS + 0.3% lysine. A correlation analysis of linear growth and plasma amino acids indicated that lysine, tryptophan, branched-chain amino acids, methionine, and phenylalanine significantly correlated with body length. Supplementation with these 5 amino acids (AA1) significantly improved the body length in rats compared to CMC treatment whereas, nitrogen-balanced amino acid supplemented controls (AA2) did not (CM +1.2 ± 0.2, CMC +2.7 ± 0.3, CMS +2.1 ± 0.3, AA1 +2.8 ± 0.2, and AA2 +2.5 ± 0.3 cm). With securing proper amino acid balance, supplementing growth-related amino acids is more effective in improving linear growth in malnourished growing male rats. Analysis of the correlation between plasma amino acids and growth represents a powerful tool to determine candidate amino acids for supplementation to prevent malnutrition. This technology is adaptable to children in developing countries. © 2018 S. Karger AG, Basel.

Elevated glutaric acid levels in Dhtkd1-/Gcdh- double knockout mice challenge our current understanding of lysine metabolism.

PubMed

Biagosch, Caroline; Ediga, Raga Deepthi; Hensler, Svenja-Viola; Faerberboeck, Michael; Kuehn, Ralf; Wurst, Wolfgang; Meitinger, Thomas; Kölker, Stefan; Sauer, Sven; Prokisch, Holger

2017-09-01

Glutaric aciduria type I (GA-I) is a rare organic aciduria caused by the autosomal recessive inherited deficiency of glutaryl-CoA dehydrogenase (GCDH). GCDH deficiency leads to disruption of l-lysine degradation with characteristic accumulation of glutarylcarnitine and neurotoxic glutaric acid (GA), glutaryl-CoA, 3-hydroxyglutaric acid (3-OHGA). DHTKD1 acts upstream of GCDH, and its deficiency leads to none or often mild clinical phenotype in humans, 2-aminoadipic 2-oxoadipic aciduria. We hypothesized that inhibition of DHTKD1 may prevent the accumulation of neurotoxic dicarboxylic metabolites suggesting DHTKD1 inhibition as a possible treatment strategy for GA-I. In order to validate this hypothesis we took advantage of an existing GA-I (Gcdh -/- ) mouse model and established a Dhtkd1 deficient mouse model. Both models reproduced the biochemical and clinical phenotype observed in patients. Under challenging conditions of a high lysine diet, only Gcdh -/- mice but not Dhtkd1 -/- mice developed clinical symptoms such as lethargic behaviour and weight loss. However, the genetic Dhtkd1 inhibition in Dhtkd1 -/- /Gcdh -/- mice could not rescue the GA-I phenotype. Biochemical results confirm this finding with double knockout mice showing similar metabolite accumulations as Gcdh -/- mice with high GA in brain and liver. This suggests that DHTKD1 inhibition alone is not sufficient to treat GA-I, but instead a more complex strategy is needed. Our data highlights the many unresolved questions within the l-lysine degradation pathway and provides evidence for a so far unknown mechanism leading to glutaryl-CoA. Copyright © 2017 Elsevier B.V. All rights reserved.

Possible Evidence of Amide Bond Formation Between Sinapinic Acid and Lysine-Containing Bacterial Proteins by Matrix-Assisted Laser Desorption/Ionization (MALDI) at 355 nm

NASA Astrophysics Data System (ADS)

Fagerquist, Clifton K.; Sultan, Omar; Carter, Michelle Q.

2012-12-01

We previously reported the apparent formation of matrix adducts of 3,5-dimethoxy-4-hydroxy-cinnamic acid (sinapinic acid or SA) via covalent attachment to disulfide bond-containing proteins (HdeA, Hde, and YbgS) from bacterial cell lysates ionized by matrix-assisted laser desorption/ionization (MALDI) time-of-flight-time-of-flight tandem mass spectrometry (TOF-TOF-MS/MS) and post-source decay (PSD). We also reported the absence of adduct formation when using α-cyano-4-hydroxycinnamic acid (CHCA) matrix. Further mass spectrometric analysis of disulfide-intact and disulfide-reduced over-expressed HdeA and HdeB proteins from lysates of gene-inserted E. coli plasmids suggests covalent attachment of SA occurs not at cysteine residues but at lysine residues. In this revised hypothesis, the attachment of SA is preceded by formation of a solid phase ammonium carboxylate salt between SA and accessible lysine residues of the protein during sample preparation under acidic conditions. Laser irradiation at 355 nm of the dried sample spot results in equilibrium retrogradation followed by nucleophilic attack by the amine group of lysine at the carbonyl group of SA and subsequent amide bond formation and loss of water. The absence of CHCA adducts suggests that the electron-withdrawing effect of the α-cyano group of this matrix may inhibit salt formation and/or amide bond formation. This revised hypothesis is supported by dissociative loss of SA (-224 Da) and the amide-bound SA (-206 Da) from SA-adducted HdeA and HdeB ions by MS/MS (PSD). It is proposed that cleavage of the amide-bound SA from the lysine side-chain occurs via rearrangement involving a pentacyclic transition state followed by hydrogen abstraction/migration and loss of 3-(4-hydroxy-3,5-dimethoxyphenyl)prop-2-ynal (-206 Da).

Source of carbohydrate and metabolizable lysine and methionine in the diet of recently weaned dairy calves on digestion and growth.

PubMed

Hill, T M; Quigley, J D; Bateman, H G; Aldrich, J M; Schlotterbeck, R L

2016-04-01

Two 56-d trials with weaned Holstein dairy calves (initially 72 ± 1.8 kg of body weight, 58 to 60 d of age) fed 95% concentrate and 5% chopped grass hay diets were conducted. Each trial used 96 calves (4 calves/pen). During 15 of the last 21 d of the first trial and 10 of 14 d of the second and third week of the second trial, fecal samples were taken to estimate digestibility using acid-insoluble ash as an internal marker. Digestibility estimates along with 56-d average daily gain (ADG), hip width change, body condition score, and fecal score were analyzed with pen as the experimental unit. In trial 1, a textured diet (19% crude protein) with high starch [52% starch, 13% neutral detergent fiber (NDF)] based on whole corn and oats or a pelleted low-starch (20% starch, 35% NDF), high-digestible fiber diet were used. Within starch level, diets were formulated from supplemental soybean meal or soybean meal with blood meal and Alimet (Novus International Inc., St. Charles, MO) to provide 2 metabolizable protein levels (1 and 1.07% metabolizable lysine plus methionine). The 4 treatments were analyzed as a completely randomized design with a 2 by 2 factorial arrangement (6 pens/diet). In trial 2, all pelleted diets (19% crude protein) were fed. Diets were based on soybean hulls, wheat middlings, or corn, which contained increasing concentrations of starch (13, 27, and 42% starch and 42, 23, and 16% NDF, respectively; 8 pens/diet). Contrast statements were constructed to separate differences in the means (soybean hulls plus wheat middlings vs. corn; soybean hulls vs. wheat middlings). In trial 1, intake of organic matter (OM) did not differ. Digestibility of OM was greater in calves fed high- versus low starch-diets. Digestibility of NDF and starch were less in calves fed the high- versus low-starch diets. Calf ADG and hip width change were greater for high- versus low-starch diets. Source of protein did not influence digestibility or ADG. In trial 2, intake of OM was not

Interaction studies of human prion protein (HuPrP109-111: methionine-lysine-histidine) tripeptide model with transition metal cations.

PubMed

Pitchumani Violet Mary, C; Shankar, R; Vijayakumar, S; Kolandaivel, P

2016-09-01

In the present study, the coordination bonds between the Methionine-Lysine-Histidine (Ac-MKH-NHMe) tripeptide model associated with the fifth metal binding site, which triggers the β-sheet formation of human prion protein and the divalent metal cations such as Mn(2+), Cu(2+) and Zn(2+) were studied using B3LYP and M052X levels of theory with LANL2DZ basis set. For each transition divalent metal cation, three different coordination modes (4N, 3NO, and 2NSO) were analyzed. The present result reveals that overall structural parameters of MKH model tripeptide are altered due to the interaction of divalent metal cations. Among these three coordination modes, the 4N-M(2)(+) and 4N2O-Mn(2+) complexes are found to have the larger interaction energy, MIA and deformation energies. The triply deprotonated coordination mode of the Ac-MKH-NHMe tripeptide transfers more amount of charge to the divalent metal cations than the dually and singly deprotonated complexes. Furthermore, the atoms in molecules (AIM) topological analysis confirm that, the interaction between the metal cations Mn(2+), Cu(2+) and Zn(2+) and Ac-MKH-NHMe tripeptide are electrostatic dominant and the coordination modes with triply deprotonation states possess larger electron density at their BCP corresponding to their coordination bonds. The electrostatic potential difference maps of the most stable 4N-M(2+) (M(2+)=Cu(2+) and Zn(2+)) and 4N2O-Mn(2+) reveals that, as the ionic radii of the metal ion increases, the delocalization charges localized on the metal cations are found to be decreased. The Infra-red stretching frequencies of NH, CH, and CH2 groups of each coordination complexes are observed with shift in their stretching frequencies. From these observations we conclude that, the transition divalent metal cations binding in 4N coordination mode will induce more conformational changes of the Prion protein. Copyright © 2016 Elsevier Inc. All rights reserved.

Ancient Regulatory Role of Lysine Acetylation in Central Metabolism

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

Nakayasu, Ernesto S.; Burnet, Meagan C.; Walukiewicz, Hanna E.

ABSTRACT Lysine acetylation is a common protein post-translational modification in bacteria and eukaryotes. Unlike phosphorylation, whose functional role in signaling has been established, it is unclear what regulatory mechanism acetylation plays and whether it is conserved across evolution. By performing a proteomic analysis of 48 phylogenetically distant bacteria, we discovered conserved acetylation sites on catalytically essential lysine residues that are invariant throughout evolution. Lysine acetylation removes the residue’s charge and changes the shape of the pocket required for substrate or cofactor binding. Two-thirds of glycolytic and tricarboxylic acid (TCA) cycle enzymes are acetylated at these critical sites. Our data suggestmore » that acetylation may play a direct role in metabolic regulation by switching off enzyme activity. We propose that protein acetylation is an ancient and widespread mechanism of protein activity regulation. IMPORTANCEPost-translational modifications can regulate the activity and localization of proteins inside the cell. Similar to phosphorylation, lysine acetylation is present in both eukaryotes and prokaryotes and modifies hundreds to thousands of proteins in cells. However, how lysine acetylation regulates protein function and whether such a mechanism is evolutionarily conserved is still poorly understood. Here, we investigated evolutionary and functional aspects of lysine acetylation by searching for acetylated lysines in a comprehensive proteomic data set from 48 phylogenetically distant bacteria. We found that lysine acetylation occurs in evolutionarily conserved lysine residues in catalytic sites of enzymes involved in central carbon metabolism. Moreover, this modification inhibits enzymatic activity. Our observations suggest that lysine acetylation is an evolutionarily conserved mechanism of controlling central metabolic activity by directly blocking enzyme active sites.« less

Ancient Regulatory Role of Lysine Acetylation in Central Metabolism

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

Nakayasu, Ernesto S.; Burnet, Meagan C.; Walukiewicz, Hanna E.

ABSTRACT Lysine acetylation is a common protein post-translational modification in bacteria and eukaryotes. Unlike phosphorylation, whose functional role in signaling has been established, it is unclear what regulatory mechanism acetylation plays and whether it is conserved across evolution. By performing a proteomic analysis of 48 phylogenetically distant bacteria, we discovered conserved acetylation sites on catalytically essential lysine residues that are invariant throughout evolution. Lysine acetylation removes the residue’s charge and changes the shape of the pocket required for substrate or cofactor binding. Two-thirds of glycolytic and tricarboxylic acid (TCA) cycle enzymes are acetylated at these critical sites. Our data suggestmore » that acetylation may play a direct role in metabolic regulation by switching off enzyme activity. We propose that protein acetylation is an ancient and widespread mechanism of protein activity regulation. IMPORTANCE Post-translational modifications can regulate the activity and localization of proteins inside the cell. Similar to phosphorylation, lysine acetylation is present in both eukaryotes and prokaryotes and modifies hundreds to thousands of proteins in cells. However, how lysine acetylation regulates protein function and whether such a mechanism is evolutionarily conserved is still poorly understood. Here, we investigated evolutionary and functional aspects of lysine acetylation by searching for acetylated lysines in a comprehensive proteomic data set from 48 phylogenetically distant bacteria. We found that lysine acetylation occurs in evolutionarily conserved lysine residues in catalytic sites of enzymes involved in central carbon metabolism. Moreover, this modification inhibits enzymatic activity. Our observations suggest that lysine acetylation is an evolutionarily conserved mechanism of controlling central metabolic activity by directly blocking enzyme active sites.« less

Ancient Regulatory Role of Lysine Acetylation in Central Metabolism

DOE PAGES

Nakayasu, Ernesto S.; Burnet, Meagan C.; Walukiewicz, Hanna E.; ...

2017-11-28

ABSTRACT Lysine acetylation is a common protein post-translational modification in bacteria and eukaryotes. Unlike phosphorylation, whose functional role in signaling has been established, it is unclear what regulatory mechanism acetylation plays and whether it is conserved across evolution. By performing a proteomic analysis of 48 phylogenetically distant bacteria, we discovered conserved acetylation sites on catalytically essential lysine residues that are invariant throughout evolution. Lysine acetylation removes the residue’s charge and changes the shape of the pocket required for substrate or cofactor binding. Two-thirds of glycolytic and tricarboxylic acid (TCA) cycle enzymes are acetylated at these critical sites. Our data suggestmore » that acetylation may play a direct role in metabolic regulation by switching off enzyme activity. We propose that protein acetylation is an ancient and widespread mechanism of protein activity regulation. IMPORTANCE Post-translational modifications can regulate the activity and localization of proteins inside the cell. Similar to phosphorylation, lysine acetylation is present in both eukaryotes and prokaryotes and modifies hundreds to thousands of proteins in cells. However, how lysine acetylation regulates protein function and whether such a mechanism is evolutionarily conserved is still poorly understood. Here, we investigated evolutionary and functional aspects of lysine acetylation by searching for acetylated lysines in a comprehensive proteomic data set from 48 phylogenetically distant bacteria. We found that lysine acetylation occurs in evolutionarily conserved lysine residues in catalytic sites of enzymes involved in central carbon metabolism. Moreover, this modification inhibits enzymatic activity. Our observations suggest that lysine acetylation is an evolutionarily conserved mechanism of controlling central metabolic activity by directly blocking enzyme active sites.« less

Volatile sulphur compounds and pathways of L-methionine catabolism in Williopsis yeasts.

PubMed

Tan, Amelia W J; Lee, Pin-Rou; Seow, Yi-Xin; Ong, Peter K C; Liu, Shao-Quan

2012-08-01

Volatile sulphur compounds (VSCs) are important to the food industry due to their high potency and presence in many foods. This study assessed for the first time VSC production and pathways of L: -methionine catabolism in yeasts from the genus Williopsis with a view to understanding VSC formation and their potential flavour impact. Five strains of Williopsis saturnus (var. saturnus, var. subsufficiens, var. suavolens, var. sargentensis and var. mrakii) were screened for VSC production in a synthetic medium supplemented with L: -methionine. A diverse range of VSCs were produced including dimethyl disulphide, dimethyl trisulphide, 3-(methylthio)-1-propanal (methional), 3-(methylthio)-1-propanol (methionol), 3-(methylthio)-1-propene, 3-(methylthio)-1-propyl acetate, 3-(methylthio)-1-propanoic acid (methionic acid) and ethyl 3-(methylthio)-1-propanoate, though the production of these VSCs varied between yeast strains. W. saturnus var. saturnus NCYC22 was selected for further studies due to its relatively high VSC production. VSC production was characterised step-wise with yeast strain NCYC22 in coconut cream at different L: -methionine concentrations (0.00-0.20%) and under various inorganic sulphate (0.00-0.20%) and nitrogen (ammonia) supplementation (0.00-0.20%), respectively. Optimal VSC production was obtained with 0.1% of L: -methionine, while supplementation of sulphate had no significant effect. Nitrogen supplementation showed a dramatic inhibitory effect on VSC production. Based on the production of VSCs, the study suggests that the Ehrlich pathway of L: -methionine catabolism is operative in W. saturnus yeasts and can be manipulated by adjusting certain nutrient parameters to control VSC production.

Therapeutic modulation of cerebral L-lysine metabolism in a mouse model for glutaric aciduria type I.

PubMed

Sauer, Sven W; Opp, Silvana; Hoffmann, Georg F; Koeller, David M; Okun, Jürgen G; Kölker, Stefan

2011-01-01

Glutaric aciduria type I, an inherited deficiency of glutaryl-coenzyme A dehydrogenase localized in the final common catabolic pathway of L-lysine, L-hydroxylysine and L-tryptophan, leads to accumulation of neurotoxic glutaric and 3-hydroxyglutaric acid, as well as non-toxic glutarylcarnitine. Most untreated patients develop irreversible brain damage during infancy that can be prevented in the majority of cases if metabolic treatment with a low L-lysine diet and L-carnitine supplementation is started in the newborn period. The biochemical effect of this treatment remains uncertain, since cerebral concentrations of neurotoxic metabolites can only be determined by invasive techniques. Therefore, we studied the biochemical effect and mechanism of metabolic treatment in glutaryl-coenzyme A dehydrogenase-deficient mice, an animal model with complete loss of glutaryl-coenzyme A dehydrogenase activity, focusing on the tissue-specific changes of neurotoxic metabolites and key enzymes of L-lysine metabolism. Here, we demonstrate that low L-lysine diet, but not L-carnitine supplementation, lowered the concentration of glutaric acid in brain, liver, kidney and serum. L-carnitine supplementation restored the free L-carnitine pool and enhanced the formation of glutarylcarnitine. The effect of low L-lysine diet was amplified by add-on therapy with L-arginine, which we propose to result from competition with L-lysine at system y(+) of the blood-brain barrier and the mitochondrial L-ornithine carriers. L-lysine can be catabolized in the mitochondrial saccharopine or the peroxisomal pipecolate pathway. We detected high activity of mitochondrial 2-aminoadipate semialdehyde synthase, the rate-limiting enzyme of the saccharopine pathway, in the liver, whereas it was absent in the brain. Since we found activity of the subsequent enzymes of L-lysine oxidation, 2-aminoadipate semialdehyde dehydrogenase, 2-aminoadipate aminotransferase and 2-oxoglutarate dehydrogenase complex as well as

The effects of high dietary protein and nitrogen levels on the preformed methyl group requirement and methionine-induced growth depression in chicks.

PubMed

Pesti, G M; Benevenga, N J; Harper, A E; Sunde, M L

1981-02-01

The chick's choline and methionine requirements are both increased by high dietary protein level. Studies were conducted to test the hypothesis that the chicks' need for preformed methyl groups is increased by high protein diets (not methionine or choline per se). Chicks fed 25% isolated soybean protein (ISP) diets responded to methionine supplementation (162 vs 110 g gained in 14 days) but not to choline (119 g vs. 110 g), while those fed 50% ISP responded to either methionine (174 g vs. 126 g) or choline (181 g vs. 126 g) supplementation. Further, neither cystine nor homocystine could replace methionine in improving the growth of chicks fed the high protein diet. In other experiments, L-methionine and betaine HCl were found to alleviate the growth depression caused by excessive levels of L-glutamic acid. Excessive levels of L-methionine had a protective effect against growth depression caused by L-glutamate and diammonium citrate, and conversely, supplementary L-serine and sodium formate were not protective against glutamic acid- or arginine-induced growth depression. The results are consistent with the hypothesis that the preformed methyl group requirement is increased by high levels of dietary protein and excessive nitrogen from a single amino acid.

Comparison of the effects of seleno-l-methionine, seleno-dl-methionine, and selenized yeast on reproduction of mallards

USGS Publications Warehouse

Heinz, G.H.; Hoffman, D.J.

1996-01-01

The toxicities of seleno-L-methionine, seleno-DL-methionine, and selenized yeast were compared. Ten pairs of mallards were fed a control diet and 15 pairs were fed diets containing 10 ppm selenium as seleno-DL-methionine, seleno-L-methionine, or selenized yeast. Hatching of fertile eggs was significantly lower for females fed 10 ppm selenium as seleno-DL-methionine (7.6%) and seleno-L-methionine (6.4%) than for controls (41.3%). Survival of ducklings was lower when their parents had been fed 10 ppm selenium as seleno-L-methionine (20.0%) than for controls (98.4%). The number of 6-day-old ducklings produced per female was significantly lower for mallards fed 10 ppm selenium as seleno-DL-methionine (0.47) or selenized yeast (2.67) than for controls (6.10), and was significantly lower for mallards fed seleno-L-methionine (0.13) than for mallards fed selenized yeast. The eighth eggs of females fed the DL or L forms of selenomethionine contained means of 9.2 and 8.9 ppm selenium, wet weight; these means were higher than the mean (6.6 ppm) for females fed selenized yeast. Among embryos that died at 7 days of age or older, the percentage of embryos that were deformed was 1.3% for controls, 24.6% for seleno-DL-methionine, 28.2% for seleno-L-methionine, and 11.0% for selenized yeast. The results suggested that seleno-DL-methionine and seleno-L-methionine were of similar toxicity and were both more toxic than selenium from selenized yeast.

Bacillus methanolicus pyruvate carboxylase and homoserine dehydrogenase I and II and their roles for L-lysine production from methanol at 50 degrees C.

PubMed

Brautaset, Trygve; Jakobsen, Øyvind M; Degnes, Kristin F; Netzer, Roman; Naerdal, Ingemar; Krog, Anne; Dillingham, Rick; Flickinger, Michael C; Ellingsen, Trond E

2010-07-01

We here present the pyc gene encoding pyruvate carboxylase (PC), and the hom-1 and hom-2 genes encoding two active homoserine dehydrogenase (HD) proteins, in methylotrophic Bacillus methanolicus MGA3. In general, both PC and HD are regarded as key targets for improving bacterial L-lysine production; PC plays a role in precursor oxaloacetate (OAA) supply while HD controls an important branch point in the L-lysine biosynthetic pathway. The hom-1 and hom-2 genes were strongly repressed by L-threonine and L-methionine, respectively. Wild-type MGA3 cells secreted 0.4 g/l L-lysine and 59 g/l L-glutamate under optimised fed batch methanol fermentation. The hom-1 mutant M168-20 constructed herein secreted 11 g/l L-lysine and 69 g/l of L-glutamate, while a sixfold higher L-lysine overproduction (65 g/l) of the previously constructed classical B. methanolicus mutant NOA2#13A52-8A66 was accompanied with reduced L-glutamate production (28 g/l) and threefold elevated pyc transcription level. Overproduction of PC and its mutant enzyme P455S in M168-20 had no positive effect on the volumetric L-lysine yield and the L-lysine yield on methanol, and caused significantly reduced volumetric L-glutamate yield and L: -glutamate yield on methanol. Our results demonstrated that hom-1 represents one key target for achieving L-lysine overproduction, PC activity plays an important role in controlling L-glutamate production from methanol, and that OAA precursor supply is not a major bottleneck for L-lysine overproduction by B. methanolicus.

A Proteomic Approach to Analyze the Aspirin-mediated Lysine Acetylome*

PubMed Central

Tatham, Michael H.; Cole, Christian; Scullion, Paul; Wilkie, Ross; Westwood, Nicholas J.; Stark, Lesley A.; Hay, Ronald T.

2017-01-01

Aspirin, or acetylsalicylic acid is widely used to control pain, inflammation and fever. Important to this function is its ability to irreversibly acetylate cyclooxygenases at active site serines. Aspirin has the potential to acetylate other amino acid side-chains, leading to the possibility that aspirin-mediated lysine acetylation could explain some of its as-yet unexplained drug actions or side-effects. Using isotopically labeled aspirin-d3, in combination with acetylated lysine purification and LC-MS/MS, we identified over 12000 sites of lysine acetylation from cultured human cells. Although aspirin amplifies endogenous acetylation signals at the majority of detectable endogenous sites, cells tolerate aspirin mediated acetylation very well unless cellular deacetylases are inhibited. Although most endogenous acetylations are amplified by orders of magnitude, lysine acetylation site occupancies remain very low even after high doses of aspirin. This work shows that while aspirin has enormous potential to alter protein function, in the majority of cases aspirin-mediated acetylations do not accumulate to levels likely to elicit biological effects. These findings are consistent with an emerging model for cellular acetylation whereby stoichiometry correlates with biological relevance, and deacetylases act to minimize the biological consequences of nonspecific chemical acetylations. PMID:27913581

Influence of dietary protein level on the broiler chicken's response to methionine and betaine supplements.

PubMed

Garcia Neto, M; Pesti, G M; Bakalli, R I

2000-10-01

Two experiments were conducted to compare broiler chicken responses to methionine and betaine supplements when fed diets with low protein and relatively high metabolizable energy levels (17%, 3.3 kcal/g) or moderate protein and lower metabolizable energy levels (24%, 3.0 kcal/g), resulting in different levels of carcass fat. In Experiment 1, the basal diets were formulated with corn, soybean meal, poultry by-product meal, and poultry oil. In Experiment 2, glucose monohydrate was also added, so that identical amino acid profiles could be maintained in the 17 and 24% protein diets. On average, feeding the 17 vs. 24% protein diet decreased 21-d body weight gain by 20%, increased feed conversion ratio (FCR) by 13%, and increased abdominal fat pad weight by 104%. Methionine and betaine supplements improved the performance of chicks fed the 24% protein diet in both experiments, as indicated by body weight gain and FCR. Only supplementary methionine increased performance of chicks fed 17% protein diets, and then only in Experiment 2. Neither methionine nor betaine decreased abdominal fat pad size in either experiment. Methionine supplementation decreased relative liver size and increased breast muscle protein. Both methionine and betaine increased sample feather weight, but when expressed as a percentage of body weight, no significant differences were detected. It is concluded that increasing carcass fat by manipulating percentage dietary protein level or amino acid balance does not influence betaine's activity as a lipotropic agent.

Molecular cloning and characterization of l-methionine γ-lyase from Streptomyces avermitilis.

PubMed

Kudou, Daizou; Yasuda, Eri; Hirai, Yoshiyuki; Tamura, Takashi; Inagaki, Kenji

2015-10-01

A pyridoxal 5'-phosphate-dependent methionine γ-lyase (MGL) was cloned from Streptomyces avermitilis catalyzed the degradation of methionine to α-ketobutyrate, methanethiol, and ammonia. The sav7062 gene (1,242 bp) was corresponded to 413 amino acid residues with a molecular mass of 42,994 Da. The deduced amino acid sequence showed a high degree of similarity to those of other MGL enzymes. The sav7062 gene was overexpressed in Escherichia coli. The enzyme was purified to homogeneity and exhibited the MGL catalytic activities. We cloned the enzyme that has the MGL activity in Streptomyces for the first time. Copyright © 2015 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

Co-expression of bacterial aspartate kinase and adenylylsulfate reductase genes substantially increases sulfur amino acid levels in transgenic alfalfa (Medicago sativa L.).

PubMed

Tong, Zongyong; Xie, Can; Ma, Lei; Liu, Liping; Jin, Yongsheng; Dong, Jiangli; Wang, Tao

2014-01-01

Alfalfa (Medicago sativa L.) is one of the most important forage crops used to feed livestock, such as cattle and sheep, and the sulfur amino acid (SAA) content of alfalfa is used as an index of its nutritional value. Aspartate kinase (AK) catalyzes the phosphorylation of aspartate to Asp-phosphate, the first step in the aspartate family biosynthesis pathway, and adenylylsulfate reductase (APR) catalyzes the conversion of activated sulfate to sulfite, providing reduced sulfur for the synthesis of cysteine, methionine, and other essential metabolites and secondary compounds. To reduce the feedback inhibition of other metabolites, we cloned bacterial AK and APR genes, modified AK, and introduced them into alfalfa. Compared to the wild-type alfalfa, the content of cysteine increased by 30% and that of methionine increased substantially by 60%. In addition, a substantial increase in the abundance of essential amino acids (EAAs), such as aspartate and lysine, was found. The results also indicated a close connection between amino acid metabolism and the tricarboxylic acid (TCA) cycle. The total amino acid content and the forage biomass tested showed no significant changes in the transgenic plants. This approach provides a new method for increasing SAAs and allows for the development of new genetically modified crops with enhanced nutritional value.

Co-Expression of Bacterial Aspartate Kinase and Adenylylsulfate Reductase Genes Substantially Increases Sulfur Amino Acid Levels in Transgenic Alfalfa (Medicago sativa L.)

PubMed Central

Tong, Zongyong; Xie, Can; Ma, Lei; Liu, Liping; Jin, Yongsheng; Dong, Jiangli; Wang, Tao

2014-01-01

Alfalfa (Medicago sativa L.) is one of the most important forage crops used to feed livestock, such as cattle and sheep, and the sulfur amino acid (SAA) content of alfalfa is used as an index of its nutritional value. Aspartate kinase (AK) catalyzes the phosphorylation of aspartate to Asp-phosphate, the first step in the aspartate family biosynthesis pathway, and adenylylsulfate reductase (APR) catalyzes the conversion of activated sulfate to sulfite, providing reduced sulfur for the synthesis of cysteine, methionine, and other essential metabolites and secondary compounds. To reduce the feedback inhibition of other metabolites, we cloned bacterial AK and APR genes, modified AK, and introduced them into alfalfa. Compared to the wild-type alfalfa, the content of cysteine increased by 30% and that of methionine increased substantially by 60%. In addition, a substantial increase in the abundance of essential amino acids (EAAs), such as aspartate and lysine, was found. The results also indicated a close connection between amino acid metabolism and the tricarboxylic acid (TCA) cycle. The total amino acid content and the forage biomass tested showed no significant changes in the transgenic plants. This approach provides a new method for increasing SAAs and allows for the development of new genetically modified crops with enhanced nutritional value. PMID:24520364

Proteomic and Biochemical Studies of Lysine Malonylation Suggest Its Malonic Aciduria-associated Regulatory Role in Mitochondrial Function and Fatty Acid Oxidation*

PubMed Central

Colak, Gozde; Pougovkina, Olga; Dai, Lunzhi; Tan, Minjia; te Brinke, Heleen; Huang, He; Cheng, Zhongyi; Park, Jeongsoon; Wan, Xuelian; Liu, Xiaojing; Yue, Wyatt W.; Wanders, Ronald J. A.; Locasale, Jason W.; Lombard, David B.; de Boer, Vincent C. J.; Zhao, Yingming

2015-01-01

The protein substrates of sirtuin 5-regulated lysine malonylation (Kmal) remain unknown, hindering its functional analysis. In this study, we carried out proteomic screening, which identified 4042 Kmal sites on 1426 proteins in mouse liver and 4943 Kmal sites on 1822 proteins in human fibroblasts. Increased malonyl-CoA levels in malonyl-CoA decarboxylase (MCD)-deficient cells induces Kmal levels in substrate proteins. We identified 461 Kmal sites showing more than a 2-fold increase in response to MCD deficiency as well as 1452 Kmal sites detected only in MCD−/− fibroblast but not MCD+/+ cells, suggesting a pathogenic role of Kmal in MCD deficiency. Cells with increased lysine malonylation displayed impaired mitochondrial function and fatty acid oxidation, suggesting that lysine malonylation plays a role in pathophysiology of malonic aciduria. Our study establishes an association between Kmal and a genetic disease and offers a rich resource for elucidating the contribution of the Kmal pathway and malonyl-CoA to cellular physiology and human diseases. PMID:26320211

Differential distribution of amino acids in plants.

PubMed

Kumar, Vinod; Sharma, Anket; Kaur, Ravdeep; Thukral, Ashwani Kumar; Bhardwaj, Renu; Ahmad, Parvaiz

2017-05-01

Plants are a rich source of amino acids and their individual abundance in plants is of great significance especially in terms of food. Therefore, it is of utmost necessity to create a database of the relative amino acid contents in plants as reported in literature. Since in most of the cases complete analysis of profiles of amino acids in plants was not reported, the units used and the methods applied and the plant parts used were different, amino acid contents were converted into relative units with respect to lysine for statistical analysis. The most abundant amino acids in plants are glutamic acid and aspartic acid. Pearson's correlation analysis among different amino acids showed that there were no negative correlations between the amino acids. Cluster analysis (CA) applied to relative amino acid contents of different families. Alismataceae, Cyperaceae, Capparaceae and Cactaceae families had close proximity with each other on the basis of their relative amino acid contents. First three components of principal component analysis (PCA) explained 79.5% of the total variance. Factor analysis (FA) explained four main underlying factors for amino acid analysis. Factor-1 accounted for 29.4% of the total variance and had maximum loadings on glycine, isoleucine, leucine, threonine and valine. Factor-2 explained 25.8% of the total variance and had maximum loadings on alanine, aspartic acid, serine and tyrosine. 14.2% of the total variance was explained by factor-3 and had maximum loadings on arginine and histidine. Factor-4 accounted 8.3% of the total variance and had maximum loading on the proline amino acid. The relative content of different amino acids presented in this paper is alanine (1.4), arginine (1.8), asparagine (0.7), aspartic acid (2.4), cysteine (0.5), glutamic acid (2.8), glutamine (0.6), glycine (1.0), histidine (0.5), isoleucine (0.9), leucine (1.7), lysine (1.0), methionine (0.4), phenylalanine (0.9), proline (1.1), serine (1.0), threonine (1

Technical note: Methionine, a precursor of methane in living plants

NASA Astrophysics Data System (ADS)

Lenhart, K.; Althoff, F.; Greule, M.; Keppler, F.

2014-11-01

When terrestrial plants were identified as producers of the greenhouse gas methane, much discussion and debate ensued, not only about their contribution to the global methane budget, but also with regard to the validity of the observation itself. Although the phenomenon has now become more accepted for both living and dead plants, the mechanism of methane formation in living plants remains to be elucidated and its precursor compounds identified. We made use of stable isotope techniques to verify in vivo formation of methane and, in order to identify the carbon precursor, 13C-positionally labelled organic compounds were employed. Here we show that the amino acid L-methionine acts as a methane precursor in living plants. Employing 13C-labelled methionine clearly identified the sulphur-bound methyl group of methionine as a carbon precursor of methane released from lavender (Lavandula angustifolia). Furthermore, when lavender plants were stressed physically, methane release rates and the stable carbon isotope values of the emitted methane greatly increased. Our results provide additional support that plants possess a mechanism for methane production and suggest that methionine might play an important role in the formation of methane in living plants, particularly under stress conditions.

The absorption of protons with specific amino acids and carbohydrates by yeast

PubMed Central

Seaston, A.; Inkson, C.; Eddy, A. A.

1973-01-01

1. Proton uptake in the presence of various amino acids was studied in washed yeast suspensions containing deoxyglucose and antimycin to inhibit energy metabolism. A series of mutant strains of Saccharomyces cerevisiae with defective amino acid permeases was used. The fast absorption of glycine, l-citrulline and l-methionine through the general amino acid permease was associated with the uptake of about 2 extra equivalents of protons per mol of amino acid absorbed, whereas the slower absorption of l-methionine, l-proline and, possibly, l-arginine through their specific permeases was associated with about 1 proton equivalent. l-Canavanine and l-lysine were also absorbed with 1–2 equivalents of protons. 2. A strain of Saccharomyces carlsbergensis behaved similarly with these amino acids. 3. Preparations of the latter yeast grown with maltose subsequently absorbed it with 2–3 equivalents of protons. The accelerated rate of proton uptake increased up to a maximum value with the maltose concentration (Km=1.6mm). The uptake of protons was also faster in the presence of α-methylglucoside and sucrose, but not in the presence of glucose, galactose or 2-deoxyglucose. All of these compounds except the last could cause acid formation. The uptake of protons induced by maltose, α-methylglucoside and sucrose was not observed when the yeast was grown with glucose, although acid was then formed both from sucrose and glucose. 4. A strain of Saccharomyces fragilis that both fermented and formed acid from lactose absorbed extra protons in the presence of lactose. 5. The observations show that protons were co-substrates in the systems transporting the amino acids and certain of the carbohydrates. PMID:4587071

S-Adenosyl-L-methionine protects the probiotic yeast, Saccharomyces boulardii, from acid-induced cell death.

PubMed

Cascio, Vincent; Gittings, Daniel; Merloni, Kristen; Hurton, Matthew; Laprade, David; Austriaco, Nicanor

2013-02-13

Saccharomyces boulardii is a probiotic yeast routinely used to prevent and to treat gastrointestinal disorders, including the antibiotic-associated diarrhea caused by Clostridium difficile infections. However, only 1-3% of the yeast administered orally is recovered alive in the feces suggesting that this yeast is unable to survive the acidic environment of the gastrointestinal tract. We provide evidence that suggests that S. boulardii undergoes programmed cell death (PCD) in acidic environments, which is accompanied by the generation of reactive oxygen species and the appearance of caspase-like activity. To better understand the mechanism of cell death at the molecular level, we generated microarray gene expression profiles of S. boulardii cells cultured in an acidic environment. Significantly, functional annotation revealed that the up-regulated genes were significantly over-represented in cell death pathways Finally, we show that S-adenosyl-L-methionine (AdoMet), a commercially available, FDA-approved dietary supplement, enhances the viability of S. boulardii in acidic environments, most likely by preventing programmed cell death. In toto, given the observation that many of the proven health benefits of S. boulardii are dependent on cell viability, our data suggests that taking S. boulardii and AdoMet together may be a more effective treatment for gastrointestinal disorders than taking the probiotic yeast alone.

Tobacco seeds expressing feedback-insensitive cystathionine gamma-synthase exhibit elevated content of methionine and altered primary metabolic profile

PubMed Central

2013-01-01

Background The essential sulfur-containing amino acid methionine plays a vital role in plant metabolism and human nutrition. In this study, we aimed to elucidate the regulatory role of the first committed enzyme in the methionine biosynthesis pathway, cystathionine γ-synthase (CGS), on methionine accumulation in tobacco seeds. We also studied the effect of this manipulation on the seed’s metabolism. Results Two forms of Arabidopsis CGS (AtCGS) were expressed under the control of the seeds-specific promoter of legumin B4: feedback-sensitive F-AtCGS (LF seeds), and feedback-insensitive T-AtCGS (LT seeds). Unexpectedly, the soluble content of methionine was reduced significantly in both sets of transgenic seeds. Amino acids analysis and feeding experiments indicated that although the level of methionine was reduced, the flux through its synthesis had increased. As a result, the level of protein-incorporated methionine had increased significantly in LT seeds by up to 60%, but this was not observed in LF seeds, whose methionine content is tightly regulated. This increase was accompanied by a higher content of other protein-incorporated amino acids, which led to 27% protein content in the seeds although this was statistically insignificantly. In addition, the levels of reducing sugars (representing starch) were slightly but significantly reduced, while that of oil was insignificantly reduced. To assess the impact of the high expression level of T-AtCGS in seeds on other primary metabolites, metabolic profiling using GC-MS was performed. This revealed significant alterations to the primary seed metabolism manifested by a significant increase in eight annotated metabolites (mostly sugars and their oxidized derivatives), while the levels of 12 other metabolites were reduced significantly in LT compared to wild-type seeds. Conclusion Expression of T-AtCGS leads to an increase in the level of total Met, higher contents of total amino acids, and significant changes in the

The importance of transmethylation reactions to methionine metabolism in sheep: effects of supplementation with creatine and choline.

PubMed

Lobley, G E; Connell, A; Revell, D

1996-01-01

The influence of administering the methylated products choline and creatine on methionine irreversible-loss rate (ILR) and recycling from homocysteine has been investigated in sheep fed close to energy and N equilibrium. Two methods to estimate methionine recycling were compared. The first involved [U-13C]methionine infused as part of a labelled amino acid mixture obtained from hydrolysed algal protein. In this approach the isotope dilution of methionine with all five C atoms labelled (m + 5) will represent the ILR which does not recycle through homocysteine, while that which includes molecules with C-1-C-4 labelled will allow for loss of the labelled methyl (5)-C atom and replacement by an unlabelled moiety in the remethylation of homocysteine. The second method involved a combined infusion of [1-13C]- and [S-methyl-2H3]methionine. These two approaches gave similar data for methionine ILR which does not include label recycled to the amino acid from homocysteine but differed for recycled methionine fluxes. Consequently the two procedures differed in the calculated extent of homocysteine methylation under control conditions (6 v. 28%). These extents of remethylation are within the range observed for the fed human subject, despite the fact that fewer dietary methyl groups are available for the ruminant. Using combined data from the infusions, significant depression of methionine recycling occurred in blood (P < 0.05), with a similar trend for plasma (P = 0.077), when choline plus creatine were infused. Wool growth, assessed by intradermal injection of [35S]cysteine, was not altered by supplementation with the methylated products. From changes in the label pattern of free methionine in aortal, hepatic portal and hepatic venous blood during U-13C-labelled algal hydrolysate infusion, the major sites of homocysteine remethylation appear to be the portal-drained viscera and the liver. This was confirmed by analysis of free methionine enrichments in various tissues

Role of white adipose lipolysis in the development of NASH induced by methionine-and choline-deficient diet

PubMed Central

Tanaka, Naoki; Takahashi, Shogo; Fang, Zhong-Ze; Matsubara, Tsutomu; Krausz, Kristopher W.; Qu, Aijuan; Gonzalez, Frank J.

2014-01-01

Methionine- and choline-deficient diet (MCD) is a model for nonalcoholic steatohepatitis (NASH) in rodents. However, the mechanism of NASH development by dietary methionine/choline deficiency remains undetermined. To elucidate the early metabolic changes associated with MCD-NASH, serum metabolomic analysis was performed using mice treated with MCD and control diet for three days and one week, revealing significant increases in oleic and linoleic acids after MCD treatment. These increases were correlated with reduced body weight and white adipose tissue (WAT) mass, increased phosphorylation of hormone-sensitive lipase, and up-regulation of genes encoding carboxylesterase 3 and β2-adrenergic receptor in WAT, indicating accelerated lipolysis in adipocytes. The changes in serum fatty acids and WAT by MCD treatment were reversed by methionine supplementation, and similar alterations were detected in mice fed a methionine-deficient diet (MD), thus demonstrating that dietary methionine deficiency enhances lipolysis in WAT. MD treatment decreased glucose and increased fibroblast growth factor 21 in serum, thus exhibiting a similar metabolic phenotype as the fasting response. Comparison between MCD and choline-deficient diet (CD) treatments suggested that the addition of MD-induced metabolic alterations, such as WAT lipolysis, to CD-induced hepatic steatosis promotes liver injury. Collectively, these results demonstrate an important role for dietary methionine deficiency and WAT lipolysis in the development of MCD-NASH. PMID:25178843

Serine Metabolism Supports the Methionine Cycle and DNA/RNA Methylation through De Novo ATP Synthesis in Cancer Cells

PubMed Central

Maddocks, Oliver D.K.; Labuschagne, Christiaan F.; Adams, Peter D.; Vousden, Karen H.

2016-01-01

Summary Crosstalk between cellular metabolism and the epigenome regulates epigenetic and metabolic homeostasis and normal cell behavior. Changes in cancer cell metabolism can directly impact epigenetic regulation and promote transformation. Here we analyzed the contribution of methionine and serine metabolism to methylation of DNA and RNA. Serine can contribute to this pathway by providing one-carbon units to regenerate methionine from homocysteine. While we observed this contribution under methionine-depleted conditions, unexpectedly, we found that serine supported the methionine cycle in the presence and absence of methionine through de novo ATP synthesis. Serine starvation increased the methionine/S-adenosyl methionine ratio, decreasing the transfer of methyl groups to DNA and RNA. While serine starvation dramatically decreased ATP levels, this was accompanied by lower AMP and did not activate AMPK. This work highlights the difference between ATP turnover and new ATP synthesis and defines a vital function of nucleotide synthesis beyond making nucleic acids. PMID:26774282

Serine Metabolism Supports the Methionine Cycle and DNA/RNA Methylation through De Novo ATP Synthesis in Cancer Cells.

PubMed

Maddocks, Oliver D K; Labuschagne, Christiaan F; Adams, Peter D; Vousden, Karen H

2016-01-21

Crosstalk between cellular metabolism and the epigenome regulates epigenetic and metabolic homeostasis and normal cell behavior. Changes in cancer cell metabolism can directly impact epigenetic regulation and promote transformation. Here we analyzed the contribution of methionine and serine metabolism to methylation of DNA and RNA. Serine can contribute to this pathway by providing one-carbon units to regenerate methionine from homocysteine. While we observed this contribution under methionine-depleted conditions, unexpectedly, we found that serine supported the methionine cycle in the presence and absence of methionine through de novo ATP synthesis. Serine starvation increased the methionine/S-adenosyl methionine ratio, decreasing the transfer of methyl groups to DNA and RNA. While serine starvation dramatically decreased ATP levels, this was accompanied by lower AMP and did not activate AMPK. This work highlights the difference between ATP turnover and new ATP synthesis and defines a vital function of nucleotide synthesis beyond making nucleic acids. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

Standardized ileal digestibility of proteins and amino acids in sesame expeller and soya bean meal in weaning piglets.

PubMed

Aguilera, A; Reis de Souza, T C; Mariscal-Landín, G; Escobar, K; Montaño, S; Bernal, M G

2015-08-01

Apparent ileal digestibility (AID) of diets containing sesame expeller (SE) and soya bean meal (SBM) was determined using 15 piglets (Genetiporc(®)), weaned at 17 ± 0.4 days with average body weight of 6.4 ± 0.7 kg (Fertilis 20 × G Performance, Genetiporc(®), PIC México, Querétaro, México). Piglets were randomly assigned to three treatments: (i) a reference diet with casein as the sole protein source; (ii) a mixed diet of casein-SE; and (iii) a mixed diet of casein-SBM. The chemical composition of SE and SBM was determined, and AID and standardized ileal digestibility (SID) of crude protein (CP) and amino acids (AAs) were determined for each protein source. SE contained greater quantities of ether extract, neutral detergent fibre, phytic acid, methionine and arginine than SBM. Lysine and proline contents and trypsin inhibitor activity were higher in SBM than in SE. The AID and SID of CP and AA (except for lysine and proline) were similar in SE and SBM. The AID of lysine and proline was higher in SBM than in SE (p < 0.05), and the SID of proline was higher in SE than in SBM (p < 0.05). These findings indicate that SE is an appropriate alternative protein source for early weaned pigs. Journal of Animal Physiology and Animal Nutrition © 2014 Blackwell Verlag GmbH.

Kinetic isotope effects reveal early transition state of protein lysine methyltransferase SET8

PubMed Central

Linscott, Joshua A.; Kapilashrami, Kanishk; Wang, Zhen; Senevirathne, Chamara; Bothwell, Ian R.; Blum, Gil; Luo, Minkui

2016-01-01

Protein lysine methyltransferases (PKMTs) catalyze the methylation of protein substrates, and their dysregulation has been linked to many diseases, including cancer. Accumulated evidence suggests that the reaction path of PKMT-catalyzed methylation consists of the formation of a cofactor(cosubstrate)–PKMT–substrate complex, lysine deprotonation through dynamic water channels, and a nucleophilic substitution (SN2) transition state for transmethylation. However, the molecular characters of the proposed process remain to be elucidated experimentally. Here we developed a matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF-MS) method and corresponding mathematic matrix to determine precisely the ratios of isotopically methylated peptides. This approach may be generally applicable for examining the kinetic isotope effects (KIEs) of posttranslational modifying enzymes. Protein lysine methyltransferase SET8 is the sole PKMT to monomethylate histone 4 lysine 20 (H4K20) and its function has been implicated in normal cell cycle progression and cancer metastasis. We therefore implemented the MS-based method to measure KIEs and binding isotope effects (BIEs) of the cofactor S-adenosyl-l-methionine (SAM) for SET8-catalyzed H4K20 monomethylation. A primary intrinsic 13C KIE of 1.04, an inverse intrinsic α-secondary CD3 KIE of 0.90, and a small but statistically significant inverse CD3 BIE of 0.96, in combination with computational modeling, revealed that SET8-catalyzed methylation proceeds through an early, asymmetrical SN2 transition state with the C-N and C-S distances of 2.35–2.40 Å and 2.00–2.05 Å, respectively. This transition state is further supported by the KIEs, BIEs, and steady-state kinetics with the SAM analog Se-adenosyl-l-selenomethionine (SeAM) as a cofactor surrogate. The distinct transition states between protein methyltransferases present the opportunity to design selective transition-state analog inhibitors. PMID

Amino acid metabolism during exercise in trained rats: the potential role of carnitine in the metabolic fate of branched-chain amino acids.

PubMed

Ji, L L; Miller, R H; Nagle, F J; Lardy, H A; Stratman, F W

1987-08-01

The influence of endurance training and an acute bout of exercise on plasma concentrations of free amino acids and the intermediates of branched-chain amino acid (BCAA) metabolism were investigated in the rat. Training did not affect the plasma amino acid levels in the resting state. Plasma concentrations of alanine (Ala), aspartic acid (Asp), asparagine (Asn), arginine (Arg), histidine (His), isoleucine (Ile), leucine (Leu), lysine (Lys), methionine (Met), phenylalanine (Phe), proline (Pro), serine (Ser), threonine (Thr), and valine (Val) were significantly lower, whereas glutamate (Glu), glycine (Gly), ornithine (Orn), tryptophan (Trp), tyrosine (Tyr), creatinine, urea, and ammonia levels were unchanged, after one hour of treadmill running in the trained rats. Plasma concentration of glutamine (Glu), the branched-chain keto acids (BCKA) and short-chain acyl carnitines were elevated with exercise. Ratios of plasma BCAA/BCKA were dramatically lowered by exercise in the trained rats. A decrease in plasma-free carnitine levels was also observed. These data suggest that amino acid metabolism is enhanced by exercise even in the trained state. BCAA may only be partially metabolized within muscle and some of their carbon skeletons are released into the circulation in forms of BCKA and short-chain acyl carnitines.

N6-Trimethyl-lysine metabolism. 3-Hydroxy-N6-trimethyl-lysine and carnitine biosynthesis.

PubMed Central

Hoppel, C L; Cox, R A; Novak, R F

1980-01-01

Rats injected with N6-[Me-3H]trimethyl-lysine excrete in the urine five radioactively labelled metabolites. Two of these identified metabolites are carnitine and 4-trimethylammoniobutyrate. A third metabolite, identified as 5-trimethylammoniopentanoate, is not an intermediate in the biosynthesis of carnitine; the fourth and major metabolite, N2-acetyl-N6-trimethyl-lysine, is not a precursor of carnitine. The remaining metabolite (3-hydroxy-N6-trimethyl-lysine) is converted into trimethylammoniobutyrate and carnitine by rat liver slices and into trimethylammoniobutyrate by rat kidney slices. In rat liver and kidney-slice experiments, radioactivity from DL-N6-trimethyl-[1-14C]lysine and DL-N6-trimethyl-[2-14C]lysine was incorporated into N2-acetyl-N6-trimethyl-lysine and 3-hydroxy-N6-trimethyl-lysine, but not into trimethylammoniobutyrate or carnitine. A procedure was devised to purify milligram quantities of 3-hydroxy-N6-trimethyl-lysine from the urine of rats injected chronically with N6-trimethyl-lysine (100 mg/kg body wt. per day). The structure of 3-hydroxy-N6-trimethyl-lysine was confirmed chemically and by nuclear-magnetic-resonance spectrometry [Novak, Swift & Hoppel (1980) Biochem. J. 188, 521--527]. The sequence for carnitine biosynthesis in liver is: N6-trimethyl-lysine leads to 3-hydryxy-N6-trimethyl-lysine leads to leads to 4-trimethylammoniobutyrate leads to carnitine. PMID:6772168

H NMR studies of substrate hydrogen exchange reactions catalyzed by L-methionine gamma-lyase

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

Esaki, N.; Nakayama, T.; Sawada, S.

Hydrogen exchange reactions of various L-amino acids catalyzed by L-methionine gamma-lyase (EC 4.4.1.11) have been studied. The enzyme catalyzes the rapid exchange of the alpha- and beta-hydrogens of L-methionine and S-methyl-L-cysteine with deuterium from the solvent. The rate of alpha-hydrogen exchange was about 40 times faster than that of the enzymatic elimination reaction of the sulfur-containing amino acids. The enzyme also catalyzes the exchange reaction of alpha- and beta-hydrogens of the straight-chain L-amino acids which are not susceptible to elimination. The exchange rates of the alpha-hydrogen and the total beta-hydrogens of L-alanine and L-alpha-aminobutyrate with deuterium followed first-order kinetics. Formore » L-norvaline, L-norleucine, S-methyl-L-cysteine, and L-methionine, the rate of alpha-hydrogen exchange followed first-order kinetics, but the rate of total beta-hydrogen exchange decreased due to a primary isotope effect at the alpha-position. L-Phenylalanine and L-tryptophan slowly underwent alpha-hydrogen exchange. The pro-R hydrogen of glycine was deuterated stereospecifically.« less

Methionine production--a critical review.

PubMed

Willke, Thomas

2014-12-01

This paper presents an updated critical review about several attempts to contribute methionine (Met) to the world market with an emphasis on fermentation processes, especially from natural biological sources. Analytical methods for the determination of methionine are reviewed as well as applications in feed, food, pharmacy, and medicine. Fermentation studies published within the last five decades are elucidated critically, mainly with respect to the sulfur balance, substrate yield, and the analytical validity. From all the published fermentation data, it can be concluded that up to now no more than 5 g/L methionine are achievable without using genetically modified organisms (GMOs). The highest L-methionine concentration from natural sources reached so far amounts to 35 g/L and is published as a patent using a GMO of Escherichia coli. The review closes with a comprehensive overview of the role and activities of global methionine manufacturers. Some current market data is also presented.

A Methionine-Induced Animal Model of Schizophrenia: Face and Predictive Validity.

PubMed

Wang, Lien; Alachkar, Amal; Sanathara, Nayna; Belluzzi, James D; Wang, Zhiwei; Civelli, Olivier

2015-05-19

Modulating the methylation process induces broad biochemical changes, some of which may be involved in schizophrenia. Methylation is in particular central to epigenesis, which is also recognized as a factor in the etiology of schizophrenia. Because methionine administration to patients with schizophrenia has been reported to exacerbate their psychotic symptoms and because mice treated with methionine exhibited social deficits and prepulse inhibition impairment, we investigated whether methionine administration could lead to behavioral changes that reflect schizophrenic symptoms in mice. l-Methionine was administered to mice twice a day for 7 days. We found that this treatment induces behavioral responses that reflect the 3 types of schizophrenia-like symptoms (positive, negative, or cognitive deficits) as monitored in a battery of behavioral assays (locomotion, stereotypy, social interaction, forced swimming, prepulse inhibition, novel object recognition, and inhibitory avoidance). Moreover, these responses were differentially reversed by typical haloperidol and atypical clozapine antipsychotics in ways that parallel their effects in schizophrenics. We thus propose the l-methionine treatment as an animal model recapitulating several symptoms of schizophrenia. We have established the face and predictive validity for this model. Our model relies on an essential natural amino acid and on an intervention that is relatively simple and time effective and may offer an additional tool for assessing novel antipsychotics. © The Author 2015. Published by Oxford University Press on behalf of CINP.

Ontogenetic changes in digestive enzyme activities and the amino acid profile of starry flounder Platichthys stellatus

NASA Astrophysics Data System (ADS)

Song, Zhidong; Wang, Jiying; Qiao, Hongjin; Li, Peiyu; Zhang, Limin; Xia, Bin

2016-09-01

Ontogenetic changes in digestive enzyme activities and the amino acid (AA) profile of starry flounder, Platichthys stellatus, were investigated and limiting amino acids were estimated compared with the essential AA profile between larvae and live food to clarify starry flounder larval nutritional requirements. Larvae were collected at the egg stage and 0, 2, 4, 7, 12, 17, 24 days after hatching (DAH) for analysis. Larvae grew from 1.91 mm at hatching to 12.13 mm at 24 DAH. Trypsin and chymotrypsin activities changed slightly by 4 DAH and then increased significantly 4 DAH. Pepsin activity increased sharply beginning 17 DAH. Lipase activity increased significantly 4 DAH and increased progressively with larval growth. Amylase activity was also detected in newly hatched larvae and increased 7 DAH followed by a gradual decrease. High free amino acid (FAA) content was detected in starry flounder eggs (110.72 mg/g dry weight). Total FAA content dropped to 43.29 mg/g in 4-DAH larvae and then decreased gradually to 13.74 mg/g in 24-DAH larvae. Most FAAs (except lysine and methionine) decreased >50% in 4-DAH larvae compared with those in eggs and then decreased to the lowest values in 24-DAH larvae. Changes in the protein amino acid (PAA) profile were much milder than those observed for FAAs. Most PAAs increased gradually during larval development, except lysine and phenylalanine. The percentages of free threonine, valine, isoleucine, and leucine decreased until the end of the trial, whereas the protein forms of these four AAs followed the opposite trend. A comparison of the essential AA composition of live food (rotifers, Artemia nauplii, and Artemia metanauplii) and larvae suggested that methionine was potentially the first limiting AA. These results may help develop starry flounder larviculture methods by solving the AA imbalance in live food. Moreover, the increased digestive enzyme activities indicate the possibility of introducing artificial compound feed.

The development and amino acid binding ability of nano-materials based on azo derivatives: theory and experiment.

PubMed

Shang, Xuefang; Du, Jinge; Yang, Wancai; Liu, Yun; Fu, Zhiyuan; Wei, Xiaofang; Yan, Ruifang; Yao, Ningcong; Guo, Yaping; Zhang, Jinlian; Xu, Xiufang

2014-05-01

Two nano-material-containing azo groups have been designed and developed, and the binding ability of nano-materials with various amino acids has been characterized by UV-vis and fluorescence titrations. Results indicated that two nano-materials showed the strongest binding ability for homocysteine among twenty normal kinds of amino acids (alanine, valine, leucine, isoleucine, methionine, aspartic acid, glutamic acid, arginine, glycine, serine, threonine, asparagine, phenylalanine, histidine, tryptophan, proline, lysine, glutamine, tyrosine and homocysteine). The reason for the high sensitivity for homocysteine was that two nano-materials containing an aldehyde group reacted with SH in homocysteine and afforded very stable thiazolidine derivatives. Theoretical investigation further illustrated the possible binding mode in host-guest interaction and the roles of molecular frontier orbitals in molecular interplay. Thus, the two nano-materials can be used as optical sensors for the detection of homocysteine. Copyright © 2014 Elsevier B.V. All rights reserved.

Methionine supplementation influences melanin-based plumage colouration in Eurasian kestrel, Falco tinnunculus, nestlings.

PubMed

Parejo, Deseada; Silva, Nadia

2009-11-01

The extent to which the expression of melanin-based plumage colouration in birds is genetically or environmentally determined is controversial. Here, we performed a between-nest design supplementation with either the sulphur amino acid dl-methionine or with water to investigate the importance of the non-genetic component of melanin-based plumage colouration in the Eurasian kestrel, Falco tinnunculus. Methionine affects growth and immunity, thus we aimed to modify nestling growth and immunity before feather development. Then, we measured the effect of the experiment on colouration of two melanin-based plumage patches of nestling kestrels. We found that methionine slowed down nestling growth through treatment administration and that nestlings compensated by speeding up their growth later. We did not find any effects of methionine on nestling immunity (i.e. lymphocyte counts, natural antibody levels or complement-mediated immunity). Effects on growth seemed to be mirrored by changes in nestling colouration in the two sexes: methionine-nestlings showed less intense brown plumage on their backs compared with control nestlings. These results provide support for a non-genetic determination of a melanin-based plumage patch in the two sexes of nestling kestrels.

Technical Note: Methionine, a precursor of methane in living plants

NASA Astrophysics Data System (ADS)

Lenhart, K.; Althoff, F.; Greule, M.; Keppler, F.

2015-03-01

When terrestrial plants were identified as producers of the greenhouse gas methane, much discussion and debate ensued not only about their contribution to the global methane budget but also with regard to the validity of the observation itself. Although the phenomenon has now become more accepted for both living and dead plants, the mechanism of methane formation in living plants remains to be elucidated and its precursor compounds to be identified. We made use of stable isotope techniques to verify the in vivo formation of methane, and, in order to identify the carbon precursor, 13C positionally labeled organic compounds were employed. Here we show that the amino acid L-methionine acts as a methane precursor in living plants. Employing 13C-labeled methionine clearly identified the sulfur-bound methyl group of methionine as a carbon precursor of methane released from lavender (Lavandula angustifolia). Furthermore, when lavender plants were stressed physically, methane release rates and the stable carbon isotope values of the emitted methane greatly increased. Our results provide additional support that plants possess a mechanism for methane production and suggest that methionine might play an important role in the formation of methane in living plants, particularly under stress conditions.

Chemical rescue of the post-translationally carboxylated lysine mutant of allantoinase and dihydroorotase by metal ions and short-chain carboxylic acids.

PubMed

Ho, Ya-Yeh; Huang, Yen-Hua; Huang, Cheng-Yang

2013-04-01

Bacterial allantoinase (ALLase) and dihydroorotase (DHOase) are members of the cyclic amidohydrolase family. ALLase and DHOase possess similar binuclear metal centers in the active site in which two metals are bridged by a post-translationally carboxylated lysine. In this study, we determined the effects of carboxylated lysine and metal binding on the activities of ALLase and DHOase. Although DHOase is a metalloenzyme, purified DHOase showed high activity without additional metal supplementation in a reaction mixture or bacterial culture. However, unlike DHOase, ALLase had no activity unless some specific metal ions were added to the reaction mixture or culture. Substituting the metal binding sites H59, H61, K146, H186, H242, or D315 with alanine completely abolished the activity of ALLase. However, the K146C, K146D and K146E mutants of ALLase were still active with about 1-6% activity of the wild-type enzyme. These ALLase K146 mutants were found to have 1.4-1.7 mol metal per mole enzyme subunit, which may indicate that they still contained the binuclear metal center in the active site. The activity of the K146A mutant of the ALLase and the K103A mutant of DHOase can be chemically rescued by short-chain carboxylic acids, such as acetic, propionic, and butyric acids, but not by ethanol, propan-1-ol, and imidazole, in the presence of Co2+ or Mn2+ ions. However, the activity was still ~10-fold less than that of wild-type ALLase. Overall, these results indicated that the 20 natural basic amino acid residues were not sufficiently able to play the role of lysine. Accordingly, we proposed that during evolution, the post-translational modification of carboxylated lysine in the cyclic amidohydrolase family was selected for promoting binuclear metal center self-assembly and increasing the nucleophilicity of the hydroxide at the active site for enzyme catalysis. This kind of chemical rescue combined with site-directed mutagenesis may also be used to identify a binuclear metal

Effect of ascorbic acid or increasing metabolizable energy level with or without supplementation of some essential amino acids on productive and physiological traits of slow-growing chicks exposed to chronic heat stress.

PubMed

Attia, Y A; Hassan, R A; Tag El-Din, A E; Abou-Shehema, B M

2011-12-01

Four hundred and twenty, 21-day-old slow-growing chicks were divided randomly into seven treatments, each containing five replicates. Each replicate was kept in a 1 × 1-m floor pen. One treatment was kept under thermo-neutral conditions in a semi-open house and fed a corn-soybean meal diet (positive control). The other six groups were kept under chronic heat stress (CHS) at 38 °C and 60% RH for 4 h from 12:00 to 16:00 pm for three successive days per week. Chicks in CHS treatments were fed a corn-soybean meal diet without (negative control) or with increasing metabolizable energy (ME) level by oil supplementation alone, or also with increasing some essential amino acids (EAA) such as methionine (Met), methionine and lysine (Met+Lys) or methionine, lysine and arginine (Met+Lys+Arg) or supplemented with 250 mg of ascorbic acid (AA)/kg. CHS impaired (p < 0.05) growth performance, increased plasma triglycerides and total serum Ca while decreasing (p < 0.05) plasma glucose and total serum protein. Meanwhile 250 mg AA/kg diet or an increasing ME without or with some EAA partially alleviated (p < 0.0001) the negative effect of CHS on growth while increasing (p < 0.05) feed intake and improving (p < 0.05) feed:gain ratio (F:G) and crude protein (CP) digestibility (p < 0.05). AA or increasing ME with or without EAA increased (p < 0.05) percentage dressing, liver and giblets to those of the positive control. AA or increasing ME with or without EAA partially alleviated the negative effect of CHS on blood pH, packed cell volume (PCV), haemoglobin (Hgb), total serum protein and total Ca, plasma glucose and triglyceride, rectal temperature and respiration rate. Increasing ME level improved chickens' tolerance to CHS without a significant difference from those supplemented with AA. However, increasing Met, Lys and Arg concentration did not improve performance over that recorded with increasing ME level alone. Under CHS, 250 mg AA/kg diet or increasing ME level by addition of 3

Redox Proteomics of Protein-bound Methionine Oxidation*

PubMed Central

Ghesquière, Bart; Jonckheere, Veronique; Colaert, Niklaas; Van Durme, Joost; Timmerman, Evy; Goethals, Marc; Schymkowitz, Joost; Rousseau, Frederic; Vandekerckhove, Joël; Gevaert, Kris

2011-01-01

We here present a new method to measure the degree of protein-bound methionine sulfoxide formation at a proteome-wide scale. In human Jurkat cells that were stressed with hydrogen peroxide, over 2000 oxidation-sensitive methionines in more than 1600 different proteins were mapped and their extent of oxidation was quantified. Meta-analysis of the sequences surrounding the oxidized methionine residues revealed a high preference for neighboring polar residues. Using synthetic methionine sulfoxide containing peptides designed according to the observed sequence preferences in the oxidized Jurkat proteome, we discovered that the substrate specificity of the cellular methionine sulfoxide reductases is a major determinant for the steady-state of methionine oxidation. This was supported by a structural modeling of the MsrA catalytic center. Finally, we applied our method onto a serum proteome from a mouse sepsis model and identified 35 in vivo methionine oxidation events in 27 different proteins. PMID:21406390

Characterization of Agronomy, Grain Physicochemical Quality, and Nutritional Property of High-Lysine 35R Transgenic Rice with Simultaneous Modification of Lysine Biosynthesis and Catabolism.

PubMed

Yang, Qingqing; Wu, Hongyu; Li, Qianfeng; Duan, Ruxu; Zhang, Changquan; Sun, Samuel Saiming; Liu, Qiaoquan

2017-05-31

Lysine is the first limiting essential amino acid in rice. We previously constructed a series of transgenic rice lines to enhance lysine biosynthesis (35S), down-regulate its catabolism (Ri), or simultaneously achieve both metabolic effects (35R). In this study, nine transgenic lines, three from each group, were selected for both field and animal feeding trials. The results showed that the transgene(s) caused no obvious effects on field performance and main agronomic traits. Mature seeds of transgenic line 35R-17 contained 48-60-fold more free lysine than in wild type and had slightly lower apparent amylose content and softer gel consistency. Moreover, a 35-day feeding experiment showed that the body weight gain, food efficiency, and protein efficiency ratio of rats fed the 35R-17 transgenic rice diet were improved when compared with those fed wild-type rice diet. These data will be useful for further evaluation and potential commercialization of 35R high-lysine transgenic rice.

S-Adenosyl-L-Methionine protects the probiotic yeast, Saccharomyces boulardii, from acid-induced cell death

PubMed Central

2013-01-01

Background Saccharomyces boulardii is a probiotic yeast routinely used to prevent and to treat gastrointestinal disorders, including the antibiotic-associated diarrhea caused by Clostridium difficile infections. However, only 1-3% of the yeast administered orally is recovered alive in the feces suggesting that this yeast is unable to survive the acidic environment of the gastrointestinal tract. Results We provide evidence that suggests that S. boulardii undergoes programmed cell death (PCD) in acidic environments, which is accompanied by the generation of reactive oxygen species and the appearance of caspase-like activity. To better understand the mechanism of cell death at the molecular level, we generated microarray gene expression profiles of S. boulardii cells cultured in an acidic environment. Significantly, functional annotation revealed that the up-regulated genes were significantly over-represented in cell death pathways Finally, we show that S-adenosyl-L-methionine (AdoMet), a commercially available, FDA-approved dietary supplement, enhances the viability of S. boulardii in acidic environments, most likely by preventing programmed cell death. Conclusions In toto, given the observation that many of the proven health benefits of S. boulardii are dependent on cell viability, our data suggests that taking S. boulardii and AdoMet together may be a more effective treatment for gastrointestinal disorders than taking the probiotic yeast alone. PMID:23402325

Plasma Amino Acid Responses After Consumption of Beverages with Varying Protein Type

DTIC Science & Technology

2009-07-01

lysine 0.92 1.32 0.91 methionine 0.31 0.28 OJI phenylalanine 0.58 0.46 0.61 threonine 0.49 0.60 0.52 tryptophan 0.18 0.29 0.13 valine 0.69 0.64 0.68...threonine. serine. glutamine. proline. glycine, alanine, valine. isoleucine. leucine. tyrosine, phenylalanine . lysine, histidine, and arginine (Terrlink. van...with peak concentration in parentheses, were 2 ± 2 (45ŕ" ± 34%), 4 ± 3 (50% ± 32%). and 3 ± 3 mg/ dl (79% ± 37%). respectively. Postexercise, WP. CAS

Contribution of the net charge to the regulatory effects of amino acids and epsilon-poly(L-lysine) on the gelatinization behavior of potato starch granules.

PubMed

Ito, Azusa; Hattori, Makoto; Yoshida, Tadashi; Takahashi, Koji

2006-01-01

The effects of lysine (Lys), monosodium glutamate (GluNa), glycine, alanine and epsilon-poly(L-lysine) (PL) with different degrees of polymerization on the gelatinization behavior of potato starch granules were investigated by DSC, viscosity and swelling measurements, microscopic observation, and measurement of the retained amino acid amount to clarify the contribution of the net charge to their regulatory effects on the gelatinization behavior. The amino acids and PL each contributed to an increase in the gelatinization temperature, and a decrease in the peak viscosity and swelling. These effects strongly depended on the absolute value of their net charge. The disappearance of a negative or positive net charge by adjusting the pH value weakened the contribution. The swelling index and size of the potato starch granules changed according to replacement of the swelling medium. The amino acids and PL were easily retained by the swollen potato starch granules according to replacement of the outer solution of the starch granules.

Fructo-oligosaccharides and intestinal barrier function in a methionine-choline-deficient mouse model of nonalcoholic steatohepatitis.

PubMed

Matsumoto, Kotaro; Ichimura, Mayuko; Tsuneyama, Koichi; Moritoki, Yuki; Tsunashima, Hiromichi; Omagari, Katsuhisa; Hara, Masumi; Yasuda, Ichiro; Miyakawa, Hiroshi; Kikuchi, Kentaro

2017-01-01

Impairments in intestinal barrier function, epithelial mucins, and tight junction proteins have been reported to be associated with nonalcoholic steatohepatitis. Prebiotic fructo-oligosaccharides restore balance in the gastrointestinal microbiome. This study was conducted to determine the effects of dietary fructo-oligosaccharides on intestinal barrier function and steatohepatitis in methionine-choline-deficient mice. Three groups of 12-week-old male C57BL/6J mice were studied for 3 weeks; specifically, mice were fed a methionine-choline-deficient diet, a methionine-choline-deficient diet plus 5% fructo-oligosaccharides in water, or a normal control diet. Fecal bacteria, short-chain fatty acids, and immunoglobulin A (IgA) levels were investigated. Histological and immunohistochemical examinations were performed using mice livers for CD14 and Toll-like receptor-4 (TLR4) expression and intestinal tissue samples for IgA and zonula occludens-1 expression in epithelial tight junctions. The methionine-choline-deficient mice administered 5% fructo-oligosaccharides maintained a normal gastrointestinal microbiome, whereas methionine-choline-deficient mice without prebiotic supplementation displayed increases in Clostridium cluster XI and subcluster XIVa populations and a reduction in Lactobacillales spp. counts. Methionine-choline-deficient mice given 5% fructo-oligosaccharides exhibited significantly decreased hepatic steatosis (p = 0.003), decreased liver inflammation (p = 0.005), a decreased proportion of CD14-positive Kupffer cells (p = 0.01), decreased expression of TLR4 (p = 0.04), and increases in fecal short-chain fatty acid and IgA concentrations (p < 0.04) compared with the findings in methionine-choline-deficient mice that were not administered this prebiotic. This study illustrated that in the methionine-choline-deficient mouse model, dietary fructo-oligosaccharides can restore normal gastrointestinal microflora and normal intestinal epithelial barrier function

Quantification of malondialdehyde and 4-hydroxynonenal adducts to lysine residues in native and oxidized human low-density lipoprotein.

PubMed Central

Requena, J R; Fu, M X; Ahmed, M U; Jenkins, A J; Lyons, T J; Baynes, J W; Thorpe, S R

1997-01-01

Malondialdehyde (MDA) and 4-hydroxynonenal (HNE) are major end-products of oxidation of polyunsaturated fatty acids, and are frequently measured as indicators of lipid peroxidation and oxidative stress in vivo. MDA forms Schiff-base adducts with lysine residues and cross-links proteins in vitro; HNE also reacts with lysines, primarily via a Michael addition reaction. We have developed methods using NaBH4 reduction to stabilize these adducts to conditions used for acid hydrolysis of protein, and have prepared reduced forms of lysine-MDA [3-(N epsilon-lysino)propan-1-ol (LM)], the lysine-MDA-lysine iminopropene cross-link [1,3-di(N epsilon-lysino)propane (LML)] and lysine-HNE [3-(N epsilon-lysino)-4-hydroxynonan-l-ol (LHNE)]. Gas chromatography/MS assays have been developed for quantification of the reduced compounds in protein. RNase incubated with MDA or HNE was used as a model for quantification of the adducts by gas chromatography/MS. There was excellent agreement between measurement of MDA bound to RNase as LM and LML, and as thiobarbituric acid-MDA adducts measured by HPLC; these adducts accounted for 70-80% of total lysine loss during the reaction with MDA. LM and LML (0.002-0.12 mmol/ mol of lysine) were also found in freshly isolated low-density lipoprotein (LDL) from healthy subjects. LHNE was measured in RNase treated with HNE, but was not detectable in native LDL. LM, LML and LHNE increased in concert with the formation of conjugated dienes during the copper-catalysed oxidation of LDL, but accounted for modification of < 1% of lysine residues in oxidized LDL. These results are the first report of direct chemical measurement of MDA and HNE adducts to lysine residues in LDL. LM, LML and LHNE should be useful as biomarkers of lipid peroxidative modification of protein and of oxidative stress in vitro and in vivo. PMID:9078279

Investigation of Lysine-Functionalized Dendrimers as Dichlorvos Detoxification Agents.

PubMed

Durán-Lara, Esteban F; Marple, Jennifer L; Giesen, Joseph A; Fang, Yunlan; Jordan, Jacobs H; Godbey, W Terrence; Marican, Adolfo; Santos, Leonardo S; Grayson, Scott M

2015-11-09

Lysine-containing polymers have seen broad application due to their amines' inherent ability to bind to a range of biologically relevant molecules. The synthesis of multiple generations of polyester dendrimers bearing lysine groups on their periphery is described in this report. Their hydrolytic stabilities with respect to pH and time, their toxicity to a range of cell lines, and their possible application as nano-detoxification agents of organophosphate compounds are all investigated. These zeroth-, first-, and second-generation water-soluble dendrimers have been designed to bear exactly 4, 8, and 16 lysine groups, respectively, on their dendritic periphery. Such monodisperse bioactive polymers show potential for a range of applications including drug delivery, gene delivery, heavy metal binding, and the sequestration of organic toxins. These monodisperse bioactive dendrimers were synthesized using an aliphatic ester dendritic core (prepared from pentaerythritol) and protected amino acid moieties. This library of lysine-conjugated dendrimers showed the ability to efficiently capture the pesticide dichlorvos, confirming the potential of dendrimer-based antidotes to maintain acetylcholinesterase activity in response to poisoning events.

Extending the cross-linking/mass spectrometry strategy: Facile incorporation of photo-activatable amino acids into the model protein calmodulin in Escherichia coli cells.

PubMed

Piotrowski, Christine; Ihling, Christian H; Sinz, Andrea

2015-11-01

Photo-induced cross-linking is a highly promising technique to investigate protein conformations and protein-protein interactions in their natural cellular environment. One strategy relies on the non-directed incorporation of diazirine-containing photo-activatable amino acids into proteins and a subsequent cross-link formation induced by UV-A irradiation. The advantage of this photo-cross-linking strategy is that it is not restricted to lysine residues and that hydrophobic regions in proteins can also be targeted, which is advantageous for investigating membrane proteins. Here, we present a simplified protocol that relies on the use of mineral salts medium without any special requirements for the incorporation of photo-methionines into proteins in Escherichia coli cells. The possibility to perform these experiments in E. coli is especially valuable as it is the major system for recombinant protein production. The method is exemplified for the Ca(2+) regulating protein calmodulin containing nine methionines, which were found to be replaced by their photo-activatable analogues. Our protocol allows the facile and stochastic incorporation of photo-methionines as the basis for conducting photo-cross-linking experiments in E. coli in an efficient manner. Copyright © 2015 Elsevier Inc. All rights reserved.

Development of high-lysine rice via endosperm-specific expression of a foreign LYSINE RICH PROTEIN gene.

PubMed

Liu, Xin; Zhang, Cuicui; Wang, Xiurong; Liu, Qiaoquan; Yuan, Dingyang; Pan, Gang; Sun, Samuel S M; Tu, Jumin

2016-06-29

Lysine (Lys) is considered to be the first limiting essential amino acid in rice. Although there have been extensive efforts to improve the Lys content of rice through traditional breeding and genetic engineering, no satisfactory products have been achieved to date. We expressed a LYSINE-RICH PROTEIN gene (LRP) from Psophocarpus tetragonolobus (L.) DC using an endosperm-specific GLUTELIN1 promoter (GT1) in Peiai64S (PA64S), an elite photoperiod-thermo sensitive male sterility (PTSMS) line. The expression of the foreign LRP protein was confirmed by Western blot analysis. The Lys level in the transgenic rice seeds increased more than 30 %, the total amount of other amino acids also increased compared to wild-type. Persistent investigation of amino acids in 3 generations showed that the Lys content was significantly increased in seeds of transgenic rice. Furthermore, Lys content in the hybrid of the transgenic plants also had an approximate 20 % increase compared to hybrid control. At the grain-filling stage, we monitored the transcript abundance of many genes encoding key enzymes involved in amino acid metabolism, and the results suggested that reduced amino acid catabolism led to the accumulation of amino acids in the transgenic plants. The genetically engineered rice showed unfavorable grain phenotypes compared to wild-type, however, its hybrid displayed little negative effects on grain. Endosperm-specific expression of foreign LRP significantly increased the Lys content in the seeds of transgenic plant, and the the Lys increase was stably heritable with 3 generation investigation. The hybrid of the transgenic plants also showed significant increases of Lys content in the seeds. These results indicated that expression of LRP in rice seeds may have promising applications in improving Lys levels in rice.

Alpha-lipoic acid affects the oxidative stress in various brain structures in mice with methionine and choline deficiency.

PubMed

Veskovic, Milena; Mladenovic, Dusan; Jorgacevic, Bojan; Stevanovic, Ivana; de Luka, Silvio; Radosavljevic, Tatjana

2015-04-01

Deficiency in methionine or choline can induce oxidative stress in various organs such as liver, kidney, heart, and brain. This study was to examine the effects of alpha-lipoic acid (LA) on oxidative stress induced by methionine and choline deficiency (MCD) in several brain structures. Male mice C57BL/6 (n = 28) were divided into four groups: (1) control - continuously fed with standard chow; (2) LA - fed with standard chow and receiving LA; (3) MCD2 - fed with MCD diet for two weeks, and (4) MCD2+LA - fed with MCD diet for two weeks and receiving LA (100 mg/kg/day intraperitonealy [i.p.]). Brain tissue (cortex, hypothalamus, striatum and hippocampus) was taken for determination of oxidative stress parameters. MCD diet induced a significant increase in malondialdehyde and NOx concentration in all brain regions, while LA restored their content to normal values. Similar to this, in MCD2 group, activity of total SOD, MnSOD, and Cu/ZnSOD was reduced by MCD diet, while LA treatment improved their activities in all brain structures. Besides, in MCD2 group a decrease in catalase activity in cortex and GSH content in hypothalamus was evident, while LA treatment induced an increase in catalase activity in cortex and striatum and GSH content in hypothalamus. LA treatment can significantly reduce lipid peroxidation and nitrosative stress, caused by MCD diet, in all brain regions by restoring antioxidant enzymes activities, predominantly total SOD, MnSOD, and Cu/ZnSOD, and to a lesser extent by modulating catalase activity and GSH content. LA supplementation may be used in order to prevent brain oxidative injury induced by methionine and choline deficiency. © 2014 by the Society for Experimental Biology and Medicine.

Synthesis of Lysine Methyltransferase Inhibitors

NASA Astrophysics Data System (ADS)

Ye, Tao; Hui, Chunngai

2015-07-01

Lysine methyltransferase which catalyze methylation of histone and nonhistone proteins, play a crucial role in diverse biological processes and has emerged as a promising target for the development of various human diseases, including cancer, inflammation, and psychiatric disorders. However, inhibiting Lysine methyltransferases selectively has presented many challenges to medicinal chemists. During the past decade, lysine methyltransferase inhibitors covering many different structural classes have been designed and developed. In this review, we describe the development of selective, small-molecule inhibitors of lysine methyltransferases with an emphasis on their discovery and chemical synthesis. We highlight the current state of lysine methyltransferase inhibitors and discuss future directions and opportunities for lysine methyltransferase inhibitor discovery.

Dose-dependent effects of higher methionine levels on the transcriptome and metabolome of transgenic Arabidopsis seeds.

PubMed

Cohen, Hagai; Amir, Rachel

2017-05-01

Higher methionine levels in transgenic Arabidopsis seeds trigger the accumulation of stress-related transcripts and primary metabolites. These responses depend on the levels of methionine within seeds. Methionine, a sulfur-containing amino acid, is a key metabolite in plant cells. To reveal the regulatory role of the Arabidopsis thaliana CYSTATHIONINE γ-SYNTHASE (AtCGS), methionine main regulatory enzyme, in the synthesis of methionine in seeds, we generated transgenic RNAi seeds with targeted repression of AtCGS during late developmental stages of seeds. Unexpectedly, these seeds accumulated 2.5-fold more methionine than wild-type seeds. To study the nature of these seeds, transcriptomic and primary metabolite profiling were employed using Affymetrix ATH1 microarray and gas chromatography-mass spectrometry analyses, respectively. The results were compared to transgenic Arabidopsis seeds expressing a feedback-insensitive form of AtCGS (named SSE-AtD-CGS) that were previously showed to accumulate up to sixfold more soluble methionine than wild-type seeds. Statistical assessments showed that the nature of transcriptomic and metabolic changes that occurred in RNAi::AtCGS seeds were relatively similar, but to lesser extents, to those previously reported for SSE-AtD-CGS seeds, and linked to the induction of global transcriptomic and metabolic responses associated with stronger desiccation stress. As transgenic seeds obtained by both manipulations exhibited higher, but different methionine levels, the data strongly suggest that these changes depend on the absolute amounts of methionine within seeds and much less to the expression level of AtCGS.

Methionine deficiency in rats fed soy protein induces hypercholesterolemia and potentiates lipoprotein susceptibility to peroxidation.

PubMed

Moundras, C; Rémésy, C; Levrat, M A; Demigné, C

1995-09-01

A number of studies have provided evidence that plant proteins, especially soy protein, have a cholesterol-lowering effect as compared with casein. However, dietary supply of sulfur amino acids may be deficient when soy protein is present in the diet at a suboptimal level, which could affect lipid metabolism. Accordingly, in rats fed 13% protein diets, soy protein feeding resulted in a cholesterol-increasing effect (+18%), which could be counteracted by methionine supplementation (0.4%). In contrast, soy protein was effective in decreasing plasma triglyceride, as compared with levels in rats fed casein; this triglyceride-lowering effect was entirely abolished by methionine supplementation. The hypercholesterolemic effect of soy protein was characterized by a higher cholesterol content in low-density lipoprotein (LDL) and high-density lipoprotein 1 (HDL1) fractions, together with a marked induction of hepatic hydroxymethyl glutaryl coenzyme A (HMG CoA) reductase activity and to a lesser extent cholesterol 7 alpha-hydroxylase. There was practically no induction of these enzymes, as compared with levels in rats fed casein diets, when the soy protein diet was supplemented with methionine. Very-low-density lipoprotein (VLDL) plus LDL susceptibility to peroxidation was higher in rats fed soy protein than in casein-fed rats, which could reflect in part the lack of sulfur amino acid availability, since methionine supplementation led to a partial recovery of lipoprotein resistance to peroxidation. These findings suggest that amino acid imbalance could be atherogenic by increasing circulating cholesterol and leading to a higher lipoprotein susceptibility to peroxidation.

Safety of methionine, a novel biopesticide, to adult and larval honey bees (Apis mellifera L.).

PubMed

Weeks, Emma N I; Schmehl, Daniel R; Baniszewski, Julie; Tomé, Hudson V V; Cuda, James P; Ellis, James D; Stevens, Bruce R

2018-03-01

Methionine is an essential/indispensible amino acid nutrient required by adult and larval honey bees (Apis mellifera L. [Hymenoptera: Apidae]). Bees are unable to rear broods on pollen deficient in methionine, and reportedly behaviorally avoid collecting pollen or nectar from florets deficient in methioinine. In contrast, it has been demonstrated that methionine is toxic to certain pest insects; thus it has been proposed as an effective biopesticide. As an ecofriendly integrated pest management agent, methionine boasts a novel mode of action differentiating it from conventional pesticides, while providing non-target safety. Pesticides that minimize collateral effects on bees are desirable, given the economic and ecological concerns about honey bee health. The aim of the present study was to assess the potential impact of the biopesticide methionine on non-target adult and larval honey bees. Acute contact adult toxicology bioassays, oral adult assessments and chronic larval toxicity assessments were performed as per U.S. Environmental Protection Agency (EPA) requirements. Our results demonstrated that methionine fits the U.S. EPA category of practically nontoxic (i.e. lethal dose to 50% mortality or LD 50 > 11µg/bee) to adult honey bees. The contact LD 50 was > 25µg/bee and the oral LD 50 was > 100µg/bee. Mortality was observed in larval bees that ingested DL-methionine (effective concentration to 50% mortality or EC 50 560µg/bee). Therefore, we conclude that methionine poses little threat to the health of the honey bee, due to unlikely exposure at concentrations shown to elicit toxic effects. Copyright © 2017 Elsevier Inc. All rights reserved.

The relative contribution of genes operating in the S-methylmethionine cycle to methionine metabolism in Arabidopsis seeds.

PubMed

Cohen, Hagai; Salmon, Asaf; Tietel, Zipora; Hacham, Yael; Amir, Rachel

2017-05-01

Enzymes operating in the S -methylmethionine cycle make a differential contribution to methionine synthesis in seeds. In addition, mutual effects exist between the S -methylmethionine cycle and the aspartate family pathway in seeds. Methionine, a sulfur-containing amino acid, is a key metabolite in plant cells. The previous lines of evidence proposed that the S-methylmethionine (SMM) cycle contributes to methionine synthesis in seeds where methionine that is produced in non-seed tissues is converted to SMM and then transported via the phloem into the seeds. However, the relative regulatory roles of the S-methyltransferases operating within this cycle in seeds are yet to be fully understood. In the current study, we generated transgenic Arabidopsis seeds with altered expression of three HOMOCYSTEINE S-METHYLTRANSFERASEs (HMTs) and METHIONINE S-METHYLTRANSFERASE (MMT), and profiled them for transcript and metabolic changes. The results revealed that AtHMT1 and AtHMT3, but not AtHMT2 and AtMMT, are the predominant enzymes operating in seeds as altered expression of these two genes affected the levels of methionine and SMM in transgenic seeds. Their manipulations resulted in adapted expression level of genes participating in methionine synthesis through the SMM and aspartate family pathways. Taken together, our findings provide new insights into the regulatory roles of the SMM cycle and the mutual effects existing between the two methionine biosynthesis pathways, highlighting the complexity of the metabolism of methionine and SMM in seeds.

Cobalamin inactivation by nitrous oxide produces severe neurological impairment in fruit bats: protection by methionine and aggravation by folates

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

van der Westhuyzen, J.; Fernandes-Costa, F.; Metz, J.

Nitrous oxide, which inactivates cobalamin when administered to fruit bats, results in severe neurological impairment leading to ataxia, paralysis and death. This occurs after about 6 weeks in animals depleted of cobalamin by dietary restriction, and after about 10 weeks in cobalamin replete bats. Supplementation of the diet with pteroylglutamic acid caused acceleration of the neurological impairment--the first unequivocal demonstration of aggravation of the neurological lesion in cobalamin deficiency by pteroylglutamic acid. The administration of formyltetrahydropteroylglutamic acid produced similar aggravation of the neurological lesion. Supplementation of the diet with methionine protected the bats from neurological impairment, but failed to preventmore » death. Methionine supplementation protected against the exacerbating effect of folate, preventing the development of neurological changes. These findings lend support to the hypothesis that the neurological lesion in cobalamin deficiency may be related to a deficiency in the methyl donor S-adenosylmethionine which follows diminished synthesis of methionine.« less

Solubility of xenon in amino-acid solutions. II. Nine less-soluble amino acids

NASA Astrophysics Data System (ADS)

Kennan, Richard P.; Himm, Jeffrey F.; Pollack, Gerald L.

1988-05-01

Ostwald solubility (L) of xenon gas, as the radioisotope 133Xe, has been measured as a function of solute concentration, at 25.0 °C, in aqueous solutions of nine amino acids. The amino-acid concentrations investigated covered much of their solubility ranges in water, viz., asparagine monohydrate (0-0.19 M), cysteine (0-1.16 M), glutamine (0-0.22 M), histidine (0-0.26 M), isoleucine (0-0.19 M), methionine (0-0.22 M), serine (0-0.38 M), threonine (0-1.4 M), and valine (0-0.34 M). We have previously reported solubility results for aqueous solutions of six other, generally more soluble, amino acids (alanine, arginine, glycine, hydroxyproline, lysine, and proline), of sucrose and sodium chloride. In general, L decreases approximately linearly with increasing solute concentration in these solutions. If we postulate that the observed decreases in gas solubility are due to hydration, the results under some assumptions can be used to calculate hydration numbers (H), i.e., the number of H2O molecules associated with each amino-acid solute molecule. The average values of hydration number (H¯) obtained at 25.0 °C are 15.3±1.5 for asparagine, 6.8±0.3 for cysteine, 11.5±1.1 for glutamine, 7.3±0.7 for histidine, 5.9±0.4 for isoleucine, 10.6±0.8 for methionine, 11.2±1.3 for serine, 7.7± 1.0 for threonine, and 6.6±0.6 for valine. We have also measured the temperature dependence of solubility L(T) from 5-40 °C for arginine, glycine, and proline, and obtained hydration numbers H¯(T) in this range. Between 25-40 °C, arginine has an H¯ near zero. This may be evidence for an attractive interaction between xenon and arginine molecules in aqueous solution.

Influence of aspartic acid and lysine on the uptake of gold nanoparticles in rice.

PubMed

Ye, Xinxin; Li, Hongying; Wang, Qingyun; Chai, Rushan; Ma, Chao; Gao, Hongjian; Mao, Jingdong

2018-02-01

The interactions between plants and nanomaterials (NMs) can shed light on the environmental consequences of nanotechnology. We used the major crop plant rice (Oryza sativa L.) to investigate the uptake of gold nanoparticles (GNPs) coated with either negatively or positively charged ligands, over a 5-day period, in the absence or presence of one of two amino acids, aspartic acid (Asp) or lysine (Lys), acting as components of rice root exudates. The presence of Asp or Lys influenced the uptake and distribution of GNPs in rice, which depended on the electrical interaction between the coated GNPs and each amino acid. When the electrical charge of the amino acid was the same as that of the surface ligand coated onto the GNPs, the GNPs could disperse well in nutrient solution, resulting in increased uptake of GNPs into rice tissue. The opposite was true where the charge on the surface ligand was different from that on the amino acid, resulting in agglomeration and reduced Au uptake into rice tissue. The behavior of GNPs in the hydroponic nutrient solution was monitored in terms of agglomeration, particle size distribution, and surface charge in the presence and absence of Asp or Lys, which depended strongly on the electrostatic interaction. Results from this study indicated that the species of root exudates must be taken into account in assessing the bioavailability of nanomaterials to plants. Copyright © 2017 Elsevier Inc. All rights reserved.

Nuclear magnetic resonance studies of amino acids and proteins. Side-chain mobility of methionine in the crystalline amonio acid and in crystallne sperm whale (Physeter catodon) myoglobin

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

Keniry, M.A.; Rothgeb, T.M.; Smith, R.L.

1983-04-12

Deuterium (/sup 2/H) nuclear magnetic resonance (NMR) spectra and spin-lattice relaxation times (T/sub 1/) were obtained of L-(epsilon-/sup 2/H/sub 3/)methionine, L-(epsilon-/sup 2/H/sub 3/)methionine in a D,L lattice, and (S-methyl-/sup 2/H/sub 3/)methionine in the crystalline solid state, as a function of temperature, in addition to obtaining /sup 2/H T/sub 1/ and line-width results as a function of temperature on (epsilon-/sup 2/H/sub 3/)methionine-labeled sperm whale (Physeter catodon) myoglobins by using the method of magnetic ordering. Also recorded were /sup 13/C cross-polarization ''magic-angle'' sample-spinning NMR spectra of (epsilon-/sup 13/C)methionine-labeled crystalline cyanoferrimyoglobin (at 37.7 MHz, corresponding to a magnetic field strength of 3.52 T)more » and of the same protein in aqueous solution. (JMT)« less

Characterisation of methionine adenosyltransferase from Mycobacterium smegmatis and M. tuberculosis

PubMed Central

Berger, Bradley J; Knodel, Marvin H

2003-01-01

Background Tuberculosis remains a serious world-wide health threat which requires the characterisation of novel drug targets for the development of future antimycobacterials. One of the key obstacles in the definition of new targets is the large variety of metabolic alterations that occur between cells in the active growth and chronic/dormant phases of tuberculosis. The ideal biochemical target should be active in both growth phases. Methionine adenosyltransferase, which catalyses the formation of S-adenosylmethionine from methionine and ATP, is involved in polyamine biosynthesis during active growth and is also required for the methylation and cyclopropylation of mycolipids necessary for survival in the chronic phase. Results The gene encoding methionine adenosyltransferase has been cloned from Mycobacterium tuberculosis and the model organism M. smegmatis. Both enzymes retained all amino acids known to be involved in catalysing the reaction. While the M. smegmatis enzyme could be functionally expressed, the M. tuberculosis homologue was insoluble and inactive under a large variety of expression conditions. For the M. smegmatis enzyme, the Vmax for S-adenosylmethionine formation was 1.30 μmol/min/mg protein and the Km for methionine and ATP was 288 μM and 76 μM respectively. In addition, the enzyme was competitively inhibited by 8-azaguanine and azathioprine with a Ki of 4.7 mM and 3.7 mM respectively. Azathioprine inhibited the in vitro growth of M. smegmatis with a minimal inhibitory concentration (MIC) of 500 μM, while the MIC for 8-azaguanine was >1.0 mM. Conclusion The methionine adenosyltransferase from both organisms had a primary structure very similar those previously characterised in other prokaryotic and eukaryotic organisms. The kinetic properties of the M. smegmatis enzyme were also similar to known prokaryotic methionine adenosyltransferases. Inhibition of the enzyme by 8-azaguanine and azathioprine provides a starting point for the synthesis of

Quantification of nitrogen in the liquid fraction and in vitro assessment of lysine bioavailability in the solid fraction of soybean meal hydrolysates.

PubMed

Luján-Rhenals, D; Morawicki, R; Shi, Z; Ricke, S C

2018-01-02

Soybean meal (SBM) is a product generated from the manufacture of soybean oil and has the potential for use as a source of fermentable sugars for ethanol production or as a protein source for animal feeds. Knowing the levels of nitrogen available from ammonium is a necessary element of the ethanolic fermentation process while identifying the levels of essential amino acids such as lysine is important in determining usage as a feed source. As such the purpose of this study was to quantify total nitrogen and ammonium in the liquid fraction of hydrolyzed SBM and to evaluate total and bioavailable lysine in the solid fraction of the hydrolyzed SBM. The effects of acid concentration, cellulase and β-glucosidase on total and ammonium nitrogen were studied with analysis indicating that higher acid concentrations increased nitrogen compounds with ammonium concentrations ranging from 0.20 to 1.24 g L -1 while enzymatic treatments did not significantly increase nitrogen levels. Total and bioavailable lysine was quantified by use of an auxotrophic gfpmut3 E.coli whole-cell bioassay organism incapable of lysine biosynthesis. Acid and enzymatic treatments were applied with lysine bioavailability increasing from a base of 82% for untreated SBM to up to 97%. Our results demonstrated that SBM has the potential to serve in ethanolic fermentation and as an optimal source essential amino acid lysine.

Toxicity of seleno-l-methionine, seleno-dl-methionine, high selenium wheat, and selenized yeast to mallard ducklings

USGS Publications Warehouse

Heinz, G.H.; Hoffman, D.J.; LeCaptain, L.J.

1996-01-01

The toxicity of four chemical forms of selenium (seleno-L-methionine, seleno-DL-methionine, selenized yeast, and high selenium wheat) was compared in day-old mallard ducklings (Anas platyrhynchos). In the first experiment, in which the basal diet was 75% wheat, survival after 2 weeks was lower for ducklings fed 30 ?g/g selenium as seleno-L-methionine (36%) than for ducklings fed 30 ?g/g selenium as seleno-DL-methionine (100%) or 30 ?g/g selenium from high selenium yeast (88%). In a second experiment, in which the basal diet was a commercial duck feed, survival after 2 weeks was 100% in ducklings fed 30 ?g/g selenium as seleno-DL-methionine, seleno-L-methionine, or selenized yeast. The greater toxicity of the L form of selenomethionine was probably related to the palatability or nutritional nature of the wheat-based diet used in experiment 1, but the exact reason for the difference between the DL and L forms is unknown. Biologically incorporated selenium, derived from high selenium wheat was no more toxic than selenium derived from the two purified forms of selenomethionine, and the selenium in selenized yeast was not as toxic as that in the two forms of selenomethionine.

21 CFR 172.399 - Zinc methionine sulfate.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Zinc methionine sulfate. 172.399 Section 172.399... CONSUMPTION Special Dietary and Nutritional Additives § 172.399 Zinc methionine sulfate. Zinc methionine... conditions: (a) The additive is the product of the reaction between equimolar amounts of zinc sulfate and DL...

Fatty Acid Comprising Lysine Conjugates: Anti-MRSA Agents That Display In Vivo Efficacy by Disrupting Biofilms with No Resistance Development.

PubMed

Konai, Mohini M; Haldar, Jayanta

2017-04-19

Methicillin-resistant Staphylococcus aureus (MRSA) has developed resistance to antibiotics of last resort such as vancomycin, linezolid, and daptomycin. Additionally, their biofilm forming capability has set an alarming situation in the treatment of bacterial infections. Herein we report the potency of fatty acid comprising lysine conjugates as novel anti-MRSA agents, which were not only capable of killing growing planktonic MRSA at low concentration (MIC = 3.1-6.3 μg/mL), but also displayed potent activity against nondividing stationary phase cells. Furthermore, the conjugates eradicated established biofilms of MRSA. The bactericidal activity of d-lysine conjugated tetradecanoyl analogue (D-LANA-14) is attributed to its membrane disruption against these metabolically distinct cells. In a mouse model of superficial skin infection, D-LANA-14 displayed potent in vivo anti-MRSA activity (2.7 and 3.9 Log reduction at 20 mg/kg and 40 mg/kg, respectively) without showing any skin toxicity even at 200 mg/kg of the compound exposure. Additionally, MRSA could not develop resistance against D-LANA-14 even after 18 subsequent passages, whereas the topical anti-MRSA antibiotic fusidic acid succumbed to rapid resistance development. Collectively, the results suggested that this new class of membrane targeting conjugates bear immense potential to treat MRSA infections over conventional antibiotic therapy.

Why Nature Uses Radical SAM Enzymes so Widely: Electron Nuclear Double Resonance Studies of Lysine 2,3-Aminomutase Show the 5'-dAdo• "Free Radical" Is Never Free.

PubMed

Horitani, Masaki; Byer, Amanda S; Shisler, Krista A; Chandra, Tilak; Broderick, Joan B; Hoffman, Brian M

2015-06-10

Lysine 2,3-aminomutase (LAM) is a radical S-adenosyl-L-methionine (SAM) enzyme and, like other members of this superfamily, LAM utilizes radical-generating machinery comprising SAM anchored to the unique Fe of a [4Fe-4S] cluster via a classical five-membered N,O chelate ring. Catalysis is initiated by reductive cleavage of the SAM S-C5' bond, which creates the highly reactive 5'-deoxyadenosyl radical (5'-dAdo•), the same radical generated by homolytic Co-C bond cleavage in B12 radical enzymes. The SAM surrogate S-3',4'-anhydroadenosyl-L-methionine (anSAM) can replace SAM as a cofactor in the isomerization of L-α-lysine to L-β-lysine by LAM, via the stable allylic anhydroadenosyl radical (anAdo•). Here electron nuclear double resonance (ENDOR) spectroscopy of the anAdo• radical in the presence of (13)C, (2)H, and (15)N-labeled lysine completes the picture of how the active site of LAM from Clostridium subterminale SB4 "tames" the 5'-dAdo• radical, preventing it from carrying out harmful side reactions: this "free radical" in LAM is never free. The low steric demands of the radical-generating [4Fe-4S]/SAM construct allow the substrate target to bind adjacent to the S-C5' bond, thereby enabling the 5'-dAdo• radical created by cleavage of this bond to react with its partners by undergoing small motions, ∼0.6 Å toward the target and ∼1.5 Å overall, that are controlled by tight van der Waals contact with its partners. We suggest that the accessibility to substrate and ready control of the reactive C5' radical, with "van der Waals control" of small motions throughout the catalytic cycle, is common within the radical SAM enzyme superfamily and is a major reason why these enzymes are the preferred means of initiating radical reactions in nature.

The specific features of methionine biosynthesis and metabolism in plants

PubMed Central

Ravanel, Stéphane; Gakière, Bertrand; Job, Dominique; Douce, Roland

1998-01-01

Plants, unlike other higher eukaryotes, possess all the necessary enzymatic equipment for de novo synthesis of methionine, an amino acid that supports additional roles than simply serving as a building block for protein synthesis. This is because methionine is the immediate precursor of S-adenosylmethionine (AdoMet), which plays numerous roles of being the major methyl-group donor in transmethylation reactions and an intermediate in the biosynthesis of polyamines and of the phytohormone ethylene. In addition, AdoMet has regulatory function in plants behaving as an allosteric activator of threonine synthase. Among the AdoMet-dependent reactions occurring in plants, methylation of cytosine residues in DNA has raised recent interest because impediment of this function alters plant morphology and induces homeotic alterations in flower organs. Also, AdoMet metabolism seems somehow implicated in plant growth via an as yet fully understood link with plant-growth hormones such as cytokinins and auxin and in plant pathogen interactions. Because of this central role in cellular metabolism, a precise knowledge of the biosynthetic pathways that are responsible for homeostatic regulation of methionine and AdoMet in plants has practical implications, particularly in herbicide design. PMID:9636232

Effect of dietary supplementation with amino acids on boar sperm quality and fertility.

PubMed

Dong, Hong-Jun; Wu, De; Xu, Sheng-Yu; Li, Qiang; Fang, Zheng-Feng; Che, Lian-Qiang; Wu, Cai-Mei; Xu, Xue-Yu; Lin, Yan

2016-09-01

The aim of this study was to evaluate the effects of dietary supplementation with amino acids on sperm quality and fertility rates after insemination with boar semen. Twelve Yorkshire boars were paired by age and allocated to one of two dietary treatments composed of total lysine levels of 0.64% (T1) and 0.96% (T2), with the lysine: methionine: threonine: tryptophan: valine ratio in the diets set to 100:27:73:19:69 through the addition of synthetic amino acids. Semen was collected twice weekly (phase 1, 1-12 wk); every other day (phase 2, 13-16 wk); twice weekly (phase 3, 17-26 wk); and daily (phase 4, 27-28 wk). Semen was collected from boars during phase 3 and used to inseminate 64 multiparous sows. Our results showed that sperm concentration and total sperm cells were greater in boars in T2 than in boars in T1 in phases 2 and 4 (P<0.05). Sperm motility parameters, morphologically normal sperm, and acrosome integrity in T2 boars were greater than those in T1 boars (P<0.05) during the experiment. Free amino acid concentrations in seminal plasma increased in T2 boars (P<0.05). Furthermore, sows inseminated with semen collected from T2 boars gave birth to more live piglets than those inseminated with semen collected from T1 boars (P=0.04). In conclusion, supplementation of boar diet with amino acids improves sperm quality, and subsequently increases fertilization capacity and the number of live piglets. Copyright © 2016. Published by Elsevier B.V.

A 100-Year Review: Protein and amino acid nutrition in dairy cows.

PubMed

Schwab, Charles G; Broderick, Glen A

2017-12-01

Considerable progress has been made in understanding the protein and amino acid (AA) nutrition of dairy cows. The chemistry of feed crude protein (CP) appears to be well understood, as is the mechanism of ruminal protein degradation by rumen bacteria and protozoa. It has been shown that ammonia released from AA degradation in the rumen is used for bacterial protein formation and that urea can be a useful N supplement when lower protein diets are fed. It is now well documented that adequate rumen ammonia levels must be maintained for maximal synthesis of microbial protein and that a deficiency of rumen-degradable protein can decrease microbial protein synthesis, fiber digestibility, and feed intake. Rumen-synthesized microbial protein accounts for most of the CP flowing to the small intestine and is considered a high-quality protein for dairy cows because of apparent high digestibility and good AA composition. Much attention has been given to evaluating different methods to quantify ruminal protein degradation and escape and for measuring ruminal outflows of microbial protein and rumen-undegraded feed protein. The methods and accompanying results are used to determine the nutritional value of protein supplements and to develop nutritional models and evaluate their predictive ability. Lysine, methionine, and histidine have been identified most often as the most-limiting amino acids, with rumen-protected forms of lysine and methionine available for ration supplementation. Guidelines for protein feeding have evolved from simple feeding standards for dietary CP to more complex nutrition models that are designed to predict supplies and requirements for rumen ammonia and peptides and intestinally absorbable AA. The industry awaits more robust and mechanistic models for predicting supplies and requirements of rumen-available N and absorbed AA. Such models will be useful in allowing for feeding lower protein diets and increased efficiency of microbial protein synthesis

Lysine acetylation sites prediction using an ensemble of support vector machine classifiers.

PubMed

Xu, Yan; Wang, Xiao-Bo; Ding, Jun; Wu, Ling-Yun; Deng, Nai-Yang

2010-05-07

Lysine acetylation is an essentially reversible and high regulated post-translational modification which regulates diverse protein properties. Experimental identification of acetylation sites is laborious and expensive. Hence, there is significant interest in the development of computational methods for reliable prediction of acetylation sites from amino acid sequences. In this paper we use an ensemble of support vector machine classifiers to perform this work. The experimentally determined acetylation lysine sites are extracted from Swiss-Prot database and scientific literatures. Experiment results show that an ensemble of support vector machine classifiers outperforms single support vector machine classifier and other computational methods such as PAIL and LysAcet on the problem of predicting acetylation lysine sites. The resulting method has been implemented in EnsemblePail, a web server for lysine acetylation sites prediction available at http://www.aporc.org/EnsemblePail/. Copyright (c) 2010 Elsevier Ltd. All rights reserved.

Dietary Deficiency of Essential Amino Acids Rapidly Induces Cessation of the Rat Estrous Cycle

PubMed Central

Bannai, Makoto; Ichimaru, Toru; Nakano, Sayako; Murata, Takuya; Higuchi, Takashi; Takahashi, Michio

2011-01-01

Reproductive functions are regulated by the sophisticated coordination between the neuronal and endocrine systems and are sustained by a proper nutritional environment. Female reproductive function is vulnerable to effects from dietary restrictions, suggesting a transient adaptation that prioritizes individual survival over reproduction until a possible future opportunity for satiation. This adaptation could also partially explain the existence of amenorrhea in women with anorexia nervosa. Because amino acid nutritional conditions other than caloric restriction uniquely alters amino acid metabolism and affect the hormonal levels of organisms, we hypothesized that the supply of essential amino acids in the diet plays a pivotal role in the maintenance of the female reproductive system. To test this hypothesis, we examined ovulatory cyclicity in female rats under diets that were deficient in threonine, lysine, tryptophan, methionine or valine. Ovulatory cyclicity was monitored by daily cytological evaluations of vaginal smears. After continuous feeding of the deficient diet, a persistent diestrus or anovulatory state was induced most quickly by the valine-deficient diet and most slowly by the lysine-deficient diet. A decline in the systemic insulin-like growth factor 1 level was associated with a dietary amino acid deficiency. Furthermore, a paired group of rats that were fed an isocaloric diet with balanced amino acids maintained normal estrous cyclicity. These disturbances of the estrous cycle by amino acid deficiency were quickly reversed by the consumption of a normal diet. The continuous anovulatory state in this study is not attributable to a decrease in caloric intake but to an imbalance in the dietary amino acid composition. With a shortage of well-balanced amino acid sources, reproduction becomes risky for both the mother and the fetus. It could be viewed as an adaptation to the diet, diverting resources away from reproduction and reallocating them to

Multifactorial modulation of susceptibility to l-lysine in an animal model of glutaric aciduria type I.

PubMed

Sauer, Sven W; Opp, Silvana; Komatsuzaki, Shoko; Blank, Anna-Eva; Mittelbronn, Michel; Burgard, Peter; Koeller, D M; Okun, Jürgen G; Kölker, Stefan

2015-05-01

Glutaric aciduria type I is an inherited defect in L-lysine, L-hydroxylysine and L-tryptophan degradation caused by deficiency of glutaryl-CoA dehydrogenase (GCDH). The majority of untreated patients presents with accumulation of neurotoxic metabolites - glutaric acid (GA) and 3-hydroxyglutaric acid (3-OHGA) - and striatal injury. Gcdh(-/-) mice display elevated levels of GA and 3-OH-GA but do not spontaneously develop striatal lesions. L-lysine-enriched diets (appr. 235 mg/d) were suggested to induce a neurological phenotype similar to affected patients. In our hands 93% of mice stressed according to the published protocol remained asymptomatic. To understand the underlying mechanism, we modified their genetic background (F1 C57BL6/Jx129/SvCrl) and increased the daily oral L-lysine supply (235-433 mg). We identified three modulating factors, (1) gender, (2) genetic background, and (3) amount of L-lysine. Male mice displayed higher vulnerability and inbreeding for more than two generations as well as elevating L-lysine supply increased the diet-induced mortality rate (up to 89%). Onset of first symptoms leads to strongly reduced intake of food and, thus, L-lysine suggesting a threshold for toxic metabolite production to induce neurological disease. GA and 3-OH-GA tissue concentrations did not correlate with dietary L-lysine supply but differed between symptomatic and asymptomatic mice. Cerebral activities of glyceraldehyde 3-phosphate dehydrogenase, 2-oxoglutarate dehydrogenase complex, and aconitase were decreased. Symptomatic mice did not develop striatal lesions or intracerebral hemorrhages. We found severe spongiosis in the hippocampus of Gcdh(-/-) mice which was independent of dietary L-lysine supply. In conclusion, the L-lysine-induced pathology in Gcdh(-/-) mice depends on genetic and dietary parameters. Copyright © 2014. Published by Elsevier B.V.

Storage proteins of common bean identified with 2D-PAGE

USDA-ARS?s Scientific Manuscript database

The common bean is a significant source of protein, complex carbohydrates, fiber, and minerals. Seeds of most dry beans contain 15 to 25% protein and are rich in lysine but low in the sulfur containing amino acids cysteine and methionine. Knowledge of common bean proteins is important for research a...

Characterization and crystal structure of lysine insensitive Corynebacterium glutamicum dihydrodipicolinate synthase (cDHDPS) protein

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

Rice, E.A.; Bannon, G.A.; Glenn, K.C.

2008-11-21

The lysine insensitive Corynebacterium glutamicum dihydrodipicolinate synthase enzyme (cDHDPS) was recently successfully introduced into maize plants to enhance the level of lysine in the grain. To better understand lysine insensitivity of the cDHDPS, we expressed, purified, kinetically characterized the protein, and solved its X-ray crystal structure. The cDHDPS enzyme has a fold and overall structure that is highly similar to other DHDPS proteins. A noteworthy feature of the active site is the evidence that the catalytic lysine residue forms a Schiff base adduct with pyruvate. Analyses of the cDHDPS structure in the vicinity of the putative binding site for S-lysinemore » revealed that the allosteric binding site in the Escherichia coli DHDPS protein does not exist in cDHDPS due to three non-conservative amino acids substitutions, and this is likely why cDHDPS is not feedback inhibited by lysine.« less

Effect of technological processing and preservation method on amino acid content and protein quality in kale (Brassica oleracea L. var. acephala) leaves.

PubMed

Korus, Anna

2012-02-01

The aim of the investigation was to evaluate the level of amino acids and quality of protein in raw and processed kale leaves. In all samples the dominant amino acids in g kg⁻¹ raw matter were glutamic acid, aspartic acid and proline. In raw kale leaves the limiting amino acids were lysine, isoleucine and cystine with methionine, and in the remaining products also valine and leucine. Blanched kale leaves contained 88% of the amino acid content in raw leaves, 76% in cooked leaves, and 69-77% and 71-72% of initial levels in frozen and canned products, respectively. In raw, blanched and cooked leaves essential amino acids comprised 44%, 44% and 47%, respectively, of total amino acids; in frozen and canned leaves the proportions were 46% and 44%, respectively. The essential amino acid index was 97 for canned products, 100-109 for frozen leaves, and 117 for raw kale leaves. Raw and processed (blanched or cooked) kale leaves are a good source of amino acids. Copyright © 2011 Society of Chemical Industry.

Quantification of Nε-(2-Furoylmethyl)-L-lysine (furosine), Nε-(Carboxymethyl)-L-lysine (CML), Nε-(Carboxyethyl)-L-lysine (CEL) and total lysine through stable isotope dilution assay and tandem mass spectrometry.

PubMed

Troise, Antonio Dario; Fiore, Alberto; Wiltafsky, Markus; Fogliano, Vincenzo

2015-12-01

The control of Maillard reaction (MR) is a key point to ensure processed foods quality. Due to the presence of a primary amino group on its side chain, lysine is particularly prone to chemical modifications with the formation of Amadori products (AP), Nε-(Carboxymethyl)-L-lysine (CML), Nε-(Carboxyethyl)-L-lysine (CEL). A new analytical strategy was proposed which allowed to simultaneously quantify lysine, CML, CEL and the Nε-(2-Furoylmethyl)-L-lysine (furosine), the indirect marker of AP. The procedure is based on stable isotope dilution assay followed by liquid chromatography tandem mass spectrometry. It showed high sensitivity and good reproducibility and repeatability in different foods. The limit of detection and the RSD% were lower than 5 ppb and below 8%, respectively. Results obtained with the new procedure not only improved the knowledge about the reliability of thermal treatment markers, but also defined new insights in the relationship between Maillard reaction products and their precursors. Copyright © 2015 Elsevier Ltd. All rights reserved.

Distance restraints from crosslinking mass spectrometry: mining a molecular dynamics simulation database to evaluate lysine-lysine distances.

PubMed

Merkley, Eric D; Rysavy, Steven; Kahraman, Abdullah; Hafen, Ryan P; Daggett, Valerie; Adkins, Joshua N

2014-06-01

Integrative structural biology attempts to model the structures of protein complexes that are challenging or intractable by classical structural methods (due to size, dynamics, or heterogeneity) by combining computational structural modeling with data from experimental methods. One such experimental method is chemical crosslinking mass spectrometry (XL-MS), in which protein complexes are crosslinked and characterized using liquid chromatography-mass spectrometry to pinpoint specific amino acid residues in close structural proximity. The commonly used lysine-reactive N-hydroxysuccinimide ester reagents disuccinimidylsuberate (DSS) and bis(sulfosuccinimidyl)suberate (BS(3) ) have a linker arm that is 11.4 Å long when fully extended, allowing Cα (alpha carbon of protein backbone) atoms of crosslinked lysine residues to be up to ∼24 Å apart. However, XL-MS studies on proteins of known structure frequently report crosslinks that exceed this distance. Typically, a tolerance of ∼3 Å is added to the theoretical maximum to account for this observation, with limited justification for the chosen value. We used the Dynameomics database, a repository of high-quality molecular dynamics simulations of 807 proteins representative of diverse protein folds, to investigate the relationship between lysine-lysine distances in experimental starting structures and in simulation ensembles. We conclude that for DSS/BS(3), a distance constraint of 26-30 Å between Cα atoms is appropriate. This analysis provides a theoretical basis for the widespread practice of adding a tolerance to the crosslinker length when comparing XL-MS results to structures or in modeling. We also discuss the comparison of XL-MS results to MD simulations and known structures as a means to test and validate experimental XL-MS methods. © 2014 The Protein Society.

Effect of multi-nutrient insufficiency on markers of one carbon metabolism in young women: response to a methionine load.

PubMed

Katre, P; Joshi, S; Bhat, D S; Deshmukh, M; Gurav, N; Pandit, S; Lubree, H; Marczewski, S; Bennett, C; Gruca, L; Kalyanaraman, K; Naik, S S; Yajnik, C S; Kalhan, S C

2016-06-01

Multi-nutrient insufficiencies as a consequence of nutritional and economic factors are common in India and other developing countries. We have examined the impact of multi-nutrient insufficiency on markers of one carbon (1C) metabolism in the blood, and response to a methionine load in clinically healthy young women. Young women from Pune, India (n=10) and Cleveland, USA (n=13) were studied. Blood samples were obtained in the basal state and following an oral methionine load (50 mg/kg of body weight in orange juice). Plasma concentrations of vitamin B12, folate and B6 were measured in the basal state. The effect of methionine load on the levels of methionine, total homocysteine, cysteine, glutathione and amino acids was examined. Indian women were significantly shorter and lighter compared with the American women and had lower plasma concentration of vitamins B12, folate and B6, essential amino acids and glutathione, but higher concentration of total homocysteine. The homocysteine response to methionine load was higher in Indian women. The plasma concentrations of glycine and serine increased in the Indian women after methionine (in juice) load. A significant negative correlation between plasma B6 and homocysteine (r= -0.70), and plasma folate and glycine and serine levels were observed in the Indian group (P<0.05) but not in the American group. Multi-nutrient insufficiency in the Indian women caused unique changes in markers of whole body protein and 1C metabolism. These data would be useful in developing nutrient intervention strategies.

Child Stunting is Associated with Low Circulating Essential Amino Acids.

PubMed

Semba, Richard D; Shardell, Michelle; Sakr Ashour, Fayrouz A; Moaddel, Ruin; Trehan, Indi; Maleta, Kenneth M; Ordiz, M Isabel; Kraemer, Klaus; Khadeer, Mohammed A; Ferrucci, Luigi; Manary, Mark J

2016-04-01

Stunting affects about one-quarter of children under five worldwide. The pathogenesis of stunting is poorly understood. Nutritional interventions have had only modest effects in reducing stunting. We hypothesized that insufficiency in essential amino acids may be limiting the linear growth of children. We used a targeted metabolomics approach to measure serum amino acids, glycerophospholipids, sphingolipids, and other metabolites using liquid chromatography-tandem mass spectrometry in 313 children, aged 12-59months, from rural Malawi. Children underwent anthropometry. Sixty-two percent of the children were stunted. Children with stunting had lower serum concentrations of all nine essential amino acids (tryptophan, isoleucine, leucine, valine, methionine, threonine, histidine, phenylalanine, lysine) compared with nonstunted children (p<0.01). In addition, stunted children had significantly lower serum concentrations of conditionally essential amino acids (arginine, glycine, glutamine), non-essential amino acids (asparagine, glutamate, serine), and six different sphingolipids compared with nonstunted children. Stunting was also associated with alterations in serum glycerophospholipid concentrations. Our findings support the idea that children with a high risk of stunting may not be receiving an adequate dietary intake of essential amino acids and choline, an essential nutrient for the synthesis of sphingolipids and glycerophospholipids. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

Adsorption of Lysine on Na-Montmorillonite and Competition with Ca(2+): A Combined XRD and ATR-FTIR Study.

PubMed

Yang, Yanli; Wang, Shengrui; Liu, Jingyang; Xu, Yisheng; Zhou, Xiaoyun

2016-05-17

Lysine adsorption at clay/aqueous interfaces plays an important role in the mobility, bioavailability, and degradation of amino acids in the environment. Knowledge of these interfacial interactions facilitates our full understanding of the fate and transport of amino acids. Here, X-ray diffraction (XRD) and attenuated total reflectance Fourier-transform infrared spectroscopy (ATR-FTIR) measurements were used to explore the dynamic process of lysine adsorption on montmorillonite and the competition with Ca(2+) at the molecular level. Density functional theory (DFT) calculations were employed to determine the peak assignments of dissolved lysine in the solution phase. Three surface complexes, including dicationic, cationic, and zwitterionic structures, were observed to attach to the clay edge sites and penetrate the interlayer space. The increased surface coverage and Ca(2+) competition did not affect the interfacial lysine structures at a certain pH, whereas an elevated lysine concentration contributed to zwitterionic-type coordination at pH 10. Moreover, clay dissolution at pH 4 could be inhibited at a higher surface coverage with 5 and 10 mM lysine, whereas the inhibition effect was inconspicuous or undetected at pH 7 and 10. The presence of Ca(2+) not only could remove a part of the adsorbed lysine but also could facilitate the readsorption of dissolved Si(4+) and Al(3+) and surface protonation. Our results provide new insights into the process of lysine adsorption and its effects on montmorillonite surface sites.

Oxidation of methionine - is it limiting the diagnostic properties of 99mTc-labeled Exendin-4, a Glucagon-Like Peptide-1 receptor agonist?

PubMed

Janota, Barbara; Karczmarczyk, Urszula; Laszuk, Ewa; Garnuszek, Piotr; Mikołajczak, Renata

2016-01-01

Preliminary clinical evaluation of 99mTc-EDDA/HYNIC-Met14-Exendin-4 showed that the complex offers new diagnostic possibilities for insulinoma and MTC. Exendin-4 contains methionine at position 14 in the amino acid chain, which may be oxidized to methionine sulfoxide and, from the pharmaceutical point of view, the oxidized moiety becomes an undesired impurity in the final radioactive preparation. Therefore, the aim of this study was to investigate the influence of commonly used methods to eliminate the effect of methionine oxidation in peptides, i.e. the replacement of methionine by norleucine (Nle) and the addition of L-methionine, on the in vitro stability and the biodistribution. 99mTc-EDDA/HYNIC-Met14-Exendin-4, 99mTc-EDDA/HYNIC-Nle14-Exendin-4, 99mTc-EDDA/HYNIC-Met14-Ex-endin-4 with the addition of L-methionine and an oxidized form of Exendin-4, i.e. 99mTc-EDDA/HYNIC-Met14(ox)-Exendin-4 were compared in vivo with 68Ga-NODAGA-Nle14-Exendin-4 in normal Wistar rats. The stability and lipophilicity were determined in vitro. Biodistribution studies confirmed the specific uptake of all tested complexes in the GLP-1 positive organs: lungs, pancreas and stomach. The uptake of 99mTc-EDDA/HYNIC-Met14-Exendin-4 with the addition of L-methionine and for 68Ga-NODAGA-Nle14-Exendin-4 at 1h p.i. was around 2-fold higher than that of 99mTc-EDDA/HYNIC-Met14-Exendin-4 and 99mTc-EDDA/HYNIC-Nle14-Exendin-4. Although the substitution of methionine by norleucine in the HYNIC-Exendin-4 did not result in improved bio-distribution, the use of L-methionine, as the excipient that inhibits the oxidation of methionine in the peptide chain resulted in higher lung/blood and stomach/blood uptake ratios. Our results confirmed that methionine at position 14 of amino acid chain of Exendin-4 plays an important role in the interaction with GLP-1 receptor positive tissue.

Lysine Succinylation Contributes to Aflatoxin Production and Pathogenicity in Aspergillus flavus*

PubMed Central

Ren, Silin; Yang, Mingkun; Yue, Yuewei; Ge, Feng; Li, Yu; Guo, Xiaodong; Zhang, Jia; Zhang, Feng; Nie, Xinyi; Wang, Shihua

2018-01-01

Aspergillus flavus (A. flavus) is a ubiquitous saprophytic and pathogenic fungus that produces the aflatoxin carcinogen, and A. flavus can have tremendous economic and health impacts worldwide. Increasing evidence demonstrates that lysine succinylation plays an important regulatory role in metabolic processes in both bacterial and human cells. However, little is known about the extent and function of lysine succinylation in A. flavus. Here, we performed a global succinylome analysis of A. flavus using high accuracy nano-LC-MS/MS in combination with the enrichment of succinylated peptides from digested cell lysates and subsequent peptide identification. In total, 985 succinylation sites on 349 succinylated proteins were identified in this pathogen. Bioinformatics analysis revealed that the succinylated proteins were involved in various biological processes and were particularly enriched in the aflatoxin biosynthesis process. Site-specific mutagenesis and biochemical studies showed that lysine succinylation on the norsolorinic acid reductase NorA (AflE), a key enzyme in aflatoxins biosynthesis, can affect the production of sclerotia and aflatoxins biosynthesis in A. flavus. Together, our findings reveal widespread roles for lysine succinylation in regulating metabolism and aflatoxins biosynthesis in A. flavus. Our data provide a rich resource for functional analyses of lysine succinylation and facilitate the dissection of metabolic networks in this pathogen. PMID:29298838

Why Nature Uses Radical SAM Enzymes so Widely: Electron Nuclear Double Resonance Studies of Lysine 2,3-Aminomutase Show the 5′-dAdo• “Free Radical” Is Never Free

PubMed Central

Horitani, Masaki; Byer, Amanda S.; Shisler, Krista A.; Chandra, Tilak; Broderick, Joan B.; Hoffman, Brian M.

2015-01-01

Lysine 2,3-aminomutase (LAM) is a radical S-adenosyl-L-methionine (SAM) enzyme and, like other members of this superfamily, LAM utilizes radical-generating machinery comprising SAM anchored to the unique Fe of a [4Fe-4S] cluster via a classical five-membered N,O chelate ring. Catalysis is initiated by reductive cleavage of the SAM S–C5′ bond, which creates the highly reactive 5′-deoxyadenosyl radical (5′-dAdo•), the same radical generated by homolytic Co–C bond cleavage in B12 radical enzymes. The SAM surrogate S-3′,4′-anhydroadenosyl-L-methionine (anSAM) can replace SAM as a cofactor in the isomerization of L-α-lysine to L-β-lysine by LAM, via the stable allylic anhydroadenosyl radical (anAdo•). Here electron nuclear double resonance (ENDOR) spectroscopy of the anAdo• radical in the presence of 13C, 2H, and 15N-labeled lysine completes the picture of how the active site of LAM from Clostridium subterminale SB4 “tames” the 5′-dAdo• radical, preventing it from carrying out harmful side reactions: this “free radical” in LAM is never free. The low steric demands of the radical-generating [4Fe-4S]/SAM construct allow the substrate target to bind adjacent to the S–C5′ bond, thereby enabling the 5′-dAdo• radical created by cleavage of this bond to react with its partners by undergoing small motions, ~0.6 Å toward the target and ~1.5 Å overall, that are controlled by tight van der Waals contact with its partners. We suggest that the accessibility to substrate and ready control of the reactive C5′ radical, with “van der Waals control” of small motions throughout the catalytic cycle, is common within the radical SAM enzyme superfamily and is a major reason why these enzymes are the preferred means of initiating radical reactions in nature. PMID:25923449

Crystal growth, structural, spectral, thermal, dielectric, linear and nonlinear optical characteristics of a new organic acentric material: L-Methionine-Succinic acid (2/1)

NASA Astrophysics Data System (ADS)

Nageshwari, M.; Kumari, C. Rathika Thaya; Vinitha, G.; Mohamed, M. Peer; Sudha, S.; Caroline, M. Lydia

2018-03-01

L-Methionine-Succinic acid (2/1) (LMSA), 2C5H11NO2S·C4H6O4, a novel nonlinear optical material which belongs to the class of organic category was grown-up for the first time by the technique of slow evaporation. Purity of LMSA was improved using repetitive recrystallization. LMSA was analyzed by single crystal and powder X-ray diffraction investigation to affirm the crystal structure and crystalline character. The single crystal XRD revealed that LMSA corresponds to the crystal system of triclinic with P1 as space group showing the asymmetric unit consists of a neutral succinic acid molecule and two methionine residues which are crystallographically independent existing in zwitterionic form. The functional groups existing in LMSA was accomplished using Fourier transform infrared spectroscopy. The optical transparency and the band gap energy were identified utilizing UV-Visible spectrum. The optical constants specifically reflectance and extinction coefficient clearly indicate the elevated transparency of LMSA. The thermal analyses affirmed its thermal stability. The luminescence behavior of LMSA has been analyzed by Photoluminescence (PL) spectral study. The mechanical, laser damage threshold and dielectric investigation of LMSA was done to suggest the material for practical applications. The second and third harmonic generation efficacy was confirmed by means of Kurtz-Perry and Z-scan procedure which attest its potentiality in the domain of nonlinear optics.

THE EFFECT OF dl-METHIONINE, l-CYSTINE, AND dl-ISOLEUCINE ON THE UTILIZATION OF PARENTERALLY ADMINISTERED DOG HEMOGLOBIN

PubMed Central

Miller, Leon L.; Alling, Eric L.

1947-01-01

1. Further observations on the utilization of parenterally administered dog hemoglobin show that oral supplements of dl-methionine and l-cystine improve the efficiency of utilization of hemoglobin N, while a fed supplement of dl-isoleucine alone is without effect. 2. When N-isoleucine is added to a fed supplement of methionine or methionine and cystine, the utilization of parenterally given hemoglobin N is even better than with the sulfur-containing amino acids alone. 3. A suggested approach to the problem of designing the quantitatively "ideal" amino acid mixture lies in the definition of what may be called total organism-amino acid patterns of rat, dog, man, etc. These may vary considerably not only at different developmental stages in a given species, but also certainly from one species to another. 4. Further attempts to detect globin in the peripheral circulation have pointed to the need for a highly specific procedure such as that an immunologic method may offer. 5. Reduced hemin in dog plasma migrates with α1-globulin and albumin in veronal buffer at pH 8.5 and the colored zones give strong hemochromogen absorption bands. PMID:19871599

Lysine and novel hydroxylysine lipids in soil bacteria: amino acid membrane lipid response to temperature and pH in Pseudopedobacter saltans

PubMed Central

Moore, Eli K.; Hopmans, Ellen C.; Rijpstra, W. Irene C.; Sánchez-Andrea, Irene; Villanueva, Laura; Wienk, Hans; Schoutsen, Frans; Stams, Alfons J. M.; Sinninghe Damsté, Jaap S.

2015-01-01

Microbial decomposition of organic matter is an essential process in the global carbon cycle. The soil bacteria Pseudopedobacter saltans and Flavobacterium johnsoniae are both able to degrade complex organic molecules, but it is not fully known how their membrane structures are adapted to their environmental niche. The membrane lipids of these species were extracted and analyzed using high performance liquid chromatography-electrospray ionization/ion trap/mass spectrometry (HPLC-ESI/IT/MS) and high resolution accurate mass/mass spectrometry (HRAM/MS). Abundant unknown intact polar lipids (IPLs) from P. saltans were isolated and further characterized using amino acid analysis and two dimensional nuclear magnetic resonance (NMR) spectroscopy. Ornithine IPLs (OLs) with variable (hydroxy) fatty acid composition were observed in both bacterial species. Lysine-containing IPLs (LLs) were also detected in both species and were characterized here for the first time using HPLC-MS. Novel LLs containing hydroxy fatty acids and novel hydroxylysine lipids with variable (hydroxy) fatty acid composition were identified in P. saltans. The confirmation of OL and LL formation in F. johnsoniae and P. saltans and the presence of OlsF putative homologs in P. saltans suggest the OlsF gene coding protein is possibly involved in OL and LL biosynthesis in both species, however, potential pathways of OL and LL hydroxylation in P. saltans are still undetermined. Triplicate cultures of P. saltans were grown at three temperature/pH combinations: 30°C/pH 7, 15°C/pH 7, and 15°C/pH 9. The fractional abundance of total amino acid containing IPLs containing hydroxylated fatty acids was significantly higher at higher temperature, and the fractional abundance of lysine-containing IPLs was significantly higher at lower temperature and higher pH. These results suggest that these amino acid-containing IPLs, including the novel hydroxylysine lipids, could be involved in temperature and pH stress

Ex-vivo absorption study of lysine R-lipoate salt, a new pharmaceutical form of R-ALA.

PubMed

Amenta, Francesco; Buccioni, Michela; Ben, Diego Dal; Lambertucci, Catia; Navia, Aleix Martí; Ngouadjeu Ngnintedem, Michael A; Ricciutelli, Massimo; Spinaci, Andrea; Volpini, Rosaria; Marucci, Gabriella

2018-06-15

Alpha-lipoic acid (ALA) oral supplements were used in many pathologies associated with increased oxidative stress. Although only R-ALA is considered the biologically active form, R,S-ALA is used in therapeutic applications even showing poor water solubility. The aim of this work was to study the absorption and transport mechanism across the intestinal barrier of new R-ALA stable and water soluble form, consisting in the lysine R-ALA salt, in presence and absence of specific inhibitors of Na + /multivitamin (SMVT) and monocarboxylic acids (MCT). The absorption of a new ALA form was investigated at rat everted sacs in comparison with R-ALA, S-ALA, and R,S-ALA. Results showed that duodenum is the best portion of intestine for ALA forms absorption. The absorption percentage of R-ALA, S-ALA, R,S-ALA, and lysine R-ALA salt was 66%, 43%, 55%, and 70%, respectively. The modest effect of the SMVT inhibitor biotin demonstrated that this transporter system is not principally involved in the absorption of lysine R-lipoate salt across the rat intestinal barrier. On the contrary, the MCT inhibitor octanoic acid significantly reduced the transport of this salt, whit an absorption decrease of R-ALA and lysine R-lipoate salt of 28% and 24%, respectively. Since the highest concentration of these inhibitors did not completely inhibit the absorption of lysine R-lipoate salt, other transport mechanisms probably operate for its intracellular delivery. The new form of ALA, lysine R-lipoate salt, was the most absorbed respect to the other ALA forms demonstrating that this compound is more suitable for oral administration. This new salt could represent a promising candidate for ALA oral supplementation. Copyright © 2018 Elsevier B.V. All rights reserved.

Amino Acid and Vitamin Requirements of Several Bacteroides Strains

PubMed Central

Quinto, Grace

1966-01-01

Nutritional studies were performed on nine Bacteroides strains, by use of the methodology and media of anaerobic rumen microbiology. Ristella perfoetens CCI required l-arginine hydrochloride, l-tryptophan, l-leucine, l-histidine hydrochloride, l-cysteine hydrochloride, dl-valine, dl-tyrosine, and the vitamin calcium-d-pantothenate, since scant turbidity developed in media without these nutrients. R. perfoetens was stimulated by glycine, dl-lysine hydrochloride, dl-isoleucine, l-proline, l-glutamic acid, dl-alanine, dl-phenylalanine, dl-methionine, and the vitamins nicotinamide and p-aminobenzoic acid, since maximal turbidity developed more slowly in media without these nutrients than in complete medium. Medium A-23, which was devised for R. perfoetens, contained salts, 0.0002% nicotinamide and calcium d-pantothenate, 0.00001% p-aminobenzoic acid, 0.044% l-tryptophan, 0.09% l-glutamic acid, and 0.1% of the other 13 amino acids listed above. Zuberella clostridiformis and seven strains of R. pseudoinsolita did not require vitamins, and showed no absolute requirement for any one amino acid. Various strains produced maximal turbidity more slowly in media deficient in l-proline, glycine, l-glutamic acid, dl-serine, l-histidine hydrochloride, dl-alanine, or l-cysteine hydrochloride, than in complete medium. These eight strains grew optimally in medium A-23 plus 0.1% dl-serine but without vitamins. PMID:16349673

Effects of ensiling cereal grains (barley, wheat, triticale and rye) on total and pre-caecal digestibility of proximate nutrients and amino acids in pigs.

PubMed

Hackl, W; Pieper, B; Pieper, R; Korn, U; Zeyner, A

2010-12-01

Inclemency of weather frequently causes critical water contents in cereal grains above 15%. Ensiling in pre-mature condition may be an alternative to other techniques of preservation. Aim of this study was to compare apparent total tract digestibility (D(t) ; barley, wheat, triticale, rye) of proximate nutrients and pre-caecal digestibility (D(pc); barley, wheat) of amino acids (AA), respectively, from cereal grains in ensiled and almost dry condition. Moistly harvested cereal grains (67-73% dry matter) were milled through a 4-mm sieve and ensiled with lactic acid bacteria (LAB, 3 × 10(5) colony forming units/g Lactobacillus plantarum DSMZ 8862 and 8866). To investigate D(t), two trials were conducted with six Mini-Lewe pigs and four German Landrace pigs, respectively. D(pc) of AA was determined using four German Landrace pigs with ileo-rectal anastomosis. D(t) of proximate nutrients did not differ between cereal grains and their silages, except for ether extract, which was more digestible in ensiled than dry wheat, triticale and rye (p < 0.05). Lysine content was lower in ensiled than dry barley and wheat. In barley, ensiling was accompanied by reduced D(pc) of lysine and histidine (p < 0.05). In wheat, ensiling increased D(pc) of lysine, methionine, threonine and leucin (p < 0.05). Ensiling of pre-mature cereal grains with LAB can serve as a reasonable storage alternative. However, as limited data are yet available, further research is required to understand completely the impact of ensiling on nutritional value as indicated, for example, by the lysine content and the D(pc) of certain AA. © 2010 Blackwell Verlag GmbH.

Polydiacetylenyl β-cyclodextrin based smart vesicles for colorimetric assay of arginine and lysine

NASA Astrophysics Data System (ADS)

Cho, Eunae; Kim, Hwanhee; Choi, Youngjin; Paik, Seung R.; Jung, Seunho

2016-08-01

Selective visualization of arginine and lysine has been explored among 20 amino acids using the hybrid conjugate of β-cyclodextrin (β-CD) and polydiacetylene (PDA). The mono pentacosa-10,12-diynyl aminomethyl group was successfully coupled to either the primary or the secondary face of β-CD, where mono-6-amino-6-deoxy-β-CD or mono-3-amino-3-deoxy-β-CD reacted with the N-hydroxysuccinimide ester of 10,12-pentacosadiynoic acid. In this combinatorial system, the cylindrical β-cyclodextrin functions as a channel for the introduction of the cationic amino acids to the artificial membrane. The membrane perturbation and aggregation by the target amino acids could be exclusively visualized as a blue to red color change based on the responsive polydiacetylene domain. These interesting findings demonstrated that the developed β-CD conjugated PDA system may offer a new method of cell-penetrating mechanism, a promising vector system, as well as impact the production industry of arginine or lysine.

Postnatal development of plasma amino acids in hyperphagic rats.

PubMed

Salvadó, M J; Segués, T; Arola, L

1991-01-01

The effect of feeding a highly palatable high-energy cafeteria diet on individual amino acid levels in plasma during postnatal development of the rat has been evaluated and compared to chow-fed controls. The cafeteria diet selected by the rats was hypercaloric and hyperlipidic, with practically the same amount of carbohydrate as the control diet, and slightly hyperproteic. In response to cafeteria feeding, significant decreases were observed in plasma serine and cysteine along the period studied. Significant changes with age during the growth period were shown by cafeteria-fed animals, which were not observed in control rats. Citrulline levels were lower on days 10 and 14 in cafeteria pups than in chow pups. Methionine was highest on day 30. Threonine was also higher at days 20 and 30, as was valine but with a nadir at day 10. Lysine showed maximal values on days 14 and 30.

Reactions of cisplatin with cysteine and methionine at constant pH; a computational study.

PubMed

Zimmermann, Tomás; Burda, Jaroslav V

2010-02-07

Interactions of hydrated cisplatin complexes cis-[Pt(NH(3))(2)Cl(H(2)O)](+) and cis-[Pt(NH(3))(2)(OH)(H(2)O)](+) with cysteine and methionine in an aqueous solution at constant pH were explored using computational methods. Thermodynamic parameters of considered reactions were studied in a broad pH range, taking up to 4 protonation states of each molecule into account. Reaction free energies at constant pH were obtained from standard Gibbs free energies using the Legendre transformation. Solvation free energies and pK(a) values were calculated using the PCM model with UAHF cavities, recently adapted by us for transition metal complexes. The root mean square error of pK(a) values on a set of model platinum complexes and amino acids was equal to 0.74. At pH 7, the transformed Gibbs free energies differ by up to 15 kcal mol(-1) from the Gibbs free energies of model reactions with a constant number of protons. As for cysteine, calculations confirmed a strong preference for kappaS monodenate bonding in a broad pH range. The most stable product of the second reaction step, which proceeds from monodentate to chelate complex, is the kappa(2)S,N coordinated chelate. The reaction with methionine is more complex. In the first step all three considered methionine donor atoms (N, S and O) are thermodynamically preferred products depending on the platinum complex and the pH. This is in accordance with the experimental observation of a pH dependent migration between N and S donor atoms in a chemically related system. The most stable chelates of platinum with methionine are kappa(2)S,N and kappa(2)N,O bonded complexes. The comparison of reaction free energies of both amino acids suggests, that the bidentate methionine ligand can be displaced even by the monodentate cysteine ligand under certain conditions.

Nutritional and medicinal aspects of D-amino acids.

PubMed

Friedman, Mendel; Levin, Carol E

2012-05-01

This paper reviews and interprets a method for determining the nutritional value of D-amino acids, D-peptides, and amino acid derivatives using a growth assay in mice fed a synthetic all-amino acid diet. A large number of experiments were carried out in which a molar equivalent of the test compound replaced a nutritionally essential amino acid such as L-lysine (L-Lys), L-methionine (L-Met), L-phenylalanine (L-Phe), and L-tryptophan (L-Trp) as well as the semi-essential amino acids L-cysteine (L-Cys) and L-tyrosine (L-Tyr). The results show wide-ranging variations in the biological utilization of test substances. The method is generally applicable to the determination of the biological utilization and safety of any amino acid derivative as a potential nutritional source of the corresponding L-amino acid. Because the organism is forced to use the D-amino acid or amino acid derivative as the sole source of the essential or semi-essential amino acid being replaced, and because a free amino acid diet allows better control of composition, the use of all-amino-acid diets for such determinations may be preferable to protein-based diets. Also covered are brief summaries of the widely scattered literature on dietary and pharmacological aspects of 27 individual D-amino acids, D-peptides, and isomeric amino acid derivatives and suggested research needs in each of these areas. The described results provide a valuable record and resource for further progress on the multifaceted aspects of D-amino acids in food and biological samples.

Gene cloning, recombinant expression, purification and characterization of l-methionine decarboxylase from Streptomyces sp. 590.

PubMed

Hayashi, Masaya; Okada, Akane; Yamamoto, Kumiko; Okugochi, Tomomi; Kusaka, Chika; Kudou, Daizou; Nemoto, Michiko; Inagaki, Junko; Hirose, Yuu; Okajima, Toshihide; Tamura, Takashi; Soda, Kenji; Inagaki, Kenji

2017-04-01

l-Methionine decarboxylase (MetDC) from Streptomyces sp. 590 depends on pyridoxal 5'-phosphate and catalyzes the non-oxidative decarboxylation of l-methionine to produce 3-methylthiopropylamine and carbon dioxide. MetDC gene (mdc) was determined to consist of 1,674 bp encoding 557 amino acids, and the amino acid sequence is similar to that of l-histidine decarboxylases and l-valine decarboxylases from Streptomyces sp. strains. The mdc gene was cloned and recombinant MetDC was heterologously expressed by Escherichia coli. The purification of recombinant MetDC was carried out by DEAE-Toyopearl and Ni-NTA agarose column chromatography. The recombinant enzyme was homodimeric with a molecular mass of 61,000 Da and showed optimal activity between 45 to 55 °C and at pH 6.6, and the stability below 30 °C and between pH 4.6 to 7.0. l-Methionine and l-norleucine were good substrates for MetDC. The Michaelis constants for l-methionine and l-norleucine were 30 and 73 mM, respectively. The recombinant MetDC (0.50 U/ml) severely inhibited growth of human tumour cells A431 (epidermoid ovarian carcinoma cell line) and MDA-MB-231 (breast cancer cell line), however showed relatively low cytotoxicity for human normal cell NHDF-Neo (dermal fibroblast cell line from neonatal foreskin). This study revealed the properties of the gene and the protein sequence of MetDC for the first time. © The Authors 2017. Published by Oxford University Press on behalf of the Japanese Biochemical Society. All rights reserved.

Dietary protein reduction on microbial protein, amino acid digestibility, and body retention in beef cattle: 2. Amino acid intestinal absorption and their efficiency for whole-body deposition.

PubMed

Mariz, L D S; Amaral, P M; Valadares Filho, S C; Santos, S A; Detmann, E; Marcondes, M I; Pereira, J M V; Silva Júnior, J M; Prados, L F; Faciola, A P

2018-03-06

The objective of this study was to determine the apparent and true intestinal digestibility of total and individual AA, and to estimate the efficiency of whole-body AA retention from individual and total absorbed AA. Four Nellore animals (241.3 kg initial BW) and four crossbred Angus × Nellore (263.4 kg initial BW) cannulated in rumen and ileum were randomly allocated in two 4 × 4 Latin squares. The experiment lasted four 17 d periods, with 10 d for adaptation to diets and another 7 d for data collection. The diets consisted of increasing CP levels: 100, 120, or 140 g/kg of DM offered ad libitum, and restricted intake diet with 120 g CP/kg DM (experiment 1). In experiment 2, forty-four bulls (22 Nellore and 22 crossbred F1 Angus × Nellore) with 8 months and initial shrunk BW 215.0 ± 15.0 kg (Nellore = 208.0 ± 12.78 kg; Angus × Nellore = 221.9 ± 14.16 kg) were used. Eight of those animals were slaughtered at the beginning of the experiment. The remaining 36 bulls were allocated in a completely randomized design with six replicates, in a 2 (genetic groups) × 3 (CP contents) factorial scheme. The amount of essential AA (EAA) and nonessential AA (NEAA) reaching the small intestine increased linearly (P < 0.05) in response to CP content. The apparent digestibility of EAA was not affected (P > 0.05) by CP content, with exception for histidine (P = 0.07, linear effect), leucine (P = 0.01, linear effect), and methionine (P = 0.05, linear effect). Differences existed among AA when compared the apparent digestibility of NEAA. The apparent digestibility of alanine (P = 0.05), aspartic acid (P = 0.07), glutamic acid (P = 0.02), glycine (P = 0.05), proline (P = 0.02), and serine (P = 0.04) responded quadratically to CP content increase. However, the apparent digestibility of cystine and tyrosine was not affected (P > 0.05) by increasing dietary CP. The true intestinal digestibilities of total, essential, nonessential AA, lysine, and methionine were 75.0%, 77.0%, 74

Impact of primary amine group from aminophospholipids and amino acids on marine phospholipids stability: non-enzymatic browning and lipid oxidation.

PubMed

Lu, F S H; Nielsen, N S; Baron, C P; Diehl, B W K; Jacobsen, C

2013-11-15

The main objective of this study was to investigate the oxidative stability and non-enzymatic browning reactions of marine PL in the presence or in the absence of primary amine group from aminophospholipids and amino acids. Marine phospholipids liposomal dispersions were prepared from two authentic standards (phosphatidylcholine and phosphatidylethanolamine) and two purified PL from marine sources with and without addition of amino acids (leucine, methionine and lysine). Samples were incubated at 60°C for 0, 2, 4 and 6days. Non-enzymatic browning reactions were investigated through measurement of (i) Strecker derived volatiles, (ii) yellowness index (YI), (iii) hydrophobic and (iv) hydrophilic pyrroles content. The oxidative stability of the samples was assessed through measurement of secondary lipid derived volatile oxidation products. The result showed that the presence of PE and amino acids caused the formation of pyrroles, generated Strecker derived volatiles, decreased the YI development and lowered lipid oxidation. The lower degree of lipid oxidation in liposomal dispersions containing amino acids might be attributed to antioxidative properties of pyrroles or amino acids. Copyright © 2013 Elsevier Ltd. All rights reserved.

A machine learning approach for predicting methionine oxidation sites.

PubMed

Aledo, Juan C; Cantón, Francisco R; Veredas, Francisco J

2017-09-29

The oxidation of protein-bound methionine to form methionine sulfoxide, has traditionally been regarded as an oxidative damage. However, recent evidences support the view of this reversible reaction as a regulatory post-translational modification. The perception that methionine sulfoxidation may provide a mechanism to the redox regulation of a wide range of cellular processes, has stimulated some proteomic studies. However, these experimental approaches are expensive and time-consuming. Therefore, computational methods designed to predict methionine oxidation sites are an attractive alternative. As a first approach to this matter, we have developed models based on random forests, support vector machines and neural networks, aimed at accurate prediction of sites of methionine oxidation. Starting from published proteomic data regarding oxidized methionines, we created a hand-curated dataset formed by 113 unique polypeptides of known structure, containing 975 methionyl residues, 122 of which were oxidation-prone (positive dataset) and 853 were oxidation-resistant (negative dataset). We use a machine learning approach to generate predictive models from these datasets. Among the multiple features used in the classification task, some of them contributed substantially to the performance of the predictive models. Thus, (i) the solvent accessible area of the methionine residue, (ii) the number of residues between the analyzed methionine and the next methionine found towards the N-terminus and (iii) the spatial distance between the atom of sulfur from the analyzed methionine and the closest aromatic residue, were among the most relevant features. Compared to the other classifiers we also evaluated, random forests provided the best performance, with accuracy, sensitivity and specificity of 0.7468±0.0567, 0.6817±0.0982 and 0.7557±0.0721, respectively (mean ± standard deviation). We present the first predictive models aimed to computationally detect methionine sites that

Advances in protein-amino acid nutrition of poultry.

PubMed

Baker, David H

2009-05-01

The ideal protein concept has allowed progress in defining requirements as well as the limiting order of amino acids in corn, soybean meal, and a corn-soybean meal mixture for growth of young chicks. Recent evidence suggests that glycine (or serine) is a key limiting amino acid in reduced protein [23% crude protein (CP) reduced to 16% CP] corn-soybean meal diets for broiler chicks. Research with sulfur amino acids has revealed that small excesses of cysteine are growth depressing in chicks fed methionine-deficient diets. Moreover, high ratios of cysteine:methionine impair utilization of the hydroxy analog of methionine, but not of methionine itself. A high level of dietary L: -cysteine (2.5% or higher) is lethal for young chicks, but a similar level of DL: -methionine, L: -cystine or N-acetyl-L: -cysteine causes no mortality. A supplemental dietary level of 3.0% L: -cysteine (7x requirement) causes acute metabolic acidosis that is characterized by a striking increase in plasma sulfate and decrease in plasma bicarbonate. S-Methylmethionine, an analog of S-adenosylmethionine, has been shown to have choline-sparing activity, but it only spares methionine when diets are deficient in choline and(or) betaine. Creatine, or its precursor guanidinoacetic acid, can spare dietary arginine in chicks.

Specificity determinants for lysine incorporation in Staphylococcus aureus peptidoglycan as revealed by the structure of a MurE enzyme ternary complex.

PubMed

Ruane, Karen M; Lloyd, Adrian J; Fülöp, Vilmos; Dowson, Christopher G; Barreteau, Hélène; Boniface, Audrey; Dementin, Sébastien; Blanot, Didier; Mengin-Lecreulx, Dominique; Gobec, Stanislav; Dessen, Andréa; Roper, David I

2013-11-15

Formation of the peptidoglycan stem pentapeptide requires the insertion of both L and D amino acids by the ATP-dependent ligase enzymes MurC, -D, -E, and -F. The stereochemical control of the third position amino acid in the pentapeptide is crucial to maintain the fidelity of later biosynthetic steps contributing to cell morphology, antibiotic resistance, and pathogenesis. Here we determined the x-ray crystal structure of Staphylococcus aureus MurE UDP-N-acetylmuramoyl-L-alanyl-D-glutamate:meso-2,6-diaminopimelate ligase (MurE) (E.C. 6.3.2.7) at 1.8 Å resolution in the presence of ADP and the reaction product, UDP-MurNAc-L-Ala-γ-D-Glu-L-Lys. This structure provides for the first time a molecular understanding of how this Gram-positive enzyme discriminates between L-lysine and D,L-diaminopimelic acid, the predominant amino acid that replaces L-lysine in Gram-negative peptidoglycan. Despite the presence of a consensus sequence previously implicated in the selection of the third position residue in the stem pentapeptide in S. aureus MurE, the structure shows that only part of this sequence is involved in the selection of L-lysine. Instead, other parts of the protein contribute substrate-selecting residues, resulting in a lysine-binding pocket based on charge characteristics. Despite the absolute specificity for L-lysine, S. aureus MurE binds this substrate relatively poorly. In vivo analysis and metabolomic data reveal that this is compensated for by high cytoplasmic L-lysine concentrations. Therefore, both metabolic and structural constraints maintain the structural integrity of the staphylococcal peptidoglycan. This study provides a novel focus for S. aureus-directed antimicrobials based on dual targeting of essential amino acid biogenesis and its linkage to cell wall assembly.

Specificity Determinants for Lysine Incorporation in Staphylococcus aureus Peptidoglycan as Revealed by the Structure of a MurE Enzyme Ternary Complex*

PubMed Central

Ruane, Karen M.; Lloyd, Adrian J.; Fülöp, Vilmos; Dowson, Christopher G.; Barreteau, Hélène; Boniface, Audrey; Dementin, Sébastien; Blanot, Didier; Mengin-Lecreulx, Dominique; Gobec, Stanislav; Dessen, Andréa; Roper, David I.

2013-01-01

Formation of the peptidoglycan stem pentapeptide requires the insertion of both l and d amino acids by the ATP-dependent ligase enzymes MurC, -D, -E, and -F. The stereochemical control of the third position amino acid in the pentapeptide is crucial to maintain the fidelity of later biosynthetic steps contributing to cell morphology, antibiotic resistance, and pathogenesis. Here we determined the x-ray crystal structure of Staphylococcus aureus MurE UDP-N-acetylmuramoyl-l-alanyl-d-glutamate:meso-2,6-diaminopimelate ligase (MurE) (E.C. 6.3.2.7) at 1.8 Å resolution in the presence of ADP and the reaction product, UDP-MurNAc-l-Ala-γ-d-Glu-l-Lys. This structure provides for the first time a molecular understanding of how this Gram-positive enzyme discriminates between l-lysine and d,l-diaminopimelic acid, the predominant amino acid that replaces l-lysine in Gram-negative peptidoglycan. Despite the presence of a consensus sequence previously implicated in the selection of the third position residue in the stem pentapeptide in S. aureus MurE, the structure shows that only part of this sequence is involved in the selection of l-lysine. Instead, other parts of the protein contribute substrate-selecting residues, resulting in a lysine-binding pocket based on charge characteristics. Despite the absolute specificity for l-lysine, S. aureus MurE binds this substrate relatively poorly. In vivo analysis and metabolomic data reveal that this is compensated for by high cytoplasmic l-lysine concentrations. Therefore, both metabolic and structural constraints maintain the structural integrity of the staphylococcal peptidoglycan. This study provides a novel focus for S. aureus-directed antimicrobials based on dual targeting of essential amino acid biogenesis and its linkage to cell wall assembly. PMID:24064214

Inhibitory Effects of Lysine Analogues on t-PA Induced Whole Blood Clot Lysis

DTIC Science & Technology

1994-01-01

aminocaproic acid (EACA) and trans-4-amino- methyl cyclohexane carboxylic acid (AMCA) are used to prevent excessive bleeding in patients with... aminocaproic acid (EACA) and the others have lower affinity binding sites (K&=5 mM) (5). The lysine analogues EACA and trans-4-aniinomethyl...JL, Wissler FC. Quantitative determination of the binding of epsilon- aminocaproic acid to native plasminogen. J Biol Chem 253, 727-732, 1978. 6

Regulation of thrombosis and vascular function by protein methionine oxidation

PubMed Central

Gu, Sean X.; Stevens, Jeff W.

2015-01-01

Redox biology is fundamental to both normal cellular homeostasis and pathological states associated with excessive oxidative stress. Reactive oxygen species function not only as signaling molecules but also as redox regulators of protein function. In the vascular system, redox reactions help regulate key physiologic responses such as cell adhesion, vasoconstriction, platelet aggregation, angiogenesis, inflammatory gene expression, and apoptosis. During pathologic states, altered redox balance can cause vascular cell dysfunction and affect the equilibrium between procoagulant and anticoagulant systems, contributing to thrombotic vascular disease. This review focuses on the emerging role of a specific reversible redox reaction, protein methionine oxidation, in vascular disease and thrombosis. A growing number of cardiovascular and hemostatic proteins are recognized to undergo reversible methionine oxidation, in which methionine residues are posttranslationally oxidized to methionine sulfoxide. Protein methionine oxidation can be reversed by the action of stereospecific enzymes known as methionine sulfoxide reductases. Calcium/calmodulin-dependent protein kinase II is a prototypical methionine redox sensor that responds to changes in the intracellular redox state via reversible oxidation of tandem methionine residues in its regulatory domain. Several other proteins with oxidation-sensitive methionine residues, including apolipoprotein A-I, thrombomodulin, and von Willebrand factor, may contribute to vascular disease and thrombosis. PMID:25900980

Regulation of thrombosis and vascular function by protein methionine oxidation.

PubMed

Gu, Sean X; Stevens, Jeff W; Lentz, Steven R

2015-06-18

Redox biology is fundamental to both normal cellular homeostasis and pathological states associated with excessive oxidative stress. Reactive oxygen species function not only as signaling molecules but also as redox regulators of protein function. In the vascular system, redox reactions help regulate key physiologic responses such as cell adhesion, vasoconstriction, platelet aggregation, angiogenesis, inflammatory gene expression, and apoptosis. During pathologic states, altered redox balance can cause vascular cell dysfunction and affect the equilibrium between procoagulant and anticoagulant systems, contributing to thrombotic vascular disease. This review focuses on the emerging role of a specific reversible redox reaction, protein methionine oxidation, in vascular disease and thrombosis. A growing number of cardiovascular and hemostatic proteins are recognized to undergo reversible methionine oxidation, in which methionine residues are posttranslationally oxidized to methionine sulfoxide. Protein methionine oxidation can be reversed by the action of stereospecific enzymes known as methionine sulfoxide reductases. Calcium/calmodulin-dependent protein kinase II is a prototypical methionine redox sensor that responds to changes in the intracellular redox state via reversible oxidation of tandem methionine residues in its regulatory domain. Several other proteins with oxidation-sensitive methionine residues, including apolipoprotein A-I, thrombomodulin, and von Willebrand factor, may contribute to vascular disease and thrombosis. © 2015 by The American Society of Hematology.

Effect of lysine clonixinate on the pharmacokinetics and anticoagulant activity of phenprocoumon.

PubMed

Russmann, S; Dilger, K; Trenk, D; Nagyivanyi, P; Jähnchen, E

2001-11-01

The effect of the non-steroidal anti-inflammatory drug lysine clonixinate ([2-(3-chloro-o-toluidino)nicotinic acid]-L-lysinate, CAS 55837-30-4) on the pharmacokinetics and anticoagulant activity of phenprocoumon (4-hydroxy-3-(1-phenylpropyl)-coumarin, CAS 435-97-2) was investigated in an open, randomised, two-fold, cross-over study in 12 healthy male volunteers. These subjects received a single dose of 18 mg phenprocoumon without or with concomitant treatment with lysine clonixinate (125 mg five times a day for 3 days before and 13 days after ingestion of a single dose of phenprocoumon). Pharmacokinetic parameters of phenprocoumon following oral administration were: CL/f: 0.779 +/- 0.157 ml/min, half-life of elimination: 147.2 +/- 19.9 h; free fraction in serum: 0.51 +/- 0.20%. These parameters were not significantly altered by concomitant treatment with lysine clonixinate. Prothrombin time increased from 13.3 +/- 1.3 s (at time 0) to 17.7 +/- 2.7 s following phenprocoumon and from 13.3 +/- 1.2 s to 18.0 +/- 2.2 s following combined administration. Prothrombin time returned to the pretreatment values 240 h after administration of phenprocoumon. The integrated effect (AUEC0-288 h) was identical following both treatments (4.303 +/- 461 and 4.303 +/- 312 s x h for phenprocoumon alone and phenprocoumon with lysine clonixinate, respectively). Thus, lysine clonixinate administered in therapeutic doses does not affect the pharmacokinetics and anticoagulant activity of phenproxoumon.

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.

Lysine Requirements of Healthy Pregnant Women are Higher During Late Stages of Gestation Compared to Early Gestation.

PubMed

Payne, Magdalene; Stephens, Trina; Lim, Kenneth; Ball, Ronald O; Pencharz, Paul B; Elango, Rajavel

2018-01-01

Lysine is the first limiting amino acid in cereal proteins and is found mainly in animal-derived products. Current Dietary Reference Intake (DRI) recommendations extrapolate lysine requirements during pregnancy from nonpregnant adult data, and may underestimate true requirements. Our objective is to define a quantitative lysine requirement in healthy pregnant women and to determine whether requirements vary between 2 phases of gestation. Fourteen pregnant women in early (12-19 wk) and 19 women in late (33-39 wk) gestation were studied using the indicator amino acid oxidation technique. Individual lysine intakes (6-84 mg · kg-1 · d-1, deficient to excess) were tested on each study day as a crystalline amino acid mixture based on egg protein composition. Isonitrogenous diets maintained protein intake at 1.5 g · kg-1 · d-1 and calorie intake at 1.7 times resting energy expenditure during each study day. Phenylalanine and tyrosine intakes were held constant across all lysine intakes. Breath and urine samples were collected at baseline and isotopic steady state. Lysine requirements were determined by measuring the oxidation of L-[1-13C]-phenylalanine to 13CO2 (F13CO2). Biphase linear regression crossover analysis was used to determine a breakpoint (which represents the estimated average requirement, EAR) in F13CO2. The EAR for lysine during early gestation was determined to be 36.6 mg · kg-1 · d-1 (R2 = 0.484, upper 95% CI = 46.2 mg · kg-1 · d-1), similar to an earlier adult requirement of 36 mg · kg-1 · d-1. The EAR for lysine during late gestation was determined to be 50.3 mg · kg-1 · d-1 (R2 = 0.664, upper 95% CI = 60.4 mg · kg-1 · d-1), 23% higher than the current pregnancy DRI EAR recommendation of 41 mg · kg-1 · d-1. Our results suggest that lysine requirements are higher during late gestation compared to early gestation, and that current dietary lysine recommendations during late

Adaptive antioxidant methionine accumulation in respiratory chain complexes explains the use of a deviant genetic code in mitochondria.

PubMed

Bender, Aline; Hajieva, Parvana; Moosmann, Bernd

2008-10-28

Humans and most other animals use 2 different genetic codes to translate their hereditary information: the standard code for nuclear-encoded proteins and a modern variant of this code in mitochondria. Despite the pivotal role of the genetic code for cell biology, the functional significance of the deviant mitochondrial code has remained enigmatic since its first description in 1979. Here, we show that profound and functionally beneficial alterations on the encoded protein level were causative for the AUA codon reassignment from isoleucine to methionine observed in most mitochondrial lineages. We demonstrate that this codon reassignment leads to a massive accumulation of the easily oxidized amino acid methionine in the highly oxidative inner mitochondrial membrane. This apparently paradoxical outcome can yet be smoothly settled if the antioxidant surface chemistry of methionine is taken into account, and we present direct experimental evidence that intramembrane accumulation of methionine exhibits antioxidant and cytoprotective properties in living cells. Our results unveil that methionine is an evolutionarily selected antioxidant building block of respiratory chain complexes. Collective protein alterations can thus constitute the selective advantage behind codon reassignments, which authenticates the "ambiguous decoding" hypothesis of genetic code evolution. Oxidative stress has shaped the mitochondrial genetic code.

PLASMA PROTEIN AND HEMOGLOBIN PRODUCTION : DELETION OF INDIVIDUAL AMINO ACIDS FROM GROWTH MIXTURE OF TEN ESSENTIAL AMINO ACIDS. SIGNIFICANT CHANGES IN URINARY NITROGEN.

PubMed

Robscheit-Robbins, F S; Miller, L L; Whipple, G H

1947-02-28

Given healthy dogs fed abundant iron and protein-free or low protein diets with sustained anemia and hypoproteinemia, we can study the capacity of these animals to produce simultaneously new hemoglobin and plasma protein. Reserve stores of blood protein-building materials are measurably depleted and levels of 6 to 8 gm. per cent for hemoglobin and 4 to 5 gm. per cent for plasma protein can be maintained for weeks or months depending upon the intake of food proteins or amino acid mixtures. These dogs are very susceptible to infection and various poisons. Dogs tire of these diets and loss of appetite terminates many experiments. Under these conditions (double depletion) standard growth mixtures of essential amino acids are tested to show the response in blood protein output and urinary nitrogen balance. As a part of each tabulated experiment one of the essential amino acids is deleted from the complete growth mixture to compare such response with that of the whole mixture. Methionine, threonine, phenylalanine, and tryptophane when singly eliminated from the complete amino acid mixture do effect a sharp rise in urinary nitrogen. This loss of urinary nitrogen is corrected when the individual amino acid is replaced in the mixture. Histidine, lysine, and valine have a moderate influence upon urinary nitrogen balance toward nitrogen conservation. Leucine, isoleucine, and arginine have minimal or no effect upon urinary nitrogen balance when these individual amino acids are deleted from the complete growth mixture of amino acids during 3 to 4 week periods. Tryptophane and to a less extent phenylalanine and threonine when returned to the amino acid mixture are associated with a conspicuous preponderance of plasma protein output over the hemoglobin output (Table 4). Arginine, lysine, and histidine when returned to the amino acid mixture are associated with a large preponderance of hemoglobin output. Various amino acid mixtures under these conditions may give a positive

Structural analysis, plastid localization, and expression of the biotin carboxylase subunit of acetyl-coenzyme A carboxylase from tobacco.

PubMed

Shorrosh, B S; Roesler, K R; Shintani, D; van de Loo, F J; Ohlrogge, J B

1995-06-01

Acetyl-coenzyme A carboxylase (ACCase, EC 6.4.1.2) catalyzes the synthesis of malonyl-coenzyme A, which is utilized in the plastid for de novo fatty acid synthesis and outside the plastid for a variety of reactions, including the synthesis of very long chain fatty acids and flavonoids. Recent evidence for both multifunctional and multisubunit ACCase isozymes in dicot plants has been obtained. We describe here the isolation of a tobacco (Nicotiana tabacum L. cv bright yellow 2 [NT1]) cDNA clone (E3) that encodes a 58.4-kD protein that shares 80% sequence similarity and 65% identity with the Anabaena biotin carboxylase subunit of ACCase. Similar to other biotin carboxylase subunits of acetyl-CoA carboxylase, the E3-encoded protein contains a putative ATP-binding motif but lacks a biotin-binding site (methionine-lysine-methionine or methionine-lysine-leucine). The deduced protein sequence contains a putative transit peptide whose function was confirmed by its ability to direct in vitro chloroplast uptake. The subcellular localization of this biotin carboxylase has also been confirmed to be plastidial by western blot analysis of pea (Pisum sativum), alfalfa (Medicago sativa L.), and castor (Ricinus communis L.) plastid preparations. Northern blot analysis indicates that the plastid biotin carboxylase transcripts are expressed at severalfold higher levels in castor seeds than in leaves.

Structural analysis, plastid localization, and expression of the biotin carboxylase subunit of acetyl-coenzyme A carboxylase from tobacco.

PubMed Central

Shorrosh, B S; Roesler, K R; Shintani, D; van de Loo, F J; Ohlrogge, J B

1995-01-01

Acetyl-coenzyme A carboxylase (ACCase, EC 6.4.1.2) catalyzes the synthesis of malonyl-coenzyme A, which is utilized in the plastid for de novo fatty acid synthesis and outside the plastid for a variety of reactions, including the synthesis of very long chain fatty acids and flavonoids. Recent evidence for both multifunctional and multisubunit ACCase isozymes in dicot plants has been obtained. We describe here the isolation of a tobacco (Nicotiana tabacum L. cv bright yellow 2 [NT1]) cDNA clone (E3) that encodes a 58.4-kD protein that shares 80% sequence similarity and 65% identity with the Anabaena biotin carboxylase subunit of ACCase. Similar to other biotin carboxylase subunits of acetyl-CoA carboxylase, the E3-encoded protein contains a putative ATP-binding motif but lacks a biotin-binding site (methionine-lysine-methionine or methionine-lysine-leucine). The deduced protein sequence contains a putative transit peptide whose function was confirmed by its ability to direct in vitro chloroplast uptake. The subcellular localization of this biotin carboxylase has also been confirmed to be plastidial by western blot analysis of pea (Pisum sativum), alfalfa (Medicago sativa L.), and castor (Ricinus communis L.) plastid preparations. Northern blot analysis indicates that the plastid biotin carboxylase transcripts are expressed at severalfold higher levels in castor seeds than in leaves. PMID:7610168

Thermodynamic Effects of Noncoded and Coded Methionine Substitutions in Calmodulin

PubMed Central

Yamniuk, Aaron P.; Ishida, Hiroaki; Lippert, Dustin; Vogel, Hans J.

2009-01-01

The methionine residues in the calcium (Ca2+) regulatory protein calmodulin (CaM) are structurally and functionally important. They are buried within the N- and C-domains of apo-CaM but become solvent-exposed in Ca2+-CaM, where they interact with numerous target proteins. Previous structural studies have shown that methionine substitutions to the noncoded amino acids selenomethionine, ethionine, or norleucine, or mutation to leucine do not impact the main chain structure of CaM. Here we used differential scanning calorimetry to show that these substitutions enhance the stability of both domains, with the largest increase in melting temperature (19–26°C) achieved with leucine or norleucine in the apo-C-domain. Nuclear magnetic resonance spectroscopy experiments also revealed the loss of a slow conformational exchange process in the Leu-substituted apo-C-domain. In addition, isothermal titration calorimetry experiments revealed considerable changes in the enthalpy and entropy of target binding to apo-CaM and Ca2+-CaM, but the free energy of binding was largely unaffected due to enthalpy-entropy compensation. Collectively, these results demonstrate that noncoded and coded methionine substitutions can be accommodated in CaM because of the structural plasticity of the protein. However, adjustments in side-chain packing and dynamics lead to significant differences in protein stability and the thermodynamics of target binding. PMID:19217866

Requirements of juvenile milkfish (Chanos chanos Forsskal) for essential amino acids.

PubMed

Borlongan, I G; Coloso, R M

1993-01-01

The dietary requirements of juvenile milkfish (Chanos chanos Forsskal) for essential amino acids were determined in a series of experiments. The fish (< or = 8.0 g) were reared in fiber glass tanks provided with flow-through seawater at 28 degrees C and salinity of 32 g/L for 12 wk. In each experiment, a series of amino acid test diets was formulated containing a combination of intact protein sources (casein-gelatin, fish meal-gelatin, fish meal-soybean meal or fish meal-zein) and crystalline amino acids to simulate the levels found in milkfish tissue proteins except for the test amino acid. Each set of isonitrogenous diets contained 40-45% protein and graded levels of the amino acid to be tested. At the end of the feeding experiment, growth, survival and feed efficiency were determined. The requirement level for each essential amino acid was estimated from breakpoint analysis of the growth curve. The dietary essential amino acid requirements (as the percentage of dietary protein) of milkfish juveniles were as follows: arginine, 5.25; histidine, 2.00; isoleucine, 4.00; leucine, 5.11; lysine, 4.00; methionine, 2.50 (cystine, 0.75); phenylalanine, 4.22 (tyrosine, 1.00) or 2.80 (tyrosine, 2.67); threonine, 4.50; tryptophan, 0.60; valine, 3.55. This information is valuable in developing cost-effective practical or commercial feeds and research diets for milkfish juveniles.

21 CFR 172.399 - Zinc methionine sulfate.

Code of Federal Regulations, 2010 CFR

2010-04-01

... Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) FOOD ADDITIVES PERMITTED FOR DIRECT ADDITION TO FOOD FOR HUMAN CONSUMPTION Special Dietary and Nutritional Additives § 172.399 Zinc methionine sulfate. Zinc methionine...

The Preventive Effect of L-Lysine on Lysozyme Glycation in Type 2 Diabetes.

PubMed

Mirmiranpour, Hossein; Khaghani, Shahnaz; Bathaie, S Zahra; Nakhjavani, Manouchehr; Kebriaeezadeh, Abbas; Ebadi, Maryam; Gerayesh-Nejad, Siavash; Zangooei, Mohammad

2016-01-01

Lysozyme is a bactericidal enzyme whose structure and functions change in diabetes. Chemical chaperones are small molecules including polyamines (e.g. spermine), amino acids (e.g. L-lysine) and polyols (e.g. glycerol). They can improve protein conformation in several stressful conditions such as glycation. In this study, the authors aimed to observe the effect of L-lysine as a chemical chaperone on structure and function of glycated lysozyme. In this study, in vitro and in vivo effects of L-lysine on lysozyme glycation were investigated. Lysozyme was incubated with glucose and/or L-lysine, followed by an investigation of its structure by electrophoresis, fluorescence spectroscopy, and circular dichroism spectroscopy and also assessment of its bactericidal activity against M. lysodeikticus. In the clinical trial, patients with type 2 diabetes mellitus (T2DM) were randomly divided into two groups of 25 (test and control). All patients received metformin and glibenclamide for a three months period. The test group was supplemented with 3 g/day of L-lysine. The quantity and activity of lysozyme and other parameters were then measured. Among the test group, L-lysine was found to reduce the advanced glycation end products (AGEs) in the sera of patients with T2DM and in vitro condition. This chemical chaperone reversed the alteration in lysozyme structure and function due to glycation and resulted in increased lysozyme activity. Structure and function of glycated lysozyme are significantly improved by l-lysine; therefore it can be considered an effective therapeutic supplementation in T2DM, decreasing the risk of infection in these patients.

Global Proteomics Analysis of Protein Lysine Methylation.

PubMed

Cao, Xing-Jun; Garcia, Benjamin A

2016-11-01

Lysine methylation is a common protein post-translational modification dynamically mediated by protein lysine methyltransferases (PKMTs) and protein lysine demethylases (PKDMs). Beyond histone proteins, lysine methylation on non-histone proteins plays a substantial role in a variety of functions in cells and is closely associated with diseases such as cancer. A large body of evidence indicates that the dysregulation of some PKMTs leads to tumorigenesis via their non-histone substrates. However, most studies on other PKMTs have made slow progress owing to the lack of approaches for extensive screening of lysine methylation sites. However, recently, there has been a series of publications to perform large-scale analysis of protein lysine methylation. In this unit, we introduce a protocol for the global analysis of protein lysine methylation in cells by means of immunoaffinity enrichment and mass spectrometry. © 2016 by John Wiley & Sons, Inc. Copyright © 2016 John Wiley & Sons, Inc.

Lysine Malonylation Is Elevated in Type 2 Diabetic Mouse Models and Enriched in Metabolic Associated Proteins*

PubMed Central

Du, Yipeng; Cai, Tanxi; Li, Tingting; Xue, Peng; Zhou, Bo; He, Xiaolong; Wei, Peng; Liu, Pingsheng; Yang, Fuquan; Wei, Taotao

2015-01-01

Protein lysine malonylation, a newly identified protein post-translational modification (PTM), has been proved to be evolutionarily conserved and is present in both eukaryotic and prokaryotic cells. However, its potential roles associated with human diseases remain largely unknown. In the present study, we observed an elevated lysine malonylation in a screening of seven lysine acylations in liver tissues of db/db mice, which is a typical model of type 2 diabetes. We also detected an elevated lysine malonylation in ob/ob mice, which is another model of type 2 diabetes. We then performed affinity enrichment coupled with proteomic analysis on liver tissues of both wild-type (wt) and db/db mice and identified a total of 573 malonylated lysine sites from 268 proteins. There were more malonylated lysine sites and proteins in db/db than in wt mice. Five proteins with elevated malonylation were verified by immunoprecipitation coupled with Western blot analysis. Bioinformatic analysis of the proteomic results revealed the enrichment of malonylated proteins in metabolic pathways, especially those involved in glucose and fatty acid metabolism. In addition, the biological role of lysine malonylation was validated in an enzyme of the glycolysis pathway. Together, our findings support a potential role of protein lysine malonylation in type 2 diabetes with possible implications for its therapy in the future. PMID:25418362

Physiological and molecular mechanisms of methionine restriction

USDA-ARS?s Scientific Manuscript database

The activation of miRNAs during methionine restriction (MR) provides a potential link between changes in methylation and the integrated stress responses in cells. Studies utilizing rainbow trout myosatellite cells in vitro and in vivo, have shown that methionine can regulate the level of expression ...

Metal-Catalyzed Oxidation of Protein Methionine Residues in Human Parathyroid Hormone (1-34): Formation of Homocysteine and a Novel Methionine-Dependent Hydrolysis Reaction

PubMed Central

Mozziconacci, Olivier; Ji, Junyan A.; Wang, Y. John; Schöneich, Christian

2013-01-01

The oxidation of PTH(1-34) catalyzed by ferrous ethylenediaminetetraacetic acid (EDTA) is site-specific. The oxidation of PTH(1-34) is localized primarily to the residues Met[8] and His[9]. Beyond the transformation of Met[8] and His[9] into methionine sulfoxide and 2-oxo-histidine, respectively, we observed a hydrolytic cleavage between Met[8] and His[9]. This hydrolysis requires the presence of FeII and oxygen and can be prevented by diethylenetriaminepentaacetic acid (DTPA) and phosphate buffer. Conditions leading to this site-specific hydrolysis also promote the transformation of Met[8] into homocysteine, indicating that the hydrolysis and transformation of homocysteine may proceed through a common intermediate. PMID:23289936

Design and Application of Synthetic Receptors for Recognition of Methylated Lysine and Supramolecular Affinity Labeling

NASA Astrophysics Data System (ADS)

Gober, Isaiah Nathaniel

possible ways for detecting PTMs and may find use in the development of new assays for enzymes that lack robust methods for measuring their activity. The third section explores the development of new small molecule receptors capable of selectively binding hydrophilic guests in water, such as the lower methylation states of lysine. We identified a receptor, A2I, that has improved binding affinity and selectivity for dimethyllysine (Kme2). The receptor was discovered and synthesized by using dynamic combinatorial chemistry (DCC) to redesign a small molecule receptor (A2B ) that preferentially binds trimethyllysine (Kme3). Incorporating a biphenyl monomer with ortho-di-substituted carboxylates into the receptor lead to the formation of a salt bridge interaction with Kme2. These favorable electrostatic and hydrogen bonding interactions produced a receptor with 32-fold tighter binding to Kme2, which is the highest affinity synthetic receptor for Kme2 in the context of a peptide that has been reported. This work provides insight into effective strategies for binding hydrophilic, cationic guests in water and is an encouraging result toward a synthetic receptor that selectively binds Kme2 over other methylation states of lysine. In the final section, a small molecule receptor for Kme3 (A 2B) was redesigned using DCC to incorporate either aromatic or acidic amino acids into the receptor. We proposed that the incorporation of amino acids could introduce additional non-covalent interactions (such as cation-pi, electrostatic, and hydrogen bonding) with a guest bound inside the pocket of the receptor. However, selective non-covalent interactions between the amino acid side chain on the modified receptor and the bound methylated lysine guest could not be achieved. This is most likely due to the conformational flexibility of the amino acid-functionalized receptors. Furthermore, attaching amino acids to the receptor seemed to increase non-specific electrostatic interactions, resulting in

Restriction of dietary methyl donors limits methionine availability and affects the partitioning of dietary methionine for creatine and phosphatidylcholine synthesis in the neonatal piglet.

PubMed

Robinson, Jason L; McBreairty, Laura E; Randell, Edward W; Brunton, Janet A; Bertolo, Robert F

2016-09-01

Methionine is required for protein synthesis and provides a methyl group for >50 critical transmethylation reactions including creatine and phosphatidylcholine synthesis as well as DNA and protein methylation. However, the availability of methionine depends on dietary sources as well as remethylation of demethylated methionine (i.e., homocysteine) by the dietary methyl donors folate and choline (via betaine). By restricting dietary methyl supply, we aimed to determine the extent that dietary methyl donors contribute to methionine availability for protein synthesis and transmethylation reactions in neonatal piglets. Piglets 4-8 days of age were fed a diet deficient (MD-) (n=8) or sufficient (MS+) (n=7) in folate, choline and betaine. After 5 days, dietary methionine was reduced to 80% of requirement in both groups to elicit a response. On day 8, animals were fed [(3)H-methyl]methionine for 6h to measure methionine partitioning into hepatic protein, phosphatidylcholine, creatine and DNA. MD- feeding reduced plasma choline, betaine and folate (P<.05) and increased homocysteine ~3-fold (P<.05). With MD- feeding, hepatic phosphatidylcholine synthesis was 60% higher (P<.05) at the expense of creatine synthesis, which was 30% lower during MD- feeding (P<.05); protein synthesis as well as DNA and protein methylation were unchanged. In the liver, ~30% of dietary label was traced to phosphatidylcholine and creatine together, with ~50% traced to methylation of proteins and ~20% incorporated in synthesized protein. Dietary methyl donors are integral to neonatal methionine requirements and can affect methionine availability for transmethylation pathways. Copyright © 2016 Elsevier Inc. All rights reserved.

Enhanced immune responses in broiler chicks fed methionine-supplemented diets.

PubMed

Tsiagbe, V K; Cook, M E; Harper, A E; Sunde, M L

1987-07-01

Effects of feeding supplementary methionine and choline on broiler growth and immunity were examined by supplementing a corn-soybean diet that contained 21% crude protein, 3,255 kcal metabolizable energy/kg diet, .35% methionine, .37% cystine, and .13% choline. Methionine (.063, .125, .25%) and choline (.125, .25%) were dietary variables. Sulfate (.055%) was added either alone or along with methionine (.125 or .25%) and choline (.125%). In one study, the .25% methionine diet was supplemented with .121% betaine. Sodium and chloride levels were constant in all the diets. Feed and distilled water were supplied ad libitum. Total antibodies, immunoglobulin (Ig) G (2-mercaptoethanol-resistant antibodies) and IgM (2-mercaptoethanol-sensitive antibodies) were determined in 3-wk-old chicks inoculated intraperitoneally with sheep red blood cells. The thymus-derived (T)-cell-dependent in vivo mitogen response to phytohemagglutinin-P (PHA-P) was assessed via wing web swelling. The methionine requirement for growth (0 to 3 wk of age) was approximately .413% of the diet (.35% in the basal diet plus .063% added). Supplementation of the basal diet with .125% choline stimulated growth to the same extent as did the extra .063% of methionine. Addition of .055% sulfate with .125% choline did not improve the ability of the latter to spare methionine. Supplemental methionine resulted in significant (P less than .05) dose-related increases in total antibody, IgG, and response to the mitogen PHA-P, but not in IgM. There were no effects of choline on the immune variables studied. These results suggest that methionine is required for select components of the antibody response, which effect might be related to T-cell help.

Activation of Nrf2 is required for up-regulation of the π class of glutathione S-transferase in rat primary hepatocytes with L-methionine starvation.

PubMed

Lin, Ai-Hsuan; Chen, Haw-Wen; Liu, Cheng-Tze; Tsai, Chia-Wen; Lii, Chong-Kuei

2012-07-04

Numerous genes expression is regulated in response to amino acid shortage, which helps organisms adapt to amino acid limitation. The expression of the π class of glutathione (GSH) S-transferase (GSTP), a highly inducible phase II detoxification enzyme, is regulated mainly by activates activating protein 1 (AP-1) binding to the enhancer I of GSTP (GPEI). Here we show the critical role of nuclear factor erythroid-2-related factor 2 (Nrf2) in up-regulating GSTP gene transcription. Primary rat hepatocytes were cultured in a methionine-restricted medium, and immunoblotting and RT-PCR analyses showed that methionine restriction time-dependently increased GSTP protein and mRNA expression over a 48 h period. Nrf2 translocation to the nucleus, nuclear proteins binding to GPEI, and antioxidant response element (ARE) luciferase reporter activity were increased by methionine restriction as well as by l-buthionine sulfoximine (BSO), a GSH synthesis inhibitor. Transfection with Nrf2 siRNA knocked down Nrf2 expression and reversed the methionine-induced GSTP expression and GPEI binding activity. Chromatin immunoprecipitation assay confirmed the binding of Nrf2 to the GPEI. Phosphorylation of extracellular signal-regulated kinase 2 (ERK2) was increased in methionine-restricted and BSO-treated cells. ERK2 siRNA abolished methionine restriction-induced Nrf2 nuclear translocation, GPEI binding activity, ARE-luciferase reporter activity, and GSTP expression. Our results suggest that the up-regulation of GSTP gene transcription in response to methionine restriction likely occurs via the ERK-Nrf2-GPEI signaling pathway.

Cloning and expression of VB12-independent methionine synthase gene responsive to alkaline stress in rice.

PubMed

Xie, Guo-Sheng; Liu, Shen-Kui; Takano, Tetsuo; You, Zong-Bin; Zhang, Duan-Pin

2002-12-01

VB12-independent methionine synthase is present in higher plants, and catalyzes the methylation of C-homocysteine to form methionine, which is very important for methylation reactions and syntheses of polyamines and ethylene. Under the alkaline condition, using cDNA-RAPD method, a new VB12-independent methionine synthase gene has been cloned and characterized for the first time in rice in this study. The results exhibited that, the cDNA gene entailed 2740 bp, had single copy in the rice genome and encoded peptide of 765 amino acids, the peptide showed 92% and 83% identity with that from Mesembryanthemum cystallinum (U84889) and Cathararanthus roseus (X83499), respectively. It enhanced the transcription more greatly after sodium carbonate treatment for 12 h and 24 h than that of sodium chloride treatment, and then obviously reduced in 48 h later, suggesting that it is related to this stress tolerance in rice.

21 CFR 172.399 - Zinc methionine sulfate.

Code of Federal Regulations, 2013 CFR

2013-04-01

... FOR HUMAN CONSUMPTION (CONTINUED) FOOD ADDITIVES PERMITTED FOR DIRECT ADDITION TO FOOD FOR HUMAN CONSUMPTION Special Dietary and Nutritional Additives § 172.399 Zinc methionine sulfate. Zinc methionine... conditions: (a) The additive is the product of the reaction between equimolar amounts of zinc sulfate and DL...

21 CFR 172.399 - Zinc methionine sulfate.

Code of Federal Regulations, 2012 CFR

2012-04-01

... FOR HUMAN CONSUMPTION (CONTINUED) FOOD ADDITIVES PERMITTED FOR DIRECT ADDITION TO FOOD FOR HUMAN CONSUMPTION Special Dietary and Nutritional Additives § 172.399 Zinc methionine sulfate. Zinc methionine... conditions: (a) The additive is the product of the reaction between equimolar amounts of zinc sulfate and DL...

Tug of war: adding and removing histone lysine methylation in Arabidopsis.

PubMed

Xiao, Jun; Lee, Un-Sa; Wagner, Doris

2016-12-01

Histone lysine methylation plays a fundamental role in the epigenetic regulation of gene expression in multicellular eukaryotes, including plants. It shapes plant developmental and growth programs as well as responses to the environment. The methylation status of certain amino-acids, in particular of the histone 3 (H3) lysine tails, is dynamically controlled by opposite acting histone methyltransferase 'writers' and histone demethylase 'erasers'. The methylation status is interpreted by a third set of proteins, the histone modification 'readers', which specifically bind to a methylated amino-acid on the H3 tail. Histone methylation writers, readers, and erasers themselves are regulated by intrinsic or extrinsic stimuli; this forms a feedback loop that contributes to development and environmental adaptation in Arabidopsis and other plants. Recent studies have expanded our knowledge regarding the biological roles and dynamic regulation of histone methylation. In this review, we will discuss recent advances in understanding the regulation and roles of histone methylation in plants and animals. Copyright © 2016 Elsevier Ltd. All rights reserved.

Crystal Structure of Ll-Diaminopimelate Aminotransferase From 'Arabidopsis Thaliana': a Recently-Discovered Enzyme in the Biosynthesis of L-Lysine By Plants And 'Chlamydia'

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

Watanabe, N.; Cherney, M.M.; van Belkum, M.J.

2007-07-13

The essential biosynthetic pathway to l-Lysine in bacteria and plants is an attractive target for the development of new antibiotics or herbicides because it is absent in humans, who must acquire this amino acid in their diet. Plants use a shortcut of a bacterial pathway to l-Lysine in which the pyridoxal-5-phosphate (PLP)-dependent enzyme ll-diaminopimelate aminotransferase (LL-DAP-AT) transforms l-tetrahydrodipicolinic acid (L-THDP) directly to LL-DAP. In addition, LL-DAP-AT was recently found in Chlamydia sp., suggesting that inhibitors of this enzyme may also be effective against such organisms. In order to understand the mechanism of this enzyme and to assist in the designmore » of inhibitors, the three-dimensional crystal structure of LL-DAP-AT was determined at 1.95 Angstroms resolution. The cDNA sequence of LL-DAP-AT from Arabidopsis thaliana (AtDAP-AT) was optimized for expression in bacteria and cloned in Escherichia coli without its leader sequence but with a C-terminal hexahistidine affinity tag to aid protein purification. The structure of AtDAP-AT was determined using the multiple-wavelength anomalous dispersion (MAD) method with a seleno-methionine derivative. AtDAP-AT is active as a homodimer with each subunit having PLP in the active site. It belongs to the family of type I fold PLP-dependent enzymes. Comparison of the active site residues of AtDAP-AT and aspartate aminotransferases revealed that the PLP binding residues in AtDAP-AT are well conserved in both enzymes. However, Glu97* and Asn309* in the active site of AtDAP-AT are not found at similar positions in aspartate aminotransferases, suggesting that specific substrate recognition may require these residues from the other monomer. A malate-bound structure of AtDAP-AT allowed LL-DAP and L-glutamate to be modeled into the active site. These initial three-dimensional structures of LL-DAP-AT provide insight into its substrate specificity and catalytic mechanism.« less

Methionine as a Precursor of Ethylene—Commentary

USDA-ARS?s Scientific Manuscript database

Lieberman et al. showed in a 1966 publication of Plant Physiology that methionine is a precursor of ethylene. It was the first paper that showed ethylene carbons are derived from carbons 3 and 4 of methionine. This paper catalyzed remarkable interest among plant biologists to elucidate the biosynth...

21 CFR 172.399 - Zinc methionine sulfate.

Code of Federal Regulations, 2014 CFR

2014-04-01

... ADDITIVES PERMITTED FOR DIRECT ADDITION TO FOOD FOR HUMAN CONSUMPTION Special Dietary and Nutritional Additives § 172.399 Zinc methionine sulfate. Zinc methionine sulfate, CAS Reg. No. 56329-42-1, may be safely used in accordance with the following prescribed conditions: (a) The additive is the product of the...

Computational Prediction of Protein Epsilon Lysine Acetylation Sites Based on a Feature Selection Method.

PubMed

Gao, JianZhao; Tao, Xue-Wen; Zhao, Jia; Feng, Yuan-Ming; Cai, Yu-Dong; Zhang, Ning

2017-01-01

Lysine acetylation, as one type of post-translational modifications (PTM), plays key roles in cellular regulations and can be involved in a variety of human diseases. However, it is often high-cost and time-consuming to use traditional experimental approaches to identify the lysine acetylation sites. Therefore, effective computational methods should be developed to predict the acetylation sites. In this study, we developed a position-specific method for epsilon lysine acetylation site prediction. Sequences of acetylated proteins were retrieved from the UniProt database. Various kinds of features such as position specific scoring matrix (PSSM), amino acid factors (AAF), and disorders were incorporated. A feature selection method based on mRMR (Maximum Relevance Minimum Redundancy) and IFS (Incremental Feature Selection) was employed. Finally, 319 optimal features were selected from total 541 features. Using the 319 optimal features to encode peptides, a predictor was constructed based on dagging. As a result, an accuracy of 69.56% with MCC of 0.2792 was achieved. We analyzed the optimal features, which suggested some important factors determining the lysine acetylation sites. We developed a position-specific method for epsilon lysine acetylation site prediction. A set of optimal features was selected. Analysis of the optimal features provided insights into the mechanism of lysine acetylation sites, providing guidance of experimental validation. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Structural, kinetic and computational investigation of Vitis vinifera DHDPS reveals new insight into the mechanism of lysine-mediated allosteric inhibition.

PubMed

Atkinson, Sarah C; Dogovski, Con; Downton, Matthew T; Czabotar, Peter E; Dobson, Renwick C J; Gerrard, Juliet A; Wagner, John; Perugini, Matthew A

2013-03-01

Lysine is one of the most limiting amino acids in plants and its biosynthesis is carefully regulated through inhibition of the first committed step in the pathway catalyzed by dihydrodipicolinate synthase (DHDPS). This is mediated via a feedback mechanism involving the binding of lysine to the allosteric cleft of DHDPS. However, the precise allosteric mechanism is yet to be defined. We present a thorough enzyme kinetic and thermodynamic analysis of lysine inhibition of DHDPS from the common grapevine, Vitis vinifera (Vv). Our studies demonstrate that lysine binding is both tight (relative to bacterial DHDPS orthologs) and cooperative. The crystal structure of the enzyme bound to lysine (2.4 Å) identifies the allosteric binding site and clearly shows a conformational change of several residues within the allosteric and active sites. Molecular dynamics simulations comparing the lysine-bound (PDB ID 4HNN) and lysine free (PDB ID 3TUU) structures show that Tyr132, a key catalytic site residue, undergoes significant rotational motion upon lysine binding. This suggests proton relay through the catalytic triad is attenuated in the presence of lysine. Our study reveals for the first time the structural mechanism for allosteric inhibition of DHDPS from the common grapevine.

White clover fractions as protein source for monogastrics: dry matter digestibility and protein digestibility-corrected amino acid scores.

PubMed

Stødkilde, Lene; Damborg, Vinni K; Jørgensen, Henry; Laerke, Helle N; Jensen, Søren K

2018-05-01

The present study aimed to evaluate the use of white clover as an alternative protein source for monogastrics. White clover plant and leaves were processed using a screw-press resulting in a solid pulp and a juice from which protein was acid-precipitated. The chemical composition of all fractions was determined and digestibility of dry matter (DM) and protein was assessed in an experiment with growing rats. Protein concentrates were produced with crude protein (CP) contents of 451 g kg -1 and 530 g kg -1 DM for white clover plant and leaves, respectively, and a pulp with CP contents of 313 and 374 g kg -1 DM from plant and leaves, respectively. The amino acid composition ranged from 4.72 to 6.49 g per 16 g of nitrogen (N) for lysine, 1.82-2.6 g per 16 g N for methionine and cysteine, and 3.66-5.24 g per 16 g N for threonine. True faecal digestibility of protein varied from 0.81 to 0.88, whereas DM digestibility was in the range 0.72-0.80. Methionine and cysteine were found to be limiting in all fractions, regardless of the reference group used. A high digestibility of white clover protein was found irrespective of the physical fractionation. Together with a well-balanced amino acid composition, this makes white clover a promising protein source for monogastrics. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

HDAC inhibitors induce global changes in histone lysine and arginine methylation and alter expression of lysine demethylases.

PubMed

Lillico, Ryan; Sobral, Marina Gomez; Stesco, Nicholas; Lakowski, Ted M

2016-02-05

Histone deacetylase (HDAC) inhibitors are cancer treatments that inhibit the removal of the epigenetic modification acetyllysine on histones, resulting in altered gene expression. Such changes in expression may influence other histone epigenetic modifications. We describe a validated liquid chromatography-tandem mass spectrometry (LC-MS/MS) method to quantify lysine acetylation and methylation and arginine methylation on histones extracted from cultured cells treated with HDAC inhibitors. The HDAC inhibitors vorinostat, mocetinostat and entinostat induced 400-600% hyperacetylation in HEK 293 and K562 cells. All HDAC inhibitors decreased histone methylarginines in HEK 293 cells but entinostat produced dose dependent reductions in asymmetric dimethylarginine, not observed in K562 cells. Vorinostat produced increases in histone lysine methylation and decreased expression of some lysine demethylases (KDM), measured by quantitative PCR. Entinostat had variable effects on lysine methylation and decreased expression of some KDM while increasing expression of others. Mocetinostat produced dose dependent increases in histone lysine methylation by LC-MS/MS. This was corroborated with a multiplex colorimetric assay showing increases in histone H3 lysine 4, 9, 27, 36 and 79 methylation. Increases in lysine methylation were correlated with dose dependent decreases in the expression of seven KDM. Mocetinostat functions as an HDAC inhibitor and a de facto KDM inhibitor. Copyright © 2015 Elsevier B.V. All rights reserved.

Effect of supplementation of crystalline lysine on the performance of WL layers in tropics during summer.

PubMed

Kumari, K Naga Raja; Reddy, V Ravinder; Preetham, V Chinni; Kumar, D Srinivas; Sen, Arup Ratan; Rao, S Venkata Rama

2016-04-01

A trial was conducted to evaluate the effect of lysine concentration in the diet of WL layers with constant ratio of other essential amino acids to lysine. Pullets (528) aged 25 to 36 weeks were fed with test diet containing two protein levels (13.36 and 15.78%) each with 5% concentration of lysine (0.50, 0.55, 0.60, 0.65, and 0.70) and a control with 17% CP and 0.70%, lysine. Each test diet was fed ad libitum to six replicates of eight birds for a period of 12 weeks. Egg production (EP), egg weight (EW), egg mass (EM), feed efficiency (g/g) (FE), body weight gain (BWG), Haugh unit (HU) and yolk colour (YC) were measured. Increased (P ≤ 0.05) EP, EW, EM, FE and BWG were obtained with increasing lysine concentration in diets. Whereas, feed intake/h/day, feed intake/egg, egg shell defects (ESD), mortality and shell thickness were not affected (P ≥ 0.05) by the concentration of lysine in diet. However, higher (P ≤ 0.05) HU score and YC were noticed at low lysine (0.50 %) concentrations. Based on this, it was concluded that WL layers (25-36 weeks) reared in open-sided houses in the tropics require approximately 0.70 % lysine (597.90 vs. 584.39 mg/h/day) in low (13.36% CP) and high (15.78% CP) protein groups in diets containing approximately 2700 kcal of ME/kg in summer.

Chemical composition and nutritional evaluation of the seeds of Acacia tortilis (Forssk.) Hayne ssp. raddiana.

PubMed

Embaby, Hassan E; Rayan, Ahmed M

2016-06-01

Chemical composition and nutritional evaluation as well as physicochemical and functional properties of seed flour of Acacia tortilis (Forssk.) Hayne ssp. raddiana were studied. The results indicated that seeds contained 5.30% moisture, 3.99% ash, 9.19% fat, 14.31% fiber, 27.21% protein and 45.30% carbohydrates. Potassium was the predominant element followed by calcium and then phosphorous. Phytic acid, tannins and trypsin inhibitor as antinutrients were detected. The amino acid profile compared well with FAO/WHO recommended pattern except for cystine/methionine, isoleucine, tyrosine/phenylalanine, lysine and threonine. Also, the first limiting amino acid was lysine. Fatty acid composition showed that linoleic acid was the major fatty acid, followed by palmitic, stearic, oleic and arachidic acids. The seed oil showed absorbance in the ultraviolet ranges, thus it can be used as a broad spectrum UV protectant. For physicochemical and functional properties, acacia seeds flour had excellent water holding index, swelling index, foaming capacity and foam stability. Copyright © 2016 Elsevier Ltd. All rights reserved.

Druggability of methyl-lysine binding sites

NASA Astrophysics Data System (ADS)

Santiago, C.; Nguyen, K.; Schapira, M.

2011-12-01

Structural modules that specifically recognize—or read—methylated or acetylated lysine residues on histone peptides are important components of chromatin-mediated signaling and epigenetic regulation of gene expression. Deregulation of epigenetic mechanisms is associated with disease conditions, and antagonists of acetyl-lysine binding bromodomains are efficacious in animal models of cancer and inflammation, but little is known regarding the druggability of methyl-lysine binding modules. We conducted a systematic structural analysis of readers of methyl marks and derived a predictive druggability landscape of methyl-lysine binding modules. We show that these target classes are generally less druggable than bromodomains, but that some proteins stand as notable exceptions.

Deficiency in methionine, tryptophan, isoleucine, or choline induces apoptosis in cultured cells.

PubMed

Yen, Chi-Liang E; Mar, Mei-Heng; Craciunescu, Corneliu N; Edwards, Lloyd J; Zeisel, Steven H

2002-07-01

Cells in culture die by apoptosis when deprived of the essential nutrient choline. We now report that cells (both proliferating PC12 cells and postmitotic neurons isolated from fetal rat brains) undergo apoptosis when deprived of other individual essential nutrients (methionine, tryptophan or isoleucine). In PC12 cells, deficiencies of each nutrient independently led to ceramide accumulation and to caspase activation, both recognized signals of several apoptotic pathways. A similar profile of caspases was activated in PC12 cells deprived of choline, methionine, tryptophan or isoleucine. More than one caspase was involved and these caspases appeared to transmit parallel signals for apoptosis induction because only broad-spectrum caspase inhibitors, but not inhibitors for specific individual caspases inhibited apoptosis in choline- or methionine-deprived cells. The induction of these caspase-dependent apoptosis pathways likely did not involve the same upstream signals. Choline deficiency perturbed choline metabolism but did not affect protein synthesis, whereas amino acid deficiencies inhibited protein synthesis but did not perturb choline metabolism. In addition, a subclone of PC12 cells that was resistant to choline deficiency-induced apoptosis was not resistant to tryptophan deficiency-induced apoptosis. These observations suggest that deficiency of each studied nutrient activates different pathways for signaling apoptosis that ultimately converge on a common execution pathway.

Mechanistic and Kinetic Study of Singlet O2 Oxidation of Methionine by On-Line Electrospray Ionization Mass Spectrometry.

PubMed

Liu, Fangwei; Lu, Wenchao; Yin, Xunlong; Liu, Jianbo

2016-01-01

We report a reaction apparatus developed to monitor singlet oxygen ((1)O2) reactions in solution using on-line ESI mass spectrometry and spectroscopy measurements. (1)O2 was generated in the gas phase by the reaction of H2O2 with Cl2, detected by its emission at 1270 nm, and bubbled into aqueous solution continuously. (1)O2 concentrations in solution were linearly related to the emission intensities of airborne (1)O2, and their absolute scales were established based on a calibration using 9,10-anthracene dipropionate dianion as an (1)O2 trapping agent. Products from (1)O2 oxidation were monitored by UV-Vis absorption and positive/negative ESI mass spectra, and product structures were elucidated using collision-induced dissociation-tandem mass spectrometry. To suppress electrical discharge in negative ESI of aqueous solution, methanol was added to electrospray via in-spray solution mixing using theta-glass ESI emitters. Capitalizing on this apparatus, the reaction of (1)O2 with methionine was investigated. We have identified methionine oxidation intermediates and products at different pH, and measured reaction rate constants. (1)O2 oxidation of methionine is mediated by persulfoxide in both acidic and basic solutions. Persulfoxide continues to react with another methionine, yielding methionine sulfoxide as end-product albeit with a much lower reaction rate in basic solution. Density functional theory was used to explore reaction potential energy surfaces and establish kinetic models, with solvation effects simulated using the polarized continuum model. Combined with our previous study of gas-phase methionine ions with (1)O2, evolution of methionine oxidation pathways at different ionization states and in different media is described.

Loss of conformational stability in calmodulin upon methionine oxidation.

PubMed Central

Gao, J; Yin, D H; Yao, Y; Sun, H; Qin, Z; Schöneich, C; Williams, T D; Squier, T C

1998-01-01

We have used electrospray ionization mass spectrometry (ESI-MS), circular dichroism (CD), and fluorescence spectroscopy to investigate the secondary and tertiary structural consequences that result from oxidative modification of methionine residues in wheat germ calmodulin (CaM), and prevent activation of the plasma membrane Ca-ATPase. Using ESI-MS, we have measured rates of modification and molecular mass distributions of oxidatively modified CaM species (CaMox) resulting from exposure to H2O2. From these rates, we find that oxidative modification of methionine to the corresponding methionine sulfoxide does not predispose CaM to further oxidative modification. These results indicate that methionine oxidation results in no large-scale alterations in the tertiary structure of CaMox, because the rates of oxidative modification of individual methionines are directly related to their solvent exposure. Likewise, CD measurements indicate that methionine oxidation results in little change in the apparent alpha-helical content at 28 degrees C, and only a small (0.3 +/- 0.1 kcal mol(-1)) decrease in thermal stability, suggesting the disruption of a limited number of specific noncovalent interactions. Fluorescence lifetime, anisotropy, and quenching measurements of N-(1-pyrenyl)-maleimide (PMal) covalently bound to Cys26 indicate local structural changes around PMal in the amino-terminal domain in response to oxidative modification of methionine residues in the carboxyl-terminal domain. Because the opposing globular domains remain spatially distant in both native and oxidatively modified CaM, the oxidative modification of methionines in the carboxyl-terminal domain are suggested to modify the conformation of the amino-terminal domain through alterations in the structural features involving the interdomain central helix. The structural basis for the linkage between oxidative modification and these global conformational changes is discussed in terms of possible alterations in

Effect of methionine supplementation in chicken feed on the quality and shelf life of fresh poultry meat.

PubMed

Albrecht, Antonia; Herbert, Ulrike; Miskel, Dennis; Heinemann, Celine; Braun, Carina; Dohlen, Sophia; Zeitz, Johanna O; Eder, Klaus; Saremi, Behnam; Kreyenschmidt, Judith

2017-08-01

The aim of this study was to investigate the influence of different methionine sources and concentrations on the quality and spoilage process of broiler meat. The trial was comprised of 7 treatment groups: one basal group (suboptimal in Methionine+Cysteine; i.e., 0.89, 0.74, 0.69% in DM SID Met+Cys in starter, grower, and finisher diets, respectively) and 3 doses (0.10, 0.25, and 0.40%) of either DL-Methionine (DLM) or DL-2-hydroxy-4-methylthio butanoic acid (DL-HMTBA) on an equimolar basis of the DLM-supplemented groups. The broilers were fed the diets for 35 d, then slaughtered and processed. The filets were aerobically packed and stored under temperature controlled conditions at 4°C. Meat quality investigations were comprised of microbial investigations (total viable count and Pseudomonas spp.), pH and drip loss measurements of the filets. The shelf life of the meat samples was determined based on sensory parameters. After slaughtering, all supplemented meat samples showed a high quality, whereby no differences between the 2 methionine sources could be detected for the microbial load, pH, and drip loss. In comparison to the control group, the supplemented samples showed a higher sensory quality, characterized by a fresh smell and fresh red color. Methionine supplementation had a significant influence on meat quality parameters during storage. The microbial load, pH and drip loss of the chicken filets were positively correlated to the methionine concentration. Additionally, the microbial load at the end of storage was positively correlated to pH and drip loss values. Nevertheless, the microbial parameters were in a normal range and the positive correlation to methionine concentration did not affect the sensory shelf life. The mean sensory shelf life of the broiler filets varied between 7 to 9 d. During storage, no difference in the development of sensory parameters was observed between the supplemented groups, while the spoilage process of the basal group

l-Methionine anti-biofilm activity against Pseudomonas aeruginosa is enhanced by the cystic fibrosis transmembrane conductance regulator potentiator, ivacaftor.

PubMed

Cho, Do-Yeon; Lim, Dong-Jin; Mackey, Calvin; Weeks, Christopher G; Peña Garcia, Jaime A; Skinner, Daniel; Grayson, Jessica W; Hill, Harrison S; Alexander, David K; Zhang, Shaoyan; Woodworth, Bradford A

2018-05-01

Biofilms may contribute to refractory chronic rhinosinusitis (CRS), as they lead to antibiotic resistance and failure of effective clinical treatment. l-Methionine is an amino acid with reported biofilm-inhibiting properties. Ivacaftor is a cystic fibrosis transmembrane conductance regulator (CFTR) potentiator with mild antimicrobial activity via inhibition of bacterial DNA gyrase and topoisomerase IV. The objective of this study was to evaluate whether co-treatment with ivacaftor and l-methionine can reduce the formation of Pseudomonas aeruginosa biofilms. P aeruginosa (PAO-1 strain) biofilms were studied in the presence of l-methionine and/or ivacaftor. For static biofilm assays, PAO-1 was cultured in a 48-well plate for 72 hours with stepwise combinations of these agents. Relative biofilm inhibitions were measured according to optical density of crystal violet stain at 590 nm. Live/dead assays (BacTiter-Glo™ assay, Promega) were imaged with laser scanning confocal microscopy. An agar diffusion test was used to confirm antibacterial effects of the drugs. l-Methionine (0.5 μM) significantly reduced PAO-1 biofilm mass (32.4 ± 18.0%; n = 4; p < 0.001) compared with controls. Low doses of ivacaftor alone (4, 8, and 12 μg/mL) had no effect on biofilm formation. When combined with ivacaftor (4 μg/mL), a synergistic anti-biofilm effect was noted at 0.05 μM and 0.5 μM of l-methionine (two-way analysis of variane, p = 0.0415) compared with corresponding concentrations of l-methionine alone. Ivacaftor enhanced the anti-biofilm activity of l-methionine against the PAO-1 strain of P aeruginosa. Further studies evaluating the efficacy of ivacaftor/l-methionine combinations for P aeruginosa sinusitis are planned. © 2018 ARS-AAOA, LLC.

Characterizing Lysine Acetylation of Isocitrate Dehydrogenase in Escherichia coli.

PubMed

Venkat, Sumana; Chen, Hao; Stahman, Alleigh; Hudson, Denver; McGuire, Paige; Gan, Qinglei; Fan, Chenguang

2018-06-22

The Escherichia coli isocitrate dehydrogenase (ICDH) is one of the tricarboxylic acid cycle enzymes, playing key roles in energy production and carbon flux regulation. E. coli ICDH was the first bacterial enzyme shown to be regulated by reversible phosphorylation. However, the effect of lysine acetylation on E. coli ICDH, which has no sequence similarity with its counterparts in eukaryotes, is still unclear. Based on previous studies of E. coli acetylome and ICDH crystal structures, eight lysine residues were selected for mutational and kinetic analyses. They were replaced with acetyllysine by the genetic code expansion strategy or substituted with glutamine as a classic approach. Although acetylation decreased the overall ICDH activity, its effects were different site by site. Deacetylation tests demonstrated that the CobB deacetylase could deacetylate ICDH both in vivo and in vitro, but CobB was only specific for lysine residues at the protein surface. On the other hand, ICDH could be acetylated by acetyl-phosphate chemically in vitro. And in vivo acetylation tests indicated that the acetylation level of ICDH was correlated with the amounts of intracellular acetyl-phosphate. This study nicely complements previous proteomic studies to provide direct biochemical evidence for ICDH acetylation. Copyright © 2018 Elsevier Ltd. All rights reserved.

Studies of lysine cyclodeaminase from Streptomyces pristinaespiralis: Insights into the complex transition NAD+ state.

PubMed

Ying, Hanxiao; Wang, Jing; Shi, Ting; Zhao, Yilei; Wang, Xin; Ouyang, Pingkai; Chen, Kequan

2018-01-01

Lysine cyclodeaminase (LCD) catalyzes the piperidine ring formation in macrolide-pipecolate natural products metabolic pathways from a lysine substrate through a combination of cyclization and deamination. This enzyme belongs to a unique enzyme class, which uses NAD + as the catalytic prosthetic group instead of as the co-substrate. To understand the molecular details of NAD + functions in lysine cyclodeaminase, we have determined four ternary crystal structure complexes of LCD-NAD + with pipecolic acid (LCD-PA), lysine (LCD-LYS), and an intermediate (LCD-INT) as ligands at 2.26-, 2.00-, 2.17- and 1.80 Å resolutions, respectively. By combining computational studies, a NAD + -mediated "gate keeper" function involving NAD + /NADH and Arg49 that control the binding and entry of the ligand lysine was revealed, confirming the critical roles of NAD + in the substrate access process. Further, in the gate opening form, a substrate delivery tunnel between ε-carboxyl moiety of Glu264 and the α-carboxyl moiety of Asp236 was observed through a comparison of four structure complexes. The LCD structure details including NAD + -mediated "gate keeper" and substrate tunnel may assist in the exploration the NAD + function in this unique enzyme class, and in regulation of macrolide-pipecolate natural product synthesis. Copyright © 2017 Elsevier Inc. All rights reserved.

Oxidation of Hepatic Carnitine Palmitoyl Transferase-I (CPT-I) Impairs Fatty Acid Beta-Oxidation in Rats Fed a Methionine-Choline Deficient Diet

PubMed Central

Bellanti, Francesco; Priore, Paola; Rollo, Tiziana; Tamborra, Rosanna; Siculella, Luisa; Vendemiale, Gianluigi; Altomare, Emanuele; Gnoni, Gabriele V.

2011-01-01

There is growing evidence that mitochondrial dysfunction, and more specifically fatty acid β-oxidation impairment, is involved in the pathophysiology of non-alcoholic steatohepatitis (NASH). The goal of the present study was to achieve more understanding on the modification/s of carnitinepalmitoyltransferase-I (CPT-I), the rate-limiting enzyme of the mitochondrial fatty acid β-oxidation, during steatohepatitis. A high fat/methionine-choline deficient (MCD) diet, administered for 4 weeks, was used to induce NASH in rats. We demonstrated that CPT-Iactivity decreased, to the same extent, both in isolated liver mitochondria and in digitonin-permeabilized hepatocytes from MCD-diet fed rats. At the same time, the rate of total fatty acid oxidation to CO2 and ketone bodies, measured in isolated hepatocytes, was significantly lowered in treated animals when compared to controls. Finally, an increase in CPT-I mRNA abundance and protein content, together with a high level of CPT-I protein oxidation was observed in treated rats. A posttranslational modification of rat CPT-I during steatohepatitis has been here discussed. PMID:21909411

Stabilization of collagen nanofibers with l-lysine improves the ability of carbodiimide cross-linked amniotic membranes to preserve limbal epithelial progenitor cells

PubMed Central

Lai, Jui-Yang; Wang, Pei-Ran; Luo, Li-Jyuan; Chen, Si-Tan

2014-01-01

To overcome the drawbacks associated with limited cross-linking efficiency of carbodiimide modified amniotic membrane, this study investigated the use of l-lysine as an additional amino acid bridge to enhance the stability of a nanofibrous tissue matrix for a limbal epithelial cell culture platform. Results of ninhydrin assays and zeta potential measurements showed that the amount of positively charged amino acid residues incorporated into the tissue collagen chains is highly correlated with the l-lysine-pretreated concentration. The cross-linked structure and hydrophilicity of amniotic membrane scaffolding materials affected by the lysine molecular bridging effects were determined. With an increase in the l-lysine-pretreated concentration from 1 to 30 mM, the cross-linking density was significantly increased and water content was markedly decreased. The variations in resistance to thermal denaturation and enzymatic degradation were in accordance with the number of cross-links per unit mass of amniotic membrane, indicating l-lysine-modulated stabilization of collagen molecules. It was also noteworthy that the carbodiimide cross-linked tissue samples prepared using a relatively high l-lysine-pretreated concentration (ie, 30 mM) appeared to have decreased light transmittance and biocompatibility, probably due to the influence of a large nanofiber size and a high charge density. The rise in stemness gene and protein expression levels was dependent on improved cross-link formation, suggesting the crucial role of amino acid bridges in constructing suitable scaffolds to preserve limbal progenitor cells. It is concluded that mild to moderate pretreatment conditions (ie, 3–10 mM l-lysine) can provide a useful strategy to assist in the development of carbodiimide cross-linked amniotic membrane as a stable stem cell niche for corneal epithelial tissue engineering. PMID:25395849

Histone H3 Lysine 36 Trimethylation Is Established over the Xist Promoter by Antisense Tsix Transcription and Contributes to Repressing Xist Expression

PubMed Central

Ohhata, Tatsuya; Matsumoto, Mika; Leeb, Martin; Shibata, Shinwa; Sakai, Satoshi; Kitagawa, Kyoko; Niida, Hiroyuki

2015-01-01

One of the two X chromosomes in female mammals is inactivated by the noncoding Xist RNA. In mice, X chromosome inactivation (XCI) is regulated by the antisense RNA Tsix, which represses Xist on the active X chromosome. In the absence of Tsix, PRC2-mediated histone H3 lysine 27 trimethylation (H3K27me3) is established over the Xist promoter. Simultaneous disruption of Tsix and PRC2 leads to derepression of Xist and in turn silencing of the single X chromosome in male embryonic stem cells. Here, we identified histone H3 lysine 36 trimethylation (H3K36me3) as a modification that is recruited by Tsix cotranscriptionally and extends over the Xist promoter. Reduction of H3K36me3 by expression of a mutated histone H3.3 with a substitution of methionine for lysine at position 36 causes a significant derepression of Xist. Moreover, depletion of the H3K36 methylase Setd2 leads to upregulation of Xist, suggesting H3K36me3 as a modification that contributes to the mechanism of Tsix function in regulating XCI. Furthermore, we found that reduction of H3K36me3 does not facilitate an increase in H3K27me3 over the Xist promoter, indicating that additional mechanisms exist by which Tsix blocks PRC2 recruitment to the Xist promoter. PMID:26370508

The methionine salvage pathway in Bacillus subtilis

PubMed Central

Sekowska, Agnieszka; Danchin, Antoine

2002-01-01

Background Polyamine synthesis produces methylthioadenosine, which has to be disposed of. The cell recycles it into methionine through methylthioribose (MTR). Very little was known about MTR recycling for methionine salvage in Bacillus subtilis. Results Using in silico genome analysis and transposon mutagenesis in B. subtilis we have experimentally uncovered the major steps of the dioxygen-dependent methionine salvage pathway, which, although similar to that found in Klebsiella pneumoniae, recruited for its implementation some entirely different proteins. The promoters of the genes have been identified by primer extension, and gene expression was analyzed by Northern blotting and lacZ reporter gene expression. Among the most remarkable discoveries in this pathway is the role of an analog of ribulose diphosphate carboxylase (Rubisco, the plant enzyme used in the Calvin cycle which recovers carbon dioxide from the atmosphere) as a major step in MTR recycling. Conclusions A complete methionine salvage pathway exists in B. subtilis. This pathway is chemically similar to that in K. pneumoniae, but recruited different proteins to this purpose. In particular, a paralogue or Rubisco, MtnW, is used at one of the steps in the pathway. A major observation is that in the absence of MtnW, MTR becomes extremely toxic to the cell, opening an unexpected target for new antimicrobial drugs. In addition to methionine salvage, this pathway protects B. subtilis against dioxygen produced by its natural biotope, the surface of leaves (phylloplane). PMID:12022921

[Effect of the lysine guanidination on proteomic analysis].

PubMed

Zheng, Hao; Mao, Jiawei; Pan, Yanbo; Liu, Zhongshan; Liu, Zheyi; Ye, Mingliang; Zou, Hanfa

2014-04-01

The guanidination of lysine side chain was paid great attention in recent years. It plays an important role in qualitative and quantitative proteomics. In this study, based on the results of separated peptides extracted from HeLa cells before and after the guanidination by liquid chromatography-tandem mass spectrometry (LC-MS/MS), the effect of the guanidination of three different kinds of peptides was systematically analyzed. It was found that the selectivity of the guanidination of the lysine side chain was as high as 96.8%. The ratio of identified peptides with lysine at C-term to all peptides increased from 51.7% to 57.3% and more new peptides were identified, while the ratio of peptides with lysine in the middle or without lysine changed little. Further study on the ratio of b and y ions indicated that there were more y ions of peptides with lysine at C-term after the guanidination. The results proved that the selective conversion of lysine to homoarginine by the guanidination could increase the sensitivity and selectivity of mass spectrum. The increased basicity and ability to sequester proton of lysine produced more y ions fragmentation information, which contributed to more identified peptides. It concluded that the lysine guanidination can improve the coverage of proteomic analysis.

Global analysis of lysine acetylation in strawberry leaves.

PubMed

Fang, Xianping; Chen, Wenyue; Zhao, Yun; Ruan, Songlin; Zhang, Hengmu; Yan, Chengqi; Jin, Liang; Cao, Lingling; Zhu, Jun; Ma, Huasheng; Cheng, Zhongyi

2015-01-01

Protein lysine acetylation is a reversible and dynamic post-translational modification. It plays an important role in regulating diverse cellular processes including chromatin dynamic, metabolic pathways, and transcription in both prokaryotes and eukaryotes. Although studies of lysine acetylome in plants have been reported, the throughput was not high enough, hindering the deep understanding of lysine acetylation in plant physiology and pathology. In this study, taking advantages of anti-acetyllysine-based enrichment and high-sensitive-mass spectrometer, we applied an integrated proteomic approach to comprehensively investigate lysine acetylome in strawberry. In total, we identified 1392 acetylation sites in 684 proteins, representing the largest dataset of acetylome in plants to date. To reveal the functional impacts of lysine acetylation in strawberry, intensive bioinformatic analysis was performed. The results significantly expanded our current understanding of plant acetylome and demonstrated that lysine acetylation is involved in multiple cellular metabolism and cellular processes. More interestingly, nearly 50% of all acetylated proteins identified in this work were localized in chloroplast and the vital role of lysine acetylation in photosynthesis was also revealed. Taken together, this study not only established the most extensive lysine acetylome in plants to date, but also systematically suggests the significant and unique roles of lysine acetylation in plants.

Immunomodulatory activity of chicken NK-lysin peptides

USDA-ARS?s Scientific Manuscript database

Chicken NK-lysin (cNK-lysin), the chicken homologue of human granulysin, is a cationic amphiphilic antimicrobial peptide (AMP) produced by cytotoxic T cells and natural killer cells. We have previously demonstrated that cNK-lysin and cNK-2, which is a synthetic peptide incorporating core alpha-helic...

Increasing the availability of threonine, isoleucine, valine, and leucine relative to lysine while maintaining an ideal ratio of lysine:methionine alters mammary cellular metabolites, mammalian target of rapamycin signaling, and gene transcription.

PubMed

Dong, X; Zhou, Z; Wang, L; Saremi, B; Helmbrecht, A; Wang, Z; Loor, J J

2018-06-01

Amino acids not only serve as precursors for protein synthesis but also function as signaling molecules that can regulate the mammalian target of rapamycin (mTOR) pathway. Methionine and Lys are the most-limiting AA for milk production and a ratio of ∼3:1 Lys:Met in the metabolizable protein has been determined to be ideal. Besides Met and Lys, recent studies have evaluated Ile, Leu, Val, and Thr as potentially limiting for milk protein synthesis. The objective of this experiment was to determine if varying the ratio of Lys:Thr, Lys:Ile, Lys:Val, and Lys:Leu while maintaining an ideal ratio of Lys:Met and fixed ratio of other essential AA (IPAA) elicits changes in intracellular metabolites, gene transcription related to protein synthesis, and phosphorylation status of mTOR pathway proteins. Immortalized bovine mammary epithelial cell line (MAC-T) cells were incubated for 12 h (n = 5 replicates/treatment) with IPAA (2.9:1 Lys:Met; 1.8:1 Lys:Thr; 2.38:1 Lys:His; 1.23:1 Lys:Val; 1.45:1 Lys:Ile; 0.85:1 Lys:Leu; 2.08:1 Lys:Arg) or IPAA supplemented with Thr, Ile, Val, and Leu to achieve a Lys:Thr 1.3:1 (LT1.3), Lys:Ile 1.29:1 (LI1.29), Lys:Val 1.12:1 (LV1.12), or Lys:Leu 0.78:1 (LL0.78). Compared with IPAA, metabolomics via gas chromatography-mass spectrometry revealed that increases in availability of Thr, Ile, Val, and Leu led to greater concentrations of essential AA (Leu, Ile, Thr), nonessential AA (Gly, Glu, Gln, Ser, Pro, Asp), and various metabolites including uric acid, phosphoric acid, N-acetylglutamic acid, and intermediates of glycolysis and the tricarboxylic acid cycle. Compared with other treatments, LV1.12 led to greater phosphorylation status of serine/threonine kinase B (Akt), mTORC1, and ribosomal protein S6 and lower phosphorylation of α subunit of eukaryotic translation initiation factor 2. In addition, LV1.12 upregulated abundance of CSN2 and both the abundance and promoter methylation of CSN1S1. Although LI1.29 led to the second highest response

40 CFR 711.6 - Chemical substances for which information is not required.

Code of Federal Regulations, 2013 CFR

2013-07-01

... Partially Exempt Chemical Substances CASRN Chemical 50-70-4 D-glucitol. 50-81-7 L-ascorbic acid. 50-99-7 D-glucose. 56-81-5 1,2,3-Propanetriol. 56-87-1 L-lysine. 57-50-1 .alpha.-D-Glucopyranoside, .beta.-D...- trimethyltridecyl]-, (2R)-. 59-51-8 Methionine. 69-65-8 D-mannitol. 87-79-6 L-sorbose. 87-99-0 Xylitol. 96-10-6...

40 CFR 711.6 - Chemical substances for which information is not required.

Code of Federal Regulations, 2012 CFR

2012-07-01

... Partially Exempt Chemical Substances CASRN Chemical 50-70-4 D-glucitol. 50-81-7 L-ascorbic acid. 50-99-7 D-glucose. 56-81-5 1,2,3-Propanetriol. 56-87-1 L-lysine. 57-50-1 .alpha.-D-Glucopyranoside, .beta.-D...- trimethyltridecyl]-, (2R)-. 59-51-8 Methionine. 69-65-8 D-mannitol. 87-79-6 L-sorbose. 87-99-0 Xylitol. 96-10-6...

40 CFR 711.6 - Chemical substances for which information is not required.

Code of Federal Regulations, 2014 CFR

2014-07-01

... Partially Exempt Chemical Substances CASRN Chemical 50-70-4 D-glucitol. 50-81-7 L-ascorbic acid. 50-99-7 D-glucose. 56-81-5 1,2,3-Propanetriol. 56-87-1 L-lysine. 57-50-1 .alpha.-D-Glucopyranoside, .beta.-D...- trimethyltridecyl]-, (2R)-. 59-51-8 Methionine. 69-65-8 D-mannitol. 87-79-6 L-sorbose. 87-99-0 Xylitol. 96-10-6...

A Lysine at the C-Terminus of an Odorant-Binding Protein is Involved in Binding Aldehyde Pheromone Components in Two Helicoverpa Species

PubMed Central

Sun, Ya-Lan; Huang, Ling-Qiao; Pelosi, Paolo; Wang, Chen-Zhu

2013-01-01

Odorant-binding proteins (OBPs) are soluble proteins, whose role in olfaction of insects is being recognized as more and more important. We have cloned, expressed and purified an OBP (HarmOBP7) from the antennae of the moth Helicoverpa armigera. Western blot experiments indicate specific expression of this protein in the antennae of adults. HarmOBP7 binds both pheromone components Z-11-hexadecenal and Z-9-hexadecenal with good affinity. We have also performed a series of binding experiments with linear aldehydes, alcohols and esters, as well as with other compounds and found a requirement of medium size for best affinity. The affinity of OBP7, as well as that of a mutant lacking the last 6 residues does not substantially decrease in acidic conditions, but increases at basic pH values with no significant differences between wild-type and mutant. Binding to both pheromone components, instead, is negatively affected by the lack of the C-terminus. A second mutant, where one of the three lysine residues in the C-terminus (Lys123) was replaced by methionine showed reduced affinity to both pheromone components, as well as to their analogues, thus indicating that Lys123 is involved in binding these compounds, likely forming hydrogen bonds with the functional groups of the ligands. PMID:23372826

Novel mechanism for scavenging of hypochlorite involving a periplasmic methionine-rich peptide and methionine sulfoxide reductase

DOE PAGES

Melnyk, Ryan A.; Youngblut, Matthew D.; Clark, Iain C.; ...

2015-05-12

Reactive chlorine species (RCS) defense mechanisms are important for bacterial fitness in diverse environments. In addition to the anthropogenic use of RCS in the form of bleach, these compounds are also produced naturally through photochemical reactions of natural organic matter and in vivo by the mammalian immune system in response to invading microorganisms. To gain insight into bacterial RCS defense mechanisms, we investigated Azospira suillum strain PS, which produces periplasmic RCS as an intermediate of perchlorate respiration. Our studies identified an RCS response involving an RCS stress-sensing sigma/anti-sigma factor system (SigF/NrsF), a soluble hypochlorite-scavenging methionine-rich periplasmic protein (MrpX), and amore » putative periplasmic methionine sulfoxide reductase (YedY1). We investigated the underlying mechanism by phenotypic characterization of appropriate gene deletions, chemogenomic profiling of barcoded transposon pools, transcriptome sequencing, and biochemical assessment of methionine oxidation. Our results demonstrated that SigF was specifically activated by RCS and initiated the transcription of a small regulon centering around yedY1 and mrpX. A yedY1 paralog ( yedY2) was found to have a similar fitness to yedY1 despite not being regulated by SigF. Markerless deletions of yedY2 confirmed its synergy with the SigF regulon. MrpX was strongly induced and rapidly oxidized by RCS, especially hypochlorite. Our results suggest a mechanism involving hypochlorite scavenging by sacrificial oxidation of the MrpX in the periplasm. Reduced MrpX is regenerated by the YedY methionine sulfoxide reductase activity. The phylogenomic distribution of this system revealed conservation in several Proteobacteria of clinical importance, including uropathogenic Escherichia coli and Brucella spp., implying a putative role in immune response evasion in vivo. In addition, bacteria are often stressed in the environment by reactive chlorine species (RCS) of

Novel mechanism for scavenging of hypochlorite involving a periplasmic methionine-rich peptide and methionine sulfoxide reductase

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

Melnyk, Ryan A.; Youngblut, Matthew D.; Clark, Iain C.

Reactive chlorine species (RCS) defense mechanisms are important for bacterial fitness in diverse environments. In addition to the anthropogenic use of RCS in the form of bleach, these compounds are also produced naturally through photochemical reactions of natural organic matter and in vivo by the mammalian immune system in response to invading microorganisms. To gain insight into bacterial RCS defense mechanisms, we investigated Azospira suillum strain PS, which produces periplasmic RCS as an intermediate of perchlorate respiration. Our studies identified an RCS response involving an RCS stress-sensing sigma/anti-sigma factor system (SigF/NrsF), a soluble hypochlorite-scavenging methionine-rich periplasmic protein (MrpX), and amore » putative periplasmic methionine sulfoxide reductase (YedY1). We investigated the underlying mechanism by phenotypic characterization of appropriate gene deletions, chemogenomic profiling of barcoded transposon pools, transcriptome sequencing, and biochemical assessment of methionine oxidation. Our results demonstrated that SigF was specifically activated by RCS and initiated the transcription of a small regulon centering around yedY1 and mrpX. A yedY1 paralog ( yedY2) was found to have a similar fitness to yedY1 despite not being regulated by SigF. Markerless deletions of yedY2 confirmed its synergy with the SigF regulon. MrpX was strongly induced and rapidly oxidized by RCS, especially hypochlorite. Our results suggest a mechanism involving hypochlorite scavenging by sacrificial oxidation of the MrpX in the periplasm. Reduced MrpX is regenerated by the YedY methionine sulfoxide reductase activity. The phylogenomic distribution of this system revealed conservation in several Proteobacteria of clinical importance, including uropathogenic Escherichia coli and Brucella spp., implying a putative role in immune response evasion in vivo. In addition, bacteria are often stressed in the environment by reactive chlorine species (RCS) of

Variation in plasma amino acid concentrations during a cycling competition.

PubMed

Medelli, J; Lounana, J; Hill, D

2003-06-01

The variations in plasma concentrations of 24 amino acids (AAs) were measured, taking into account modifications in plasma volume, in 7 male subjects, professional cyclists, during the first 2 stages (EI and EII) of the competition "4 Days of Dunkirk 1999". Blood samples were taken before the start and at the end of each stage. At the end of EI a significant reduction (p<0.02) in alpha-aminobutyric acid was observed (-38%) and a significant increase (Wilcoxon 0.01acid (33%), arginine (-21%), cystine (-15%), glycocholic acid (26%), hydroxyproline (-28%), leucine (-17%), lysine (-26%), methionine (-19%), threonine (-15%) and valine (-16%). The recovery period was characterised by increases in previously reduced AAs and vice versa. These results show that cellular use of plasma AAs in the endurance cyclist could differ between the first hours of competition and the subsequent stages, possibly in relation to the gradual increase in stress level as the stages progress; they also suggest that appropriate consideration should be given to the quality of protein inputs in the nutrition of cyclists involved in a high-level stage competition.

Nutritional quality and amino acid composition of diets consumed by scavenging hens and cocks across seasons.

PubMed

Ncobela, Cyprial Ndumiso; Chimonyo, Michael

2016-04-01

The objective of the study was to determine the effect of season on nutritional quality and amino acid composition of diets that scavenging hens and cocks consume. Thirty hens and 30 cocks were purchased and slaughtered during each of the rainy, post rainy, cool dry and hot dry seasons. A total of 240 birds were used in the study. Fresh crop content weights were high (P < 0.05) during the cool dry season. Cereal grains, kitchen wastes, green materials, animal protein sources and inorganic materials were the main components of the crop contents. Crop contents varied with season and sex of bird (P < 0.05). The cereal grain weights were high during cool dry and hot dry seasons. Weights of animal protein sources (insects, locusts and termites) were higher (P < 0.05) during the rainy and post rainy seasons. Hens contained more animal protein sources (P < 0.05) than cocks. Hens had a higher (P < 0.05) lysine content during the rainy season than cocks. Histidine, serine, arginine, threonine, cysteine and lysine contents varied with seasons (P < 0.05). Methionine did not vary with season and sex of the bird. Nutritional supplementation of village chickens should, therefore, vary with seasons.

N6-Trimethyl-lysine metabolism. Structural identification of the metabolite 3-hydroxy-N6-trimethyl-lysine

PubMed Central

Novak, Raymond F.; Swift, Terrence J.; Hoppel, Charles L.

1980-01-01

1H and 13C nuclear-magnetic-resonance spectroscopy and functional-group analysis were used to determine the molecular structure of an isolated metabolite (IIb) of trimethyl-lysine as 3-hydroxy-N6-trimethyl-lysine, an important intermediate in the conversion of trimethyl-lysine into trimethylammoniobutyrate and carnitine [Hoppel, Cox & Novak (1980) Biochem. J. 188, 509–519]. Functional-group analysis revealed the presence of a primary amine and reaction of metabolite (IIb) with periodate yielded 4-N-trimethylammoniobutyrate as a product, showing 2,3-substitution on the molecule and suggesting that the 3-substitution on the molecule may be an alcohol ([unk]CH–OH), amine ([unk]CH[unk]–NH2) or carbonyl ([unk]C=O) functional group. 1H integration ratios, 1H and 13C chemical-shift data and 1H and 13C signal multiplicities from the sample (IIb) were used to complete the identification of metabolite (IIb) as 3-hydroxy-N6-trimethyl-lysine. For example, the proton multiplet at δ 4.2p.p.m. and doublet at δ 4.1p.p.m., positions representative of amine or alcohol substitution on methylene carbon atoms, integration ratios of 1:1:2:9:4 and a positive ninhydrin test suggest 3-hydroxy-N6-trimethyl-lysine as the molecular structure for metabolite (IIb). 13C chemical-shift data obtained from the sample (IIb) and compared with several model compounds (trimethylammoniohexanoate, trimethyl-lysine and 3-hydroxylysine) resulted in generation of the spectrum of the metabolite and allowed independent identification of metabolite (IIb) as 3-hydroxy-N6-trimethyl-lysine. The 1H spectrum of erythro- and threo-3-hydroxylysine are presented for comparison, and the 1H and 13C n.m.r. spectra of the erythro-isomer support this analysis. PMID:6772169

6th Amino Acid Assessment Workshop

USDA-ARS?s Scientific Manuscript database

The focus of the 6th workshop is on lysine, arginine, and related amino acids. Functions, metabolic pathways, clinical uses, and upper tolerance intakes are emphasized in the articles that follow. Lysine is arguably the most deficient amino acid in the food supply of countries where poverty exists, ...

Short-term methionine deprivation improves metabolic health via sexually dimorphic, mTORC1-independent mechanisms.

PubMed

Yu, Deyang; Yang, Shany E; Miller, Blake R; Wisinski, Jaclyn A; Sherman, Dawn S; Brinkman, Jacqueline A; Tomasiewicz, Jay L; Cummings, Nicole E; Kimple, Michelle E; Cryns, Vincent L; Lamming, Dudley W

2018-06-01

Obesity and diabetes are major challenges to global health, and there is an urgent need for interventions that promote weight loss. Dietary restriction of methionine promotes leanness and improves metabolic health in mice and humans. However, poor long-term adherence to this diet limits its translational potential. In this study, we develop a short-term methionine deprivation (MD) regimen that preferentially reduces fat mass, restoring normal body weight and glycemic control to diet-induced obese mice of both sexes. The benefits of MD do not accrue from calorie restriction, but instead result from increased energy expenditure. MD promotes increased energy expenditure in a sex-specific manner, inducing the fibroblast growth factor (Fgf)-21-uncoupling protein (Ucp)-1 axis only in males. Methionine is an agonist of the protein kinase mechanistic target of rapamycin complex (mTORC)-1, which has been proposed to play a key role in the metabolic response to amino acid-restricted diets. In our study, we used a mouse model of constitutive hepatic mTORC1 activity and demonstrate that suppression of hepatic mTORC1 signaling is not required for the metabolic effects of MD. Our study sheds new light on the mechanisms by which dietary methionine regulates metabolic health and demonstrates the translational potential of MD for the treatment of obesity and type 2 diabetes.-Yu, D., Yang, S. E., Miller, B. R., Wisinski, J. A., Sherman, D. S., Brinkman, J. A., Tomasiewicz, J. L., Cummings, N. E., Kimple, M. E., Cryns, V. L., Lamming, D. W. Short-term methionine deprivation improves metabolic health via sexually dimorphic, mTORC1-independent mechanisms.

Gender differences in methionine accumulation and metabolism in freshly isolated mouse hepatocytes: Potential roles in toxicity

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

Dever, Joseph T.; Elfarra, Adnan A.

L-Methionine (Met) is hepatotoxic at high concentrations. Because Met toxicity in freshly isolated mouse hepatocytes is gender-dependent, the goal of this study was to assess the roles of Met accumulation and metabolism in the increased sensitivity of male hepatocytes to Met toxicity compared with female hepatocytes. Male hepatocytes incubated with Met (30 mM) at 37 {sup o}C exhibited higher levels of intracellular Met at 0.5, 1.0, and 1.5 h, respectively, compared to female hepatocytes. Conversely, female hepatocytes had higher levels of S-adenosyl-L-methionine compared to male hepatocytes. Female hepatocytes also exhibited higher L-methionine-L-sulfoxide levels relative to control hepatocytes, whereas the increasesmore » in L-methionine-D-sulfoxide (Met-D-O) levels were similar in hepatocytes of both genders. Addition of aminooxyacetic acid (AOAA), an inhibitor of Met transamination, significantly increased Met levels at 1.5 h and increased Met-D-O levels at 1.0 and 1.5 h only in Met-exposed male hepatocytes. No gender differences in cytosolic Met transamination activity by glutamine transaminase K were detected. However, female mouse liver cytosol exhibited higher methionine-DL-sulfoxide (MetO) reductase activity than male mouse liver cytosol at low (0.25 and 0.5 mM) MetO concentrations. Collectively, these results suggest that increased cellular Met accumulation, decreased Met transmethylation, and increased Met and MetO transamination in male mouse hepatocytes may be contributing to the higher sensitivity of the male mouse hepatocytes to Met toxicity in comparison with female mouse hepatocytes.« less

Differences in the efficiency of reductive activation of methionine synthase and exogenous electron acceptors between the common polymorphic variants of human methionine synthase reductase.

PubMed

Olteanu, Horatiu; Munson, Troy; Banerjee, Ruma

2002-11-12

Methionine synthase reductase (MSR) catalyzes the conversion of the inactive form of human methionine synthase to the active state of the enzyme. This reaction is of paramount physiological importance since methionine synthase is an essential enzyme that plays a key role in the methionine and folate cycles. A common polymorphism in human MSR has been identified (66A --> G) that leads to replacement of isoleucine with methionine at residue 22 and has an allele frequency of 0.5. Another polymorphism is 524C --> T, which leads to the substitution of serine 175 with leucine, but its allele frequency is not known. The I22M polymorphism is a genetic determinant for mild hyperhomocysteinemia, a risk factor for cardiovascular disease. In this study, we have examined the kinetic properties of the M22/S175 and I22/S175 and the I22/L175 and I22/S175 pairs of variants. EPR spectra of the semiquinone forms of variants I22/S175 and M22/S175 are indistinguishable and exhibit an isotropic signal at g = 2.00. In addition, the electronic absorption and reduction stoichiometries with NADPH are identical in these variants. Significantly, the variants activate methionine synthase with the same V(max); however, a 3-4-fold higher ratio of MSR to methionine synthase is required to elicit maximal activity with the M22/S175 and I22/L175 variant versus the I22/S175 enzyme. Differences are also observed between the variants in the efficacies of reduction of the artificial electron acceptors: ferricyanide, 2,6-dichloroindophenol, 3-acetylpyridine adenine dinucleotide phosphate, menadione, and the anticancer drug doxorubicin. These results reveal differences in the interactions between the natural and artificial electron acceptors and MSR variants in vitro, which are predicted to result in less efficient reductive repair of methionine synthase in vivo.

Reduction of hydrogen peroxide stress derived from fatty acid beta-oxidation improves fatty acid utilization in Escherichia coli.

PubMed

Doi, Hidetaka; Hoshino, Yasushi; Nakase, Kentaro; Usuda, Yoshihiro

2014-01-01

Fatty acids are a promising raw material for substance production because of their highly reduced and anhydrous nature, which can provide higher fermentation yields than sugars. However, they are insoluble in water and are poorly utilized by microbes in industrial fermentation production. We used fatty acids as raw materials for L-lysine fermentation by emulsification and improved the limited fatty acid-utilization ability of Escherichia coli. We obtained a fatty acid-utilizing mutant strain by laboratory evolution and demonstrated that it expressed lower levels of an oxidative-stress marker than wild type. The intracellular hydrogen peroxide (H₂O₂) concentration of a fatty acid-utilizing wild-type E. coli strain was higher than that of a glucose-utilizing wild-type E. coli strain. The novel mutation rpsA(D210Y) identified in our fatty acid-utilizing mutant strain enabled us to promote cell growth, fatty-acid utilization, and L-lysine production from fatty acid. Introduction of this rpsA(D210Y) mutation into a wild-type strain resulted in lower H₂O₂ concentrations. The overexpression of superoxide dismutase (sodA) increased intracellular H₂O₂ concentrations and inhibited E. coli fatty-acid utilization, whereas overexpression of an oxidative-stress regulator (oxyS) decreased intracellular H₂O₂ concentrations and promoted E. coli fatty acid utilization and L-lysine production. Addition of the reactive oxygen species (ROS) scavenger thiourea promoted L-lysine production from fatty acids and decreased intracellular H₂O₂ concentrations. Among the ROS generated by fatty-acid β-oxidation, H₂O₂ critically affected E. coli growth and L-lysine production. This indicates that the regression of ROS stress promotes fatty acid utilization, which is beneficial for fatty acids used as raw materials in industrial production.

Comprehensive assessment of the L-lysine production process from fermentation of sugarcane molasses.

PubMed

Anaya-Reza, Omar; Lopez-Arenas, Teresa

2017-07-01

L-Lysine is an essential amino acid that can be produced by chemical processes from fossil raw materials, as well as by microbial fermentation, the latter being a more efficient and environmentally friendly procedure. In this work, the production process of L-lysine-HCl is studied using a systematic approach based on modeling and simulation, which supports decision making in the early stage of process design. The study considers two analysis stages: first, the dynamic analysis of the fermentation reactor, where the conversion of sugars from sugarcane molasses to L-lysine with a strain of Corynebacterium glutamicum is carried out. In this stage, the operation mode (either batch or fed batch) and operating conditions of the fermentation reactor are defined to reach the maximum technical criteria. Afterwards, the second analysis stage relates to the industrial production process of L-lysine-HCl, where the fermentation reactor, upstream processing, and downstream processing are included. In this stage, the influence of key parameters on the overall process performance is scrutinized through the evaluation of several technical, economic, and environmental criteria, to determine a profitable and sustainable design of the L-lysine production process. The main results show how the operating conditions, process design, and selection of evaluation criteria can influence in the conceptual design. The best plant design shows maximum product yield (0.31 g L-lysine/g glucose) and productivity (1.99 g/L/h), achieving 26.5% return on investment (ROI) with a payback period (PBP) of 3.8 years, decreasing water and energy consumption, and with a low potential environmental impact (PEI) index.

Global Analysis of Protein Lysine Succinylation Profiles and Their Overlap with Lysine Acetylation in the Marine Bacterium Vibrio parahemolyticus.

PubMed

Pan, Jianyi; Chen, Ran; Li, Chuchu; Li, Weiyan; Ye, Zhicang

2015-10-02

Protein lysine acylation, including acetylation and succinylation, has been found to be a major post-translational modification (PTM) and is associated with the regulation of cellular processes that are widespread in bacteria. Vibrio parahemolyticus is a model marine bacterium that causes seafood-borne illness in humans worldwide. The lysine acetylation of V. parahemolyticus has been extensively characterized in our previous work, and here, we report the first global analysis of lysine succinylation and the overlap between the two types of acylation in this bacterium. Using high-accuracy nano liquid chromatography-tandem mass spectrometry combined with affinity purification, we identified 1931 lysine succinylated peptides matched on 642 proteins, with the quantity of the succinyl-proteins accounting for 13.3% of the total proteins in cells. Bioinformatics analysis results showed that these succinylated proteins are involved in almost every cellular process, particularly in protein biosynthesis and metabolism, and are distributed in diverse subcellular compartments. Moreover, several sequence motifs were identified, including succinyl-lysine flanked by a lysine or arginine residue at the -8, -7, or +7 position and without these residues at the -1 or +2 position, and these motifs differ from those found in other bacteria and eukaryotic cells. Furthermore, a total of 517 succinyl-lysine sites (26.7%) on 288 proteins (44.9%) were also found to be acetylated, suggesting extensive overlap between succinylation and acetylation in this bacterium. This systematic analysis provides a promising starting point for further investigations of the physiologic and pathogenic roles of lysine succinylation and acetylation in V. parahemolyticus.

Removing a bottleneck in the Bacillus subtilis biotin pathway: bioA utilizes lysine rather than S-adenosylmethionine as the amino donor in the KAPA-to-DAPA reaction.

PubMed

Van Arsdell, Scott W; Perkins, John B; Yocum, R Rogers; Luan, Linda; Howitt, C Linda; Chatterjee, Nilu Prasad; Pero, Janice G

2005-07-05

In biotin biosynthesis, DAPA aminotransferase encoded by the bioA gene catalyzes the formation of the intermediate 7,8-diaminopelargonic acid (DAPA) from 7-keto-8-aminopelargonic acid (KAPA). DAPA aminotransferases from Escherichia coli, Serratia marcescens, and Bacillus sphaericus use S-adenosylmethionine (SAM) as the amino donor. Our observation that SAM is not an amino donor for B. subtilis DAPA aminotransferase led to a search for an alternative amino donor for this enzyme. Testing of 26 possible amino acids in a cell-free extract assay revealed that only l-lysine was able to dramatically stimulate the in vitro conversion of KAPA to DAPA by the B. subtilis DAPA aminotransferase. The K(m) for lysine and KAPA was estimated to be between 2 and 25 mM, which is significantly higher than the K(m) of purified E. coli BioA for SAM (0.15 mM). This higher requirement for lysine resulted in accumulation of KAPA during fermentation of B. subtilis biotin producing strains. However, this pathway bottleneck could be relieved by either addition of exogenous lysine to the medium or by introduction of lysine deregulated mutations into the production strains.

Antibacterial Activity of a Novel Peptide-Modified Lysin Against Acinetobacter baumannii and Pseudomonas aeruginosa

PubMed Central

Yang, Hang; Wang, Mengyue; Yu, Junping; Wei, Hongping

2015-01-01

The global emergence of multidrug-resistant (MDR) bacteria is a growing threat to public health worldwide. Natural bacteriophage lysins are promising alternatives in the treatment of infections caused by Gram-positive pathogens, but not Gram-negative ones, like Acinetobacter baumannii and Pseudomonas aeruginosa, due to the barriers posed by their outer membranes. Recently, modifying a natural lysin with an antimicrobial peptide was found able to break the barriers, and to kill Gram-negative pathogens. Herein, a new peptide-modified lysin (PlyA) was constructed by fusing the cecropin A peptide residues 1–8 (KWKLFKKI) with the OBPgp279 lysin and its antibacterial activity was studied. PlyA showed good and broad antibacterial activities against logarithmic phase A. baumannii and P. aeruginosa, but much reduced activities against the cells in stationary phase. Addition of outer membrane permeabilizers (EDTA and citric acid) could enhance the antibacterial activity of PlyA against stationary phase cells. Finally, no antibacterial activity of PlyA could be observed in some bio-matrices, such as culture media, milk, and sera. In conclusion, we reported here a novel peptide-modified lysin with significant antibacterial activity against both logarithmic (without OMPs) and stationary phase (with OMPs) A. baumannii and P. aeruginosa cells in buffer, but further optimization is needed to achieve broad activity in diverse bio-matrices. PMID:26733995

Development and validation of a rapid, selective, and sensitive LC-MS/MS method for simultaneous determination of D- and L-amino acids in human serum: application to the study of hepatocellular carcinoma.

PubMed

Han, Minlu; Xie, Mengyu; Han, Jun; Yuan, Daoyi; Yang, Tian; Xie, Ying

2018-04-01

A validated liquid chromatography-tandem mass spectrometry method was developed for the simultaneous determination of D- and L-amino acids in human serum. Under the optimum conditions, except for DL-proline, L-glutamine, and D-lysine, the enantioseparation of the other 19 enantiomeric pairs of proteinogenic amino acids and nonchiral glycine was achieved with a CROWNPAK CR-I(+) chiral column within 13 min. The lower limits of quantitation for L-amino acids (including glycine) and D-amino acids were 5-56.25 μM and 0.625-500 nM, respectively, in human serum. The intraday precision and interday precision for all the analytes were less than 15%, and the accuracy ranged from -12.84% to 12.37% at three quality control levels. The proposed method, exhibiting high rapidity, enantioresolution, and sensitivity, was successfully applied to the quantification of D- and L-amino acid levels in serum from hepatocellular carcinoma patients and healthy individuals. The serum concentrations of L-arginine, L-isoleucine, L-aspartate, L-tryptophan, L-alanine, L-methionine, L-serine, glycine, L-valine, L-leucine, L-phenylalanine, L-threonine, D-isoleucine, D-alanine, D-glutamate, D-glutamine, D-methionine, and D-threonine were significantly reduced in the hepatocellular carcinoma patients compared with the healthy individuals (P < 0.01). D-Glutamate and D-glutamine were identified as the most downregulated serum markers (fold change greater than 1.5), which deserves further attention in hepatocellular carcinoma research. Graphical abstract Simultaneous determination of D- and L-amino acids in human serum from hepatocellular carcinoma patients and healthy individuals. AA amino acid, HCC hepatocellular carcinoma, LC liquid chromatography, MS/MS tandem mass spectrometry, NC normal control, TIC total ion chromatogram.

21 CFR 582.5477 - Methionine hydroxy analog and its calcium salts.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Methionine hydroxy analog and its calcium salts... Nutrients and/or Dietary Supplements 1 § 582.5477 Methionine hydroxy analog and its calcium salts. (a) Product. Methionine hydroxy analog and its calcium salts. (b) [Reserved] (c) Limitations, restrictions, or...

21 CFR 582.5477 - Methionine hydroxy analog and its calcium salts.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Methionine hydroxy analog and its calcium salts... Nutrients and/or Dietary Supplements 1 § 582.5477 Methionine hydroxy analog and its calcium salts. (a) Product. Methionine hydroxy analog and its calcium salts. (b) [Reserved] (c) Limitations, restrictions, or...

Effects of essential amino acids on lipid metabolism in mice and humans.

PubMed

Xiao, Fei; Du, Ying; Lv, Ziquan; Chen, Shanghai; Zhu, Jianmin; Sheng, Hongguang; Guo, Feifan

2016-11-01

Eight amino acids are considered essential for human nutrition, and three of them, including leucine, isoleucine and valine, are called as branched-chain amino acids (BCAAs). We recently discovered that dietary deficiency of any BCAA for 7 days rapidly reduces the abdominal fat mass in mice. The goal of this study was to investigate (1) whether dietary deficiency of the other five essential amino acids (EAAs), including phenylalanine, threonine, tryptophan, methionine and lysine, would produce similar effects and (2) whether an association between serum AAs and obesity was observed in humans in Chinese Han population. Similar to BCAAs deprivation, dietary deficiency of any of these five EAAs for 7 days significantly reduced abdominal fat mass, which is likely caused by increased energy expenditure. Expression of genes and proteins related to lipolysis, however, were differentially regulated by different EAAs. These results suggest a crucial role of EAAs deprivation on lipid metabolism in mice. Our human studies revealed that levels of four EAAs (leucine, isoleucine, valine and phenylalanine) were elevated in obese humans compared with those in lean controls in Chinese Han population. Based on the results obtained from mice, we speculate that these four EAAs might play important roles in human obesity. © 2016 Society for Endocrinology.

Differential lysine acetylation profiles of Erwinia amylovora strains revealed by proteomics

PubMed Central

Wu, Xia; Vellaichamy, Adaikkalam; Wang, Dongping; Zamdborg, Leonid; Kelleher, Neil L.; Huber, Steven C.; Zhao, Youfu

2015-01-01

Protein lysine acetylation (LysAc) has recently been demonstrated to be widespread in E. coli and Salmonella, and to broadly regulate bacterial physiology and metabolism. However, LysAc in plant pathogenic bacteria is largely unknown. Here we first report the lysine acetylome of Erwinia amylovora, an enterobacterium causing serious fire blight disease of apples and pears. Immunoblots using generic anti-lysine acetylation antibodies demonstrated that growth conditions strongly affected the LysAc profiles in E. amylovora. Differential LysAc profiles were also observed for two E. amylovora strains, known to have differential virulence in plants, indicating translational modification of proteins may be important in determining virulence of bacterial strains. Proteomic analysis of LysAc in two E. amylovora strains identified 141 LysAc sites in 96 proteins that function in a wide range of biological pathways. Consistent with previous reports, 44% of the proteins are involved in metabolic processes, including central metabolism, lipopolysaccharide, nucleotide and amino acid metabolism. Interestingly, for the first time, several proteins involved in E. amylovora virulence, including exopolysaccharide amylovoran biosynthesis- and type III secretion-associated proteins, were found to be lysine acetylated, suggesting that LysAc may play a major role in bacterial virulence. Comparative analysis of LysAc sites in E. amylovora and E. coli further revealed the sequence and structural commonality for LysAc in the two organisms. Collectively, these results reinforce the notion that LysAc of proteins is widespread in bacterial metabolism and virulence. PMID:23234799

Understanding cerebral L-lysine metabolism: the role of L-pipecolate metabolism in Gcdh-deficient mice as a model for glutaric aciduria type I.

PubMed

Posset, Roland; Opp, Silvana; Struys, Eduard A; Völkl, Alfred; Mohr, Heribert; Hoffmann, Georg F; Kölker, Stefan; Sauer, Sven W; Okun, Jürgen G

2015-03-01

Inherited deficiencies of the L-lysine catabolic pathway cause glutaric aciduria type I and pyridoxine-dependent epilepsy. Dietary modulation of cerebral L-lysine metabolism is thought to be an important therapeutic intervention for these diseases. To better understand cerebral L-lysine degradation, we studied in mice the two known catabolic routes -- pipecolate and saccharopine pathways -- using labeled stable L-lysine and brain peroxisomes purified according to a newly established protocol. Experiments with labeled stable L-lysine show that cerebral L-pipecolate is generated along two pathways: i) a minor proportion retrograde after ε-deamination of L-lysine along the saccharopine pathway, and ii) a major proportion anterograde after α-deamination of L-lysine along the pipecolate pathway. In line with these findings, we observed only little production of saccharopine in the murine brain. L-pipecolate oxidation was only detectable in brain peroxisomes, but L-pipecolate oxidase activity was low (7 ± 2μU/mg protein). In conclusion, L-pipecolate is a major degradation product from L-lysine in murine brain generated by α-deamination of this amino acid.

New insights into sulfur amino acids function in gut health and disease

USDA-ARS?s Scientific Manuscript database

The gastrointestinal tract (GIT) is a metabolically significant site of sulfur amino acids (SAAs) metabolism in the body. Aside from their role in protein synthesis, methionine and cysteine are involved in many biological functions and diseases. Methionine (MET) is an indispensable amino acid and is...

New insights into the interplay between the lysine transporter LysP and the pH sensor CadC in Escherichia coli.

PubMed

Rauschmeier, Martina; Schüppel, Valentina; Tetsch, Larissa; Jung, Kirsten

2014-01-09

The coordination of signal transduction and substrate transport represents a sophisticated way to integrate information on metabolite fluxes into transcriptional regulation. This widely distributed process involves protein-protein interactions between two integral membrane proteins. Here we report new insights into the molecular mechanism of the regulatory interplay between the lysine-specific permease LysP and the membrane-integrated pH sensor CadC, which together induce lysine-dependent adaptation of E. coli under acidic stress. In vivo analyses revealed that, in the absence of either stimulus, the two proteins form a stable association, which is modulated by lysine and low pH. In addition to its transmembrane helix, the periplasmic domain of CadC also participated in the interaction. Site-directed mutagenesis pinpointed Arg265 and Arg268 in CadC as well as Asp275 and Asp278 in LysP as potential periplasmic interaction sites. Moreover, a systematic analysis of 100 LysP variants with single-site replacements indicated that the lysine signal is transduced from co-sensor to sensor via lysine-dependent conformational changes (upon substrate binding and/or transport) of LysP. Our results suggest a scenario in which CadC is inhibited by LysP via intramembrane and periplasmic contacts under non-inducing conditions. Upon induction, lysine-dependent conformational changes in LysP transduce the lysine signal via a direct conformational coupling to CadC without resolving the interaction completely. Moreover, concomitant pH-dependent protonation of periplasmic amino acids in both proteins dissolves their electrostatic connections resulting in further destabilization of the CadC/LysP interaction. © 2013.

Lysine supplementation is not effective for the prevention or treatment of feline herpesvirus 1 infection in cats: a systematic review.

PubMed

Bol, Sebastiaan; Bunnik, Evelien M

2015-11-16

Feline herpesvirus 1 is a highly contagious virus that affects many cats. Virus infection presents with flu-like signs and irritation of ocular and nasal regions. While cats can recover from active infections without medical treatment, examination by a veterinarian is recommended. Lysine supplementation appears to be a popular intervention (recommended by > 90 % of veterinarians in cat hospitals). We investigated the scientific merit of lysine supplementation by systematically reviewing all relevant literature. NCBI's PubMed database was used to search for published work on lysine and feline herpesvirus 1, as well as lysine and human herpesvirus 1. Seven studies on lysine and feline herpesvirus 1 (two in vitro studies and 5 studies with cats), and 10 publications on lysine and human herpesvirus 1 (three in vitro studies and 7 clinical trials) were included for qualitative analysis. There is evidence at multiple levels that lysine supplementation is not effective for the prevention or treatment of feline herpesvirus 1 infection in cats. Lysine does not have any antiviral properties, but is believed to act by lowering arginine levels. However, lysine does not antagonize arginine in cats, and evidence that low intracellular arginine concentrations would inhibit viral replication is lacking. Furthermore, lowering arginine levels is highly undesirable since cats cannot synthesize this amino acid themselves. Arginine deficiency will result in hyperammonemia, which may be fatal. In vitro studies with feline herpesvirus 1 showed that lysine has no effect on the replication kinetics of the virus. Finally, and most importantly, several clinical studies with cats have shown that lysine is not effective for the prevention or the treatment of feline herpesvirus 1 infection, and some even reported increased infection frequency and disease severity in cats receiving lysine supplementation. We recommend an immediate stop of lysine supplementation because of the complete lack of

The effects of L-cysteine and N-acetyl-L-cysteine on homocysteine metabolism and haemostatic markers, and on cardiac and aortic histology in subchronically methionine-treated Wistar male rats.

PubMed

Kostić, Sanja; Mićovic, Žarko; Andrejević, Lazar; Cvetković, Saša; Stamenković, Aleksandra; Stanković, Sanja; Obrenović, Radmila; Labudović-Borović, Milica; Hrnčić, Dragan; Jakovljević, Vladimir; Djurić, Dragan

2018-06-23

Methionine is the precursor of homocysteine, a sulfur amino acid intermediate in the methylation and transsulfuration pathways; methionine-rich diets were used to induce hyperhomocysteinemia, and cardiovascular pathology was often observed. Other sulfur amino acids interfere with this metabolism, i.e., L-cysteine (Cys) and N-aceyl-L-cysteine (NAC), and probably also affect cardiovascular system. Their effects are controversial due to their ability to act both as anti- or pro-oxidant. Thus, this study aimed to elucidate their influence on levels of homocysteine, folate and vitamin B12, levels of different haemostatic parameters (fibrinogen, D-dimer, vWF Ag, vWF Ac) in rat serum or plasma as well as their effects on cardiac and aortic tissue histology in subchronically methionine-treated rats. Wistar albino rats were divided into 4 experimental groups: (a) control group (0.9% sodium chloride 0.1-0.2 mL/day) (n = 10) (K); (b) DL-methionine (0.8 mmol/kg/bw/day) (n = 10) (M); (c) DL-methionine (0.8 mmol/kg/bw/day) + L-cysteine (7 mg/kg/bw/day) (n = 8) (C); (d) DL-methionine (0.8 mmol/ kg/bw/day) + N-acetyl-L-cysteine (50 mg/kg/bw/day) (n = 8) (N). All substances were applied i.p., treatment duration 3 weeks. Lower levels of vitamin B12 in all the groups were found. Folate was reduced only in N group. Decreased fibrinogen was noted in C and N groups and increased D-dimer only in C. VWF activity was reduced in M and C groups. Deleterious effects in heart were observed, especially after Cys and NAC application. Aortic tissue remained unchanged. In conclusion, it could be said that sulfur amino acids have the significant impact on cardiovascular system in subchronically methionine-treated rats. This study points out the relevance of their complex interactions and deleterious effects mediated by either direct influence or procoagulant properties.

Determination of branched chain amino acids, methionine, phenylalanine, tyrosine and alpha-keto acids in plasma and dried blood samples using HPLC with fluorescence detection.

PubMed

Kand'ár, Roman; Záková, Pavla; Jirosová, Jana; Sladká, Michaela

2009-01-01

The determination of branched chain amino acids [BCAA; valine (Val), leucine (Leu), isoleucine (Ile)], alpha-keto acids derived from BCAA [BCKA; alpha-ketoisovaleric acid (KIV), alpha-ketoisocaproic acid (KIC), alpha-ketomethylvaleric acid (KMV)], methionine (Met), phenylalanine (Phe) and tyrosine (Tyr) is currently the most reliable approach for the diagnosis of maple syrup urine disease (MSUD), hypermethioninemia, phenylketonuria (PKU) and tyrosinemia. The aim of this study was to develop rapid and simple HPLC methods for measurement of BCAA, Met, Phe, Tyr and BCKA in plasma and dried blood samples. Samples of peripheral venous blood with EDTA as anticoagulant were obtained from a group of healthy blood donors (n=70, 35 females, 27-41 years of age and 35 males, 28-43 years of age). Blood-spot samples from a group of newborns (n=80, 40 girls and 40 boys 3-5 days of age) were collected onto #903 Specimen Collection Paper and allowed to dry for at least 24 h before analysis. Prior to separation, the amino acids (AA) were derivatized with o-phthaldialdehyde (OPA) and BCKA with o-phenylenediamine (OPD). Reverse phase column chromatography (LiChroCart 125-4 Purospher RP-18e, 5 microm) was used for separation and fluorescence detection used to monitoring of effluent. For AA analysis, 25 mmol/L sodium hydrogenphosphate-methanol (90:10, v/v), pH 6.5+/-0.1 was used as mobile phase A and 100% methanol was used as mobile phase B. Measurement of BCKA used a mixture of methanol and deionized water (55:45, v/v) as mobile phase A and mobile phase B consisted of 100% methanol. Analytical performance of these methods was satisfactory for the determination of all AA and BCKA. The intra-assay and inter-assay coefficients of variation were below 10% and recovery ranged from 90%-110%. We have developed simple, rapid and selective HPLC methods with fluorescence detection for the determination of BCAA, Met, Phe, Tyr and BCKA in plasma and dried blood samples.

Sulfur amino acids are necessary for normal intestinal mucosal growth in neonatal piglets

USDA-ARS?s Scientific Manuscript database

Sulfur amino acids (SAAs) methionine and cysteine play important metabolic and functional role in human health and disease. Gastrointestinal tract is an important site of transmethylation and transsulfuration of methionine and metabolizes approx. 20% of the dietary methionine intake (Riedijk et al. ...

Lysine and glutamate transport in the erythrocytes of common brushtail possum, Tammar Wallaby and eastern grey, kangaroo.

PubMed

Ogawa, E; Kuchel, P W; Agar, N S

1998-04-01

It was recently coincidentally discovered, using 1H NMR spectroscopy, that the erythrocytes of two species of Australian marsupials, Tammar Wallaby (Macropus eugenii) and Bettong (Bettongia penicillata), contain relatively high concentrations of the essential amino acid lysine (Agar NS, Rae CD, Chapman BE, Kuchel PW. Comp Biochem Physiol 1991;99B:575-97). Hence, in the present work the rates of transport of lysine into the erythrocytes from the Common Brushtail Possum (Dactylopsilia trivirgata) and Eastern Grey Kangaroo (Macropus giganteus) (which both have low lysine concentrations), and Tammar Wallaby were studied, to explore the mechanistic basis of this finding. The concentration-dependence of the uptake was studied with lysine alone and in the presence of arginine, which may be a competitor of the transport in some species. In relation to GSH metabolism, glutamate uptake was determined in the presence and absence of Na+. The data was analysed to yield estimates of the maximal velocity (Vmax) and the Km in each of the species. Erythrocytes from Tammar Wallaby lacked saturable lysine transport in contrast to the other two species. The glutamate uptake was normal in all three animals for adequate GSH biosynthesis.

Selective Tuning of Elastin-like Polypeptide Properties via Methionine Oxidation.

PubMed

Petitdemange, Rosine; Garanger, Elisabeth; Bataille, Laure; Dieryck, Wilfrid; Bathany, Katell; Garbay, Bertrand; Deming, Timothy J; Lecommandoux, Sébastien

2017-02-13

We have designed and prepared a recombinant elastin-like polypeptide (ELP) containing precisely positioned methionine residues, and performed the selective and complete oxidation of its methionine thioether groups to both sulfoxide and sulfone derivatives. Since these oxidation reactions substantially increase methionine residue polarity, they were found to be a useful means to precisely adjust the temperature responsive behavior of ELPs in aqueous solutions. In particular, lower critical solution temperatures were found to be elevated in oxidized sample solutions, but were not eliminated. These transition temperatures were found to be further tunable by the use of solvents containing different Hofmeister salts. Overall, the ability to selectively and fully oxidize methionine residues in ELPs proved to be a convenient postmodification strategy for tuning their transition temperatures in aqueous media.

Emerging roles of lysine methylation on non-histone proteins.

PubMed

Zhang, Xi; Huang, Yaling; Shi, Xiaobing

2015-11-01

Lysine methylation is a common posttranslational modification (PTM) of histones that is important for the epigenetic regulation of transcription and chromatin in eukaryotes. Increasing evidence demonstrates that in addition to histones, lysine methylation also occurs on various non-histone proteins, especially transcription- and chromatin-regulating proteins. In this review, we will briefly describe the histone lysine methyltransferases (KMTs) that have a broad spectrum of non-histone substrates. We will use p53 and nuclear receptors, especially estrogen receptor alpha, as examples to discuss the dynamic nature of non-histone protein lysine methylation, the writers, erasers, and readers of these modifications, and the crosstalk between lysine methylation and other PTMs in regulating the functions of the modified proteins. Understanding the roles of lysine methylation in normal cells and during development will shed light on the complex biology of diseases associated with the dysregulation of lysine methylation on both histones and non-histone proteins.

Terrestrial evolution of polymerization of amino acids - Heat to ATP

NASA Technical Reports Server (NTRS)

Fox, S. W.; Nakashima, T.

1981-01-01

Sets of amino acids containing sufficient trifunctional monomer are thermally polymerized at temperatures such as 65 deg; the amino acids order themselves. Various polymers have diverse catalytic activities. The polymers aggregate, in aqueous solution, to cell-like structures having those activities plus emergent properties, e.g. proliferatability. Polyamino acids containing sufficient lysine catalyze conversion of free amino acids, by ATP, to small peptides and a high molecular weight fraction. The lysine-rich proteinoid is active in solution, within suspensions of cell-like particles, or in other particles composed of lysine-rich proteinoid and homopolyribonucleotide. Selectivities are observed. An archaic polyamino acid prelude to coded protein synthesis is indicated.

Pyruvate kinase deletion as an effective phenotype to enhance lysine production in Corynebacterium glutamicum ATCC13032: Redirecting the carbon flow to a precursor metabolite.

PubMed

Yanase, Masaki; Aikoh, Tohru; Sawada, Kazunori; Ogura, Kotaro; Hagiwara, Takuya; Imai, Keita; Wada, Masaru; Yokota, Atsushi

2016-08-01

Various attempts have been made to enhance lysine production in Corynebacterium glutamicum. Pyruvate kinase (PYK) defect is one of the strategies used to enhance the supply of oxaloacetic acid (OAA), a precursor metabolite for lysine biosynthesis. However, inconsistent effects of this mutation have been reported: positive effects of PYK defect in mutants having phosphoenolpyruvate carboxylase (PEPC) desensitized to feedback inhibition by aspartic acid, while negative effects in simple PYK gene (pyk) knockout mutants. To address these discrepancies, the effects of pyk deletion on lysine yield were investigated with or without the D299N mutation in ppc rendering PEPC desensitization. C. glutamicum ATCC13032 mutant strain P with a feedback inhibition-desensitized aspartokinase was used as the parent strain, producing 9.36 g/L lysine from 100 g/L glucose in a jar fermentor culture. Under these conditions, while the simple mutant D2 with pyk deletion or R2 with the PEPC-desensitization mutation showed marginally increased lysine yield (∼1.1-fold, not significant), the mutant DR2 strain having both mutations showed synergistically increased lysine productivity (1.38-fold, 12.9 g/L). Therefore, the pyk deletion is effective under a PEPC-desensitized background, which ensures enhanced supply of OAA, thus clarifying the discrepancies. A citrate synthase defective mutation (S252C in gltA) further increased the lysine yield in strain DR2 (1.68-fold, 15.7 g/L). Thus, these three mutations coordinately enhanced the lysine yield. Both the malate:quinone oxidoreductase activity and respiration rate were significantly reduced in strains D2 and DR2. Overall, these results provide valuable knowledge for engineering the anaplerotic reaction to increase lysine yield in C. glutamicum. Copyright © 2016 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

Biotinylation of lysine method identifies acetylated histone H3 lysine 79 in Saccharomyces cerevisiae as a substrate for Sir2.

PubMed

Bheda, Poonam; Swatkoski, Stephen; Fiedler, Katherine L; Boeke, Jef D; Cotter, Robert J; Wolberger, Cynthia

2012-04-17

Although the biological roles of many members of the sirtuin family of lysine deacetylases have been well characterized, a broader understanding of their role in biology is limited by the challenges in identifying new substrates. We present here an in vitro method that combines biotinylation and mass spectrometry (MS) to identify substrates deacetylated by sirtuins. The method permits labeling of deacetylated residues with amine-reactive biotin on the ε-nitrogen of lysine. The biotin can be utilized to purify the substrate and identify the deacetylated lysine by MS. The biotinyl-lysine method was used to compare deacetylation of chemically acetylated histones by the yeast sirtuins, Sir2 and Hst2. Intriguingly, Sir2 preferentially deacetylates histone H3 lysine 79 as compared to Hst2. Although acetylation of K79 was not previously reported in Saccharomyces cerevisiae, we demonstrate that a minor population of this residue is indeed acetylated in vivo and show that Sir2, and not Hst2, regulates the acetylation state of H3 lysine 79. The in vitro biotinyl-lysine method combined with chemical acetylation made it possible to identify this previously unknown, low-abundance histone acetyl modification in vivo. This method has further potential to identify novel sirtuin deacetylation substrates in whole cell extracts, enabling large-scale screens for new deacetylase substrates.

An integrative analysis of tissue-specific transcriptomic and metabolomic responses to short-term dietary methionine restriction in mice

PubMed Central

Ghosh, Sujoy; Forney, Laura A.; Wanders, Desiree; Stone, Kirsten P.

2017-01-01

Dietary methionine restriction (MR) produces a coordinated series of transcriptional responses in peripheral tissues that limit fat accretion, remodel lipid metabolism in liver and adipose tissue, and improve overall insulin sensitivity. Hepatic sensing of reduced methionine leads to induction and release of fibroblast growth factor 21 (FGF21), which acts centrally to increase sympathetic tone and activate thermogenesis in adipose tissue. FGF21 also has direct effects in adipose to enhance glucose uptake and oxidation. However, an understanding of how the liver senses and translates reduced dietary methionine into these transcriptional programs remains elusive. A comprehensive systems biology approach integrating transcriptomic and metabolomic readouts in MR-treated mice confirmed that three interconnected mechanisms (fatty acid transport and oxidation, tricarboxylic acid cycle, and oxidative phosphorylation) were activated in MR-treated inguinal adipose tissue. In contrast, the effects of MR in liver involved up-regulation of anti-oxidant responses driven by the nuclear factor, erythroid 2 like 2 transcription factor, NFE2L2. Metabolomic analysis provided evidence for redox imbalance, stemming from large reductions in the master anti-oxidant molecule glutathione coupled with disproportionate increases in ophthalmate and its precursors, glutamate and 2-aminobutyrate. Thus, cysteine and its downstream product, glutathione, emerge as key early hepatic signaling molecules linking dietary MR to its metabolic phenotype. PMID:28520765

D-METHIONINE REDUCES TOBRAMYCIN-INDUCED OTOTOXICITY WITHOUT ANTIMICROBIAL INTERFERENCE IN ANIMAL MODELS

PubMed Central

Fox, Daniel J.; Cooper, Morris D.; Speil, Cristian A.; Roberts, Melissa H.; Yanik, Susan C.; Meech, Robert P.; Hargrove, Tim L.; Verhulst, Steven J.; Rybak, Leonard P.; Campbell, Kathleen C. M.

2015-01-01

Background Tobramycin is a critical cystic fibrosis treatment however it causes ototoxicity. This study tested D-methionine protection from tobramycin-induced ototoxicity and potential antimicrobial interference. Methods Auditory brainstem responses (ABR) and outer hair cell (OHC) quantifications measured protection in guinea pigs treated with tobramycin and a range of D-methionine doses. In vitro antimicrobial interference studies tested inhibition and post antibiotic effect assays. In vivo antimicrobial interference studies tested normal and neutropenic E. coli murine survival and intraperitoneal lavage bacterial counts. Results D-methionine conferred significant ABR threshold shift reductions. OHC protection was less robust but significant at 20 kHz in the 420 mg/kg/day group. In vitro studies did not detect D-methionine-induced antimicrobial interference. In vivo studies did not detect D-methionine-induced interference in normal or neutropenic mice. Conclusions D-methionine protects from tobramycin-induced ototoxicity without antimicrobial interference. The study results suggest D-met as a potential otoprotectant from clinical tobramycin use in cystic fibrosis patients. PMID:26166286

d-Methionine reduces tobramycin-induced ototoxicity without antimicrobial interference in animal models.

PubMed

Fox, Daniel J; Cooper, Morris D; Speil, Cristian A; Roberts, Melissa H; Yanik, Susan C; Meech, Robert P; Hargrove, Tim L; Verhulst, Steven J; Rybak, Leonard P; Campbell, Kathleen C M

2016-07-01

Tobramycin is a critical cystic fibrosis treatment however it causes ototoxicity. This study tested d-methionine protection from tobramycin-induced ototoxicity and potential antimicrobial interference. Auditory brainstem responses (ABRs) and outer hair cell (OHC) quantifications measured protection in guinea pigs treated with tobramycin and a range of d-methionine doses. In vitro antimicrobial interference studies tested inhibition and post antibiotic effect assays. In vivo antimicrobial interference studies tested normal and neutropenic Escherichia coli murine survival and intraperitoneal lavage bacterial counts. d-Methionine conferred significant ABR threshold shift reductions. OHC protection was less robust but significant at 20kHz in the 420mg/kg/day group. In vitro studies did not detect d-methionine-induced antimicrobial interference. In vivo studies did not detect d-methionine-induced interference in normal or neutropenic mice. d-Methionine protects from tobramycin-induced ototoxicity without antimicrobial interference. The study results suggest d-met as a potential otoprotectant from clinical tobramycin use in cystic fibrosis patients. Published by Elsevier B.V.

Lysine Restriction and Pyridoxal Phosphate Administration in a NADK2 Patient.

PubMed

Tort, Frederic; Ugarteburu, Olatz; Torres, Maria Angeles; García-Villoria, Judit; Girós, Marisa; Ruiz, Angeles; Ribes, Antonia

2016-11-01

We report the case of a 10-year-old Spanish girl with mutations in NADK2 Prenatal central nervous system abnormalities showed ventriculomegaly, colpocephaly, and hypoplasia of the corpus callosum. At birth, axial hypotonia, uncoordinated movements, microcephaly, and generalized cerebellar atrophy were detected. Metabolic investigations revealed high lysine, lactate, and pipecolic acid levels in blood and cerebrospinal fluid. Pyruvate carboxylase and pyruvate dehydrogenase activity in fibroblasts were normal. Beginning at birth she received biotin, thiamine, and carnitine supplementation. A lysine-restricted diet was started when she was 1 month old. Because pipecolic acid was high, pyridoxine was added to treatment. At 3 years old, astatic myoclonic epilepsy appeared, with no response to levetiracetam. We switched pyridoxine to pyridoxal phosphate, with electroclinical improvement. Because the activity of mitochondrial respiratory chain complexes III and IV was slightly low in muscle, other cofactors such as ubidecarenone, idebenone, vitamin E, and creatine were added to the treatment. At 8 years old, plasma acylcarnitine testing was performed, and high levels of 2-trans, 4-cis-decadienoylcarnitine were found. Whole exome sequencing identified a homozygous splice site mutation in NADK2 (c.956+6T>C; p.Trp319Cysfs*21). This substitution generates exon skipping, leading to a truncated protein. In fact, NADK2 messenger RNA and the corresponding protein were almost absent. Now, at 10 years of age she presents with ataxia and incoordination. She has oromotor dysphasia but is able to understand fluid language and is a very friendly girl. We hypothesize that the patient's clinical improvement could be due to her lysine-restricted diet together with cofactors and pyridoxal phosphate administration. Copyright © 2016 by the American Academy of Pediatrics.

Investigation into the Emerging Role of the Basic Amino Acid L-Lysine in Enhancing Solubility and Permeability of BCS Class II and BCS Class IV Drugs.

PubMed

Abdelkader, Hamdy; Fathalla, Zeinab

2018-06-18

The search for a simple and scalable approach that can improve the two key biopharmaceutical processes (solubility and permeability) for BCS Class II and BCS Class IV has still been unmet need. In this study, L-lysine was investigated as a potential excipient to tackle problems with solubility and permeability. Bendazac (Class II); quercetin and rutin (Class IV) were employed. Drugs-lysine complexes in 1:1 M ratios were prepared by co-precipitation and co-grinding; characterized for solubility, partition coefficient, DSC, FTIR, SEM, dissolution rate and permeability. Chemical stability of quercetin-lysine and rutin-lysine was studied by assessing antioxidant capacity using Trolox and CUPRAC assays. Drugs-lysine salt/complexes were confirmed. Solubility enhancement factors ranged from 68- to 433-fold increases and dissolution rates were also significantly enhanced by up to 6-times, compared with drugs alone. With the exception of rutin-lysine, P app for bendazac-lysine and quercetin-lysine enhanced by 2.3- to 4-fold. P app for quercetin (Class IV) benefited more than bendazac (Class II) when complexed with lysine. This study warrants the use of L-lysine as a promising excipient for enhanced solubility and permeability of Class II and Class IV, providing that the solubility of the drug is ensured at 'the door step' of absorption sites.

Biosynthesis of vanillin via ferulic acid in Vanilla planifolia.

PubMed

Negishi, Osamu; Sugiura, Kenji; Negishi, Yukiko

2009-11-11

(14)C-Labeled phenylalanine, 4-coumaric acid, 4-hydroxybenzaldehyde, 4-hydroxybenzyl alcohol, ferulic acid, and methionine were applied to disks of green vanilla pods 3 and 6 months after pollination (immature and mature pods), and the conversion of these compounds to vanillin or glucovanillin was investigated. In mature green vanilla pods, radioactivities of 11, 15, 29, and 24% from (14)C-labeled phenylalanine, 4-coumaric acid, ferulic acid, and methionine, respectively, were incorporated into glucovanillin within 24 h. In the incorporation processes of methionine and phenylalanine into glucovanillin, some of the (14)C labels were also trapped by the unlabeled ferulic acid. However, (14)C-labeled 4-hydroxybenzaldehyde and 4-hydroxybenzyl alcohol were not converted to glucovanillin. On the other hand, in immature green vanilla pods radioactivities of the above six compounds were not incorporated into glucovanillin. Although 4-coumaric acid, ferulic acid, 4-hydroxybenzaldehyde, and 4-hydroxybenzyl alcohol were converted to the respective glucose esters or glucosides and vanillin was converted to glucovanillin, their conversions were believed to be from the detoxication of the aglycones. These results suggest that the biosynthetic pathway for vanillin is 4-coumaric acid --> --> ferulic acid --> --> vanillin --> glucovanillin in mature vanilla pods.

A Method to Determine Lysine Acetylation Stoichiometries

DOE PAGES

Nakayasu, Ernesto S.; Wu, Si; Sydor, Michael A.; ...

2014-01-01

Lysine acetylation is a common protein posttranslational modification that regulates a variety of biological processes. A major bottleneck to fully understanding the functional aspects of lysine acetylation is the difficulty in measuring the proportion of lysine residues that are acetylated. Here we describe a mass spectrometry method using a combination of isotope labeling and detection of a diagnostic fragment ion to determine the stoichiometry of protein lysine acetylation. Using this technique, we determined the modification occupancy for ~750 acetylated peptides from mammalian cell lysates. Furthermore, the acetylation on N-terminal tail of histone H4 was cross-validated by treating cells with sodiummore » butyrate, a potent deacetylase inhibitor, and comparing changes in stoichiometry levels measured by our method with immunoblotting measurements. Of note we observe that acetylation stoichiometry is high in nuclear proteins, but very low in mitochondrial and cytosolic proteins. In summary, our method opens new opportunities to study in detail the relationship of lysine acetylation levels of proteins with their biological functions.« less

Differential lysine acetylation profiles of Erwinia amylovora strains revealed by proteomics.

PubMed

Wu, Xia; Vellaichamy, Adaikkalam; Wang, Dongping; Zamdborg, Leonid; Kelleher, Neil L; Huber, Steven C; Zhao, Youfu

2013-02-21

Protein lysine acetylation (LysAc) has recently been demonstrated to be widespread in E. coli and Salmonella, and to broadly regulate bacterial physiology and metabolism. However, LysAc in plant pathogenic bacteria is largely unknown. Here we first report the lysine acetylome of Erwinia amylovora, an enterobacterium causing serious fire blight disease of apples and pears. Immunoblots using generic anti-lysine acetylation antibodies demonstrated that growth conditions strongly affected the LysAc profiles in E. amylovora. Differential LysAc profiles were also observed for two E. amylovora strains, known to have differential virulence in plants, indicating translational modification of proteins may be important in determining virulence of bacterial strains. Proteomic analysis of LysAc in two E. amylovora strains identified 141 LysAc sites in 96 proteins that function in a wide range of biological pathways. Consistent with previous reports, 44% of the proteins are involved in metabolic processes, including central metabolism, lipopolysaccharide, nucleotide and amino acid metabolism. Interestingly, for the first time, several proteins involved in E. amylovora virulence, including exopolysaccharide amylovoran biosynthesis- and type III secretion-associated proteins, were found to be lysine acetylated, suggesting that LysAc may play a major role in bacterial virulence. Comparative analysis of LysAc sites in E. amylovora and E. coli further revealed the sequence and structural commonality for LysAc in the two organisms. Collectively, these results reinforce the notion that LysAc of proteins is widespread in bacterial metabolism and virulence. Copyright © 2012 Elsevier B.V. All rights reserved.

Phospholipid bilayer-perturbing properties underlying lysis induced by pH-sensitive cationic lysine-based surfactants in biomembranes.

PubMed

Nogueira, Daniele Rubert; Mitjans, Montserrat; Busquets, M Antonia; Pérez, Lourdes; Vinardell, M Pilar

2012-08-14

Amino acid-based surfactants constitute an important class of natural surface-active biomolecules with an unpredictable number of industrial applications. To gain a better mechanistic understanding of surfactant-induced membrane destabilization, we assessed the phospholipid bilayer-perturbing properties of new cationic lysine-based surfactants. We used erythrocytes as biomembrane models to study the hemolytic activity of surfactants and their effects on cells' osmotic resistance and morphology, as well as on membrane fluidity and membrane protein profile with varying pH. The antihemolytic capacity of amphiphiles correlated negatively with the length of the alkyl chain. Anisotropy measurements showed that the pH-sensitive surfactants, with the positive charge on the α-amino group of lysine, significantly increased membrane fluidity at acidic conditions. SDS-PAGE analysis revealed that surfactants induced significant degradation of membrane proteins in hypo-osmotic medium and at pH 5.4. By scanning electron microscopy examinations, we corroborated the interaction of surfactants with lipid bilayer. We found that varying the surfactant chemical structure is a way to modulate the positioning of the molecule inside bilayer and, thus, the overall effect on the membrane. Our work showed that pH-sensitive lysine-based surfactants significantly disturb the lipid bilayer of biomembranes especially at acidic conditions, which suggests that these compounds are promising as a new class of multifunctional bioactive excipients for active intracellular drug delivery.

Nonhistone Lysine Methylation in the Regulation of Cancer Pathways.

PubMed

Carlson, Scott M; Gozani, Or

2016-11-01

Proteins are regulated by an incredible array of posttranslational modifications (PTMs). Methylation of lysine residues on histone proteins is a PTM with well-established roles in regulating chromatin and epigenetic processes. The recent discovery that hundreds and likely thousands of nonhistone proteins are also methylated at lysine has opened a tremendous new area of research. Major cellular pathways involved in cancer, such as growth signaling and the DNA damage response, are regulated by lysine methylation. Although the field has developed quickly in recent years many fundamental questions remain to be addressed. We review the history and molecular functions of lysine methylation. We then discuss the enzymes that catalyze methylation of lysine residues, the enzymes that remove lysine methylation, and the cancer pathways known to be regulated by lysine methylation. The rest of the article focuses on two open questions that we suggest as a roadmap for future research. First is understanding the large number of candidate methyltransferase and demethylation enzymes whose enzymatic activity is not yet defined and which are potentially associated with cancer through genetic studies. Second is investigating the biological processes and cancer mechanisms potentially regulated by the multitude of lysine methylation sites that have been recently discovered. Copyright © 2016 Cold Spring Harbor Laboratory Press; all rights reserved.

Simultaneous Detection of Dopamine and Uric Acid Using a Poly(l-lysine)/Graphene Oxide Modified Electrode

PubMed Central

Zhang, Yuehua; Lei, Wu; Xu, Yujuan; Xia, Xifeng; Hao, Qingli

2016-01-01

A novel, simple and selective electrochemical method was investigated for the simultaneous detection of dopamine (DA) and uric acid (UA) on a poly(l-lysine)/graphene oxide (GO) modified glassy carbon electrode (PLL/GO/GCE) by differential pulse voltammetry (DPV). The electrochemically prepared PLL/GO sensory platform toward the oxidation of UA and DA exhibited several advantages, including high effective surface area, more active sites and enhanced electrochemical activity. Compared to the PLL-modified GCE (PLL/GCE), GO-modified GCE and bare GCE, the PLL/GO/GCE exhibited an increase in the anodic potential difference and a remarkable enhancement in the current responses for both UA and DA. For the simultaneous detection of DA and UA, the detection limits of 0.021 and 0.074 μM were obtained, while 0.031 and 0.018 μM were obtained as the detection limits for the selective detection of UA and DA, using DPV in the linear concentration ranges of 0.5 to 20.0 and 0.5 to 35 μM, respectively. In addition, the PLL/GO/GCE demonstrated good reproducibility, long-term stability, excellent selectivity and negligible interference of ascorbic acid (AA). The proposed modified electrode was successfully implemented in the simultaneous detection of DA and UA in human blood serum, urine and dopamine hydrochloride injection with satisfactory results. PMID:28335305

Heterologous Production of Cyanobacterial Mycosporine-Like Amino Acids Mycosporine-Ornithine and Mycosporine-Lysine in Escherichia coli

PubMed Central

Katoch, Meenu; Mazmouz, Rabia; Chau, Rocky; Pearson, Leanne A.; Pickford, Russell

2016-01-01

ABSTRACT Mycosporine-like amino acids (MAAs) are an important class of secondary metabolites known for their protection against UV radiation and other stress factors. Cyanobacteria produce a variety of MAAs, including shinorine, the active ingredient in many sunscreen creams. Bioinformatic analysis of the genome of the soil-dwelling cyanobacterium Cylindrospermum stagnale PCC 7417 revealed a new gene cluster with homology to MAA synthase from Nostoc punctiforme. This newly identified gene cluster is unusual because it has five biosynthesis genes (mylA to mylE), compared to the four found in other MAA gene clusters. Heterologous expression of mylA to mylE in Escherichia coli resulted in the production of mycosporine-lysine and the novel compound mycosporine-ornithine. To our knowledge, this is the first time these compounds have been heterologously produced in E. coli and structurally characterized via direct spectral guidance. This study offers insight into the diversity, biosynthesis, and structure of cyanobacterial MAAs and highlights their amenability to heterologous production methods. IMPORTANCE Mycosporine-like amino acids (MAAs) are significant from an environmental microbiological perspective as they offer microbes protection against a variety of stress factors, including UV radiation. The heterologous expression of MAAs in E. coli is also significant from a biotechnological perspective as MAAs are the active ingredient in next-generation sunscreens. PMID:27520810

Estimation of the optimum digestible lysine level for Cherry Valley ducks.

PubMed

Zhou, Y F; Liu, Y Q; Wei, H K; Peng, J

2017-04-01

The aim of the current study was to determine the digestible lysine (DLys) requirement of Cherry Valley ducks from 1 to 14 d and from 15 to 35 d of age. One-day-old male Cherry Valley ducks (n = 320) were divided randomly and evenly into five treatments with 8 replicates of 8 birds. Ducks were fed adequate levels of digestible amino acid but with graded levels of DLys: 0.80, 0.88, 0.96, 1.04, and 1.12% from 1 to 14 d; 0.60, 0.68, 0.76, 0.84, and 0.92% from 15 to 35 d. At 35 d of age, 8 ducks per treatment were slaughtered for evaluating the yields of abdominal fat, subcutaneous fat, breast meat, and leg meat. Additionally, a 7-d metabolizable experiment was conducted with ducks of the same hatch beginning on d 35 (8 ducks per treatment). The results showed that the DLys level in diet had a quadratic relationship both with the average daily gain (ADG) and feed:gain ratio (F/G). According to the quadratic model, an optimum digestible lysine level was 0.948% from 0 to 14 d and 0.758% from 15 to 35 d based on ADG. The digestible lysine level for obtaining minimum F/G were 0.986% (0 ∼ 14 d) and 0.792% (15 ∼ 35 d), respectively. Breast meat yield (P = 0.110) and subcutaneous fat percentage (P = 0.021) showed a quadratic or linear response to the increasing dietary DLys level. To achieve maximum breast meat yield, the digestible lysine level of 0.961% and 0.761% were needed for the starter period (1 ∼ 14 d) and the growth period (14 ∼ 35 d), respectively. N excretion showed a quadratic response to the increasing dietary DLys level (P = 0.103). The results of the current study suggested that the optimum digestible lysine level was very different with the response criterion. The dietary digestible lysine levels were 0.948, 0.961% in the starter period (1 ∼ 14 d) and 0.758, 0.761% in the growth period (15 ∼ 35 d) for ADG, F/G, respectively. © 2016 Poultry Science Association Inc.

Novel Mechanism for Scavenging of Hypochlorite Involving a Periplasmic Methionine-Rich Peptide and Methionine Sulfoxide Reductase

PubMed Central

Melnyk, Ryan A.; Youngblut, Matthew D.; Clark, Iain C.; Carlson, Hans K.; Wetmore, Kelly M.; Price, Morgan N.; Iavarone, Anthony T.; Deutschbauer, Adam M.; Arkin, Adam P.

2015-01-01

ABSTRACT Reactive chlorine species (RCS) defense mechanisms are important for bacterial fitness in diverse environments. In addition to the anthropogenic use of RCS in the form of bleach, these compounds are also produced naturally through photochemical reactions of natural organic matter and in vivo by the mammalian immune system in response to invading microorganisms. To gain insight into bacterial RCS defense mechanisms, we investigated Azospira suillum strain PS, which produces periplasmic RCS as an intermediate of perchlorate respiration. Our studies identified an RCS response involving an RCS stress-sensing sigma/anti-sigma factor system (SigF/NrsF), a soluble hypochlorite-scavenging methionine-rich periplasmic protein (MrpX), and a putative periplasmic methionine sulfoxide reductase (YedY1). We investigated the underlying mechanism by phenotypic characterization of appropriate gene deletions, chemogenomic profiling of barcoded transposon pools, transcriptome sequencing, and biochemical assessment of methionine oxidation. Our results demonstrated that SigF was specifically activated by RCS and initiated the transcription of a small regulon centering around yedY1 and mrpX. A yedY1 paralog (yedY2) was found to have a similar fitness to yedY1 despite not being regulated by SigF. Markerless deletions of yedY2 confirmed its synergy with the SigF regulon. MrpX was strongly induced and rapidly oxidized by RCS, especially hypochlorite. Our results suggest a mechanism involving hypochlorite scavenging by sacrificial oxidation of the MrpX in the periplasm. Reduced MrpX is regenerated by the YedY methionine sulfoxide reductase activity. The phylogenomic distribution of this system revealed conservation in several Proteobacteria of clinical importance, including uropathogenic Escherichia coli and Brucella spp., implying a putative role in immune response evasion in vivo. PMID:25968643

Methionine Sulfoxide Reductase A (MsrA) and Its Function in Ubiquitin-Like Protein Modification in Archaea

DOE PAGES

Fu, Xian; Adams, Zachary; Liu, Rui; ...

2017-09-05

Methionine sulfoxide reductase A (MsrA) is an antioxidant enzyme found in all domains of life that catalyzes the reduction of methionine-S-sulfoxide (MSO) to methionine in proteins and free amino acids. We demonstrate that archaeal MsrA has a ubiquitin-like (Ubl) protein modification activity that is distinct from its stereospecific reduction of MSO residues. MsrA catalyzes this Ubl modification activity, with the Ubl-activating E1 UbaA, in the presence of the mild oxidant dimethyl sulfoxide (DMSO) and in the absence of reductant. In contrast, the MSO reductase activity of MsrA is inhibited by DMSO and requires reductant. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysismore » reveals that MsrA-dependent Ubl conjugates are associated with DNA replication, protein remodeling, and oxidative stress and include the Ubl-modified MsrA, Orc3 (Orc1/Cdc6), and Cdc48d (Cdc48/p97 AAA+ ATPase). Overall, we found archaeal MsrA to have opposing MSO reductase and Ubl modifying activities that are associated with oxidative stress responses and controlled by exposure to mild oxidant.« less

Methionine Sulfoxide Reductase A (MsrA) and Its Function in Ubiquitin-Like Protein Modification in Archaea

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

Fu, Xian; Adams, Zachary; Liu, Rui

Methionine sulfoxide reductase A (MsrA) is an antioxidant enzyme found in all domains of life that catalyzes the reduction of methionine-S-sulfoxide (MSO) to methionine in proteins and free amino acids. We demonstrate that archaeal MsrA has a ubiquitin-like (Ubl) protein modification activity that is distinct from its stereospecific reduction of MSO residues. MsrA catalyzes this Ubl modification activity, with the Ubl-activating E1 UbaA, in the presence of the mild oxidant dimethyl sulfoxide (DMSO) and in the absence of reductant. In contrast, the MSO reductase activity of MsrA is inhibited by DMSO and requires reductant. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysismore » reveals that MsrA-dependent Ubl conjugates are associated with DNA replication, protein remodeling, and oxidative stress and include the Ubl-modified MsrA, Orc3 (Orc1/Cdc6), and Cdc48d (Cdc48/p97 AAA+ ATPase). Overall, we found archaeal MsrA to have opposing MSO reductase and Ubl modifying activities that are associated with oxidative stress responses and controlled by exposure to mild oxidant.« less

Sulphur Atoms from Methionines Interacting with Aromatic Residues Are Less Prone to Oxidation

PubMed Central

Aledo, Juan C.; Cantón, Francisco R.; Veredas, Francisco J.

2015-01-01

Methionine residues exhibit different degrees of susceptibility to oxidation. Although solvent accessibility is a relevant factor, oxidation at particular sites cannot be unequivocally explained by accessibility alone. To explore other possible structural determinants, we assembled different sets of oxidation-sensitive and oxidation-resistant methionines contained in human proteins. Comparisons of the proteins containing oxidized methionines with all proteins in the human proteome led to the conclusion that the former exhibit a significantly higher mean value of methionine content than the latter. Within a given protein, an examination of the sequence surrounding the non-oxidized methionine revealed a preference for neighbouring tyrosine and tryptophan residues, but not for phenylalanine residues. However, because the interaction between sulphur atoms and aromatic residues has been reported to be important for the stabilization of protein structure, we carried out an analysis of the spatial interatomic distances between methionines and aromatic residues, including phenylalanine. The results of these analyses uncovered a new determinant for methionine oxidation: the S-aromatic motif, which decreases the reactivity of the involved sulphur towards oxidants. PMID:26597773

Study of morphology, chemical, and amino acid composition of red deer meat.

PubMed

Okuskhanova, Eleonora; Assenova, Bahytkul; Rebezov, Maksim; Amirkhanov, Kumarbek; Yessimbekov, Zhanibek; Smolnikova, Farida; Nurgazezova, Almagul; Nurymkhan, Gulnur; Stuart, Marilyne

2017-06-01

The aim of this study was to evaluate red deer (maral) meat quality based on chemical composition, pH, water-binding capacity (WBC), and amino acid content. Maral meat surface morphology measurements were obtained by scanning electron microscopy. Active acidity (pH) was determined by potentiometry. Samples were analyzed for WBC by exudation of moisture to a filter paper by the application of pressure. Chemical composition (moisture, protein, fat, and ash fractions) was obtained by drying at 150°C and by extraction, using ethylic ether, and ashing at 500-600°C. The amino acid composition was obtained by liquid chromatography. Maral meat, with a pH of 5.85 and an average moisture content of 76.82%, was found to be low in fat (2.26%). Its protein content was 18.71% while its ash content was 2.21%. The amino acid composition showed that lysine (9.85 g/100 g), threonine (5.38 g/100 g), and valine (5.84 g/100 g) predominated in maral meat, while phenylalanine (4.08 g/100 g), methionine (3.29 g/100 g), and tryptophan (0.94 g/100 g) were relatively low in maral meat compared to other meats. The average WBC was found to be 65.82% and WBC was found to inversely correlate with moisture content. Low-fat content, high mineral content, and balanced amino-acid composition qualify maral meat as a worthy dietary and functional food.

Nutriepigenetic regulation by folate-homocysteine-methionine axis: a review.

PubMed

Bhargava, Seema; Tyagi, S C

2014-02-01

Although normally folic acid is given during pregnancy, presumably to prevent neural tube defects, the mechanisms of this protection are unknown. More importantly it is unclear whether folic acid has other function during development. It is known that folic acid re-methylates homocysteine (Hcy) to methionine by methylene tetrahydrofolate reductase-dependent pathways. Folic acid also generates high-energy phosphates, behaves as an antioxidant and improves nitric oxide (NO) production by endothelial NO synthase. Interestingly, during epigenetic modification, methylation of DNA/RNA generate homocysteine unequivocally. The enhanced overexpression of methyl transferase lead to increased yield of Hcy. The accumulation of Hcy causes vascular dysfunction, reduces perfusion in the muscles thereby causing musculopathy. Another interesting fact is that children with severe hyperhomocysteinaemia (HHcy) have skeletal deformities, and do not live past teenage. HHcy is also associated with the progeria syndrome. Epilepsy is primarily caused by inhibition of gamma-amino-butyric-acid (GABA) receptor, an inhibitory neurotransmitter in the neuronal synapse. Folate deficiency leads to HHcy which then competes with GABA for binding on the GABA receptors. With so many genetic and clinical manifestations associated with folate deficiency, we propose that folate deficiency induces epigenetic alterations in the genes and thereby results in disease.

Electrodeposited reduced graphene oxide incorporating polymerization of l-lysine on electrode surface and its application in simultaneous electrochemical determination of ascorbic acid, dopamine and uric acid.

PubMed

Zhang, Dongdong; Li, Lingzhi; Ma, Weina; Chen, Xia; Zhang, Yanmin

2017-01-01

This paper demonstrates a novel strategy for the construction of a graphene hybrid composites film, which was fabricated by electrodeposited reduced graphene oxide (ERGO) incorporating polymerization of l-lysine (PLL) onto glassy carbon electrode (GCE). Here we show that graphene films can be prepared on electrodes directly from GO dispersions by one-step electrodeposition technique based on electropolymerized PLL as a positively charged polymer interface to adsorb negatively charged GO nanosheets through electrostatic attraction. The thickness of graphene film can be easily controlled by using the electrodeposition technique, a distinct advantage over previously developed methods. The electrochemically reduced process of GO and electropolymerization of l-lysine were investigated by cyclic voltammetry with a wide potential range. The surface morphology of the modified electrode was characterized by scanning electron microscopy. The ERGO/PLL/GCE shows conducive to electron transfer kinetics for Fe(CN) 6 3- /Fe(CN) 6 4- redox probes, compared with bare GCE, PLL/GCE and ERGO/GCE. The electrochemical behaviors of ascorbic acid (AA), dopamine (DA) and uric acid (UA) at ERGO/PLL/GCE were investigated by cyclic voltammetry, and the results suggest that the modified electrode exhibits enhanced electrocatalytic activity toward these important molecules. Under physiological condition and in the co-existence system of AA, DA and UA, the ERGO/PLL/GCE showed linear voltammetric responses in the concentration of 100μM-1200μM for AA, 2.0μM-60μM for DA and 20μM-200μM for UA, and with the detection limits (S/N=3) of 2.0μM, 0.10μM and 0.15μM for AA, DA and UA, respectively. The developed method has been applied to simultaneous determination of AA, DA and UA in human urine with satisfactory recoveries of 104.2%, 95.4% and 99.9%, respectively. This work demonstrates that the attractive features of ERGO/PLL provide promising applications in simultaneous determination of AA, DA

Substitution of lysine-181 to aspartic acid in the third transmembrane region of the endothelin (ET) type B receptor selectively reduces its high-affinity binding with ET-3 peptide.

PubMed

Mauzy, C; Wu, L H; Egloff, A M; Mirzadegan, T; Chung, F Z

1992-01-01

In the G protein-coupled receptor family, a highly conserved aspartic acid located within the third transmembrane domain has been shown to be involved in ligand binding. Within the endothelin (ET) peptide receptor family, this aspartic acid has been replaced by a lysine. To assess the importance of this residue in ET binding, the lysine (position 181) of rat ET type B receptor was replaced by an aspartic acid. The effects on ligand binding and phosphoinositide turnover of both the wild-type and K181D mutant receptors were examined using transient receptor expression in COS-7 cells. Using [125I]ET-1 as the radioactive peptide ligand in displacement binding studies, the wild-type receptor displayed a typical non-isopeptide-selective binding profile with similar IC50 values (0.2-0.6 nM) for all three ET peptides (ET-1, ET-2, and ET-3). The mutant receptor showed an increase in IC50 values for ET-1 (5 nM), ET-2 (27 nM), and ET-3 (127 nM). The K181D mutant receptor still elicited full inositol phosphate (IP) accumulation responses in the presence of saturating concentrations of ETs (10 nM of ET-1, 100 nM of ET-2, or 1 microM of ET-3), indicating that the mutation did not affect G protein coupling.

Targeting methionine cycle as a potential therapeutic strategy for immune disorders.

PubMed

Li, Heng; Lu, Huimin; Tang, Wei; Zuo, Jianping

2017-08-23

Methionine cycle plays an essential role in regulating many cellular events, especially transmethylation reactions, incorporating the methyl donor S-adenosylmethionine (SAM). The transmethylations and substances involved in the cycle have shown complicated effects and mechanisms on immunocytes developments and activations, and exert crucial impacts on the pathological processes in immune disorders. Areas covered: Methionine cycle has been considered as an effective means of drug developments. This review discussed the role of methionine cycle in immune responses and summarized the potential therapeutic strategies based on the cycle, including SAM analogs, methyltransferase inhibitors, S-adenosylhomocysteine hydrolase (SAHH) inhibitors, adenosine receptors specific agonists or antagonists and homocysteine (Hcy)-lowering reagents, in treating human immunodeficiency virus (HIV) infections, systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), multiple sclerosis (MS), systemic sclerosis (SSc) and other immune disorders. Expert opinion: New targets and biomarkers grown out of methionine cycle have developed rapidly in the past decades. However, impacts of epigenetic regulations on immune disorders are unclear and whether the substances in methionine cycle can be clarified as biomarkers remains controversial. Therefore, further elucidation on the role of epigenetic regulations and substances in methionine cycle may contribute to exploring the cycle-derived biomarkers and drugs in immune disorders.

Interactions of low molecular weight aromatic acids and amino acids with goethite, kaolinite and bentonite with or without organic matter coating

NASA Astrophysics Data System (ADS)

Gao, Jiajia; Jansen, Boris; Cerli, Chiara; Kalbitz, Karsten

2015-04-01

Interaction of organic matter molecules with the soil's solid phase is a key factor influencing the stabilization of carbon in soils and thus forms a crucial aspect of the global carbon cycle. While subject of much research attention so far, we still have much to learn about such interactions at the molecular level; in particular in the light of competition between different classes of organic molecules and in the presence of previously adsorbed soil organic matter. We studied the interaction of a group of low molecular weight (LMW) aromatic acids (salicylic, syringic, vanillic and ferulic acid) and amino acids (lysine, glutamic, leucine and phenylalanine) on goethite, kaolinite and bentonite with and without previously adsorbed dissolved organic matter (DOM). For this we used batch experiments at pH = 6.0 where some of the organic compounds were positively charged (i.e. lysine) or negatively charged (i.e. glutamic and salicylic acid) while the minerals also displayed positively (i.e. goethite) or negatively charged surfaces (i.e. bentonite). We found much higher sorption of salicylic acid and lysine than other compounds. On the bare minerals we found a great variety of sorption strength, with salicylic acid strongly adsorbed, while syringic, vanillic and ferulic acid showed little or no adsorption. For the amino acids, protonated lysine showed a stronger affinity to negatively charged kaolinite and bentonite than other amino acids. While deprotonated glutamic acid showed the strongest adsorption on goethite. Leucine and phenylalanine showed hardly any adsorption on any of the minerals. When present concurrently, amino acids decreased the sorption of salicylic acid on the three types of mineral, while the presence of LMW aromatic acids increased the sorption of lysine on kaolinite and bentonite and the sorption of glutamic acid on goethite. The presence of previously adsorbed DOM reduced the sorption of salicylic acid and lysine. The results confirm that

QSAR study of anthranilic acid sulfonamides as inhibitors of methionine aminopeptidase-2 using LS-SVM and GRNN based on principal components.

PubMed

Shahlaei, Mohsen; Sabet, Razieh; Ziari, Maryam Bahman; Moeinifard, Behzad; Fassihi, Afshin; Karbakhsh, Reza

2010-10-01

Quantitative relationships between molecular structure and methionine aminopeptidase-2 inhibitory activity of a series of cytotoxic anthranilic acid sulfonamide derivatives were discovered. We have demonstrated the detailed application of two efficient nonlinear methods for evaluation of quantitative structure-activity relationships of the studied compounds. Components produced by principal component analysis as input of developed nonlinear models were used. The performance of the developed models namely PC-GRNN and PC-LS-SVM were tested by several validation methods. The resulted PC-LS-SVM model had a high statistical quality (R(2)=0.91 and R(CV)(2)=0.81) for predicting the cytotoxic activity of the compounds. Comparison between predictability of PC-GRNN and PC-LS-SVM indicates that later method has higher ability to predict the activity of the studied molecules. Copyright (c) 2010 Elsevier Masson SAS. All rights reserved.

Induction and Repression in the S-Adenosylmethionine and Methionine Biosynthetic Systems of Saccharomyces cerevisiae

PubMed Central

Ferro, A. J.; Spence, K. D.

1973-01-01

Two methionine biosynthetic enzymes and the methionine adenosyltransferase are repressed in Saccharomyces cerevisiae when grown under conditions where the intracellular levels of S-adenosylmethionine are high. The nature of the co-repressor molecule of this repression was investigated by following the intracellular levels of methionine, S-adenosylmethionine, and S-adenosylhomocysteine, as well as enzyme activities, after growth under various conditions. Under all of the conditions found to repress these enzymes, there is an accompanying induction of the S-adenosylmethionine-homocysteine methyltransferase which suggests that this enzyme may play a key role in the regulation of S-adenosylmethionine and methionine balance and synthesis. S-methylmethionine also induces the methyltransferase, but unlike S-adenosylmethionine, it does not repress the methionine adenosyltransferase or other methionine biosynthetic enzymes tested. PMID:4583251

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

PubMed

Shah, Dhawal; Shaikh, Abdul Rajjak

2016-01-01

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

Choline and methionine differentially alter methyl carbon metabolism in bovine neonatal hepatocytes

PubMed Central

Chandler, Tawny L.

2017-01-01

Intersections in hepatic methyl group metabolism pathways highlights potential competition or compensation of methyl donors. The objective of this experiment was to examine the expression of genes related to methyl group transfer and lipid metabolism in response to increasing concentrations of choline chloride (CC) and DL-methionine (DLM) in primary neonatal hepatocytes that were or were not exposed to fatty acids (FA). Primary hepatocytes isolated from 4 neonatal Holstein calves were maintained as monolayer cultures for 24 h before treatment with CC (61, 128, 2028, and 4528 μmol/L) and DLM (16, 30, 100, 300 μmol/L), with or without a 1 mmol/L FA cocktail in a factorial arrangement. After 24 h of treatment, media was collected for quantification of reactive oxygen species (ROS) and very low-density lipoprotein (VLDL), and cell lysates were collected for quantification of gene expression. No interactions were detected between CC, DLM, or FA. Both CC and DLM decreased the expression of methionine adenosyltransferase 1A (MAT1A). Increasing CC did not alter betaine-homocysteine S-methyltranferase (BHMT) but did increase 5-methyltetrahydrofolate-homocysteine methyltransferase (MTR) and methylenetetrahydrofolate reductase (MTHFR) expression. Increasing DLM decreased expression of BHMT and MTR, but did not affect MTHFR. Expression of both phosphatidylethanolamine N-methyltransferase (PEMT) and microsomal triglyceride transfer protein (MTTP) were decreased by increasing CC and DLM, while carnitine palmitoyltransferase 1A (CPT1A) was unaffected by either. Treatment with FA decreased the expression of MAT1A, MTR, MTHFR and tended to decrease PEMT but did not affect BHMT and MTTP. Treatment with FA increased CPT1A expression. Increasing CC increased secretion of VLDL and decreased the accumulation of ROS in media. Within neonatal bovine hepatocytes, choline and methionine differentially regulate methyl carbon pathways and suggest that choline may play a critical role in

Effect of Maillard browning reaction on protein utilization and plasma amino acid response by rainbow trout (Salmo gairdneri).

PubMed

Plakas, S M; Lee, T C; Wolke, R E; Meade, T L

1985-12-01

The effect of the Maillard browning reaction in the diet of rainbow trout (Salmo gairdneri) on growth and amino acid availability was investigated. Chemical and enzymatic hydrolysis methods were applied for the detection of the losses of amino acids in a model protein browning system. Arginine and lysine exhibited the greatest losses in the mixture of fish protein isolate and glucose stored for 40 d at 37 degrees C. The apparent digestibility and absorption of individual amino acids, particularly lysine, was lower in trout fed browned protein than in those fed the control protein. Plasma lysine levels were significantly depressed, while the plasma levels of glucose and most other amino acids were elevated in relation to the loss in nutritive value of dietary protein after browning. The early Maillard reaction derivative of lysine, epsilon-deoxy-fructosyl-lysine, was recovered from browned protein (by using the in vitro enzymatic hydrolysis procedure) and from the plasma of trout fed browned protein. Analysis of plasma free amino acids provided an indication of lysine bioavailability and identified lysine as the first-limiting amino acid in the diets containing browned protein.