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Sample records for plasma amino acids

  1. Plasma amino acids

    Science.gov (United States)

    Amino acids blood test ... types of methods used to determine the individual amino acid levels in the blood. ... test is done to measure the level of amino acids in the blood. An increased level of a ...

  2. Plasma amino acid relationships during parenteral nutrition.

    Science.gov (United States)

    Wells, F E; Smits, B J

    1980-01-01

    The plasma amino acidfs of 17 patients were studied before and during total parenteral nutrition (TPN). The amino acid (AA) pattern changed similarly for all patients. The AA concentration changes relative to preinfusion (PAER) were the most informative index of change. Two groups of AA were defined, the "branched chain" group (five amino acids) and the "hepatic" group (four amino acids) based on the correlation of PAER values. Comparison of PAER values with the ratio of AA intake to requirement indicated that the requirements of the sick patients were more similar to those of children than those of healthy adults.

  3. Effects of glucagon on plasma amino acids.

    OpenAIRE

    Boden, G.; Rezvani, I.; Owen, O E

    1984-01-01

    The effects of glucagon deficiency and excess on plasma concentrations of 21 amino acids were studied in six normal human subjects for 8 h. During glucagon deficiency, produced by intravenous infusion of somatostatin (0.5 mg/h) and insulin (5 mU/kg per h), amino acid concentration (sum of 21 amino acids) rose from 2,607 +/- 76 to 2,922 +/- 133 microM after 4 h (P less than 0.025). The largest increases occurred in lysine (+26%), glycine (+24%), alanine (+23%), and arginine (+23%) concentratio...

  4. Plasma amino acids in anorexia nervosa.

    Science.gov (United States)

    Moyano, D; Vilaseca, M A; Artuch, R; Lambruschini, N

    1998-09-01

    To evaluate the amino acid profile in a group of adolescents with anorexia nervosa, and to apply alternative ways of presenting and assessing results, so as to increase the information available for understanding the metabolic abnormalities developed in these patients. Plasma amino acid concentrations of a random group of patients with anorexia nervosa compared with values obtained from a 'healthy' adolescent population. The study was performed at the tertiary children's Hospital Sant Joan de Deu. Female adolescents (n = 92, age: 15+/-1.8 y) at diagnosis of anorexia nervosa. Reference values for amino acids were obtained from apparently healthy adolescents (by history and analytical data) who underwent presurgical analysis for minor operations. Plasma amino acid concentrations were measured by ion exchange chromatography. Basic laboratory analysis, carnitine and IGF-I were also determined. In anorexic patients plasma concentrations of taurine, asparagine, glutamine, glycine, methionine, phenylalanine, ornithine, and histidine were significantly higher than reference values (Mann-Whitney, P anorexia nervosa. Although absolute amino acid values cannot play a significant role in the assessment of nutritional status in this condition, the calculation of some ratios (Phe/Tyr, Met/Cys and Gly/Val) and the graphical representation of relative values may be useful. The plasma amino acid profile in anorexia nervosa is different from those of other severe malnutrition states, showing a marasmic pattern of balanced protein-energy undernutrition. Cystine and arginine may be considered limiting amino acids in this disease, and the consequences of their deficient concentrations for oxidative damage should be further evaluated.

  5. A plasma membrane association module in yeast amino acid transporters

    NARCIS (Netherlands)

    Popov-Čeleketić, Dušan; Bianchi, Frans; Ruiz, Stephanie J; Meutiawati, Febrina; Poolman, Bert

    2016-01-01

    Amino acid permeases (AAPs) in the plasma membrane (PM) of Saccharomyces cerevisiae are responsible for the uptake of amino acids and involved in regulation of their cellular levels. Here, we report on a strong and complex module for PM association found in the C-terminal tail of AAPs. Using in sili

  6. A plasma membrane association module in yeast amino acid transporters

    NARCIS (Netherlands)

    Popov-Čeleketić, Dušan; Bianchi, Frans; Ruiz, Stephanie J; Meutiawati, Febrina; Poolman, Bert

    2016-01-01

    Amino acid permeases (AAPs) in the plasma membrane (PM) of Saccharomyces cerevisiae are responsible for the uptake of amino acids and involved in regulation of their cellular levels. Here, we report on a strong and complex module for PM association found in the C-terminal tail of AAPs. Using in

  7. Interpretation of plasma amino acid profile using multiple marker approach

    Directory of Open Access Journals (Sweden)

    T. F. Subbotina

    2015-01-01

    Full Text Available In the analysis of plasma amino acid profile in a group of patients with left ventricular outflow tract pathology (n = 151 increased levels of serine, alanine, arginine, and lysine has been found. These metabolic shifts can be linked with the development of circulatory deficiency and mitochondrial dysfunction. The differentiation of the reference values intervals helps in the assessment of individual amino acid profiles.

  8. Determining important regulatory relations of amino acids from dynamic network analysis of plasma amino acids.

    Science.gov (United States)

    Shikata, Nahoko; Maki, Yukihiro; Nakatsui, Masahiko; Mori, Masato; Noguchi, Yasushi; Yoshida, Shintaro; Takahashi, Michio; Kondo, Nobuo; Okamoto, Masahiro

    2010-01-01

    The changes in the concentrations of plasma amino acids do not always follow the flow-based metabolic pathway network. We have previously shown that there is a control-based network structure among plasma amino acids besides the metabolic pathway map. Based on this network structure, in this study, we performed dynamic analysis using time-course data of the plasma samples of rats fed single essential amino acid deficient diet. Using S-system model (conceptual mathematical model represented by power-law formalism), we inferred the dynamic network structure which reproduces the actual time-courses within the error allowance of 13.17%. By performing sensitivity analysis, three of the most dominant relations in this network were selected; the control paths from leucine to valine, from methionine to threonine, and from leucine to isoleucine. This result is in good agreement with the biological knowledge regarding branched-chain amino acids, and suggests the biological importance of the effect from methionine to threonine.

  9. Bolus ingestion of individual branched-chain amino acids alters plasma amino acid profiles in young healthy men.

    Science.gov (United States)

    Matsumoto, Takuya; Nakamura, Koichi; Matsumoto, Hideki; Sakai, Ryosei; Kuwahara, Tomomi; Kadota, Yoshihiro; Kitaura, Yasuyuki; Sato, Juichi; Shimomura, Yoshiharu

    2014-01-01

    Physiological conditions in humans affect plasma amino acid profiles that might have potential for medical use. Because the branched-chain amino acids (BCAAs) leucine, isoleucine and valine are used as medicines and supplements, we investigated the acute effects of individual BCAAs (10-90 mg/kg body weight) or mixed BCAAs ingested as a bolus on plasma amino acid profiles in young healthy men. Plasma leucine levels rapidly increased and peaked around 30 min after leucine ingestion. Concentrations of plasma isoleucine, valine and phenylalanine subsequently decreased after ingestion, and those of methionine and tyrosine tended to decrease. The effects of ingested leucine on other plasma amino acids were biphasic, being higher at lower doses (10-20 mg/kg body weight). Isoleucine or valine intake also caused corresponding plasma amino acid concentrations to rapidly elevate, and peaks at 30-40 min after ingestion were much higher than that of plasma leucine after leucine ingestion. However, the increase in plasma isoleucine and valine concentrations essentially did not affect those of other plasma amino acids. The rate of decline among peak plasma BCAA concentrations was the highest for leucine, followed by isoleucine and valine. Oral mixed BCAAs promoted the decline in plasma isoleucine and valine concentrations. These results suggest that plasma leucine is a regulator of the plasma concentrations of BCAAs, methionine and aromatic amino acids.

  10. Effects of running the Bostom Marathon on plasma concentrations of large neutral amino acids

    Science.gov (United States)

    Conlay, L. A.; Wurtman, R. J.; Lopez G-Coviella, I.; Blusztajn, J. K.; Vacanti, C. A.; Logue, M.; During, M.; Caballero, B.; Maher, T. J.; Evoniuk, G.

    1989-01-01

    Plasma large neutral amino acid concentrations were measured in thirty-seven subjects before and after completing the Boston Marathon. Concentrations of tyrosine, phenylalanine, and methionine increased, as did their 'plasma ratios' (i.e., the ratio of each amino acid's concentration to the summed plasma concentrations of the other large neutral amino acids which compete with it for brain uptake). No changes were noted in the plasma concentrations of tryptophan, leucine, isoleucine, nor valine; however, the 'plasma ratios' of valine, leucine, and isoleucine all decreased. These changes in plasma amino acid patterns may influence neurotransmitter synthesis.

  11. Age-related changes of muscle and plasma amino acids in healthy children.

    Science.gov (United States)

    Hammarqvist, Folke; Angsten, Gertrud; Meurling, Staffan; Andersson, Kerstin; Wernerman, Jan

    2010-07-01

    The aim of the study was to explore if changes in muscle and plasma amino acid concentrations developed during growth and differed from levels seen in adults. The gradient and concentrations of free amino acids in muscle and plasma were investigated in relation to age in metabolic healthy children. Plasma and specimens from the abdominal muscle were obtained during elective surgery. The children were grouped into three groups (group 1: amino acids analysed increased with age, namely taurine, aspartate, threonine, alanine, valine, isoleucine, leucine, histidine, as well as the total sums of branched chain amino acids (BCAA), basic amino acids (BAA) and total sum of amino acids (P amino acids correlated with age (P < 0.05). These results indicate that there is an age dependency of the amino acid pattern in skeletal muscle and plasma during growth.

  12. Postnatal development of plasma amino acids in hyperphagic rats.

    Science.gov (United States)

    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.

  13. Plasma Amino Acids Profiles in Children with Autism: Potential Risk of Nutritional Deficiencies.

    Science.gov (United States)

    Arnold, Georgianne L.; Hyman, Susan L.; Mooney, Robert A.; Kirby, Russell S.

    2003-01-01

    The plasma amino acid profiles of 10 children with autism on gluten and casein restricted diets and 26 on unrestricted diets were reviewed. There was a trend for the children on restricted diets to have an increased prevalence of essential amino acid deficiencies and lower plasma levels of essential acids. (Contains references.) (Author/CR)

  14. Plasma Amino Acids Profiles in Children with Autism: Potential Risk of Nutritional Deficiencies.

    Science.gov (United States)

    Arnold, Georgianne L.; Hyman, Susan L.; Mooney, Robert A.; Kirby, Russell S.

    2003-01-01

    The plasma amino acid profiles of 10 children with autism on gluten and casein restricted diets and 26 on unrestricted diets were reviewed. There was a trend for the children on restricted diets to have an increased prevalence of essential amino acid deficiencies and lower plasma levels of essential acids. (Contains references.) (Author/CR)

  15. Effect of whey protein on plasma amino acids in diabetic mice.

    Science.gov (United States)

    Han, Ting; Cai, Donglian; Geng, Shanshan; Wang, Ying; Zhen, Hui; Wu, Peiying

    2013-12-01

    The aim of this study was to investigate the effect of whey protein on plasma amino acid levels in a mouse model of type II diabetes, using high-performance liquid chromatography (HPLC). The composition and content of amino acids in the whey proteins were analyzed using HPLC. Type I and type II diabetic mouse models were prepared using streptozotocin (STZ) and normal mice were used as a control. The ICR mice in each group were then randomly divided into four subgroups, to which 0, 10, 20 and 40% whey protein, respectively, was administered for four weeks. Changes in the plasma amino acid levels were observed in each group. The proportions of leucine, isoleucine and valine in the whey proteins were 14.40, 5.93 and 5.32% of the total amino acids, respectively, that is, the branched-chain amino acid content was 25.65%. The levels of branched-chain amino acids increased in the plasma of the normal and model mice following the administration of whey proteins by gavage and the amino acid levels increased as the concentration of the administered protein increased. In addition, the branched-chain amino acid levels in the blood of the model mice were higher than those in the normal mice. The levels of plasma amino acids in diabetic mice increased following gavage with whey protein, which is rich in branched-chain amino acids.

  16. Study of plasma amino acid levels in children with autism: An Egyptian sample

    Directory of Open Access Journals (Sweden)

    Farida M. ElBaz

    2014-04-01

    Conclusions: Autistic children had lower levels of some plasma amino acids except for glycine and glutamic acids and phosphoserine were increased with normal serum levels of urea, ammonia, total proteins, albumin and globulins (alpha 1, alpha 2, beta and gamma.

  17. Amino acids

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/002222.htm Amino acids To use the sharing features on this page, please enable JavaScript. Amino acids are organic compounds that combine to form proteins . ...

  18. Chemical modification of amino acids by atmospheric-pressure cold plasma in aqueous solution

    Science.gov (United States)

    Takai, Eisuke; Kitamura, Tsuyoshi; Kuwabara, Junpei; Ikawa, Satoshi; Yoshizawa, Shunsuke; Shiraki, Kentaro; Kawasaki, Hideya; Arakawa, Ryuichi; Kitano, Katsuhisa

    2014-07-01

    Plasma medicine is an attractive new research area, but the principles of plasma modification of biomolecules in aqueous solution remain elusive. In this study, we investigated the chemical effects of atmospheric-pressure cold plasma on 20 naturally occurring amino acids in aqueous solution. High-resolution mass spectrometry revealed that chemical modifications of 14 amino acids were observed after plasma treatment: (i) hydroxylation and nitration of aromatic rings in tyrosine, phenylalanine and tryptophan; (ii) sulfonation and disulfide linkage formation of thiol groups in cysteine; (iii) sulfoxidation of methionine and (iv) amidation and ring-opening of five-membered rings in histidine and proline. A competitive reaction experiment using 20 amino acids demonstrated that sulfur-containing and aromatic amino acids were preferentially decreased by the plasma treatment. These data provide fundamental information for elucidating the mechanism of protein inactivation for biomedical plasma applications.

  19. Effects of Eimeria acervulina infection severity on growth performance, apparent ileal amino acid digestibility, and plasma concentrations of amino acids, carotenoids, and α1-acid glycoprotein in broilers.

    Science.gov (United States)

    Rochell, S J; Parsons, C M; Dilger, R N

    2016-07-01

    An experiment was conducted to evaluate growth performance, apparent ileal digestibility (AID) of amino acids, and plasma concentrations of amino acids, carotenoids, and α1-acid glycoprotein, an acute-phase protein, in broilers inoculated with graded doses of E. acervulina oocysts. Ross 308 male broilers (400 total) were housed in battery cages from 1 to 21 d post-hatch and received common corn-soybean meal-based diets throughout the experiment. At 9 d post-hatch, birds were individually weighed and allotted to 4 treatment groups with 10 replicate cages of 10 birds per cage. At 15 d post-hatch, all birds were inoculated with 1 mL of distilled water that contained 0, 2.5 × 10(5), 5.0 × 10(5), or 1.0 × 10(6) sporulated E. acervulina oocysts. At 21 d, birds were euthanized for collection of blood and ileal digesta. Body weight gain and feed efficiency decreased linearly (P amino acids by an average of 2.6 percentage units for birds inoculated with 1.0 × 10(6) oocysts compared with uninfected birds. Infection with E. acervulina caused a quadratic decrease (P acid glycoprotein of broilers was not influenced (P > 0.05) by E. acervulina infection. In conclusion, E. acervulina challenge adversely impacted growth performance, plasma carotenoids, and AID of amino acids in a dose-dependent manner. However, plasma amino acid responses to graded E. acervulina inoculation doses varied considerably among amino acids. Thus, these results indicated that alterations in amino acid metabolism caused by E. acervulina infection extended beyond reduced amino acid digestibility.

  20. Amino acids in CSF and plasma in hyperammonaemic coma due to arginase1 deficiency.

    Science.gov (United States)

    Scholl-Bürgi, S; Sigl, S Baumgartner; Häberle, J; Haberlandt, E; Rostásy, K; Ertl, C; Eichinger-Öttl, U; Heinz-Erian, P; Karall, D

    2008-12-01

    We report the CSF and plasma amino acid concentrations and their ratios in a male patient with arginase1 deficiency with an unusual early presentation at 34 days of age. He developed hyperammonaemic coma (ammonia >400 μmol/L; normal amino acids were elevated but not those of the imino- and of the dibasic amino acids lysine and ornithine. The mechanism leading to the increase of most neutral amino acids in brain is not known. A normal glutamine in plasma does not exclude an increased concentration in CSF; it could be useful to ascertain by MRS that a high CSF glutamine concentration truly reflects a high concentration in brain tissue for better understanding its pathogenesis.

  1. Effects of plant proteins on postprandial, free plasma amino acid concentrations in rainbow trout (Oncorhynchus mykiss)

    DEFF Research Database (Denmark)

    Larsen, Bodil Katrine; Dalsgaard, Anne Johanne Tang; Pedersen, Per Bovbjerg

    2012-01-01

    proteins from wheat, peas, field beans, sunflower and soybean. Blood samples were obtained from the caudal vein of 7 fish in each dietary treatment group prior to feeding, as well as: 2, 4, 6, 8, 12, 24, 48 and 72 h after feeding (sampling 7 new fish at each time point), and plasma amino acid......Postprandial patterns in plasma free amino acid concentrations were investigated in juvenile rainbow trout (Oncorhynchus mykiss) fed either a fish meal based diet (FM) or a diet (VEG) where 59% of fish meal protein (corresponding to 46% of total dietary protein) was replaced by a matrix of plant...... concentrations were subsequently measured by HPLC. Nutrient digestibility and ammonia excretion of the two experimental diets were measured in a parallel experiment using a modified Guelph setup. Results showed that the appearance of most amino acids (essential and non-essential) in the plasma was delayed...

  2. Plasma free amino acid kinetics in rainbow trout (Oncorhynchus mykiss) using a bolus injection of 15N-labeled amino acids.

    Science.gov (United States)

    Robinson, Jacob William; Yanke, Dan; Mirza, Jeff; Ballantyne, James Stuart

    2011-02-01

    To gain insight into the metabolic design of the amino acid carrier systems in fish, we injected a bolus of (15)N amino acids into the dorsal aorta in mature rainbow trout (Oncorhynchus mykiss). The plasma kinetic parameters including concentration, pool size, rate of disappearance (R(d)), half-life and turnover rate were determined for 15 amino acids. When corrected for metabolic rate, the R(d) values obtained for trout for most amino acids were largely comparable to human values, with the exception of glutamine (which was lower) and threonine (which was higher). R(d) values ranged from 0.9 μmol 100 g(-1) h(-1) (lysine) to 22.1 μmol 100 g(-1) h(-1) (threonine) with most values falling between 2 and 6 μmol 100 g(-1) h(-1). There was a significant correlation between R(d) and the molar proportion of amino acids in rainbow trout whole body protein hydrolysate. Other kinetic parameters did not correlate significantly with whole body amino acid composition. This indicates that an important design feature of the plasma-free amino acids system involves proportional delivery of amino acids to tissues for protein synthesis.

  3. Effects of Dietary Garlic Extracts on Whole Body Amino Acid and Fatty Acid Composition, Muscle Free Amino Acid Profiles and Blood Plasma Changes in Juvenile Sterlet Sturgeon,

    Directory of Open Access Journals (Sweden)

    Dong-Hoon Lee

    2012-10-01

    Full Text Available A series of studies were carried out to investigate the supplemental effects of dietary garlic extracts (GE on whole body amino acids, whole body and muscle free amino acids, fatty acid composition and blood plasma changes in 6 month old juvenile sterlet sturgeon (Acipenser ruthenus. In the first experiment, fish with an average body weight of 59.6 g were randomly allotted to each of 10 tanks (two groups of five replicates, 20 fish/tank and fed diets with (0.5% or without (control GE respectively, at the level of 2% of fish body weight per day for 5 wks. Whole body amino acid composition between the GE and control groups were not different (p>0.05. Among free amino acids in muscle, L-glutamic acid, L-alanine, L-valine, L-leucine and L-phenylalanine were significantly (p0.05 were noticed at 12 h (74.6 vs 73.0. Plasma insulin concentrations (μIU/ml between the two groups were significantly (p<0.05 different at 1 (10.56 vs 5.06 and 24 h (32.56 vs 2.96 after feeding. The present results suggested that dietary garlic extracts could increase dietary glucose utilization through the insulin secretion, which result in improved fish body quality and feed utilization by juvenile sterlet sturgeon.

  4. Profiles of amino acids and biogenic amines in the plasma of Cri-du-Chat patients.

    Science.gov (United States)

    Furtado, Danielle Zildeana Sousa; de Moura Leite, Fernando Brunale Vilela; Barreto, Cleber Nunes; Faria, Bernadete; Jedlicka, Leticia Dias Lima; de Jesus Silva, Elisângela; da Silva, Heron Dominguez Torres; Bechara, Etelvino Jose Henriques; Assunção, Nilson Antonio

    2017-03-21

    Cri-du-chat syndrome (CDCS) is a rare innate disease attributed to chromosome 5p deletion characterized by a cat-like cry, craniofacial malformation, and altered behavior of affected children. Metabolomic analysis and a chemometric approach allow description of the metabolic profile of CDCS as compared to normal subjects. In the present work, UHPLC/MS was employed to analyze blood samples withdrawn from CDCS carriers (n=18) and normal parental subjects (n=18), all aged 0-34 years, aiming to set up a representative CDCS profile constructed from 33 targeted amino acids and biogenic amines. Methionine sulfoxide (MetO) was of particular concern with respect to CDCS redox balance. Increased serotonin (3-fold), methionine sulfoxide (2-fold), and Asp levels, and a little lower Orn, citrulline, Leu, Val, Ile, Asn, Gln, Trp, Thr, His, Phe, Met, and creatinine levels were found in the plasma of CDCS patients. Nitrotyrosine and Trp did not differ in normal and CDCS individuals.The accumulated metabolites may reflect, respectively, disturbances in the redox balance, deficient purine biosynthesis, and altered behavior, whereas the amino acid abatement in the latter group may affect the homeostasis of the urea cycle, citric acid cycle, branched chain amino acid synthesis, Tyr and Trp metabolism and amino acid biosynthesis. The identification of enzymatic deficiencies leading to the amino acid burden in CDCS is further required for elucidating its molecular bases and eventually propose specific or mixed amino acid supplementation to newborn patients aiming to balance their metabolism.

  5. Plasma branched chain amino acid abnormalities in sake-treated rats.

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    Watanabe,Akiharu

    1985-02-01

    Full Text Available Plasma amino acid abnormalities in rats treated with large doses of sake and whisky for 3 days were investigated under adequate nutritional conditions. A significant decrease in plasma branched-chain amino acid (BCAA levels was observed in sake- but not whisky-treated rats. However, known factors affecting BCAA levels, such as serum insulin and plasma glucagon levels ahd BCAA-metabolizing enzyme (BCAA transaminase and branched chain alpha-ketoacid dehydrogenase activities in the liver and skeletal muscle, were not significantly altered in the sake group. Furthermore, ethanol-metabolizing enzyme (alcohol and aldehyde dehydrogenases and the microsomal ethanol-oxidizing system activities in the liver were not altered in the sake group. Other mechanisms need to be considered for explaining the diminished levels of plasma BCAA in sake-treated rats.

  6. Study on the relationship between plasma free amino acid, serum miR indexes and hepatocirrhosis

    Institute of Scientific and Technical Information of China (English)

    Hui Zhang

    2016-01-01

    Objective:To study and investigate the relationships between plasma free amino acid, serum miR indexes and hepatocirrhosis. Methods:A total of 82 patients with hepatocirrhosis in our hospital from June 2013 to August 2015 were selected as the observation group, 82 health persons with the same age at the same time were selected as the control group, then the plasma free amino acid and serum miR indexes of two groups were respectively detected, and the detection results of control group and observation group, and observation group with different staging and classification were compared, then the relationship between those detection indexes and hepatocirrhosis were analyzed by the Logistic analysis. Results:The plasma free amino acid and serum miR indexes of two groups had obvious differences, and those indexes of patients with different staging of hepatocirrhosis all had significant differences, while the indexes levels of patients with different classification of hepatocirrhosis had no obvious differences, and those analysis indexes all had close relationship for the hepatocirrhosis by the Logistic analysis. Conclusion:The plasma free amino acid and serum miR indexes all had close relationship with the hepatocirrhosis, and those indexes of patients with hepatocirrhosis should be paid more monitoring.

  7. Basic Amino Acid Transport in Plasma Membrane Vesicles of Penicillium chrysogenum

    NARCIS (Netherlands)

    Hillenga, Dirk J.; Versantvoort, Hanneke J.M.; Driessen, Arnold J.M.; Konings, Wil N.

    1996-01-01

    The characteristics of the basic amino acid permease (system VI) of the filamentous fungus Penicillium chrysogenum were studied in plasma membranes fused with liposomes containing the beef heart mitochondrial cytochrome c oxidase. In the presence of reduced cytochrome c, the hybrid membranes accumul

  8. Plasma amino acid profiling identifies specific amino acid associations with cardiovascular function in patients with systolic heart failure.

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    Daihiko Hakuno

    Full Text Available The heart has close interactions with other organs' functions and concomitant systemic factors such as oxidative stress, nitric oxide (NO, inflammation, and nutrition in systolic heart failure (HF. Recently, plasma amino acid (AA profiling as a systemic metabolic indicator has attracted considerable attention in predicting the future risk of human cardiometabolic diseases, but it has been scarcely studied in HF.Thirty-eight stable but greater than New York Heart Association class II symptomatic patients with left ventricular (LV ejection fraction <45% and 33 asymptomatic individuals with normal B-type natriuretic peptide (BNP value were registered as the HF and control groups, respectively. We analyzed fasting plasma concentrations of 41 AAs using high-performance liquid chromatography, serum NO metabolite concentration, hydroperoxide and high-sensitivity C-reactive protein measurements, echocardiography, and flow-mediated dilatation.We found that 17 AAs and two ratios significantly changed in the HF group compared with those in the control group (p < 0.05. In the HF group, subsequent univariate and stepwise multivariate analyses with clinical variables revealed that Fischer ratio and five specific AAs, ie, monoethanolamine, methionine, tyrosine, 1-methylhistidine, and histidine have significant correlation with BNP, LV ejection fraction, LV end-diastolic volume index, inferior vena cava diameter, the ratio of early diastolic velocity of the mitral inflow to mitral annulus, and BNP, respectively (p < 0.05. Interestingly, further exploratory factor analysis categorized these AAs into hepatic-related (monoethanolamine, tyrosine, and Fischer ratio and skeletal muscle-related (histidine, methionine, and 1-methylhistidine components. Some categorized AAs showed unique correlations with concomitant factors: monoethanolamine, tyrosine, and Fischer ratio with serum NO concentration; histidine with serum albumin; and 1-methylhistidine with flow

  9. Arginine-deficient diets alter plasma and tissue amino acids in young and aged rats.

    Science.gov (United States)

    Gross, K L; Hartman, W J; Ronnenberg, A; Prior, R L

    1991-10-01

    Blood and urine metabolites were measured in two experiments for young (2-mo-old) and aged (20-mo-old) male Sprague-Dawley rats fed arginine-devoid diets made isonitrogenous to a control 1.12% arginine diet by adding alanine or glycine. Diet, fed for 7 or 13 d, had little effect on urinary or plasma ammonia and urea. Urinary orotate excretion was more than 40-fold higher in rats fed the arginine-deficient diets (P less than 0.01) in both experiments. Source of nonessential N (alanine or glycine) in the arginine-deficient diets did not alter orotic acid excretion or plasma or urine ammonia or urea. Changes in plasma arginine, alanine and glycine concentrations reflected the levels of these amino acids in the diet. Tissue ornithine levels reflected dietary arginine level, but tissue citrulline was unaffected by dietary arginine. Glutamate and glutamine were greater in the plasma and liver of rats fed arginine-deficient diets. Plasma concentrations of glutamate and glutamine were positively correlated with urinary orotic acid excretion (P less than 0.05) and ornithine and arginine were negatively correlated with orotic acid excretion (P less than 0.01). Increased tissue glutamine may be related to the greater orotate excretion in rats fed arginine-devoid diets. The metabolic responses to dietary arginine deficiency were similar in young and aged rats. In general, concentrations of amino acids in plasma, liver and spleen were higher in aged rats.

  10. Plasma levels and urinary excretion of amino acids by subjects with renal calculi.

    Science.gov (United States)

    Atanassova, Stoyanka Slavcheva; Panchev, P; Ivanova, M

    2010-05-01

    Plasma levels and urinary amino acid excretions were estimated by high-performance liquid chromatography in 15 control subjects and 36 stone formers (SFs) classified according to the stone type: (1) 22 cases with calcium oxalate stones; (2) four cases with pure uric acid stones; (3) 10 cases with magnesium-ammonium phosphate stones, either pure or mixed with apatite. Some types of stones (namely oxalate and uric acid calculi) are mainly formed as a result of a metabolic deficiency that may affect the amino acid metabolism, and thus may be reflected in the urinary amino acid pattern. Data demonstrated clearly that there is a general tendency towards decreased amino acid excretions in all SFs with all types of stones. As a whole, one can observe a higher percentage of patients with calcium oxalate and phosphate calculosis, who have low urine excretions of amino acids; about 50% are the SFs with lower urine excretion of serine, glycine, taurine and i-leucine; the high percentage of patients with CaOX calculi shows lower urine excretions of tyrosine and ornithine.

  11. A biotin enrichment strategy identifies novel carbonylated amino acids in proteins from human plasma

    DEFF Research Database (Denmark)

    Havelund, Jesper F.; Wojdyla, Katarzyna; Davies, Michael J.

    2017-01-01

    Protein carbonylation is an irreversible protein oxidation correlated with oxidative stress, various diseases and ageing. Here we describe a peptide-centric approach for identification and characterisation of up to 14 different types of carbonylated amino acids in proteins. The modified residues...... in vitro metal ion-catalysed oxidation. Furthermore, we assigned 133 carbonylated sites in 36 proteins in native human plasma protein samples. The optimised workflow enabled detection of 10 hitherto undetected types of carbonylated amino acids in proteins: aldehyde and ketone modifications of leucine...

  12. Alterations in the levels of plasma amino acids in polycystic ovary syndrome- A pilot study

    Science.gov (United States)

    Unni, C. Sumithra N.; Lakshman, Lakshmi R.; Vaidyanathan, Kannan; Subhakumari, K.N.; Menon, N. Leela

    2015-01-01

    Background & objectives: Plasma amino acid levels are known to be altered in conditions like sepsis and burns which are situations of metabolic stress. Polycystic ovary syndrome (PCOS), a condition which affects a woman throughout her life, is said to be associated with metabolic stress. This study was undertaken to assess if there were significant alterations in the levels of plasma amino acids in women with PCOS. Methods: Sixty five women with PCOS along with the similar number of age matched normal controls were included in this study. Levels of 14 amino acids were determined using reverse phase high performance liquid chromatography. Results: The levels of methionine, cystine, isoleucine, phenylalanine, valine, tyrosine, proline, glycine, lysine and histidine were found to be significantly (P<0.001) lower in cases than in controls. Arginine and alanine levels were found to be significantly (P<0.001) higher in cases compared with controls. Interpretation & conclusions: Our findings showed significant derangement in the levels of plasma amino acids in women with PCOS which might be due to the oxidative and metabolic stress associated with it. Further studies need to be done to confirm the findings. PMID:26658589

  13. Alterations in the levels of plasma amino acids in polycystic ovary syndrome- A pilot study

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    Sumithra N Unni C

    2015-01-01

    Full Text Available Background & objectives: Plasma amino acid levels are known to be altered in conditions like sepsis and burns which are situations of metabolic stress. Polycystic ovary syndrome (PCOS, a condition which affects a woman throughout her life, is said to be associated with metabolic stress. This study was undertaken to assess if there were significant alterations in the levels of plasma amino acids in women with PCOS. Methods: Sixty five women with PCOS along with the similar number of age matched normal controls were included in this study. Levels of 14 amino acids were determined using reverse phase high performance liquid chromatography. Results: The levels of methionine, cystine, isoleucine, phenylalanine, valine, tyrosine, proline, glycine, lysine and histidine were found to be significantly (P<0.001 lower in cases than in controls. Arginine and alanine levels were found to be significantly (P<0.001 higher in cases compared with controls. Interpretation & conclusions: Our findings showed significant derangement in the levels of plasma amino acids in women with PCOS which might be due to the oxidative and metabolic stress associated with it. Further studies need to be done to confirm the findings.

  14. Amino acid composition of parturient plasma, the intervillous space of the placenta and the umbilical vein of term newborn infants

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    J.S. Camelo Jr.

    2004-05-01

    Full Text Available The objective of the present study was to determine the levels of amino acids in maternal plasma, placental intervillous space and fetal umbilical vein in order to identify the similarities and differences in amino acid levels in these compartments of 15 term newborns from normal pregnancies and deliveries. All amino acids, except tryptophan, were present in at least 186% higher concentrations in the intervillous space than in maternal venous blood, with the difference being statistically significant. This result contradicted the initial hypothesis of the study that the plasma amino acid levels in the placental intervillous space should be similar to those of maternal plasma. When the maternal venous compartment was compared with the umbilical vein, we observed values 103% higher on the fetal side which is compatible with currently accepted mechanisms of active amino acid transport. Amino acid levels of the placental intervillous space were similar to the values of the umbilical vein except for proline, glycine and aspartic acid, whose levels were significantly higher than fetal umbilical vein levels (average 107% higher. The elevated levels of the intervillous space are compatible with syncytiotrophoblast activity, which maintain high concentrations of free amino acids inside syncytiotrophoblast cells, permitting asymmetric efflux or active transport from the trophoblast cells to the blood in the intervillous space. The plasma amino acid levels in the umbilical vein of term newborns probably may be used as a standard of local normality for clinical studies of amino acid profiles.

  15. Associations between plasma branched-chain amino acids, β-aminoisobutyric acid and body composition.

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    Rietman, Annemarie; Stanley, Takara L; Clish, Clary; Mootha, Vamsi; Mensink, Marco; Grinspoon, Steven K; Makimura, Hideo

    2016-01-01

    Plasma branched-chain amino acids (BCAA) are elevated in obesity and associated with increased cardiometabolic risk. β-Aminoisobutyric acid (B-AIBA), a recently identified small molecule metabolite, is associated with decreased cardiometabolic risk. Therefore, we investigated the association of BCAA and B-AIBA with each other and with detailed body composition parameters, including abdominal visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT). A cross-sectional study was carried out with lean (n 15) and obese (n 33) men and women. Detailed metabolic evaluations, including measures of body composition, insulin sensitivity and plasma metabolomics were completed. Plasma BCAA were higher (1·6 (se 0·08) (×10(7)) v. 1·3 (se 0·06) (×10(7)) arbitrary units; P = 0·005) in obese v. lean subjects. BCAA were positively associated with VAT (R 0·49; P = 0·0006) and trended to an association with SAT (R 0·29; P = 0·052). The association between BCAA and VAT, but not SAT, remained significant after controlling for age, sex and race on multivariate modelling (P BCAA were also associated with parameters of insulin sensitivity (Matsuda index: R -0·50, P = 0·0004; glucose AUC: R 0·53, P BCAA were not associated with B-AIBA (R -0·04; P = 0·79). B-AIBA was negatively associated with SAT (R -0·37; P = 0·01) but only trended to an association with VAT (R 0·27; P = 0·07). However, neither relationship remained significant after multivariate modelling (P > 0·05). Plasma B-AIBA was associated with parameters of insulin sensitivity (Matsuda index R 0·36, P = 0·01; glucose AUC: R -0·30, P = 0·04). Plasma BCAA levels were positively correlated with VAT and markers of insulin resistance. The results suggest a possible complex role of adipose tissue in BCAA homeostasis and insulin resistance.

  16. Maternal Low Quality Protein Diet Alters Plasma Amino Acid Concentrations of Weaning Rats

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    Arzu Kabasakal Cetin

    2015-12-01

    Full Text Available Several studies have indicated the influence of a maternal low protein diet on the fetus. However, the effect of a maternal low quality protein diet on fetal growth and development is largely unknown. Wistar rats (11 weeks old were mated and maintained on either a chow diet with 20% casein (n = 6 as the control group (C, or a low quality protein diet with 20% wheat gluten (n = 7 as the experimental group (WG through gestation and lactation. Maternal body weights were similar in both groups throughout the study. Birth weights were not influenced by maternal diet and offspring body weights during lactation were similar between the groups. Offspring’s plasma amino acid profiles showed that plasma methionine, glutamine and lysine were significantly lower and aspartic acid, ornithine and glycine-proline were significantly higher in the WG. Plant based protein comprises an important part of protein intake in developing countries. It is well-known that these diets can be inadequate in terms of essential amino acids. The current study shows differential effects of a maternal low quality protein diet on the offspring’s plasma amino acids. Future studies will examine further aspects of the influence of maternal low quality protein diets on fetal growth and development.

  17. Sodium Phenylbutyrate Decreases Plasma Branched-Chain Amino Acids in Patients with Urea Cycle Disorders

    OpenAIRE

    Burrage, Lindsay C.; Jain, Mahim; Gandolfo, Laura; Lee, Brendan H.; Nagamani, Sandesh CS

    2014-01-01

    Sodium phenylbutyrate (NaPBA) is a commonly used medication for the treatment of patients with urea cycle disorders (UCDs). Previous reports involving small numbers of patients with UCDs have shown that NaPBA treatment can result in lower plasma levels of the branched-chain amino acids (BCAA) but this has not been studied systematically. From a large cohort of patients (n=553) with UCDs enrolled in Longitudinal Study of Urea Cycle Disorders, a collaborative multicenter study of the Urea Cycle...

  18. [Characteristics of the plasma amino acid spectrum of neonatal intrahepatic cholestasis caused by citrin deficiency].

    Science.gov (United States)

    Fu, Hai-yan; Wang, Xiao-hong; Lu, Yi; Zhang, Shao-ren; Fang, Ling-juan; Chen, Rui; Yu, Hui; Zhu, Qi-rong; Wang, Jian-she

    2013-12-01

    To investigate the plasma amino acid spectrum in infants more than 1-year-old with neonatal intrahepatic cholestasis caused by citrin deficiency (NICCD) in order to identify potential diagnostic markers of NICCD. Infants less than 1 year of age who had been referred to our hospital for investigation of suspected conjugated hyperbilirubinemia between June 2003 and June 2009 were eligible for enrollment. A total of 182 infants were enrolled and divided into three groups: infants diagnosed with NICCD (n = 24), according to gene testing and/or western blotting results; infants diagnosed with biliary atresia (BA; n = 20), according to intra-operative cholangiography findings; and infants diagnosed with idiopathic neonatal intrahepatic hepatitis (INH; n = 138), according to exclusionary findings for diseases affecting the extrahepatic biliary system and no positive serology results to indicate infections with hepatitis B, C, A or E, toxoplasmosis, rubella, herpes simplex, human immunodeficiency virus-1, or syphilis. The plasma amino acid spectrum of each infant was analyzed by tandem mass spectrometry (MS/MS). The concentrations of 18 amino acids, as well as the ratio of each amino acid to total amino acids, were compared among the three groups. Selected ratios of amino acids were analyzed by receiver operating characteristic (ROC) curve analysis. Compared with the BA and INH groups, the NICCD group had significantly lower levels of alanine (Ala; 175.7 and 205.7 vs. 136.3 mumol/L, P = 0.0001), aspartic acid (Asp; 47.5 and 43.1 vs. 31.55 mumol/L, P = 0.0041), glutamic acid (Glu; 276.16 and 263.24 vs. 175.71 mumol/L, P = 0.0075) and tryptophan (Trp; 41.90 and 47.97 vs. 28.51 mumol/L, P = 0.0003), but significantly higher levels of methionine (Met; 28.24 and 29.35 vs. 71.40 mumol/L, P = 0.0390), tyrosine (Tyr; 55.8 and 57.02 vs. 116.81 mumol/L, P = 0.0072) and citrulline (Cit; 15.09 and 15.65 vs. 97.42 mumol/L, P = 0.0001). The ratio of each amino acid to total amino acids

  19. An investigation into possible xenobiotic-endobiotic inter-relationships involving the amino acid analogue drug, S-carboxymethyl-L-cysteine and plasma amino acids in humans.

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    Steventon, Glyn B; Mitchell, Stephen C; Angulo, Santigo; Barbas, Coral

    2012-05-01

    The amino acid derivative, S-carboxymethyl-L-cysteine, is an anti-oxidant agent extensively employed as adjunctive therapy in the treatment of human pulmonary conditions. A major biotransformation route of this drug, which displays considerable variation in capacity in man, involves the oxidation of the sulfide moiety to the inactive S-oxide metabolite. Previous observations have indicated that fasted plasma L-cysteine concentrations and fasted plasma L-cysteine/free inorganic sulfate ratios were correlated with the degree of sulfoxidation of this drug and that these particular parameters may be used as endobiotic biomarkers for this xenobiotic metabolism. It has been proposed also that the enzyme, cysteine dioxygenase, was responsible for the drug sulfoxidation. Further in this theme, the degree of S-oxidation of S-carboxymethyl-L-cysteine in 100 human volunteers was investigated with respect to it potential correlation with fasted plasma amino acid concentrations. Extensive statistical analyses showed no significant associations or relationships between the degree of drug S-oxidation and fasted plasma amino acid concentrations, especially with respect to the sulfur-containing compounds, methionine, L-cysteine, L-cysteine sulfinic acid, taurine and free inorganic sulfate, also the derived ratios of L-cysteine/L-cysteine sulfinic acid and L-cysteine/free inorganic sulfate. It was concluded that plasma amino acid levels or derived ratios cannot be employed to predict the degree of S-oxidation of S-carboxymethyl-L-cysteine (or vice versa) and that it is doubtful if the enzyme, cysteine dioxygenase, has any involvement in the metabolism of this drug.

  20. Sodium phenylbutyrate decreases plasma branched-chain amino acids in patients with urea cycle disorders.

    Science.gov (United States)

    Burrage, Lindsay C; Jain, Mahim; Gandolfo, Laura; Lee, Brendan H; Nagamani, Sandesh C S

    2014-01-01

    Sodium phenylbutyrate (NaPBA) is a commonly used medication for the treatment of patients with urea cycle disorders (UCDs). Previous reports involving small numbers of patients with UCDs have shown that NaPBA treatment can result in lower plasma levels of the branched-chain amino acids (BCAA) but this has not been studied systematically. From a large cohort of patients (n=553) with UCDs enrolled in the Longitudinal Study of Urea Cycle Disorders, a collaborative multicenter study of the Urea Cycle Disorders Consortium, we evaluated whether treatment with NaPBA leads to a decrease in plasma BCAA levels. Our analysis shows that NaPBA use independently affects the plasma BCAA levels even after accounting for multiple confounding covariates. Moreover, NaPBA use increases the risk for BCAA deficiency. This effect of NaPBA seems specific to plasma BCAA levels, as levels of other essential amino acids are not altered by its use. Our study, in an unselected population of UCD subjects, is the largest to analyze the effects of NaPBA on BCAA metabolism and potentially has significant clinical implications. Our results indicate that plasma BCAA levels should to be monitored in patients treated with NaPBA since patients taking the medication are at increased risk for BCAA deficiency. On a broader scale, these findings could open avenues to explore NaPBA as a therapy in maple syrup urine disease and other common complex disorders with dysregulation of BCAA metabolism.

  1. A specific protein-enriched enteral formula decreases cortisolemia and improves plasma albumin and amino acid concentrations in elderly patients

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    Pérez de la Cruz Antonio

    2010-07-01

    Full Text Available Abstract Background Old age is associated with an involuntary and progressive but physiological loss of muscle mass. The aim of this study was to evaluate the effects of exclusive consumption for 6 months of a protein-enriched enteral diet with a relatively high content of branched-chain amino acids on albuminemia, cortisolemia, plasma amino acids, insulin resistance, and inflammation biomarkers in elderly patients. Methods Thirty-two patients from the Clinical Nutrition Outpatient Unit at our hospital exclusively consumed a protein-enriched enteral diet for 6 months. Data were collected at baseline and at 3 and 6 months on anthropometric and biochemical parameters and on plasma concentrations of amino acids, cortisol, adrenocorticotropic hormone, urea, creatinine, insulin resistance, and inflammation biomarkers. Results The percentage of patients with albumin concentration below normal cut-off values decreased from 18% to 0% by the end of the study. At 6 months, concentrations of total plasma (p = 0.008 and essential amino acids (p = 0.011, especially branched-chain amino acids (p = 0.031, were higher versus baseline values, whereas 3-methylhistidine (p = 0.001, cortisol (p = 0.001 and adrenocorticotropic hormone (p = 0.004 levels were lower. Conclusions Regular intake of specific protein-enriched enteral formula increases plasma essential amino acids, especially branched-chain amino acids, and decreases cortisol and 3-methylhistidine, while plasma urea and creatinine remain unchanged.

  2. Relationship between pain and plasma amino acid levels in chronic pancreatitis.

    Science.gov (United States)

    Kawaguchi, Yoshiaki; Lin, Jung-Chun; Kawashima, Yohei; Maruno, Atsuko; Ito, Hiroyuki; Ogawa, Masami; Mine, Tetsuya

    2015-01-31

    Our aim was to investigate the relationship between imbalances of plasma amino acids and pain in chronic pancreatitis (CP). Thirty patients with alcoholic CP in an exocrine-insufficient state were examined. We divided them between diet and control group. Diet group ingested 80 g/300 kcal of the elemental diet "Elental®". This diet of 300 kcal/day was administered for two months. Selected clinical and laboratory values were compared between both groups before and after diet. Pain was observed and compared using a visual analog scale (VAS). There was no significant difference in the BMI between both groups before and after diet. The serum albumin level in diet group after diet was significantly higher than in control group (P=0.036). There was no significant difference in HbA1c between both groups before and after diet. The total amino acid concentration was significantly higher in diet group after diet than in control group (P=0.033). The concentrations of serum histidine and methionine in diet group after diet were significantly higher than in control group (histidine, P=0.022; methionine, P=0.026). The concentration of serum glutamate in diet group after diet was significantly lower than in control group (P=0.027). The balance of amino acids in diet group was normalized after the Elental® was ingested. The VAS score was significantly lower in diet group after diet than in control group (P=0.018). These amino acid levels and pancreatic pain were improved by the elemental diet. The pancreatic pain may be related to these amino acid imbalances.

  3. Relationship between Pain and Plasma Amino Acid Levels in Chronic Pancreatitis

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    Yoshiaki Kawaguchi

    2015-01-01

    Full Text Available Objective Our aim was to investigate the relationship between imbalances of plasma amino acids and pain in chronic pancreatitis (CP. Methods Thirty patients with alcoholic CP in an exocrine-insufficient state were examined. We divided them between diet and control group. Diet group ingested 80g/300 kcal of the elemental diet "Elental®". This diet of 300 kcal/day was administered for two months. Selected clinical and laboratory values were compared between both groups before and after diet. Pain was observed and compared using a visual analog scale (VAS. Results There was no significant difference in the BMI between both groups before and after diet. The serum albumin level in diet group after diet was significantly higher than in control group (P=0.036. There was no significant difference in HbA1c between both groups before and after diet. The total amino acid concentration was significantly higher in diet group after diet than in control group (P=0.033. The concentrations of serum histidine and methionine in diet group after diet were significantly higher than in control group (histidine, P=0.022; methionine, P=0.026. The concentration of serum glutamate in diet group after diet was significantly lower than in control group (P=0.027. The balance of amino acids in diet group was normalized after the Elental® was ingested. The VAS score was significantly lower in diet group after diet than in control group (P=0.018. Conclusion These amino acid levels and pancreatic pain were improved by the elemental diet. The pancreatic pain may be related to these amino acid imbalances.

  4. Effects of total gastrectomy on plasma silicon and amino acid concentrations in men.

    Science.gov (United States)

    Tatara, Marcin R; Krupski, Witold; Szpetnar, Maria; Dąbrowski, Andrzej; Bury, Paweł; Szabelska, Anna; Charuta, Anna; Boguszewska-Czubara, Anna; Maciejewski, Ryszard; Wallner, Grzegorz

    2015-12-01

    The aim of the study was to determine one-year effects of total gastrectomy on plasma silicon and free amino acid concentrations in patients and evaluate changes of volumetric bone mineral density (vBMD) in lumbar spine. Eight patients were enrolled to the control (CTR) group. Six patients subjected to total gastrectomy (GX group) were included to the experimental group. vBMD in trabecular and cortical bone was measured in lumbar vertebrae at baseline (before surgery) and one year later using quantitative computed tomography. Plasma concentrations of silicon and free amino acids were determined at baseline and one year later using photometric method and ion-exchange chromatography. Body weights within CTR and GX groups were not different after one-year follow-up when compared to the baseline values (P > 0.05). An average annual decrease of vBMD in the trabecular bone in the gastrectomized patients reached 15.0% in lumbar spine and was significantly different in comparison to the percentage changes observed in CTR group (P = 0.02). One-year percentage change of vBMD in the cortical bone in L1 and L2 has shown significantly decreased values by 10.5 and 9.1% in the GX group when compared to the percentage change observed in the controls (P silicon was significantly lowered by 26.7% one year after the total gastrectomy when compared to the baseline value (P = 0.009). Total gastrectomy in patients has induced severe osteoporotic changes in lumbar spine within one-year period. The observed osteoporotic changes were associated with decreased plasma concentration of silicon indicating importance of exocrine and endocrine functions of stomach for silicon homeostasis maintenance. Gastrectomy-induced bone loss was not related to decreased amino acid concentration in plasma obtained from overnight fasted patients.

  5. Effect of abomasal infusion of aspartate on nitrogen balance and plasma amino acids in Holstein steers.

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    Wessels, R H; Titgemeyer, E C

    1998-01-01

    We investigated the effect of abomasally infused aspartate (Asp) on N balance and plasma amino acids in steers. Four ruminally cannulated Holstein steers (180 kg) housed in metabolism crates were used in an experiment designed as a 4 x 3 Youden square. Steers received continuous abomasal infusions of water or water containing 40 or 80 g Asp/d. Steers were fed twice daily a diet containing 473 g/kg corn, 463 g/kg alfalfa hay and 52 g/kg soybean meal at levels near ad libitum intake. Abomasally infused Asp had no effect on N balance. Infusion of 80 g Asp/d increased (P < 0.05) plasma concentrations of Asp, glutamate and alanine. Metabolism of Asp by gut tissues probably prevented the large change in plasma concentration of Asp that seems necessary to trigger hormonal responses. We conclude that abomasal supplementation of steers with up to 80 g/d of Asp does not enhance performance.

  6. A clinicobiochemical study of tryptophan and other plasma and urinary amino acids in the family with Hartnup disease.

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    Milovanović, Dragoslav D

    2003-01-01

    Two cases of Hartnup disease were diagnosed in a five member family. A changeable polymorph and severe clinical features of a 16 year old girl was described. Total plasma amino acids value was significantly decreased in the girl compared to the sum of plasma amino acids value in the brother, mother, father and to the summed maximal values of normal range. Intermediate aminoaciduria was also found with atypical amino acids pattern. Total plasma amino acids concentration was significantly reduced (27.20%) in the mother, while no significant decrease in the son (1.83%) and father (7.51%) were found compared to the summed maximal values of normal range. In the clinicaly healthy father, 38 years of age, a gross aminoaciduria with atypical pattern of amino acids was also found. Urinary amino acids concentration in the son and his mother were rather normal, although low concentration of eight amino acids was found in the mother's urine. Cerebrospinal fluid 5-hydroxyindoleacetic acid level was reduced in the girl.

  7. Facile plasma-enhanced deposition of ultrathin crosslinked amino acid films for conformal biometallization.

    Science.gov (United States)

    Anderson, Kyle D; Slocik, Joseph M; McConney, Michael E; Enlow, Jesse O; Jakubiak, Rachel; Bunning, Timothy J; Naik, Rajesh R; Tsukruk, Vladimir V

    2009-03-01

    A novel method for the facile fabrication of conformal, ultrathin, and uniform synthetic amino acid coatings on a variety of practical surfaces by plasma-enhanced chemical vapor deposition is introduced. Tyrosine, which is utilized as an agent to reduce gold nanoparticles from solution, is sublimed into the plasma field and directly deposited on a variety of substrates to form a homogeneous, conformal, and robust polyamino acid coating in a one-step, solvent-free process. This approach is applicable to many practical surfaces and allows surface-induced biometallization while avoiding multiple wet-chemistry treatments that can damage many soft materials. Moreover, by placing a mask over the substrate during deposition, the tyrosine coating can be micropatterned. Upon its exposure to a solution of gold chloride, a network of gold nanoparticles forms on the surface, replicating the initial micropattern. This method of templated biometallization is adaptable to a variety of practical inorganic and organic substrates, such as silicon, glass, nitrocellulose, polystyrene, polydimethylsiloxane, polytetrafluoroethylene, polyethylene, and woven silk fibers. No special pretreatment is necessary, and the technique results in a rapid, conformal amino acid coating that can be utilized for further biometallization.

  8. A biotin enrichment strategy identifies novel carbonylated amino acids in proteins from human plasma.

    Science.gov (United States)

    Havelund, Jesper F; Wojdyla, Katarzyna; Davies, Michael J; Jensen, Ole N; Møller, Ian Max; Rogowska-Wrzesinska, Adelina

    2017-03-06

    Protein carbonylation is an irreversible protein oxidation correlated with oxidative stress, various diseases and ageing. Here we describe a peptide-centric approach for identification and characterisation of up to 14 different types of carbonylated amino acids in proteins. The modified residues are derivatised with biotin-hydrazide, enriched and characterised by tandem mass spectrometry. The strength of the method lies in an improved elution of biotinylated peptides from monomeric avidin resin using hot water (95°C) and increased sensitivity achieved by reduction of analyte losses during sample preparation and chromatography. For the first time MS/MS data analysis utilising diagnostic biotin fragment ions is used to pinpoint sites of biotin labelling and improve the confidence of carbonyl peptide assignments. We identified a total of 125 carbonylated residues in bovine serum albumin after extensive in vitro metal ion-catalysed oxidation. Furthermore, we assigned 133 carbonylated sites in 36 proteins in native human plasma protein samples. The optimised workflow enabled detection of 10 hitherto undetected types of carbonylated amino acids in proteins: aldehyde and ketone modifications of leucine, valine, alanine, isoleucine, glutamine, lysine and glutamic acid (+14Da), an oxidised form of methionine - aspartate semialdehyde (-32Da) - and decarboxylated glutamic acid and aspartic acid (-30Da).

  9. The overnight effect of dietary energy balance on postprandial plasma free amino acid (PFAA) profiles in Japanese adult men.

    Science.gov (United States)

    Nishioka, Manabu; Imaizumi, Akira; Ando, Toshihiko; Tochikubo, Osamu

    2013-01-01

    The plasma free amino acid (PFAA) profile is affected by various nutritional conditions, such as the dietary energy balance. Regarding the clinical use of PFAA profiling, it is of concern that differences in food ingestion patterns may generate systematic errors in a plasma amino acid profile and constitute a confounding factor in assessment. In this study, the overnight impact of the dietary energy balance on the postprandial plasma amino acid profile was investigated to elucidate in particular the effects of high protein meals typical in Japanese cuisine. We conducted diet-controlled, crossover trials in eleven healthy male volunteers aged 40-61 y. They consumed either a normal meal (meal N) or high protein meal (meal H) at dinner. Forearm venous blood was collected, and plasma amino acid concentrations were measured before dinner and the next morning. We found that a high protein meal in the evening that contained 40% energy would significantly increase the PFAA concentration the next morning, even more than 12 hours after the meal. Among amino acids, the most significant difference was observed in the branched-chain amino acids (BCAAs) and in some urea-cycle related compounds. If the subject consumed the high protein diet at dinner, the PFAA profile after overnight fasting might be still affected by the meal even 12 hours after the meal, suggesting that the PFAA profile does not reflect the subject's health condition, but rather the acute effect of high protein ingestion.

  10. The overnight effect of dietary energy balance on postprandial plasma free amino acid (PFAA profiles in Japanese adult men.

    Directory of Open Access Journals (Sweden)

    Manabu Nishioka

    Full Text Available The plasma free amino acid (PFAA profile is affected by various nutritional conditions, such as the dietary energy balance. Regarding the clinical use of PFAA profiling, it is of concern that differences in food ingestion patterns may generate systematic errors in a plasma amino acid profile and constitute a confounding factor in assessment. In this study, the overnight impact of the dietary energy balance on the postprandial plasma amino acid profile was investigated to elucidate in particular the effects of high protein meals typical in Japanese cuisine. We conducted diet-controlled, crossover trials in eleven healthy male volunteers aged 40-61 y. They consumed either a normal meal (meal N or high protein meal (meal H at dinner. Forearm venous blood was collected, and plasma amino acid concentrations were measured before dinner and the next morning. We found that a high protein meal in the evening that contained 40% energy would significantly increase the PFAA concentration the next morning, even more than 12 hours after the meal. Among amino acids, the most significant difference was observed in the branched-chain amino acids (BCAAs and in some urea-cycle related compounds. If the subject consumed the high protein diet at dinner, the PFAA profile after overnight fasting might be still affected by the meal even 12 hours after the meal, suggesting that the PFAA profile does not reflect the subject's health condition, but rather the acute effect of high protein ingestion.

  11. The EZ:Faast family of amino acid analysis kits: application of the GC-FID kit for rapid determination of plasma tryptophan and other amino acids.

    Science.gov (United States)

    Badawy, Abdulla A-B

    2012-01-01

    Plasma tryptophan (Trp) and other amino acids (AA) can be determined rapidly by gas (GC) or liquid (LC) chromatography using the Phenomenex EZ:Faast(™) family of kits. Three kits are available: (1) GC-FID or -NPD, (2) GC-MS, (3) LC-MS. The two GC kits can determine 32 AA, whereas the LC-MS can determine five additional AA. All three kits, however, share the same experimental procedure up to and including the preparation of derivatised AA. The method is based on solid-phase extraction (SPE), thus saving time on prior removal of plasma or other proteins and interfering substances, and can be applied to other body fluids and experimental media and to supernatants of extracts of solid material. Briefly, SPE is performed using a proprietary cation-exchange mechanism. The acid solution of the internal standard ensures that the free amino acids are in an anionic form suitable for cationic binding. The alkaline nature of the elution medium ensures that the AA cations are released prior to derivatisation. The latter involves production of chloroformate derivatives of both the amino and carboxylic acid groups. With experience, six plasma samples can be so processed within 12 min. The shortest analytical run is FID/NPD kit. Despite its many steps, the procedure becomes second nature and an enjoyable task. I have now used the GC-FID kit with manual injection to process >1,600 plasma and other samples. Limit of detection of AA is 1 μM or less. The procedure has been validated and optimised for Trp and its main five brain uptake competitors.

  12. Feed deprivation in Senegalese sole (Solea senegalensis Kaup, 1858) juveniles: effects on blood plasma metabolites and free amino acid levels.

    Science.gov (United States)

    Costas, Benjamín; Aragão, Cláudia; Ruiz-Jarabo, Ignacio; Vargas-Chacoff, Luis; Arjona, Francisco Jesús; Dinis, Maria Teresa; Mancera, Juan Miguel; Conceição, Luís E C

    2011-09-01

    The effects of prolonged feed deprivation were assessed on blood plasma metabolites and free amino acid levels in Solea senegalensis. Juvenile specimens were maintained at two experimental conditions (24 h fasted and 21 days feed-deprived). In feed-deprived fish, relative growth rate and hepatosomatic index as well as plasma triglycerides and proteins levels were significantly lower. However, plasma cortisol levels were higher in feed-deprived fish, while plasma glucose and lactate values were not significantly different between treatments. Furthermore, feed-deprived fish showed higher levels of total plasma free amino acids than 24 h fasted fish. In 21 days feed-deprived sole, an increase in plasma cortisol levels may suggest a functional role in mobilizing energy due to the catabolic action of this hormone in teleosts. Higher levels of glutamine, arginine and ornithine in 21 days feed-deprived fish may be indicative of a dual role for these amino acids: ammonia detoxification and carbon source for gluconeogenesis. The increased plasma glucogenic and branched-chain amino acid levels, together with the maintenance of plasma glucose in 21 days feed-deprived sole, suggest active liver gluconeogenic processes supported by tissue proteolysis.

  13. Distinct Plasma Profile of Polar Neutral Amino Acids, Leucine, and Glutamate in Children with Autism Spectrum Disorders

    Science.gov (United States)

    Tirouvanziam, Rabindra; Obukhanych, Tetyana V.; Laval, Julie; Aronov, Pavel A.; Libove, Robin; Banerjee, Arpita Goswami; Parker, Karen J.; O'Hara, Ruth; Herzenberg, Leonard A.; Herzenberg, Leonore A.; Hardan, Antonio Y.

    2012-01-01

    The goal of this investigation was to examine plasma amino acid (AA) levels in children with Autism Spectrum Disorders (ASD, N = 27) and neuro-typically developing controls (N = 20). We observed reduced plasma levels of most polar neutral AA and leucine in children with ASD. This AA profile conferred significant post hoc power for discriminating…

  14. Distinct Plasma Profile of Polar Neutral Amino Acids, Leucine, and Glutamate in Children with Autism Spectrum Disorders

    Science.gov (United States)

    Tirouvanziam, Rabindra; Obukhanych, Tetyana V.; Laval, Julie; Aronov, Pavel A.; Libove, Robin; Banerjee, Arpita Goswami; Parker, Karen J.; O'Hara, Ruth; Herzenberg, Leonard A.; Herzenberg, Leonore A.; Hardan, Antonio Y.

    2012-01-01

    The goal of this investigation was to examine plasma amino acid (AA) levels in children with Autism Spectrum Disorders (ASD, N = 27) and neuro-typically developing controls (N = 20). We observed reduced plasma levels of most polar neutral AA and leucine in children with ASD. This AA profile conferred significant post hoc power for discriminating…

  15. Direct tandem mass spectrometric analysis of amino acids in plasma using fluorous derivatization and monolithic solid-phase purification.

    Science.gov (United States)

    Tamashima, Erina; Hayama, Tadashi; Yoshida, Hideyuki; Imakyure, Osamu; Yamaguchi, Masatoshi; Nohta, Hitoshi

    2015-11-10

    In this study, we developed a novel direct tandem mass spectrometric method for rapid and accurate analysis of amino acids utilizing a fluorous derivatization and purification technique. Amino acids were perfluoroalkylated with 2H,2H,3H,3H-perfluoroundecan-1-al in the presence of 2-picoline borane via reductive amination. The derivatives were purified by perfluoroalkyl-modified silica-based monolithic solid-phase extraction (monolithic F-SPE), and directly analyzed by tandem mass spectrometry using electrospray ionization without liquid chromatographic separation. The perfluoroalkyl derivatives could be sufficiently distinguished from non-fluorous compounds, i.e. the biological matrix, due to their fluorous interaction. Thus, rapid and accurate determination of amino acids was accomplished. The method was validated with human plasma samples and applied to the analysis of amino acids in the plasma of mice with maple syrup urine disease or phenylketonuria.

  16. Effects of starvation, surgery and infusion of adrenocorticotrophin on plasma amino acid concentration in the pregnant ewe.

    Science.gov (United States)

    Slater, J S; Mellor, D J

    1977-01-01

    Total plasma amino acid concentrations (TAA) in 12 Scottish Blackface ewes between 80 and 140 days of pregnancy were unaltered by two days of starvation, but concentrations of essential amino acids (EAA) increased and non-essential amino acid (NAA) levels decreased. These trends were more pronounced later in pregnancy. Ewes fasted before surgery to implant fetal catheters showed marked reductions in mean TAA levels (--26 per cent, n-5) on the day after operation (day+ 1). Half of this decrease was accounted for by glycine. Mean concentrations of NAA increased after day +1 but by day +6 were still 15 per cent below baseline values. In contrast mean plasma concentrations of EAA were 31 per cent above prestarvation levels on day +6 and maximal on day +4(+39 per cent). Following a two-day fast, sheep given half rations and simultaneously infused with adrenocorticotrophin showed changes in plasma-free amino acid composition like those observed during the two days after operation. Disturbances to plasma amino acid concetrations persisted for up to 12 days after operation and are attributed to the preoperative starvation and the combined effects of irregular feeding patterns and elevated plasma corticosteroid levels during and after operation.

  17. Metabolic profiling of plasma amino acids shows that histidine increases following the consumption of pork

    Directory of Open Access Journals (Sweden)

    Samman S

    2014-06-01

    Full Text Available Samir Samman,1 Ben Crossett,2 Miles Somers,1 Kirstine J Bell,1 Nicole T Lai,1,3 David R Sullivan,3 Peter Petocz4 1Discipline of Nutrition and Metabolism, 2Discipline of Proteomics and Biotechnology, School of Molecular Bioscience, University of Sydney, Sydney, NSW, Australia; 3Department of Clinical Biochemistry, Royal Prince Alfred Hospital, Sydney, NSW, Australia; 4Department of Statistics, Macquarie University, Sydney, NSW, Australia Abstract: Amino acid (AA status is determined by factors including nutrition, metabolic rate, and interactions between the metabolism of AA, carbohydrates, and lipids. Analysis of the plasma AA profile, together with markers of glucose and lipid metabolism, will shed light on metabolic regulation. The objectives of this study were to investigate the acute responses to the consumption of meals containing either pork (PM or chicken (CM, and to identify relationships between plasma AA and markers of glycemic and lipemic control. A secondary aim was to explore AA predictors of plasma zinc concentrations. Ten healthy adults participated in a postprandial study on two separate occasions. In a randomized cross-over design, participants consumed PM or CM. The concentrations of 21 AA, glucose, insulin, triglycerides, nonesterified fatty acids, and zinc were determined over 5 hours postprandially. The meal composition did not influence glucose, insulin, triglyceride, nonesterified fatty acid, or zinc concentrations. Plasma histidine was higher following the consumption of PM (P=0.014, with consistently higher changes observed after 60 minutes (P<0.001. Greater percentage increases were noted at limited time points for valine and leucine + isoleucine in those who consumed CM compared to PM. In linear regression, some AAs emerged as predictors of the metabolic responses, irrespective of the meal that was consumed. The present study demonstrates that a single meal of PM or CM produces a differential profile of AA in the

  18. Aromatic L-amino acid decarboxylase deficiency diagnosed by clinical metabolomic profiling of plasma.

    Science.gov (United States)

    Atwal, Paldeep S; Donti, Taraka R; Cardon, Aaron L; Bacino, C A; Sun, Qin; Emrick, L; Reid Sutton, V; Elsea, Sarah H

    2015-01-01

    Aromatic L-amino acid decarboxylase (AADC) deficiency is an inborn error of metabolism affecting the biosynthesis of serotonin, dopamine, and catecholamines. We report a case of AADC deficiency that was detected using the Global MAPS platform. This is a novel platform that allows for parallel clinical testing of hundreds of metabolites in a single plasma specimen. It uses a state-of-the-art mass spectrometry platform, and the resulting spectra are compared against a library of ~2500 metabolites. Our patient is now a 4 year old boy initially seen at 11 months of age for developmental delay and hypotonia. Multiple tests had not yielded a diagnosis until exome sequencing revealed compound heterozygous variants of uncertain significance (VUS), c.286G>A (p.G96R) and c.260C>T (p.P87L) in the DDC gene, causal for AADC deficiency. CSF neurotransmitter analysis confirmed the diagnosis with elevated 3-methoxytyrosine (3-O-methyldopa). Metabolomic profiling was performed on plasma and revealed marked elevation in 3-methoxytyrosine (Z-score +6.1) consistent with the diagnosis of AADC deficiency. These results demonstrate that the Global MAPS platform is able to diagnose AADC deficiency from plasma. In summary, we report a novel and less invasive approach to diagnose AADC deficiency using plasma metabolomic profiling.

  19. Metabolic profiling of plasma amino acids shows that histidine increases following the consumption of pork.

    Science.gov (United States)

    Samman, Samir; Crossett, Ben; Somers, Miles; Bell, Kirstine J; Lai, Nicole T; Sullivan, David R; Petocz, Peter

    2014-01-01

    Amino acid (AA) status is determined by factors including nutrition, metabolic rate, and interactions between the metabolism of AA, carbohydrates, and lipids. Analysis of the plasma AA profile, together with markers of glucose and lipid metabolism, will shed light on metabolic regulation. The objectives of this study were to investigate the acute responses to the consumption of meals containing either pork (PM) or chicken (CM), and to identify relationships between plasma AA and markers of glycemic and lipemic control. A secondary aim was to explore AA predictors of plasma zinc concentrations. Ten healthy adults participated in a postprandial study on two separate occasions. In a randomized cross-over design, participants consumed PM or CM. The concentrations of 21 AA, glucose, insulin, triglycerides, nonesterified fatty acids, and zinc were determined over 5 hours postprandially. The meal composition did not influence glucose, insulin, triglyceride, nonesterified fatty acid, or zinc concentrations. Plasma histidine was higher following the consumption of PM (P=0.014), with consistently higher changes observed after 60 minutes (P<0.001). Greater percentage increases were noted at limited time points for valine and leucine + isoleucine in those who consumed CM compared to PM. In linear regression, some AAs emerged as predictors of the metabolic responses, irrespective of the meal that was consumed. The present study demonstrates that a single meal of PM or CM produces a differential profile of AA in the postprandial state. The sustained increase in histidine following the consumption of a PM is consistent with the reported effects of lean pork on cardiometabolic risk factors.

  20. Multivariable analysis of host amino acids in plasma and liver during infection of malaria parasite Plasmodium yoelii

    Directory of Open Access Journals (Sweden)

    Saiki Erisha

    2013-01-01

    Full Text Available Abstract Background Malaria is the most significant human parasitic disease, and yet understanding of the energy metabolism of the principle pathogen, Plasmodium falciparum, remains to be fully elucidated. Amino acids were shown to be essential nutritional requirements since early times and much of the current knowledge of Plasmodium energy metabolism is based on early biochemical work, performed using basic analytical techniques, carried out almost exclusively on human plasma with considerable inter-individual variability. Methods In order to further characterize the fate of amino acid metabolism in malaria parasite, multivariate analysis using statistical modelling of amino acid concentrations (aminogram of plasma and liver were determined in host infected with rodent malaria parasite, Plasmodium yoelii. Results and conclusion Comprehensive and statistical aminogram analysis revealed that P. yoelii infection caused drastic change of plasma and liver aminogram, and altered intra- and inter-correlation of amino acid concentration in plasma and liver. These findings of the interactions between amino acids and Plasmodium infection may provide insight to reveal the interaction between nutrients and parasites.

  1. Effects of Acute Exposure to Increased Plasma Branched-Chain Amino Acid Concentrations on Insulin-Mediated Plasma Glucose Turnover in Healthy Young Subjects

    OpenAIRE

    Sarah Everman; Mandarino, Lawrence J.; Carroll, Chad C.; Katsanos, Christos S.

    2015-01-01

    Background Plasma branched-chain amino acids (BCAA) are inversely related to insulin sensitivity of glucose metabolism in humans. However, currently, it is not known whether there is a cause-and-effect relationship between increased plasma BCAA concentrations and decreased insulin sensitivity. Objective To determine the effects of acute exposure to increased plasma BCAA concentrations on insulin-mediated plasma glucose turnover in humans. Methods Ten healthy subjects were randomly assigned to...

  2. Plasma amino acid and metabolite signatures tracking diabetes progression in the UCD-T2DM rat model

    Science.gov (United States)

    Elevations of plasma concentrations of branched-chain amino acids (BCAAs) are observed in human insulin resistance and type 2 diabetes mellitus (T2DM); however, there has been some controversy with respect to the passive or causative nature of the BCAA phenotype. Using untargeted metabolomics, plasm...

  3. Ingestion of protein hydrolysate and amino acid-carbohydrate mixtures increases postexercise plasma insulin responses in men

    NARCIS (Netherlands)

    Loon, L.J.C. van; Kruijshoop, M.; Verhagen, H.; Saris, W.H.M.; Wagenmakers, A.J.M.

    2000-01-01

    To optimize the postexercise insulin response and to increase plasma amino acid availability, we studied postexercise insulin levels after the ingestion of carbohydrate and wheat protein hydrolysate with and without free leucine and phenylalanine. After an overnight fast, eight male cyclists visited

  4. Ingestion of protein hydrolysate and amino acid-carbohydrate mixtures increases postexercise plasma insulin responses in men

    NARCIS (Netherlands)

    Loon, L.J.C. van; Kruijshoop, M.; Verhagen, H.; Saris, W.H.M.; Wagenmakers, A.J.M.

    2000-01-01

    To optimize the postexercise insulin response and to increase plasma amino acid availability, we studied postexercise insulin levels after the ingestion of carbohydrate and wheat protein hydrolysate with and without free leucine and phenylalanine. After an overnight fast, eight male cyclists visited

  5. Diagnosis of hepatic fibrosis in hepatitis B patients by logistic regression modeling based on plasma amino acid ratio and age

    Institute of Scientific and Technical Information of China (English)

    张占卿

    2013-01-01

    Objective To explore the efficacy of logistic regression modeling based on plasma amino acid profile and patient age,for diagnosing hepatic fibrosis in patients with chronic hepatitis B (CHB) .Methods One-hundredand-forty-eight patients (108 males;mean age:38.1±11.9 years,range:16—72 years) histologically

  6. Amino Acid Metabolism Disorders

    Science.gov (United States)

    ... this process. One group of these disorders is amino acid metabolism disorders. They include phenylketonuria (PKU) and maple syrup urine disease. Amino acids are "building blocks" that join together to form ...

  7. Effects of dietary methionine on feed utilization, plasma amino acid profiles and gene expression in rainbow trout (Oncorhynchus mykiss)

    DEFF Research Database (Denmark)

    Rolland, Marine

    (EAA) compared to dietary requirements. Supplementation with amino acids in crystalline from (CAA) is a common practice to balance the dietary amino acid profile to achieve high growth performances. However, complete substitution of fish meal using plant proteins and CAAs often results in poorer growth...... are presented in Paper I and show that the protein source itself (fish meal or plant based) does not affect the plasma EAA profiles, but rather that plasma EAA levels reflect the dietary level. Supplementation with histidine, lysine and threonine in crystalline form to a plant based diet was, on the other hand...... as an apparent “accumulation” in the plasma, compared to fish fed similar dietary level but in protein bound form. The study further showed that the nitrogen excretion resulting from feeding an AA deficient diet was higher than for the fish meal control diet. Supplementation of the plant meal diet...

  8. Meal composition and plasma amino acid ratios: Effect of various proteins or carbohydrates, and of various protein concentrations

    Science.gov (United States)

    Yokogoshi, Hidehiko; Wurtman, Richard J.

    1986-01-01

    The effects of meals containing various proteins and carbohydrates, and of those containing various proportions of protein (0 percent to 20 percent of a meal, by weight) or of carbohydrate (0 percent to 75 percent), on plasma levels of certain large neutral amino acids (LNAA) in rats previously fasted for 19 hours were examined. Also the plasma tryptophan ratios (the ratio of the plasma trytophan concentration to the summed concentrations of the other large neutral amino acids) and other plasma amino acid ratios were calculated. (The plasma tryptophan ratio has been shown to determine brain tryptophan levels and, thereby, to affect the synthesis and release of the neurotransmitter serotonin). A meal containing 70 percent to 75 percent of an insulin-secreting carbohydrate (dextrose or dextrin) increased plasma insulin levels and the tryptophan ratio; those containing 0 percent or 25 percent carbohydrate failed to do so. Addition of as little as 5 percent casein to a 70 percent carbohydrate meal fully blocked the increase in the plasma tryptophan ratio without affecting the secretion of insulin - probably by contributing much larger quantities of the other LNAA than of tryptophan to the blood. Dietary proteins differed in their ability to suppress the carbohydrate-induced rise in the plasma tryptophan ratio. Addition of 10 percent casein, peanut meal, or gelatin fully blocked this increase, but lactalbumin failed to do so, and egg white did so only partially. (Consumption of the 10 percent gelatin meal also produced a major reduction in the plasma tyrosine ratio, and may thereby have affected brain tyrosine levels and catecholamine synthesis.) These observations suggest that serotonin-releasing neurons in brains of fasted rats are capable of distinguishing (by their metabolic effects) between meals poor in protein but rich in carbohydrates that elicit insulin secretion, and all other meals. The changes in brain serotonin caused by carbohydrate-rich, protein

  9. Meal composition and plasma amino acid ratios: Effect of various proteins or carbohydrates, and of various protein concentrations

    Science.gov (United States)

    Yokogoshi, Hidehiko; Wurtman, Richard J.

    1986-01-01

    The effects of meals containing various proteins and carbohydrates, and of those containing various proportions of protein (0 percent to 20 percent of a meal, by weight) or of carbohydrate (0 percent to 75 percent), on plasma levels of certain large neutral amino acids (LNAA) in rats previously fasted for 19 hours were examined. Also the plasma tryptophan ratios (the ratio of the plasma trytophan concentration to the summed concentrations of the other large neutral amino acids) and other plasma amino acid ratios were calculated. (The plasma tryptophan ratio has been shown to determine brain tryptophan levels and, thereby, to affect the synthesis and release of the neurotransmitter serotonin). A meal containing 70 percent to 75 percent of an insulin-secreting carbohydrate (dextrose or dextrin) increased plasma insulin levels and the tryptophan ratio; those containing 0 percent or 25 percent carbohydrate failed to do so. Addition of as little as 5 percent casein to a 70 percent carbohydrate meal fully blocked the increase in the plasma tryptophan ratio without affecting the secretion of insulin - probably by contributing much larger quantities of the other LNAA than of tryptophan to the blood. Dietary proteins differed in their ability to suppress the carbohydrate-induced rise in the plasma tryptophan ratio. Addition of 10 percent casein, peanut meal, or gelatin fully blocked this increase, but lactalbumin failed to do so, and egg white did so only partially. (Consumption of the 10 percent gelatin meal also produced a major reduction in the plasma tyrosine ratio, and may thereby have affected brain tyrosine levels and catecholamine synthesis.) These observations suggest that serotonin-releasing neurons in brains of fasted rats are capable of distinguishing (by their metabolic effects) between meals poor in protein but rich in carbohydrates that elicit insulin secretion, and all other meals. The changes in brain serotonin caused by carbohydrate-rich, protein

  10. Effect of plant proteins and crystalline amino acid supplementation on postprandial plasma amino acid profiles and metabolic response in rainbow trout (Oncorhynchus mykiss)

    DEFF Research Database (Denmark)

    Rolland, Marine; Larsen, Bodil Katrine; Holm, Jørgen

    2015-01-01

    The use of aquafeeds formulated with plant protein sources supplemented with crystalline amino acids (CAAs) is believed to influence amino acid (AA) uptake patterns and AA metabolic fate. Oxygen consumption and ammonia excretion rates were measured in rainbow trout (468.5 +/- A 86.5 g) force fed 0...... to be caused by an unbalanced dietary AA profile and CAA supplementation, rather than inclusion of plant protein concentrate....

  11. Parenteral Nutrition: Amino Acids

    Science.gov (United States)

    Hoffer, Leonard John

    2017-01-01

    There is growing interest in nutrition therapies that deliver a generous amount of protein, but not a toxic amount of energy, to protein-catabolic critically ill patients. Parenteral amino acids can achieve this goal. This article summarizes the biochemical and nutritional principles that guide parenteral amino acid therapy, explains how parenteral amino acid solutions are formulated, and compares the advantages and disadvantages of different parenteral amino acid products with enterally-delivered whole protein products in the context of protein-catabolic critical illness. PMID:28287411

  12. Parenteral Nutrition: Amino Acids.

    Science.gov (United States)

    Hoffer, Leonard John

    2017-03-10

    There is growing interest in nutrition therapies that deliver a generous amount of protein, but not a toxic amount of energy, to protein-catabolic critically ill patients. Parenteral amino acids can achieve this goal. This article summarizes the biochemical and nutritional principles that guide parenteral amino acid therapy, explains how parenteral amino acid solutions are formulated, and compares the advantages and disadvantages of different parenteral amino acid products with enterally-delivered whole protein products in the context of protein-catabolic critical illness.

  13. Plasma branched-chain amino acids and incident cardiovascular disease in the PREDIMED trial

    Science.gov (United States)

    Ruiz-Canela, Miguel; Toledo, Estefania; Clish, Clary B.; Hruby, Adela; Liang, Liming; Salas-Salvadó, Jordi; Razquin, Cristina; Corella, Dolores; Estruch, Ramón; Ros, Emilio; Fitó, Montserrat; Gómez-Gracia, Enrique; Arós, Fernando; Fiol, Miquel; Lapetra, José; Serra-Majem, Lluis; Martínez-González, Miguel A.; Hu, Frank B.

    2016-01-01

    Background The role of branched-chain amino acids (BCAAs) in cardiovascular disease (CVD) remains poorly understood. We hypothesized that baseline BCAA concentrations predict future risk of CVD and that a Mediterranean Diet (MedDiet) intervention may counteract this effect. Methods We developed a case-cohort study within the “PREvención con DIeta MEDiterránea” (PREDIMED), with 226 incident CVD cases and 781 non-cases. We used LC-MS/MS to measure plasma BCAAs (leucine, isoleucine and valine), both at baseline and after 1-year follow-up. The primary outcome was a composite of incident stroke, myocardial infarction, or cardiovascular death. Results After adjustment for potential confounders, baseline leucine and isoleucine concentrations were associated with higher CVD risk: the hazard ratios (HRs) for the highest vs. lowest quartile were 1.70 (95% confidence interval, 1.05–2.76) and 2.09 (1.27–3.44), respectively. Stronger associations were found for stroke. For both CVD and stroke, we found higher HRs across successive quartiles of BCAAs in the control group than in the MedDiet groups. Using stroke as the outcome, a significant interaction (P=0.009) between the baseline BCAA score and the intervention with MedDiet was observed. No significant effect of the intervention on 1-yr changes in BCAAs nor any association between 1-year changes in BCAAs and CVD were observed. Conclusions Higher concentrations of baseline BCAAs were associated with increased risk of CVD, especially stroke, in a high cardiovascular risk population. A Mediterranean-style diet had a negligible effect on 1-year changes in BCAAs, but it may counteract the harmful effects of BCAAs on stroke. PMID:26888892

  14. Amino acids and immune function.

    Science.gov (United States)

    Li, Peng; Yin, Yu-Long; Li, Defa; Kim, Sung Woo; Wu, Guoyao

    2007-08-01

    A deficiency of dietary protein or amino acids has long been known to impair immune function and increase the susceptibility of animals and humans to infectious disease. However, only in the past 15 years have the underlying cellular and molecular mechanisms begun to unfold. Protein malnutrition reduces concentrations of most amino acids in plasma. Findings from recent studies indicate an important role for amino acids in immune responses by regulating: (1) the activation of T lymphocytes, B lymphocytes, natural killer cells and macrophages; (2) cellular redox state, gene expression and lymphocyte proliferation; and (3) the production of antibodies, cytokines and other cytotoxic substances. Increasing evidence shows that dietary supplementation of specific amino acids to animals and humans with malnutrition and infectious disease enhances the immune status, thereby reducing morbidity and mortality. Arginine, glutamine and cysteine precursors are the best prototypes. Because of a negative impact of imbalance and antagonism among amino acids on nutrient intake and utilisation, care should be exercised in developing effective strategies of enteral or parenteral provision for maximum health benefits. Such measures should be based on knowledge about the biochemistry and physiology of amino acids, their roles in immune responses, nutritional and pathological states of individuals and expected treatment outcomes. New knowledge about the metabolism of amino acids in leucocytes is critical for the development of effective means to prevent and treat immunodeficient diseases. These nutrients hold great promise in improving health and preventing infectious diseases in animals and humans.

  15. A role for plasma aromatic amino acids in injurious pecking behavior in laying hens.

    Science.gov (United States)

    Birkl, Patrick; Franke, Leonora; Bas Rodenburg, T; Ellen, Ester; Harlander-Matauschek, Alexandra

    2017-03-29

    Injurious pecking, including feather pecking (FP), is one of the most prevalent causes of mortality for commercial laying hens. The underlying biological mechanisms of FP are not yet fully understood, but they could be related to alterations in the serotonin (5-HT) and/or dopamine (DA) circuits within the brain. In the past, the central synthesis of 5-HT and DA was found to be influenced by the availability of their precursors, aromatic amino acids (AAA) such as tryptophan (TRP), phenylalanine (PHE), and tyrosine (TYR), in blood plasma, which are transported across the blood-brain-barrier into the brain. Because knowledge about plasma levels of AAA in laying hens is very limited, the present study compared the AAA profiles of a large sample of laying hens from two genetic lines: one selected for low mortality (LM) due to injurious pecking (n=129 birds) and one high production line (HP) selected for high egg-production only (n=132 birds). Head, comb, and feather covering were scored at the end of the experiment. Blood samples were collected at weeks 24 and 29 of age and were analysed for AAA using high performance liquid chromatography. Neither FP nor feather damage was observed in the present study, but aggressive pecking directed at the head/neck area occurred in several groups with an onset of this aberrant behavior between weeks 22 and 29. Eight HP pens and seven LM pens were affected by severe head/comb injuries inflicted via aggressive pecking. Therefore, our exploratory data analysis focused upon the possible interplay between the variability of our outcome measures (absolute levels of AAA in plasma as well as the ratios PHE/TYR and TRP/(PHE+TYR) and the aggressive head/comb pecking as an expression of social stress within the pens. We found significantly lower TRP availability relative to PHE and TYR (TRP/(PHE+TYR) ratio) and higher TYR concentrations at week 24 in pens with an early onset of injurious aggressive behavior at weeks 22-23. This was most

  16. Amino Acid Crossword Puzzle

    Science.gov (United States)

    Sims, Paul A.

    2011-01-01

    Learning the 20 standard amino acids is an essential component of an introductory course in biochemistry. Later in the course, the students study metabolism and learn about various catabolic and anabolic pathways involving amino acids. Learning new material or concepts often is easier if one can connect the new material to what one already knows;…

  17. Differential Effects of Military Training on Fat-Free Mass and Plasma Amino Acid Adaptations in Men and Women

    Directory of Open Access Journals (Sweden)

    James P. McClung

    2012-12-01

    Full Text Available Fat-free mass (FFM adaptations to physical training may differ between sexes based on disparities in fitness level, dietary intake, and levels of plasma amino acids (AA. This investigation aimed to determine FFM and plasma AA responses to military training, examine whether adaptations differ between male and female recruits, and explore potential associations between FFM and AA responses to training. Body composition and plasma AA levels were assessed in US Army recruits (n = 209, 118 males, 91 females before (baseline and every three weeks during basic combat training (BCT, a 10-week military training course. Body weight decreased in men but remained stable in women during BCT (sex-by-time interaction, P < 0.05. Fifty-eight percent of recruits gained FFM during BCT, with more (P < 0.05 females (88% gaining FFM than males (36%. Total plasma AA increased (P < 0.05 during BCT, with greater (P < 0.05 increases observed in females (17% then in males (4%. Essential amino acids (EAA and branched-chain amino acids (BCAA were increased (P < 0.05 in females but did not change in males (sex-by-time interaction, P < 0.05. Independent of sex, changes in EAA (r = 0.34 and BCAA (r = 0.27 from baseline were associated with changes in FFM (P < 0.05; greater (P < 0.05 increases in AA concentrations were observed for those who gained FFM. Increases in FFM and plasma AA suggest that BCT elicits a more pronounced anabolic response in women compared to men, which may reflect sex-specific differences in the relative intensity of the combined training and physiological stimulus associated with BCT.

  18. Essential polyunsaturated fatty acids in plasma and erythrocytes of children with inborn errors of amino acid metabolism.

    NARCIS (Netherlands)

    Vlaardingerbroek, H.; Hornstra, G.; Koning, T.J.; Smeitink, J.A.M.; Bakker, H.D.; Klerk, H. de; Rubio-Gozalbo, M.E.

    2006-01-01

    Essential fatty acids (EFAs), and their longer-chain more-unsaturated derivatives (LCPUFAs) in particular, are essential for normal growth and cognitive development during childhood. Children with inborn errors of amino acid metabolism represent a risk population for a reduced LCPUFA status because

  19. A Study of Bioactivity of Corn Peptides with Low Molecular Weight Ⅱ: Effect on Plasma Free Amino Acid Concentrations in Rats

    Institute of Scientific and Technical Information of China (English)

    XU Li; ZHANG Li-qiang; WU Xiao-xia; WANG Na; ZHANG Xue-zhong

    2003-01-01

    The effects of the ingestion of corn peptides with a low molecular weight(LMCP) prepared from zein on some plasma free amino acid concentrations in rats that had taken ethanol were investigated. LMCP(1.0 g/kg body weight) in 15% ethanol(10 mL/kg body weight) was given to Wister rats by intragastrical administration. The amino acid analysis showed that the concentrations of alanine, leucine, and proline in the plasma reached their maximum levels at 30 min for the LMCP-intake group. They are 582.39, 99.60 and 272.51 μg/L, respectively. But in the control group, the plasma free amino acid levels were not changed obviously. Therefore, LMCP could cause an increase in concentration of some free amino acids such as alanine, leucine and proline etc. in plasma of the rats that have taken ethanol.

  20. Dynamic monitoring of plasma amino acids and carnitine during chemotherapy of patients with alimentary canal malignancies and its clinical value

    Directory of Open Access Journals (Sweden)

    Wang XY

    2015-08-01

    Full Text Available Xiaoyu Wang,1 Jiaqi Wang,2 Zhenghua Wang,1 Qingjun Wang,1 Hua Li1 1Second Ward of Oncology Department, 2Traditional Chinese Medicine Department, The First Affiliated Hospital of Liaoning Medical University, Jinzhou, People’s Republic of ChinaObjective: The aim of this study was to observe the plasma amino acid and carnitine characteristics in patients with metastatic gastrointestinal malignancies during chemotherapy and to identify markers for the early diagnosis and evaluation of adverse reactions and prognosis of the digestive tract malignant tumor patients.Methods: Blood samples of 30 patients with metastatic gastrointestinal malignancies were collected at four time points: before chemotherapy, the first day after chemotherapy (+1 day, bone marrow depression period (+14 days, and hematopoietic recovery period (+21 days. The plasma amino acids and carnitine from those 30 patients were determined by high-performance liquid chromatography–tandem mass spectrometry method. Simultaneously, the levels of 21 amino acids were detected in 30 healthy individuals, who were considered as control. Biochemical indexes were also detected at four time points, adverse reactions were recorded during the chemotherapy process, and patients were followed up for 1 year to observe time to progression (TTP and progression-free survival (PFS.Results: Compared to healthy people in the control group, patients with malignancies showed significantly increased levels of plasma amino acids such as Arg, Asp, Cit, Gly, Orn, Tyr, Val, and carnitine (such as C2. The levels of compounds such as C3, Asn, Leu, Lys, Pip, Pro, C0, C5:1 decreased significantly before chemotherapy. The levels of Cit, Cys, Lys, Pro, Tyr, Val, C0, and C2 decreased significantly on the second day of chemotherapy (+1 day, whereas the level of C3 increased significantly. During myelosuppression (+14 days, the levels of Asp, Cit, Met, and Orn were observed to still decrease significantly, whereas the

  1. Plasma levels of nitric oxide related amino acids in demented subjects with Down syndrome are related to neopterin concentrations.

    Science.gov (United States)

    Coppus, A M W; Fekkes, D; Verhoeven, W M A; Tuinier, S; van Duijn, C M

    2010-03-01

    Subjects with Down syndrome (DS) have abnormalities in virtually all aspects of the immune system and almost all will be affected with Alzheimer's disease (AD). It is thought that nitric oxide (NO) is involved in the pathophysiology of AD. In the present study, including a total of 401 elderly DS subjects, the spectrum of plasma amino acids and neopterin was investigated and related to development of AD. Concentrations of nearly all amino acids in DS subjects differed significantly from those of healthy controls. Neopterin was increased in DS subjects, especially in dementia. The production of NO as reflected by an increased citrulline/arginine ratio (Cit/Arg ratio) was enhanced during development of clinical dementia. Neopterin concentrations correlated to the Cit/Arg ratio only in the group of prevalent demented subjects (rho = 0.48, P = 0.006). The results of this study are suggestive for an increase in oxidative processes in DS subjects with AD.

  2. Protein amino acid composition of plasma membranes affects membrane fluidity and thereby ethanol tolerance in a self-flocculating fusant of Schizosaccharomyces pombe and Saccharomyces cerevisiae.

    Science.gov (United States)

    Hu, Chun-Keng; Bai, Feng-Wu; An, Li-Jia

    2005-09-01

    A combination of three amino acids including 1.0 g/L isoleucine, 0.5 g/L methionine and 2.0 g/L phenylalanine was found to enhance ethanol tolerance of a self-flocculating fusant of Schizosaccharomyces pombe and Saccharomyces cerevisiae. When subjected to 20% (V/V) ethanol for 9 h at 30 degrees C, all cells died whereas 57% remained viable for the cells grown in the presence of the three amino acids. Based on the analysis of protein amino acid composition of plasma membranes and the determination of plasma membrane fluidity by measuring fluorescence anisotropy using diphenylhexatriene as a probe, it was found that the significantly increased ethanol tolerance of cells grown with the three amino acids was due to the incorporation of the supplementary amino acids into the plasma membranes, thus resulting in enhanced ability of the plasma membranes to efficiently counteract the fluidizing effect of ethanol when subjected to ethanol stress. This is the first time to report that plasma membrane fluidity can be influenced by protein amino acid composition of plasma membranes.

  3. Synthesis of variants of Marfey's reagent having d-amino acids as chiral auxiliaries and liquid-chromatographic enantioseparation of (RS)-Mexiletine in spiked plasma: assessment and comparison with L-amino acid analogs.

    Science.gov (United States)

    Bhushan, Ravi; Vashistha, Vinod Kumar

    2015-01-30

    Five d-amino acids have been used for the first time to synthesize chiral derivatizing reagents (as variants of Marfey's reagent) by nucleophilic displacement of one of the fluorine atoms in 1,5-difluoro-2,4-dinitrobenzene as against the literature reports on application of only l-amino acids or their amides as chiral auxiliaries in dinitrobenzene (DNB) moiety. Five other DNB based reagents were also prepared by nucleophilic substitution of fluorine atom with the set of the same amino acids in l-configuration, as chiral auxiliaries. These reagents were characterized and used for synthesis of diastereomers of (RS)-Mexiletine spiked in human plasma. Diastereomers were synthesized employing microwave irradiation and were separated on reversed-phase C18 column. Performance of the two types of chiral derivatizing reagents was compared. The reagents containing d-amino acids provided enhanced separation of diastereomers than those containing l-amino acids. The best resolution was obtained using mobile phase consisting of acetonitrile and 0.1% trifluoroacetic acid in gradient mode. The detection was carried out at 340nm. The method so developed was validated for linearity, accuracy and precision. The limit of quantitation was found to be approximately 25.2ngmL(-1) in human plasma.

  4. Amino acid racemisation dating

    Energy Technology Data Exchange (ETDEWEB)

    Murray-Wallace, C.V. [University of Wollongong, Wollongong, NSW (Australia). School of Geosciences

    1999-11-01

    The potential of the time-dependent amino acid racemisation reaction as a method of age assessment was first reported by Hare and Abelson (1968). They noted that in specimens of the bivalve mollusc Mercenaria sp., greater concentrations of amino acids in the D-configuration with increasing fossil age. Hare and Abelson (1968) also reported negligible racemisation in a modern specimen of Mecanaria sp. On this basis they suggested that the extent of amino acid racemisation (epimerisation in the case of isoleucine) may be used to assess the age of materials within and beyond the range of radiocarbon dating. For the past thirty years amino acid racemisation has been extensively applied in Quaternary research as a method of relative and numeric dating, and a particularly large literature has emerged on the subject 12 refs.

  5. Amino Acids and Chirality

    Science.gov (United States)

    Cook, Jamie E.

    2012-01-01

    Amino acids are among the most heavily studied organic compound class in carbonaceous chondrites. The abundance, distributions, enantiomeric compositions, and stable isotopic ratios of amino acids have been determined in carbonaceous chondrites fi'om a range of classes and petrographic types, with interesting correlations observed between these properties and the class and typc of the chondritcs. In particular, isomeric distributions appear to correlate with parent bodies (chondrite class). In addition, certain chiral amino acids are found in enantiomeric excess in some chondrites. The delivery of these enantiomeric excesses to the early Earth may have contributed to the origin of the homochirality that is central to life on Earth today. This talk will explore the amino acids in carbonaceous chondritcs and their relevance to the origin of life.

  6. Relation of soya bean meal level to the concentration of plasma free amino acids and body growth in white rats.

    Science.gov (United States)

    Mandal, Tapas K; Parvin, Nargish; Mondal, Santanu; Saxena, Vijaylaxmi; Saxena, Ashok K; Sarkar, Sabyasachi; Saha, Mitali

    2012-04-01

    Amino acid (AA) levels in plasma and body growth were determined in rats (n20) fed diets with different soya bean meal levels. Free AA in plasma was determined by reversed-phase high-pressure liquid chromatography. We have used four levels of protein diets like 8%, 15%, 23% and 35% in this trial. Rats which were fed the low-protein (8%) diet with low percentage of soya bean meal were found to be growth-retarded. The body weight gain of high protein group (35%) was lower than that of the 23% groups. In the rats fed with the low-soya bean meal diet, some nonessential AA (NEAA) in plasma like asparagine, aspartic acid, cysteine, glutamic acid and serine increased, whereas the essential AA (EAA), with the exception of arginine, methionine and valine decreased. Here, plasma EAA-to-NEAA ratios were not correlated to growth and experimental diet. We hypothesize that AA metabolism is associated to changes in growth in rats on different protein intake. This study has showed the sensitivity of body mass gain, feed intake, feed conversion rate of rats to four levels of protein in the diet under controlled experimental conditions. © 2011 Blackwell Verlag GmbH.

  7. Effects of Dietary Garlic Extracts on Whole Body Amino Acid and Fatty Acid Composition, Muscle Free Amino Acid Profiles and Blood Plasma Changes in Juvenile Sterlet Sturgeon, Acipenser ruthenus.

    Science.gov (United States)

    Lee, Dong-Hoon; Lim, Seong-Ryul; Ra, Chang-Six; Kim, Jeong-Dae

    2012-10-01

    A series of studies were carried out to investigate the supplemental effects of dietary garlic extracts (GE) on whole body amino acids, whole body and muscle free amino acids, fatty acid composition and blood plasma changes in 6 month old juvenile sterlet sturgeon (Acipenser ruthenus). In the first experiment, fish with an average body weight of 59.6 g were randomly allotted to each of 10 tanks (two groups of five replicates, 20 fish/tank) and fed diets with (0.5%) or without (control) GE respectively, at the level of 2% of fish body weight per day for 5 wks. Whole body amino acid composition between the GE and control groups were not different (p>0.05). Among free amino acids in muscle, L-glutamic acid, L-alanine, L-valine, L-leucine and L-phenylalanine were significantly (pexperiment, the effects of dietary garlic extracts on blood plasma changes were investigated using 6 month old juvenile sterlet sturgeon averaging 56.5 g. Fish were randomly allotted to each of 2 tanks (300 fish/tank) and fed diets with (0.5%) or without (control) GE respectively, at the rate of 2% of body weight per day for 23 d. At the end of the feeding trial, blood was taken from the tail vein (n = 5, per group) at 1, 12, and 24 h after feeding, respectively. Blood plasma glucose, insulin and the other serological characteristics were also measured to assess postprandial status of the fish. Plasma glucose concentrations (mg/dl) between two groups (GE vs control) were significantly (p0.05) were noticed at 12 h (74.6 vs 73.0). Plasma insulin concentrations (μIU/ml) between the two groups were significantly (p<0.05) different at 1 (10.56 vs 5.06) and 24 h (32.56 vs 2.96) after feeding. The present results suggested that dietary garlic extracts could increase dietary glucose utilization through the insulin secretion, which result in improved fish body quality and feed utilization by juvenile sterlet sturgeon.

  8. Effects of dietary lysine levels on plasma free amino acid profile in late-stage finishing pigs.

    Science.gov (United States)

    Regmi, Naresh; Wang, Taiji; Crenshaw, Mark A; Rude, Brian J; Wu, Guoyao; Liao, Shengfa F

    2016-01-01

    Muscle growth requires a constant supply of amino acids (AAs) from the blood. Therefore, plasma AA profile is a critical factor for maximizing the growth performance of animals, including pigs. This research was conducted to study how dietary lysine intake affects plasma AA profile in pigs at the late production stage. Eighteen crossbred (Large White × Landrace) finishing pigs (nine barrows and nine gilts; initial BW 92.3 ± 6.9 kg) were individually penned in an environment controlled barn. Pigs were assigned randomly to one of the three dietary treatments according to a randomized complete block design with sex as block and pig as experiment unit (6 pigs/treatment). Three corn- and soybean meal-based diets contained 0.43 % (lysine-deficient, Diet I), 0.71 % (lysine-adequate, Diet II), and 0.98 % (lysine-excess, Diet III) l-lysine, respectively. After a 4-week period of feeding, jugular vein blood samples were collected from the pigs and plasma was obtained for AA analysis using established HPLC methods. The change of plasma lysine concentration followed the same pattern as that of dietary lysine supply. The plasma concentrations of threonine, histidine, phenylalanine, isoleucine, valine, arginine, and citrulline of pigs fed Diet II or III were lower (P pigs fed Diet I. The plasma concentrations of alanine, glutamate, and glycine of pigs fed Diet II or III were higher (P pigs fed Diet I. The change of plasma leucine and asparagine concentrations followed the patterns similar to that of plasma lysine. Among those affected AAs, arginine was decreased (P pigs may be further increased with a lysine-excess diet if the plasma concentration of arginine can be increased through dietary supplementation or other practical nutritional management strategies.

  9. Body Position Modulates Gastric Emptying and Affects the Post-Prandial Rise in Plasma Amino Acid Concentrations Following Protein Ingestion in Humans

    Directory of Open Access Journals (Sweden)

    Andrew M. Holwerda

    2016-04-01

    Full Text Available Dietary protein digestion and amino acid absorption kinetics determine the post-prandial muscle protein synthetic response. Body position may affect gastrointestinal function and modulate the post-prandial rise in plasma amino acid availability. We aimed to assess the impact of body position on gastric emptying rate and the post-prandial rise in plasma amino acid concentrations following ingestion of a single, meal-like amount of protein. In a randomized, cross-over design, eight healthy males (25 ± 2 years, 23.9 ± 0.8 kg·m−2 ingested 22 g protein and 1.5 g paracetamol (acetaminophen in an upright seated position (control and in a −20° head-down tilted position (inversion. Blood samples were collected during a 240-min post-prandial period and analyzed for paracetamol and plasma amino acid concentrations to assess gastric emptying rate and post-prandial amino acid availability, respectively. Peak plasma leucine concentrations were lower in the inversion compared with the control treatment (177 ± 15 vs. 236 ± 15 mmol·L−1, p < 0.05, which was accompanied by a lower plasma essential amino acid (EAA response over 240 min (31,956 ± 6441 vs. 50,351 ± 4015 AU; p < 0.05. Peak plasma paracetamol concentrations were lower in the inversion vs. control treatment (5.8 ± 1.1 vs. 10.0 ± 0.6 mg·L−1, p < 0.05. Gastric emptying rate and post-prandial plasma amino acid availability are significantly decreased after protein ingestion in a head-down tilted position. Therefore, upright body positioning should be considered when aiming to augment post-prandial muscle protein accretion in both health and disease.

  10. Azetidinic amino acids

    DEFF Research Database (Denmark)

    Bräuner-Osborne, Hans; Bunch, Lennart; Chopin, Nathalie

    2005-01-01

    A set of ten azetidinic amino acids, that can be envisioned as C-4 alkyl substituted analogues of trans-2-carboxyazetidine-3-acetic acid (t-CAA) and/or conformationally constrained analogues of (R)- or (S)-glutamic acid (Glu) have been synthesized in a diastereo- and enantiomerically pure form from...... of two diastereoisomers that were easily separated and converted in two steps into azetidinic amino acids. Azetidines 35-44 were characterized in binding studies on native ionotropic Glu receptors and in functional assays at cloned metabotropic receptors mGluR1, 2 and 4, representing group I, II and III...... beta-amino alcohols through a straightforward five step sequence. The key step of this synthesis is an original anionic 4-exo-tet ring closure that forms the azetidine ring upon an intramolecular Michael addition. This reaction was proven to be reversible and to lead to a thermodynamic distribution...

  11. Simultaneous determination of 18 D-amino acids in rat plasma by an ultrahigh-performance liquid chromatography-tandem mass spectrometry method: application to explore the potential relationship between Alzheimer's disease and D-amino acid level alterations.

    Science.gov (United States)

    Xing, Yuping; Li, Xiaoyan; Guo, Xingjie; Cui, Yan

    2016-01-01

    D-Amino acids are increasingly being recognized as important signaling molecules, and abnormal levels of D-amino acids have been implicated in the pathogenesis of Alzheimer's disease. To evaluate the potential relationship between Alzheimer's disease and D-amino acids, a simple, sensitive, and reliable UPLC-MS/MS method with pre-column derivatization was developed and validated for simultaneous determination of 18 D-amino acids in rat plasma. The analytes were extracted from plasma samples by a protein precipitation procedure, and then derivatized with (S)-N-(4-nitrophenoxycarbonyl) phenylalanine methoxyethyl ester [(S)-NIFE]. Chromatographic separation was achieved using an ACQUITY UPLC BEH C18 column (2.1 mm × 50 mm, 1.7 μm) with a mobile phase composed of acetonitrile containing 8 mM ammonium hydrogen carbonate at a flow rate of 0.6 mL min(-1). The analytes were detected by electrospray ionization in positive ion multiple reaction monitoring modes. Under the optimum experimental conditions, all the linear regressions were acquired with r > 0.9932. The limits of quantitation of all derivatized D-amino acids were within 0.05-40.0 ng mL(-1) in rat plasma. The intra- and inter-day precisions, expressed as percentage relative standard deviations (%RSD), were within the range of 12.3 and 10.1%, respectively. The recoveries for all the analytes were observed over the range of 82.8-100.5% with RSD values less than 12.5%. Finally, the proposed method was successfully applied to simultaneous determination of the 18 D-amino acids in plasma from Alzheimer's disease rats and age-matched normal controls. Results showed that the concentrations of D-serine, D-aspartate, D-alanine, D-leucine, and D-proline in Alzheimer's disease rat plasma were significantly decreased compared with those in normal controls, while D-phenylalanine levels increased. It was revealed that some of these D-amino acids would be potential diagnostic biomarkers for Alzheimer's disease.

  12. Acute heat stress up-regulates neuropeptide Y precursor mRNA expression and alters brain and plasma concentrations of free amino acids in chicks.

    Science.gov (United States)

    Ito, Kentaro; Bahry, Mohammad A; Hui, Yang; Furuse, Mitsuhiro; Chowdhury, Vishwajit S

    2015-09-01

    Heat stress causes an increase in body temperature and reduced food intake in chickens. Several neuropeptides and amino acids play a vital role in the regulation of food intake. However, the responses of neuropeptides and amino acids to heat-stress-induced food-intake regulation are poorly understood. In the current study, the hypothalamic mRNA expression of some neuropeptides related to food intake and the content of free amino acids in the brain and plasma was examined in 14-day-old chicks exposed to a high ambient temperature (HT; 40±1 °C for 2 or 5 h) or to a control thermoneutral temperature (CT; 30±1 °C). HT significantly increased rectal temperature and plasma corticosterone level and suppressed food intake. HT also increased the expression of neuropeptide Y (NPY) and agouti-signaling protein (ASIP) precursor mRNA, while no change was observed in pro-opiomelanocortin, cholecystokinin, ghrelin, or corticotropin-releasing hormone precursor mRNA. It was further found that the diencephalic content of free amino acids - namely, tryptophan, leucine, isoleucine, valine and serine - was significantly higher in HT chicks with some alterations in their plasma amino acids in comparison with CT chicks. The induction of NPY and ASIP expression and the alteration of some free amino acids during HT suggest that these changes can be the results or causes the suppression of food intake.

  13. The Effect of Post-Resistance Exercise Amino Acids on Plasma MCP-1 and CCR2 Expression

    Directory of Open Access Journals (Sweden)

    Adam J. Wells

    2016-07-01

    Full Text Available The recruitment and infiltration of classical monocytes into damaged muscle is critical for optimal tissue remodeling. This study examined the effects of an amino acid supplement on classical monocyte recruitment following an acute bout of lower body resistance exercise. Ten resistance-trained men (24.7 ± 3.4 years; 90.1 ± 11.3 kg; 176.0 ± 4.9 cm ingested supplement (SUPP or placebo (PL immediately post-exercise in a randomized, cross-over design. Blood samples were obtained at baseline (BL, immediately (IP, 30-min (30P, 1-h (1H, 2-h (2H, and 5-h (5H post-exercise to assess plasma concentrations of monocyte chemoattractant protein 1 (MCP-1, myoglobin, cortisol and insulin concentrations; and expressions of C-C chemokine receptor-2 (CCR2, and macrophage-1 antigen (CD11b on classical monocytes. Magnitude-based inferences were used to provide inferences on the true effects of SUPP compared to PL. Changes in myoglobin, cortisol, and insulin concentrations were similar between treatments. Compared to PL, plasma MCP-1 was “very likely greater” (98.1% likelihood effect in SUPP at 2H. CCR2 expression was “likely greater” at IP (84.9% likelihood effect, “likely greater” at 1H (87.7% likelihood effect, “very likely greater” at 2H (97.0% likelihood effect, and “likely greater” at 5H (90.1% likelihood effect in SUPP, compared to PL. Ingestion of SUPP did not influence CD11b expression. Ingestion of an amino acid supplement immediately post-exercise appears to help maintain plasma MCP-1 concentrations and augment CCR2 expression in resistance trained men.

  14. Administration of Exogenous Growth Hormone Is Associated with Changes in Plasma and Intracellular Mammary Amino Acid Profiles and Abundance of the Mammary Gland Amino Acid Transporter SLC3A2 in Mid-Lactation Dairy Cows

    OpenAIRE

    Quentin L Sciascia; David Pacheco; McCoard, Susan A.

    2015-01-01

    The objectives of this study were to (1) identify changes in plasma and mammary intracellular amino acid (AA) profiles in dairy cows treated with growth hormone (GH), and (2) evaluate the expression of mammary gland genes involved in the transport of AA identified in (1). Eight non-pregnant (n = 4 per group) lactating dairy cows were treated with a single subcutaneous injection of either a slow-release formulation of commercially available GH (Lactotropin 500 mg) or physiological saline solut...

  15. Trend analysis of the correlation of amino acid plasma profile with glycemic status in Saudi diabetic patients

    Directory of Open Access Journals (Sweden)

    Fahad A. Al-Abbasi

    2012-10-01

    Full Text Available The role of amino acids in diabetes mellitus and its metabolic traits have been suggested previously; however, studied to a very limited scale in the Saudi patient population. Patients diagnosed with diabetes mellitus were included in the current clinical study. Sample was representative and in accordance with the national population distribution. Blood samples were drawn and assayed for glucose, total cholesterol, triglyceride, high density lipoprotein and low density lipoprotein. General biochemical markers, such as alkaline phosphatase (ALP, creatinine kinase (CK, aspartate transaminase (AST, alanine transaminase (ALT and blood urea nitrogen (BUN were assessed. Serum amino acids of different categories (essential, semi-essential and metabolic indicator amino acids were assessed. Correlation co-efficient between each amino acid and serum glucose level was calculated. The current study showed positive correlation between amino acid level and glucose serum concentration in male while it showed negative correlation in female Saudi diabetic patients. Male patients had significantly higher methionine concentration parallel to their glycemic status. Metabolic indicator amino acids significantly changed in concordance with the glycemic status of female patients more than in male patients. In conclusion, serum amino acid is positively correlated with glycemic status in Saudi male diabetic patients while negatively correlated in female patients. Yet, further study would be recommended to utilize serum amino acid profile as surrogate parameter for the metabolic complications of diabetes mellitus.

  16. Novel, objective, multivariate biomarkers composed of plasma amino acid profiles for the diagnosis and assessment of inflammatory bowel disease.

    Directory of Open Access Journals (Sweden)

    Tadakazu Hisamatsu

    Full Text Available BACKGROUND: Inflammatory bowel disease (IBD is a chronic intestinal disorder that is associated with a limited number of clinical biomarkers. In order to facilitate the diagnosis of IBD and assess its disease activity, we investigated the potential of novel multivariate indexes using statistical modeling of plasma amino acid concentrations (aminogram. METHODOLOGY AND PRINCIPAL FINDINGS: We measured fasting plasma aminograms in 387 IBD patients (Crohn's disease (CD, n = 165; ulcerative colitis (UC, n = 222 and 210 healthy controls. Based on Fisher linear classifiers, multivariate indexes were developed from the aminogram in discovery samples (CD, n = 102; UC, n = 102; age and sex-matched healthy controls, n = 102 and internally validated. The indexes were used to discriminate between CD or UC patients and healthy controls, as well as between patients with active disease and those in remission. We assessed index performances using the area under the curve of the receiver operating characteristic (ROC AUC. We observed significant alterations to the plasma aminogram, including histidine and tryptophan. The multivariate indexes established from plasma aminograms were able to distinguish CD or UC patients from healthy controls with ROC AUCs of 0.940 (95% confidence interval (CI: 0.898-0.983 and 0.894 (95%CI: 0.853-0.935, respectively in validation samples (CD, n = 63; UC, n = 120; healthy controls, n = 108. In addition, other indexes appeared to be a measure of disease activity. These indexes distinguished active CD or UC patients from each remission patients with ROC AUCs of 0.894 (95%CI: 0.853-0.935 and 0.849 (95%CI: 0.770-0.928, and correlated with clinical disease activity indexes for CD (r(s = 0.592, 95%CI: 0.385-0.742, p<0.001 or UC (r(s = 0.598, 95%CI: 0.452-0.713, p<0.001, respectively. CONCLUSIONS AND SIGNIFICANCE: In this study, we demonstrated that established multivariate indexes composed of plasma

  17. Measuring distances between TRPV1 and the plasma membrane using a noncanonical amino acid and transition metal ion FRET.

    Science.gov (United States)

    Zagotta, William N; Gordon, Moshe T; Senning, Eric N; Munari, Mika A; Gordon, Sharona E

    2016-02-01

    Despite recent advances, the structure and dynamics of membrane proteins in cell membranes remain elusive. We implemented transition metal ion fluorescence resonance energy transfer (tmFRET) to measure distances between sites on the N-terminal ankyrin repeat domains (ARDs) of the pain-transducing ion channel TRPV1 and the intracellular surface of the plasma membrane. To preserve the native context, we used unroofed cells, and to specifically label sites in TRPV1, we incorporated a fluorescent, noncanonical amino acid, L-ANAP. A metal chelating lipid was used to decorate the plasma membrane with high-density/high-affinity metal-binding sites. The fluorescence resonance energy transfer (FRET) efficiencies between L-ANAP in TRPV1 and Co(2+) bound to the plasma membrane were consistent with the arrangement of the ARDs in recent cryoelectron microscopy structures of TRPV1. No change in tmFRET was observed with the TRPV1 agonist capsaicin. These results demonstrate the power of tmFRET for measuring structure and rearrangements of membrane proteins relative to the cell membrane.

  18. D-Amino-Acid Oxidase Inhibition Increases D-Serine Plasma Levels in Mouse But not in Monkey or Dog.

    Science.gov (United States)

    Rojas, Camilo; Alt, Jesse; Ator, Nancy A; Thomas, Ajit G; Wu, Ying; Hin, Niyada; Wozniak, Krystyna; Ferraris, Dana; Rais, Rana; Tsukamoto, Takashi; Slusher, Barbara S

    2016-05-01

    D-serine has been shown to improve positive, negative, and cognitive symptoms when used as add-on therapy for the treatment of schizophrenia. However, D-serine has to be administered at high doses to observe clinical effects. This is thought to be due to D-serine undergoing oxidation by D-amino-acid oxidase (DAAO) before it reaches the brain. Consequently, co-administration of D-serine with a DAAO inhibitor could be a way to lower the D-serine dose required to treat schizophrenia. Early studies in rodents to evaluate this hypothesis showed that concomitant administration of structurally distinct DAAO inhibitors with D-serine enhanced plasma and brain D-serine levels in rodents compared with administration of D-serine alone. In the present work we used three potent DAAO inhibitors and confirmed previous results in mice. In a follow-up effort, we evaluated plasma D-serine levels in monkeys after oral administration of D-serine in the presence or absence of these DAAO inhibitors. Even though the compounds reached steady state plasma concentrations exceeding their Ki values by >60-fold, plasma D-serine levels remained the same as those in the absence of DAAO inhibitors. Similar results were obtained with dogs. In summary, in contrast to rodents, DAAO inhibition in monkeys and dogs did not influence the exposure to exogenously administered D-serine. Results could be due to differences in D-serine metabolism and/or clearance mechanisms and suggest that the role of DAAO in the metabolism of D-serine is different across species. These data provide caution regarding the utility of DAAO inhibition for patients with schizophrenia.

  19. Plasma amino acid levels are elevated in young, healthy low birth weight men exposed to short-term high-fat overfeeding

    DEFF Research Database (Denmark)

    Ribel-Madsen, Amalie; Hellgren, Lars; Brøns, Charlotte;

    2016-01-01

    and after a 5‐day high‐fat, high‐calorie diet. We demonstrated that LBW and NBW men increased plasma alanine levels and decreased valine and leucine/isoleucine levels in response to overfeeding. Also, LBW men had higher alanine, proline, methionine, citrulline, and total amino acid levels after overfeeding...

  20. Major liver resection results in a changed plasma amino acid pattern as reflected by a decreased Fischer ratio which improves by bactericidal/permeability increasing protein

    NARCIS (Netherlands)

    Nijveldt, RJ; Wiezer, MJ; Meijer, C; Prins, HA; Muller, MGS; Gouma, DJ; Teerlink, T; van Gulik, TM; Rinkes, IHMB; Tilanus, HW; van de Velde, CJH; Wiggers, T; Zoetmulder, FAN; Scotte, M; Cuesta, MA; Meijer, S; van Leeuwen, PAM

    2001-01-01

    Background/Aims: Major liver resection results in a high morbidity and mortality, and endotoxin plays a role in post-resection hepatic failure. Severe hepatic failure as seen in hepatitis and cirrhosis may be accompanied by hepatic encephalopathy and is characterized by a typical plasma amino acid p

  1. The glycemic, insulinemic and plasma amino acid responses to equi-carbohydrate milk meals, a pilot- study of bovine and human milk

    DEFF Research Database (Denmark)

    Gunnerud, Ulrika; Holst, Jens Juul; Östman, Elin

    2012-01-01

    Dairy proteins, in particular the whey fraction, exert insulinogenic properties and facilitate glycemic regulation through a mechanism involving elevation of certain plasma amino acids, and stimulation of incretins. Human milk is rich in whey protein and has not been investigated in this respect....

  2. Effects of one-seed juniper and polyethylene glycol on intake, rumen fermentation, and plasma amino acids in sheep and goats fed supplemental protein and tannins.

    Science.gov (United States)

    We tested the effect of polyethylene glycol (PEG) on juniper and total intake, rumen fermentation, and plasma amino acids (AA) of 12 does and 12 ewes fed sudangrass and basal diets containing 10% quebracho tannins with no protein supplement (Control; 5% CP) or high rumen degradable (RDP 15% CP) or u...

  3. Effects of acute exposure to increased plasma branched-chain amino acid concentrations on insulin-mediated plasma glucose turnover in healthy young subjects.

    Directory of Open Access Journals (Sweden)

    Sarah Everman

    Full Text Available Plasma branched-chain amino acids (BCAA are inversely related to insulin sensitivity of glucose metabolism in humans. However, currently, it is not known whether there is a cause-and-effect relationship between increased plasma BCAA concentrations and decreased insulin sensitivity.To determine the effects of acute exposure to increased plasma BCAA concentrations on insulin-mediated plasma glucose turnover in humans.Ten healthy subjects were randomly assigned to an experiment where insulin was infused at 40 mU/m2/min (40U during the second half of a 6-hour intravenous infusion of a BCAA mixture (i.e., BCAA; N = 5 to stimulate plasma glucose turnover or under the same conditions without BCAA infusion (Control; N = 5. In a separate experiment, seven healthy subjects were randomly assigned to receive insulin infusion at 80 mU/m2/min (80U in association with the above BCAA infusion (N = 4 or under the same conditions without BCAA infusion (N = 3. Plasma glucose turnover was measured prior to and during insulin infusion.Insulin infusion completely suppressed the endogenous glucose production (EGP across all groups. The percent suppression of EGP was not different between Control and BCAA in either the 40U or 80U experiments (P > 0.05. Insulin infusion stimulated whole-body glucose disposal rate (GDR across all groups. However, the increase (% in GDR was not different [median (1st quartile - 3rd quartile] between Control and BCAA in either the 40U ([199 (167-278 vs. 186 (94-308] or 80 U ([491 (414-548 vs. 478 (409-857] experiments (P > 0.05. Likewise, insulin stimulated the glucose metabolic clearance in all experiments (P 0.05.Short-term exposure of young healthy subjects to increased plasma BCAA concentrations does not alter the insulin sensitivity of glucose metabolism.

  4. Analysis of 26 amino acids in human plasma by HPLC using AQC as derivatizing agent and its application in metabolic laboratory.

    Science.gov (United States)

    Sharma, Gaurav; Attri, Savita Verma; Behra, Bijaylaxmi; Bhisikar, Swapnil; Kumar, Praveen; Tageja, Minni; Sharda, Sheetal; Singhi, Pratibha; Singhi, Sunit

    2014-05-01

    The present study reports the simultaneous analysis of 26 physiological amino acids in plasma along with total cysteine and homocysteine by high-performance liquid chromatography (HPLC) employing 6-aminoquinolyl-N-hydroxysuccinimidyl carbamate (AQC) as precolumn derivatizing reagent. Separations were carried out using Lichrospher 100 RP-18e (5 μm) 250 × 4.0 mm column connected to 100 CN 4.0 × 4.0 mm guard column on a quaternary HPLC system and run time was 53 min. Linearity of the peak areas for different concentrations ranging from 2.5 to 100 pmol/μL of individual amino acids was determined. A good linearity (R (2) > 0.998) was achieved in the standard mixture for each amino acid. Recovery of amino acids incorporated at the time of derivatization ranged from 95 to 106 %. Using this method we have established the normative data of amino acids in plasma, the profile being comparable to the range reported in literature and identified cases of classical homocystinuria, cobalamin defect/deficiency, non-ketotic hyperglycinemia, hyperprolinemia, ketotic hyperglycinemia, urea cycle defect and maple syrup urine disease.

  5. Plasma free amino acid profiling of five types of cancer patients and its application for early detection.

    Directory of Open Access Journals (Sweden)

    Yohei Miyagi

    Full Text Available BACKGROUND: Recently, rapid advances have been made in metabolomics-based, easy-to-use early cancer detection methods using blood samples. Among metabolites, profiling of plasma free amino acids (PFAAs is a promising approach because PFAAs link all organ systems and have important roles in metabolism. Furthermore, PFAA profiles are known to be influenced by specific diseases, including cancers. Therefore, the purpose of the present study was to determine the characteristics of the PFAA profiles in cancer patients and the possibility of using this information for early detection. METHODS AND FINDINGS: Plasma samples were collected from approximately 200 patients from multiple institutes, each diagnosed with one of the following five types of cancer: lung, gastric, colorectal, breast, or prostate cancer. Patients were compared to gender- and age- matched controls also used in this study. The PFAA levels were measured using high-performance liquid chromatography (HPLC-electrospray ionization (ESI-mass spectrometry (MS. Univariate analysis revealed significant differences in the PFAA profiles between the controls and the patients with any of the five types of cancer listed above, even those with asymptomatic early-stage disease. Furthermore, multivariate analysis clearly discriminated the cancer patients from the controls in terms of the area under the receiver-operator characteristics curve (AUC of ROC >0.75 for each cancer, regardless of cancer stage. Because this study was designed as case-control study, further investigations, including model construction and validation using cohorts with larger sample sizes, are necessary to determine the usefulness of PFAA profiling. CONCLUSIONS: These findings suggest that PFAA profiling has great potential for improving cancer screening and diagnosis and understanding disease pathogenesis. PFAA profiles can also be used to determine various disease diagnoses from a single blood sample, which involves a

  6. Amino Acid Catabolism in Plants.

    Science.gov (United States)

    Hildebrandt, Tatjana M; Nunes Nesi, Adriano; Araújo, Wagner L; Braun, Hans-Peter

    2015-11-02

    Amino acids have various prominent functions in plants. Besides their usage during protein biosynthesis, they also represent building blocks for several other biosynthesis pathways and play pivotal roles during signaling processes as well as in plant stress response. In general, pool sizes of the 20 amino acids differ strongly and change dynamically depending on the developmental and physiological state of the plant cell. Besides amino acid biosynthesis, which has already been investigated in great detail, the catabolism of amino acids is of central importance for adjusting their pool sizes but so far has drawn much less attention. The degradation of amino acids can also contribute substantially to the energy state of plant cells under certain physiological conditions, e.g. carbon starvation. In this review, we discuss the biological role of amino acid catabolism and summarize current knowledge on amino acid degradation pathways and their regulation in the context of plant cell physiology.

  7. Amino acid homeostasis and signalling in mammalian cells and organisms

    Science.gov (United States)

    Bröer, Angelika

    2017-01-01

    Cells have a constant turnover of proteins that recycle most amino acids over time. Net loss is mainly due to amino acid oxidation. Homeostasis is achieved through exchange of essential amino acids with non-essential amino acids and the transfer of amino groups from oxidised amino acids to amino acid biosynthesis. This homeostatic condition is maintained through an active mTORC1 complex. Under amino acid depletion, mTORC1 is inactivated. This increases the breakdown of cellular proteins through autophagy and reduces protein biosynthesis. The general control non-derepressable 2/ATF4 pathway may be activated in addition, resulting in transcription of genes involved in amino acid transport and biosynthesis of non-essential amino acids. Metabolism is autoregulated to minimise oxidation of amino acids. Systemic amino acid levels are also tightly regulated. Food intake briefly increases plasma amino acid levels, which stimulates insulin release and mTOR-dependent protein synthesis in muscle. Excess amino acids are oxidised, resulting in increased urea production. Short-term fasting does not result in depletion of plasma amino acids due to reduced protein synthesis and the onset of autophagy. Owing to the fact that half of all amino acids are essential, reduction in protein synthesis and amino acid oxidation are the only two measures to reduce amino acid demand. Long-term malnutrition causes depletion of plasma amino acids. The CNS appears to generate a protein-specific response upon amino acid depletion, resulting in avoidance of an inadequate diet. High protein levels, in contrast, contribute together with other nutrients to a reduction in food intake. PMID:28546457

  8. Nontargeted LC–MS Metabolomics Approach for Metabolic Profiling of Plasma and Urine from Pigs Fed Branched Chain Amino Acids for Maximum Growth Performance

    DEFF Research Database (Denmark)

    Assadi Soumeh, Elham; Hedemann, Mette Skou; Poulsen, Hanne Damgaard

    2016-01-01

    The metabolic response in plasma and urine of pigs when feeding an optimum level of branched chain amino acids (BCAAs) for best growth performance is unknown. The objective of the current study was to identify the metabolic phenotype associated with the BCAAs intake level that could be linked...... to the animal growth performance. Three dose–response studies were carried out to collect blood and urine samples from pigs fed increasing levels of Ile, Val, or Leu followed by a nontargeted LC–MS approach to characterize the metabolic profile of biofluids when dietary BCAAs are optimum for animal growth....... Results showed that concentrations of plasma hypoxanthine and tyrosine (Tyr) were higher while concentrations of glycocholic acid, tauroursodeoxycholic acid, and taurocholic acid were lower when the dietary Ile was optimum. Plasma 3-methyl-2-oxovaleric acid and creatine were lower when dietary Leu...

  9. Insulin does not stimulate muscle protein synthesis during increased plasma branched-chain amino acids alone but still decreases whole body proteolysis in humans.

    Science.gov (United States)

    Everman, Sarah; Meyer, Christian; Tran, Lee; Hoffman, Nyssa; Carroll, Chad C; Dedmon, William L; Katsanos, Christos S

    2016-10-01

    Insulin stimulates muscle protein synthesis when the levels of total amino acids, or at least the essential amino acids, are at or above their postabsorptive concentrations. Among the essential amino acids, branched-chain amino acids (BCAA) have the primary role in stimulating muscle protein synthesis and are commonly sought alone to stimulate muscle protein synthesis in humans. Fourteen healthy young subjects were studied before and after insulin infusion to examine whether insulin stimulates muscle protein synthesis in relation to the availability of BCAA alone. One half of the subjects were studied in the presence of postabsorptive BCAA concentrations (control) and the other half in the presence of increased plasma BCAA (BCAA). Compared with that prior to the initiation of the insulin infusion, fractional synthesis rate of muscle protein (%/h) did not change (P > 0.05) during insulin in either the control (0.04 ± 0.01 vs 0.05 ± 0.01) or the BCAA (0.05 ± 0.02 vs. 0.05 ± 0.01) experiments. Insulin decreased (P BCAA (0.89 ± 0.07 vs 0.61 ± 0.03) experiments, but the change was not different between the two experiments (P > 0.05). In conclusion, insulin does not stimulate muscle protein synthesis in the presence of increased circulating levels of plasma BCAA alone. Insulin's suppressive effect on proteolysis is observed independently of the levels of circulating plasma BCAA.

  10. Excess of L-alanine in amino acids synthesized in a plasma torch generated by a hypervelocity meteorite impact reproduced in the laboratory

    Science.gov (United States)

    Managadze, George G.; Engel, Michael H.; Getty, Stephanie; Wurz, Peter; Brinckerhoff, William B.; Shokolov, Anatoly G.; Sholin, Gennady V.; Terent'ev, Sergey A.; Chumikov, Alexander E.; Skalkin, Alexander S.; Blank, Vladimir D.; Prokhorov, Vyacheslav M.; Managadze, Nina G.; Luchnikov, Konstantin A.

    2016-10-01

    We present a laboratory reproduction of hypervelocity impacts of a carbon containing meteorite on a mineral substance representative of planetary surfaces. The physical conditions of the resulting impact plasma torch provide favorable conditions for abiogenic synthesis of protein amino acids: We identified glycine and alanine, and in smaller quantities serine, in the produced material. Moreover, we observe breaking of alanine mirror symmetry with L excess, which coincides with the bioorganic world. Therefore the selection of L-amino acids for the formation of proteins for living matter could have been the result from plasma processes occurring during the impact meteorites on the surface. This indicates that the plasma torch from meteorite impacts could play an important role in the formation of biomolecular homochirality. Thus, meteorite impacts possibly were the initial stage of this process and promoted conditions for the emergence of a living matter.

  11. Repeated post-exercise administration with a mixture of leucine and glucose alters the plasma amino acid profile in Standardbred trotters

    Directory of Open Access Journals (Sweden)

    Nostell Katarina EA

    2012-02-01

    Full Text Available Abstract Background The branched chain amino acid leucine is a potent stimulator of insulin secretion. Used in combination with glucose it can increase the insulin response and the post exercise re-synthesis of glycogen in man. Decreased plasma amino acid concentrations have been reported after intravenous or per oral administration of leucine in man as well as after a single per oral dose in horses. In man, a negative correlation between the insulin response and the concentrations of isoleucine, valine and methionine have been shown but results from horses are lacking. This study aims to determine the effect of repeated per oral administration with a mixture of glucose and leucine on the free amino acid profile and the insulin response in horses after glycogen-depleting exercise. Methods In a crossover design, after a glycogen depleting exercise, twelve Standardbred trotters received either repeated oral boluses of glucose, 1 g/kg body weight (BW at 0, 2 and 4 h with addition of leucine 0.1 g/kg BW at 0 and 4 h (GLU+LEU, or repeated boluses of water at 0, 2 and 4 h (CON. Blood samples for analysis of glucose, insulin and amino acid concentrations were collected prior to exercise and over a 6 h post-exercise period. A mixed model approach was used for the statistical analyses. Results Plasma leucine, isoleucine, valine, tyrosine and phenylalanine concentrations increased after exercise. Post-exercise serum glucose and plasma insulin response were significantly higher in the GLU+LEU treatment compared to the CON treatment. Plasma leucine concentrations increased after supplementation. During the post-exercise period isoleucine, valine and methionine concentrations decreased in both treatments but were significantly lower in the GLU+LEU treatment. There was no correlation between the insulin response and the response in plasma leucine, isoleucine, valine and methionine. Conclusions Repeated post-exercise administration with a mixture of leucine

  12. Chronic imipramine treatment differentially alters the brain and plasma amino acid metabolism in Wistar and Wistar Kyoto rats.

    Science.gov (United States)

    Nagasawa, Mao; Otsuka, Tsuyoshi; Yasuo, Shinobu; Furuse, Mitsuhiro

    2015-09-05

    In the present study, the amino acids which have the possibility for the therapeutic efficacy of imipramine were explored and compared between Wistar Kyoto rats, an animal model of depression, and Wistar rats as a normal model. The antidepressant-like effect caused by chronic imipramine treatment was confirmed by decreased immobility in the forced swimming test. Chronic imipramine administration altered the amino acid dynamics in the brain. In the striatum, the concentrations of asparagine, glutamine and methionine were significantly increased by chronic imipramine administration. In the thalamus and hypothalamus, chronic imipramine administration significantly decreased the valine concentration. On the other hand, no amino acid was altered by chronic imipramine administration in the hippocampus, brain stem and cerebellum. In addition, lower concentration of asparagine in the prefrontal cortex of WKY rats was improved by chronic imipramine administration. This amelioration only in WKY rats may be a specific effect of chronic imipramine administration under the depressive state. In conclusion, chronic imipramine administration altered the several amino acid dynamics in the brain. Modification of the amino acid metabolism in the brain may provide a new strategy in the development of therapeutic treatment of major depression.

  13. Low Protein Formula: Consequences of Quantitative Effects of Pre-analytical Factors on Amino Acid Concentrations in Plasma of Healthy Infants.

    Science.gov (United States)

    Bachmann, Claude; Kainz, Alexander; Haschke-Becher, Elisabeth

    2017-01-01

    Quantifying pre-analytical effects of postprandial sampling delay and daily protein intake on plasma amino acid concentrations in healthy infants fed formula with low protein content (1.8-1.9 g/100 kcal). Intake of formula with higher protein content bears a risk for later obesity (Kirchberg, J Clin Endocrinol Metab 100(1):149-158, 2015). Formulas containing less than 1.8 g protein might be adequate but not safe (Fomon, J Pediatr Gastroenterol Nutr 28:495-501, 1999). With on-demand feeding reproducible controls of indispensible amino acid concentration cannot be made at trough level. Data of 102 healthy infants aged 1 month and 79 aged 4 months fed formula with low protein content were obtained from a previous study (Haschke-Becher, J Inherit Metab Dis 39(1):25-37, 2016). They were analysed by multiple regression. Independent variables were the postprandial sampling delay from 2.25 to 4.5 h and the daily protein intake. Dependant variables were the amino acid concentrations. The combined effect was calculated with the natural logarithm of the amino acid concentration. Most amino acids fitted a significant exponential decrease due to the sampling delay, except of aspartate, citrulline, glutamine, glutamate, histidine, tryptophan and tyrosine at 1 month; and at 4 months except of citrulline, glutamine, glutamate, glycine and ornithine. Significant effects of protein intake were found for lysine and serine at 1 month and for glutamate at 4 months of age. Lowest limits of significant amino acid concentrations were calculated by extrapolation of sampling delay to 5 h and using the 10th percentile after back-transformation to μmol/L. A procedure to avoid the pitfall of overestimating amino acid concentration is presented.

  14. The Analysis of 2-amino-2-thiazoline-4-carboxylic Acid in the Plasma of Smokers and Non-Smokers

    Science.gov (United States)

    2009-01-01

    formation of thiocyanate occurs when cyanide reacts with a sulfane sulfur donor (Isom and Baskin 1997), predominantly thiosulfate. This formation ...of cyanide exposure is to analyze biological matricies for 2-amino- thiazoline-4-carboxylic acid (ATCA). The formation of ATCA from cyanide, as...Borowitz et al. 2001). When cyanide reacts with cystine , ATCA or 2-iminothiazolidine-4-carboxylic acid (ITCA) is formed. These two tautomers, ATCA and

  15. Amino acids in Arctic aerosols

    Directory of Open Access Journals (Sweden)

    E. Scalabrin

    2012-11-01

    Full Text Available Amino acids are significant components of atmospheric aerosols, affecting organic nitrogen input to marine ecosystems, atmospheric radiation balance, and the global water cycle. The wide range of amino acid reactivities suggest that amino acids may serve as markers of atmospheric transport and deposition of particles. Despite this potential, few measurements have been conducted in remote areas to assess amino acid concentrations and potential sources. Polar regions offer a unique opportunity to investigate atmospheric processes and to conduct source apportionment studies of such compounds. In order to better understand the importance of amino acid compounds in the global atmosphere, we determined free amino acids (FAAs in seventeen size-segregated aerosol samples collected in a polar station in the Svalbard Islands from 19 April until 14 September 2010. We used an HPLC coupled with a tandem mass spectrometer (ESI-MS/MS to analyze 20 amino acids and quantify compounds at fmol m−3 levels. Mean total FAA concentration was 1070 fmol m−3 where serine and glycine were the most abundant compounds in almost all samples and accounted for 45–60% of the total amino acid relative abundance. The other eighteen compounds had average concentrations between 0.3 and 98 fmol m−3. The higher amino acid concentrations were present in the ultrafine aerosol fraction (< 0.49 μm and accounted for the majority of the total amino acid content. Local marine sources dominate the boreal summer amino acid concentrations, with the exception of the regional input from Icelandic volcanic emissions.

  16. Amino acids in Arctic aerosols

    Directory of Open Access Journals (Sweden)

    E. Scalabrin

    2012-07-01

    Full Text Available Amino acids are significant components of atmospheric aerosols, affecting organic nitrogen input to marine ecosystems, atmospheric radiation balance, and the global water cycle. The wide range of amino acid reactivities suggest that amino acids may serve as markers of atmospheric transport and deposition of particles. Despite this potential, few measurements have been conducted in remote areas to assess amino acid concentrations and potential sources. Polar regions offer a unique opportunity to investigate atmospheric processes and to conduct source apportionment studies of such compounds. In order to better understand the importance of amino acid compounds in the global atmosphere, we determined free amino acids (FAAs in seventeen size-segregated aerosol samples collected in a polar station in the Svalbard Islands from 19 April until 14 September 2010. We used an HPLC coupled with a tandem mass spectrometer (ESI-MS/MS to analyze 20 amino acids to quantify compounds at fmol m−3 levels. Mean total FAA concentration was 1070 fmol m−3 where serine and glycine were the most abundant compounds in almost all samples and accounted for 45–60% of the total amino acid relative abundance. The other eighteen compounds had average concentrations between 0.3 and 98 fmol m−3. The higher amino acid concentrations were present in the ultrafine aerosol fraction (<0.49 μm and accounted for the majority of the total amino acid content. Local marine sources dominate the boreal summer amino acid concentrations, with the exception of the regional input from Icelandic volcanics.

  17. The glycemic, insulinemic and plasma amino acid responses to equi-carbohydrate milk meals, a pilot- study of bovine and human milk

    Directory of Open Access Journals (Sweden)

    Gunnerud Ulrika

    2012-10-01

    Full Text Available Abstract Background Dairy proteins, in particular the whey fraction, exert insulinogenic properties and facilitate glycemic regulation through a mechanism involving elevation of certain plasma amino acids, and stimulation of incretins. Human milk is rich in whey protein and has not been investigated in this respect. Method Nine healthy volunteers were served test meals consisting of human milk, bovine milk, reconstituted bovine whey- or casein protein in random order. All test meals contributed with 25g intrinsic or added lactose, and a white wheat bread (WWB meal was used as reference, providing 25g starch. Post-prandial levels in plasma of glucose, insulin, incretins and amino acids were investigated at time intervals for up to 2 h. Results All test meals elicited lower postprandial blood glucose responses, expressed as iAUC 0–120 min compared with the WWB (P  Conclusion This study shows that the glycemic response was significantly lower following all milk/milk protein based test meals, in comparison with WWB. The effect appears to originate from the protein fraction and early phase plasma amino acids and incretins were involved in the insulin secretion. Despite its lower protein content, the human milk was a potent GLP-1 secretagogue and showed insulinogenic properties similar to that seen with reconstituted bovine whey-protein, possibly due to the comparatively high proportion of whey in human milk.

  18. Protein and amino acid nutrition

    Science.gov (United States)

    Dairy cow protein and amino acid nutrition have a significant role in sustainable dairying. Protein, amino acids, and nitrogen are inextricably linked through effects in the rumen, metabolism of the cow, and environmental nutrient management. Feeding systems have been making progress toward emphasiz...

  19. utilisation of synthetic amino acids

    African Journals Online (AJOL)

    student

    intake, bodyweight gain, egg weight or efficiency of lysine utilisation, but ... When modelling the amino acid requirements of broiler breeder ... Two hundred and forty Cobb broiler breeder hens aged 27 weeks were housed in individual cages. ..... feeds with synthetic amino acids is of importance not only on nutritional and.

  20. Racemization of Meteoritic Amino Acids

    Science.gov (United States)

    Cohen, Barbara A.; Chyba, Christopher F.

    2000-05-01

    Meteorites may have contributed amino acids to the prebiotic Earth, affecting the global ratio of right-handed to left-handed (D/L) molecules. We calculate D/L ratios for seven biological, α-hydrogen, protein amino acids over a variety of plausible parent body thermal histories, based on meteorite evidence and asteroid modeling. We show that amino acids in meteorites do not necessarily undergo complete racemization by the time they are recovered on Earth. If the mechanism of amino acid formation imposes some enantiomeric preference on the amino acids, a chiral signature can be retained through the entire history of the meteorite. Original enantiomeric excesses in meteorites such as Murchison, which have undergone apparently short and cool alteration scenarios, should have persisted to the present time. Of the seven amino acids for which relevant data are available, we expect glutamic acid, isoleucine, and valine, respectively, to be the most likely to retain an initial enantiomeric excess, and phenylalanine, aspartic acid, and alanine the least. Were the D/L ratio initially identical in each amino acid, final D/L ratios could be used to constrain the initial ratio and the thermal history experienced by the whole suite.

  1. Amino Acids from a Comet

    Science.gov (United States)

    Cook, Jamie Elisla

    2009-01-01

    NASA's Stardust spacecraft returned samples from comet 81P/Wild 2 to Earth in January 2006. Examinations of the organic compounds in cometary samples can reveal information about the prebiotic organic inventory present on the early Earth and within the early Solar System, which may have contributed to the origin of life. Preliminary studies of Stardust material revealed the presence of a suite of organic compounds including several amines and amino acids, but the origin of these compounds (cometary- vs. terrestrial contamination) could not be identified. We have recently measured the carbon isotopic ratios of these amino acids to determine their origin, leading to the first detection of a coetary amino acid.

  2. Effects of leucine or whey protein addition to an oral glucose solution on serum insulin, plasma glucose and plasma amino acid responses in horses at rest and following exercise.

    Science.gov (United States)

    Urschel, K L; Geor, R J; Waterfall, H L; Shoveller, A K; McCutcheon, L J

    2010-11-01

    Providing protein or amino acid mixtures in combination with glucose to post exercise in man has resulted in increases in the post feeding insulin response and in muscle glycogen and protein synthesis rates. However, whether protein and/or amino acids can modify the post exercise insulin responses in horses remains to be fully elucidated. To determine whether whey protein or leucine addition to a glucose solution affects the post gavage plasma insulin, glucose and amino acid responses in horses and whether these responses are different following a period of exercise vs. rest. Six mature, conditioned Thoroughbreds received a nasogastric gavage containing either 1 g/kg bwt glucose (G), G + 0.3 g/kg bwt whey protein (GW) or G + 0.3 g/kg bwt leucine (GL), following a period of either rest (R) or an exercise test on a high speed treadmill (EX). Each horse was studied under all 6 treatment conditions, separated by 10 day intervals. Blood samples were collected pre-exercise/rest, pregavage and at regular intervals up to 300 min post gavage. Plasma was analysed for glucose and amino acid concentrations and serum insulin concentrations were determined. There was a significantly (P glucose responses were lower in G and GW but unchanged following GL administration. Plasma alanine concentrations were elevated post exercise in all EX treatments. With the exception of markedly elevated plasma leucine concentrations after GL-R and GL-EX, the plasma concentrations of all indispensable amino acids decreased during the post gavage period. Leucine but not whey protein augmented the serum insulin response to an oral glucose load. Leucine supplementation warrants further investigation as a means to increase the rate of post exercise muscle glycogen synthesis in horses. © 2010 EVJ Ltd.

  3. Impacts of acute imipramine treatment on plasma and brain amino acid metabolism in mice given graded levels of dietary chicken protein.

    Science.gov (United States)

    Nagasawa, Mao; Murakami, Tatsuro; Tomonaga, Shozo; Sato, Mikako; Takahata, Yoshihisa; Morimatsu, Fumiki; Furuse, Mitsuhiro

    2012-12-01

    Several studies have shown a relationship between depression and animal protein intake. To evaluate whether the difference of dietary chicken protein levels induces an antidepressant-like effect and potentiates acute antidepressant effects, three levels of dietary chicken protein were used as the representative animal protein with imipramine used as the antidepressant. In addition, the effects of dietary chicken protein on brain metabolism were evaluated. Open field test (OFT) and forced swimming test (FST) were conducted on the 27th and 28th days, respectively. OFT and FST were not influenced by both imipramine and dietary protein levels. However, characteristic effects of imipramine treatment on brain monoamine metabolism were observed in the cerebral cortex and hypothalamus. In addition, dietary protein significantly increased taurine and L-ornithine levels even though these amino acids were not contained in the diets. In conclusion, the metabolism of several amino acids in the plasma and brain were altered by dietary chicken protein.

  4. Amino acids regulate the intracellular trafficking of the general amino acid permease of Saccharomycescerevisiae.

    Science.gov (United States)

    Chen, Esther J; Kaiser, Chris A

    2002-11-12

    The delivery to the plasma membrane of the general amino acid permease, Gap1p, of Saccharomyces cerevisiae is regulated by the quality of the nitrogen source in the growth medium. In an effort to define how different nitrogen sources control Gap1p sorting, we find that mutations in GDH1 and GLN1 that decrease the flux through the glutamate and glutamine synthesis pathways result in increased Gap1p sorting to the plasma membrane. Conversely, deletion of MKS1, which increases glutamate and glutamine synthesis, decreases Gap1p sorting to the plasma membrane. Glutamate and glutamine are not unusual in their ability to regulate Gap1p sorting, because the addition of all natural amino acids and many amino acid analogs to the growth medium results in increased Gap1p sorting to the vacuole. Importantly, amino acids have the capacity to signal Gap1p sorting to the vacuole regardless of whether they can be used as a source of nitrogen. Finally, we show that rapamycin does not affect Gap1p sorting, indicating that Gap1p sorting is not directly influenced by the TOR pathway. Together, these data show that amino acids are a signal for sorting Gap1p to the vacuole and imply that the nitrogen-regulated Gap1p sorting machinery responds to amino acid-like compounds rather than to the overall nutritional status associated with growth on a particular nitrogen source.

  5. Soya milk exerts different effects on plasma amino acid responses and incretin hormone secretion compared with cows' milk in healthy, young men.

    Science.gov (United States)

    Sun, Lijuan; Tan, Kevin Wei Jie; Siow, Phei Ching; Henry, Christiani Jeyakumar

    2016-10-01

    Apart from the well-known action of insulin, the mechanism by which soya and cows' milk improve postprandial glycaemia control was examined. In total, twelve healthy, young, Chinese men were studied on three separate occasions, in random order with isovolumetric (322 ml) control water, soya milk and cows' milk. Plasma total amino acid concentrations increased 30 min after test meals consumption and were higher after soya milk (230 %) and cow milk (240 %) consumption compared with water. Cows' milk ingestion induced higher branched-chain amino acids (BCAA) (40 %) than soya milk. Postprandial incretin concentrations increased after meal consumption. Cows' milk meal was accompanied by higher incremental AUC (iAUC) (170 %) for glucagon-like peptide-1 (GLP-1) compared with soya milk and control (P=0·06). However, glucose-dependent insulinotropic polypeptide (GIP) concentrations increased to significantly greater levels after soya milk consumption (iAUC 60 % higher) compared with cows' milk and control. Consumption of both soya and cows' milk with carbohydrates induced a similar reduction in glycaemic response through a different mechanism, beyond insulin action. Plasma amino acids (alanine and arginine), and incretins in particular (GIP was stimulated), may be involved in the hyperinsulinaemia after soya milk meals. However, BCAA and GLP-1 release may be responsible for the reduced glycaemia after cows' milk consumption by delaying gastric emptying. This could be the result of different milk protein/amino acid composition, but also differences in milk carbohydrate composition (i.e. lactose v. sucrose). It can be concluded that soya milk is a good alternative to cows' milk with regard to glycaemic regulation, with different mechanisms involved.

  6. Large neutral amino acids in daily practice

    DEFF Research Database (Denmark)

    Ahring, Kirsten Kiær

    2010-01-01

    At the Kennedy Centre for Phenylketonuria, Denmark, large neutral amino acids (LNAAs) are being used to treat adult and adolescent patients who are nonadherent to dietary treatment for phenylketonuria (PKU). At the start of treatment, a patient must undergo dietary analysis and regular blood...... sampling to measure plasma amino acid (AA) concentrations. The aim of this analysis and treatment is that the patient receives 25-30% of the daily protein requirement from LNAA supplementation and the remaining 70-75% from natural, low-phenylalanine proteins (although some patients have difficulties...

  7. Intestinal absorption of amino acids and peptides in Hartnup disorder.

    Science.gov (United States)

    Leonard, J V; Marrs, T C; Addison, J M; Burston, D; Clegg, K M; Lloyd, J K; Matthews, D M; Seakins, J W

    1976-04-01

    Absorption of free and peptide-bound amino acids was investigated in a girl with Hartnup disorder aged 26 months. Plasma levels of amino acids were followed after oral administration of (1) an amino acid mixture simulating casein and (2) an equivalent dose of a partial enzymic hydrolysate of casein containing oligopeptides in addition to free amino acids. The results suggested that many neutral amino acids were poorly absorbed when given in the free form, but much more readily absorbed when given as peptides. Unexpectedly, the results also suggested that glutamic acid was poorly absorbed when given in the free form. The results obtained with threonine could not be interpreted. There was an increased renal clearance of many neutral amino acids, including glycine, but clearance of proline was not increased. Most amino acids with an increased renal clearance also appeared to be poorly absorbed when given by mouth in the free form.

  8. Amino acids in the sedimentary humic and fulvic acids

    Digital Repository Service at National Institute of Oceanography (India)

    Sardessai, S.

    to the coastal sedimentary humic acids implying higher association of amino acids with the carbonaceous and fine grained sedimentary humic acids. Both the humic and fulvic acids are composed of neutral, acidic, basic, aromatic and sulphur containing amino acids....

  9. Combinatorics of aliphatic amino acids.

    Science.gov (United States)

    Grützmann, Konrad; Böcker, Sebastian; Schuster, Stefan

    2011-01-01

    This study combines biology and mathematics, showing that a relatively simple question from molecular biology can lead to complicated mathematics. The question is how to calculate the number of theoretically possible aliphatic amino acids as a function of the number of carbon atoms in the side chain. The presented calculation is based on earlier results from theoretical chemistry concerning alkyl compounds. Mathematical properties of this number series are highlighted. We discuss which of the theoretically possible structures really occur in living organisms, such as leucine and isoleucine with a chain length of four. This is done both for a strict definition of aliphatic amino acids only involving carbon and hydrogen atoms in their side chain and for a less strict definition allowing sulphur, nitrogen and oxygen atoms. While the main focus is on proteinogenic amino acids, we also give several examples of non-proteinogenic aliphatic amino acids, playing a role, for instance, in signalling. The results are in agreement with a general phenomenon found in biology: Usually, only a small number of molecules are chosen as building blocks to assemble an inconceivable number of different macromolecules as proteins. Thus, natural biological complexity arises from the multifarious combination of building blocks.

  10. Serum amino acid abnormalities in pediatric patients with chronic ...

    African Journals Online (AJOL)

    Mohamad A. El Sawy

    2011-08-10

    Aug 10, 2011 ... L-Arginine has been used to improve endothelial function by increasing nitric ... between HD patients with and without history of thromboembolic manifestations. ... Plasma protein and amino acid concentrations have been.

  11. Modulatory Effects of Dietary Amino Acids on Neurodegenerative Diseases.

    Science.gov (United States)

    Rajagopal, Senthilkumar; Sangam, Supraj Raja; Singh, Shubham; Joginapally, Venkateswara Rao

    2016-01-01

    Proteins are playing a vital role in maintaining the cellular integrity and function, as well as for brain cells. Protein intake and supplementation of individual amino acids can affect the brain functioning and mental health, and many of the neurotransmitters in the brain are made from amino acids. The amino acid supplementation has been found to reduce symptoms, as they are converted into neurotransmitters which in turn extenuate the mental disorders. The biosynthesis of amino acids in the brain is regulated by the concentration of amino acids in plasma. The brain diseases such as depression, bipolar disorder, schizophrenia, obsessive-compulsive disorder (OCD), and Alzheimer's (AD), Parkinson's (PD), and Huntington's diseases (HD) are the most common mental disorders that are currently widespread in numerous countries. The intricate biochemical and molecular machinery contributing to the neurological disorders is still unknown, and in this chapter, we revealed the involvement of dietary amino acids on neurological diseases.

  12. Elevated amniotic fluid amino acid levels in fetuses with gastroschisis

    Directory of Open Access Journals (Sweden)

    A. Kale

    2006-08-01

    Full Text Available Our objective was to measure maternal plasma and amniotic fluid amino acid concentrations in pregnant women diagnosed as having fetuses with gastroschisis in the second trimester of pregnancy. Twenty-one pregnant women who had fetuses with gastroschisis detected by ultrasonography (gastroschisis group in the second trimester and 32 women who had abnormal triple screenings indicating an increased risk for Down syndrome but had healthy fetuses (control group were enrolled in the study. Amniotic fluid was obtained by amniocentesis, and maternal plasma samples were taken simultaneously. The chromosomal analysis of the study and control groups was normal. Levels of free amino acids and non-essential amino acids were measured in plasma and amniotic fluid samples using EZ:fast kits (EZ:fast GC/FID free (physiological amino acid kit by gas chromatography (Focus GC AI 3000 Thermo Finnigan analyzer. The mean levels of essential amino acids (histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, and valine and non-essential amino acids (alanine, glycine, proline, and tyrosine in amniotic fluid were found to be significantly higher in fetuses with gastroschisis than in the control group (P < 0.05. A significant positive correlation between maternal plasma and amniotic fluid concentrations of essential and nonessential amino acids was found only in the gastroschisis group (P < 0.05. The detection of significantly higher amino acid concentrations in the amniotic fluid of fetuses with a gastroschisis defect than in healthy fetuses suggests the occurrence of amino acid malabsorption or of amino acid leakage from the fetus into amniotic fluid.

  13. Dietary amino acids fed in free form and as protein components do not differently affects postprandial plasma insulin, glucagon, growth hormone and corticosterone responses in rats

    NARCIS (Netherlands)

    Nolles, J.A.; Straten, van E.M.E.; Bremer, B.I.; Koopmanschap, R.E.; Verstegen, M.W.A.; Schreurs, V.V.A.M.

    2006-01-01

    This study examined, whether the postprandial fate of dietary amino acids from different amino acid sources is regulated by the responses of insulin, glucagon, corticosterone and growth hormone (GH). Male Wistar rats were cannulated in the vena jugularis and assigned to dietary groups. The diets con

  14. Excitatory amino acid receptor antagonists

    DEFF Research Database (Denmark)

    Johansen, T N; Frydenvang, Karla Andrea; Ebert, B

    1997-01-01

    We have previously shown that (RS)-2-amino-2-(5-tert-butyl-3-hydroxyisoxazol-4-yl)acetic acid (ATAA) is an antagonist at N-methyl-D-aspartic acid (NMDA) and (RS)-2-amino-3-(3-hydroxy-5-methylisoxazol-4-yl)propionic acid (AMPA) receptors. We have now resolved ATAA via diastereomeric salt formation......)-phenylethylamine salt of N-BOC-(R)-ATAA. Like ATAA, neither (R)- nor (S)-ATAA significantly affected (IC50 > 100 microM) the receptor binding of tritiated AMPA, kainic acid, or (RS)-3-(2-carboxypiperazin-4-yl)propyl-1-phosphonic acid, the latter being a competitive NMDA antagonist. Electrophysiological experiments......, using the rat cortical wedge preparation, showed the NMDA antagonist effect as well as the AMPA antagonist effect of ATAA to reside exclusively in the (R)-enantiomer (Ki = 75 +/- 5 microM and 57 +/- 1 microM, respectively). Neither (R)- nor (S)-ATAA significantly reduced kainic acid-induced excitation...

  15. Changes in plasma amino acid profiles, growth performance and intestinal antioxidant capacity of piglets following increased consumption of methionine as its hydroxy analogue

    CERN Document Server

    Li, Hao; Mercier, Yves; Zhang, Xiaoling; Wu, Caimei; Wu, Xiuqun; Tang, Li; Che, Lianqiang; Lin, Yan; Xu, Shengyu; Tian, Gang; Wu, De; Fang, Zhengfeng

    2014-01-01

    The aim of the present study was to determine whether early weaning-induced growth retardation could be attenuated by increased consumption of methionine as DL-methionine (DLM) or DL-2-hydroxy-4-methylthiobutyrate (HMTBA) in both lactating sows and weaned piglets. Therefore, diets containing DLM and HMTBA at 25\\% of the total sulphur-containing amino acids (AA) present in the control (CON) diet were fed to lactating sows and weaned piglets and their responses were evaluated. Compared with the CON diet-fed sows, the HMTBA diet-fed sows exhibited a tendency (P<0.10) towards higher plasma taurine concentrations and the DLM diet-fed sows had higher (P<0.05) plasma taurine concentrations, but lower (P<0.05) isoleucine concentrations. Suckling piglets in the HMTBA treatment group had higher (P<0.05) intestinal reduced glutathione (GSH) content, lower (P<0.05) oxidised glutathione (GSSG): GSH ratio, and higher (P<0.05) plasma cysteine and glutathione peroxidase (GPx) activity than those in the CON ...

  16. Effects of alkyl polyglycoside, a nonionic surfactant, and forage-to-concentrate ratio on rumen fermentation, amino acid composition of rumen content, bacteria and plasma in goats.

    Science.gov (United States)

    Zeng, Bo; Tan, Zhiliang; Tang, Shaoxun; Han, Xuefeng; Tan, Chuanyan; Zhong, Rongzhen; Hea, Zhixiong; Arigbede, Oluwasanmi Moses

    2011-06-01

    In the present study, the effects of different forage-to-concentrate ratios (F:C) and an alkyl polyglycoside (APG) supplementation on parameters of rumen and blood metabolism were investigated in goats. A 2 x 2 factorial experiment was arranged within a 4 x 4 Latin square design (four 22-day periods), using four wether goats equipped with permanent ruminal cannulas. The experimental diets included two F:C levels (40:60 vs. 60:40), and two APG supplementation levels (None or 13 ml APG daily per animal). Rumen contents and blood samples were collected at the end of each period. Dietary F:C alteration affected plasma urea and influenced the proportions of leucine, histidine, arginine, glycine, proline, alanine, valine, phenylalanine, cysteine and tyrosine in rumen content, and the proportions of methionine, threonine and proline in solid-associated bacteria (SAB) significantly. Dietary APG decreased the proportions of valine and phenylalanine in rumen content, and the histidine content of liquid-associated bacteria. The interaction between dietary F:C and APG was significant for the proportions of glycine and alanine in rumen content, and the proportions of lysine and threonine in SAB. The proportion of lysine was greater, but the proportion of threonine was less in SAB for goats fed high F:C diet without APG supplementation. The proportions of plasma free amino acids and glucose concentration were not affected by experimental treatments. These results indicated that dietary APG addition affected the amino acid composition of the rumen content and ruminal bacteria, but this depended on the dietary F:C ratio. It is necessary to validate the effectiveness of dietary APG supplementation in further studies with more animals.

  17. Unnatural reactive amino acid genetic code additions

    Science.gov (United States)

    Deiters, Alexander; Cropp, Ashton T; Chin, Jason W; Anderson, Christopher J; Schultz, Peter G

    2013-05-21

    This invention provides compositions and methods for producing translational components that expand the number of genetically encoded amino acids in eukaryotic cells. The components include orthogonal tRNAs, orthogonal aminoacyl-tRNA synthetases, pairs of tRNAs/synthetases and unnatural amino acids. Proteins and methods of producing proteins with unnatural amino acids in eukaryotic cells are also provided.

  18. Unnatural reactive amino acid genetic code additions

    Science.gov (United States)

    Deiters, Alexander; Cropp, T. Ashton; Chin, Jason W.; Anderson, J. Christopher; Schultz, Peter G.

    2014-08-26

    This invention provides compositions and methods for producing translational components that expand the number of genetically encoded amino acids in eukaryotic cells. The components include orthogonal tRNAs, orthogonal aminoacyl-tRNA synthetases, orthogonal pairs of tRNAs/synthetases and unnatural amino acids. Proteins and methods of producing proteins with unnatural amino acids in eukaryotic cells are also provided.

  19. Amino acids as antioxidants for frying oil

    Science.gov (United States)

    Amino acids, proteins and hydrolysates of proteins have been known to protect edible oils from oxidation. While amino acids and related materials have high potential as antioxidants for frying oil, effectiveness of each amino acid and mechanisms of their activities are not well understood yet. Propo...

  20. Branched-chain amino acids for hepatic encephalopathy. Protocol for Cochrane Review

    DEFF Research Database (Denmark)

    Gluud, C; Koretz, RL

    2000-01-01

    Hepatic encephalopathy may be caused by a decreased plasma ratio of branched-chain amino acids (BCAA) to aromatic amino acids. Treatment with BCAA may therefore have a beneficial effect on patients with hepatic encephalopathy.......Hepatic encephalopathy may be caused by a decreased plasma ratio of branched-chain amino acids (BCAA) to aromatic amino acids. Treatment with BCAA may therefore have a beneficial effect on patients with hepatic encephalopathy....

  1. Effect of GABA on oxidative stress in the skeletal muscles and plasma free amino acids in mice fed high-fat diet.

    Science.gov (United States)

    Xie, Z X; Xia, S F; Qiao, Y; Shi, Y H; Le, G W

    2015-06-01

    Increased levels of plasma free amino acids (pFAAs) can disturb the blood glucose levels in patients with obesity, diabetes mellitus and metabolic syndrome (MS) and are associated with enhanced protein oxidation. Oxidation of proteins, especially in the muscles, can promote protein degradation and elevate the levels of pFAAs. Gamma-aminobutyric acid (GABA), a food additive, can reduce high-fat diet (HFD)-induced hyperglycaemia; however, the mechanisms remain unclear. The aim of this study was to evaluate the effects of GABA on protein oxidation and pFAAs changes. One hundred male C57BL/6 mice were randomly divided into five groups that were fed with control diet, HFD and HFD supplied with 0.2%, 0.12% and 0.06% GABA in drinking water for 20 weeks respectively. HFD feeding led to muscular oxidative stress, protein oxidation, pFAA disorders, hyperglycaemia and augmented plasma GABA levels. Treatment with GABA restored normally fasting blood glucose level and dose-dependently inhibited body weight gains, muscular oxidation and protein degradation. While medium and low doses of GABA mitigated HFD-induced pFAA disorders, the high dose of GABA deteriorated the pFAA disorders. Medium dose of GABA increased the levels of GABA, but high dose of GABA reduced the levels of plasma GABA and increased the activity of succinic semialdehyde dehydrogenase in the liver. Therefore, treatment with GABA mitigated HFD-induced hyperglycaemia probably by repairing HFD-induced muscular oxidative stress and pFAA disorders in mice. Our data also suggest that an optimal dose of GABA is crucial for the prevention of excess GABA-related decrease in the levels of pFAA and GABA as well as obesity.

  2. Amino acids as regulators of gene expression

    Directory of Open Access Journals (Sweden)

    Kimball SR

    2004-08-01

    Full Text Available The role of amino acids as substrates for protein synthesis is well documented. However, a function for amino acids in modulating the signal transduction pathways that regulate mRNA translation has only recently been described. Interesting, some of the signaling pathways regulated by amino acids overlap with those classically associated with the cellular response to hormones such as insulin and insulin-like growth factors. The focus of this review is on the signaling pathways regulated by amino acids, with a particular emphasis on the branched-chain amino acid leucine, and the steps in mRNA translation controlled by the signaling pathways.

  3. Current topics in the biotechnological production of essential amino acids, functional amino acids, and dipeptides.

    Science.gov (United States)

    Mitsuhashi, Satoshi

    2014-04-01

    Amino acids play important roles in both human and animal nutrition and in the maintenance of health. Here, amino acids are classified into three groups: first, essential amino acids, which are essential to nutrition; second, functional amino acids, recently found to be important in the promotion of physiological functions; and third, dipeptides, which are used to resolve problematic features of specific free amino acids, such as their instability or insolubility. This review focusses on recent researches concerning the microbial production of essential amino acids (lysine and methionine), functional amino acids (histidine and ornithine), and a dipeptide (L-alanyl-L-glutamine).

  4. Composition of amino acids, fatty acids and dietary fibre monomers ...

    African Journals Online (AJOL)

    Composition of amino acids, fatty acids and dietary fibre monomers in kernels of ... Nuts are rich in protein and essential amino acids, and have a high energy value ... of protein, especially when combined with foods with high lysine content.

  5. Amino acid properties conserved in molecular evolution.

    Directory of Open Access Journals (Sweden)

    Witold R Rudnicki

    Full Text Available That amino acid properties are responsible for the way protein molecules evolve is natural and is also reasonably well supported both by the structure of the genetic code and, to a large extent, by the experimental measures of the amino acid similarity. Nevertheless, there remains a significant gap between observed similarity matrices and their reconstructions from amino acid properties. Therefore, we introduce a simple theoretical model of amino acid similarity matrices, which allows splitting the matrix into two parts - one that depends only on mutabilities of amino acids and another that depends on pairwise similarities between them. Then the new synthetic amino acid properties are derived from the pairwise similarities and used to reconstruct similarity matrices covering a wide range of information entropies. Our model allows us to explain up to 94% of the variability in the BLOSUM family of the amino acids similarity matrices in terms of amino acid properties. The new properties derived from amino acid similarity matrices correlate highly with properties known to be important for molecular evolution such as hydrophobicity, size, shape and charge of amino acids. This result closes the gap in our understanding of the influence of amino acids on evolution at the molecular level. The methods were applied to the single family of similarity matrices used often in general sequence homology searches, but it is general and can be used also for more specific matrices. The new synthetic properties can be used in analyzes of protein sequences in various biological applications.

  6. ANALYSIS OF AMINO ACIDS BY HIGH PERFORMANCE LIQUID CHROMATOGRAPHY

    Directory of Open Access Journals (Sweden)

    Qurat E Noor Baig

    2016-06-01

    Full Text Available Amino acids are the building blocks of proteins and are considered as the key precursors for the formation of hormones and low molecular weight nitrogenous substances with biological importance. Since the analysis of amino acids has been carried out for both qualitative and quantitative purposes with an aim to study their levels in the plasma concentration, the quantitative determination, in particular, also helps in the diagnosis of different diseases associated with their deficiency. This review article deals with the determination of amino acids by chromatographic methods which include ion-exchange chromatography (IEC, high performance liquid chromatography (HPLC, reverse phase-high performance liquid chromatography (RP-HPLC and ultra-performance liquid chromatography (UPLC. The review will also give an idea for the preparation of samples, derivatization methods for the analysis of amino acids (direct and indirect methods and separation of amino acids by high performance liquid chromatographic technique.

  7. Microbial production of amino acids in Japan.

    Science.gov (United States)

    Kumagai, H

    2000-01-01

    The microbial biotechnology of amino acids production which was developed and industrialized in Japan have been summarized. The amino acids include L-glutamic acid, L-lysine, L-threonine, L-aspartic acid, L-alanine, L-cysteine, L-dihydroxyphenylalanine, D-p-hydroxyphenyl-glycine, and hydroxy-L-proline.

  8. Amino and fatty acids in carbonaceous meteorites

    Science.gov (United States)

    Kvenvolden, K. A.

    1974-01-01

    Analyses of two carbonaceous meteorites have provided much of the latest evidence which seems to support Oparin's theory on the origin of life. The meteorites involved are the Murray meteorite, which fell in 1950, and the Murchison meteorite, which fell in 1969. The amino acids in the two meteorites are similar in composition. Eight of the twenty amino acids found belong to amino acids present in proteins. A number of monocarboxylic and dicarboxylic fatty acids were also found in the meteorites.

  9. AMINO ACID BLOOD POOL OF CHILDREN WITH ALLERGIC DISEASES

    Directory of Open Access Journals (Sweden)

    Shmulich O. V.

    2014-01-01

    Full Text Available The amino acid blood pool of children with atopic dermatitis, bronchial asthma, urticaria, angioedema was investigated. The variability of blood plasma amino acid content (tryptophan, histidine, tyrosine, cysteine, methionine was observed. The changes of histidine and tryptophan levels might be connected with the formation of biogenic amines, such as histamine, serotonine, with take part in the development of allergic reactions and inflammatory processes in organism.

  10. Measuring distances between TRPV1 and the plasma membrane using a noncanonical amino acid and transition metal ion FRET

    OpenAIRE

    Zagotta, William N.; Gordon, Moshe T.; Senning, Eric N.; Munari, Mika A.; Gordon, Sharona E.

    2016-01-01

    Despite recent advances, the structure and dynamics of membrane proteins in cell membranes remain elusive. We implemented transition metal ion fluorescence resonance energy transfer (tmFRET) to measure distances between sites on the N-terminal ankyrin repeat domains (ARDs) of the pain-transducing ion channel TRPV1 and the intracellular surface of the plasma membrane. To preserve the native context, we used unroofed cells, and to specifically label sites in TRPV1, we incorporated a fluorescent...

  11. Amino Acid Contents of Meteorite Mineral Separates

    Science.gov (United States)

    Berger, E. L.; Burton, A. S; Locke, D.

    2017-01-01

    Indigenous amino acids have been found indigenous all 8 carbonaceous chondrite groups. However, the abundances, structural, enantiomeric and isotopic compositions of amino acids differ significantly among meteorites of different groups and petrologic types. This suggests that parent-body conditions (thermal or aqueous alteration), mineralogy, and the preservation of amino acids are linked. Previously, elucidating specific relationships between amino acids and mineralogy was not possible because the samples analyzed for amino acids were much larger than the scale at which petrologic heterogeneity is observed (sub mm-scale differences corresponding to sub-mg samples). Recent advances in amino acid measurements and application of techniques such as high resolution X-ray diffraction (HR-XRD) and scanning electron microscopy (SEM) with energy dispersive spectroscopy (EDS) for mineralogical characterizations allow us to perform coordinated analyses on the scale at which mineral heterogeneity is observed.

  12. Indigenous amino acids in primitive CR meteorites

    CERN Document Server

    Martins, Z; Orzechowska, G E; Fogel, M L; Ehrenfreund, P

    2008-01-01

    CR meteorites are among the most primitive meteorites. In this paper, we report the first measurements of amino acids in Antarctic CR meteorites, two of which show the highest amino acid concentrations ever found in a chondrite. EET92042, GRA95229 and GRO95577 were analyzed for their amino acid content using high performance liquid chromatography with UV fluorescence detection (HPLC-FD) and gas chromatographymass spectrometry (GC-MS). Our data show that EET92042 and GRA95229 are the most amino acid-rich chondrites ever analyzed, with total amino acid concentrations ranging from 180 parts-per-million (ppm) to 249 ppm. GRO95577, however, is depleted in amino acids. The most abundant amino acids present in the EET92042 and GRA95229 meteorites are the alpha-amino acids glycine, isovaline, alpha-aminoisobutyric acid (alpha-AIB), and alanine, with delta13C values ranging from +31.6per mil to +50.5per mil. The carbon isotope results together with racemic enantiomeric ratios determined for most amino acids strongly i...

  13. Different environmental temperatures affect amino acid metabolism in the eurytherm teleost Senegalese sole (Solea senegalensis Kaup, 1858) as indicated by changes in plasma metabolites.

    NARCIS (Netherlands)

    Costas, B.; Aragao, C.; Ruiz-Jarabo, I.; Vargas-Chacoff, L.; Arjona, F.J.; Mancera, J.M.; Dinis, M.T.; Conceicao, L.E.

    2012-01-01

    Senegalese sole (Solea senegalensis) is a eurytherm teleost that under natural conditions can be exposed to annual water temperature fluctuations between 12 and 26 degrees C. This study assessed the effects of temperature on sole metabolic status, in particular in what concerns plasma free amino aci

  14. Defining meal requirements for protein to optimize metabolic roles of amino acids

    Science.gov (United States)

    Dietary protein provides essential amino acids (EAAs) for the synthesis of new proteins plus an array of other metabolic functions; many of these functions are sensitive to postprandial plasma and intracellular amino acid concentrations. Recent research has focused on amino acids as metabolic signal...

  15. Kinetics, dynamics and localization of basic amino acid transporters in Saccharomyces cerevisiae

    NARCIS (Netherlands)

    Bianchi, Frans

    2016-01-01

    Amino acid permeases (AAPs) in the plasma membrane (PM) of Saccharomyces cerevisiae are responsible for the uptake and regulation of the cellular levels of amino acids. The focus of my thesis is on the AAP’s responsible for the uptake of basic amino acids. Curiously these AAPs have been reported to

  16. Plasma Free Amino Acid Profiles Predict Four-Year Risk of Developing Diabetes, Metabolic Syndrome, Dyslipidemia, and Hypertension in Japanese Population

    Science.gov (United States)

    Yamakado, Minoru; Nagao, Kenji; Imaizumi, Akira; Tani, Mizuki; Toda, Akiko; Tanaka, Takayuki; Jinzu, Hiroko; Miyano, Hiroshi; Yamamoto, Hiroshi; Daimon, Takashi; Horimoto, Katsuhisa; Ishizaka, Yuko

    2015-01-01

    Plasma free amino acid (PFAA) profile is highlighted in its association with visceral obesity and hyperinsulinemia, and future diabetes. Indeed PFAA profiling potentially can evaluate individuals’ future risks of developing lifestyle-related diseases, in addition to diabetes. However, few studies have been performed especially in Asian populations, about the optimal combination of PFAAs for evaluating health risks. We quantified PFAA levels in 3,701 Japanese subjects, and determined visceral fat area (VFA) and two-hour post-challenge insulin (Ins120 min) values in 865 and 1,160 subjects, respectively. Then, models between PFAA levels and the VFA or Ins120 min values were constructed by multiple linear regression analysis with variable selection. Finally, a cohort study of 2,984 subjects to examine capabilities of the obtained models for predicting four-year risk of developing new-onset lifestyle-related diseases was conducted. The correlation coefficients of the obtained PFAA models against VFA or Ins120 min were higher than single PFAA level. Our models work well for future risk prediction. Even after adjusting for commonly accepted multiple risk factors, these models can predict future development of diabetes, metabolic syndrome, and dyslipidemia. PFAA profiles confer independent and differing contributions to increasing the lifestyle-related disease risks in addition to the currently known factors in a general Japanese population. PMID:26156880

  17. Amino acid composition of some Mexican foods.

    Science.gov (United States)

    Morales de León, Josefina; Camacho, M Elena; Bourges, Héctor

    2005-06-01

    Knowledge of the amino acid composition of foods is essential to calculate their chemical score, which is used to predict protein quality of foods and diets. Though amino acid composition of many foods is reasonably well established, better knowledge is needed on native foods consumed in different regions and countries. This paper presents the amino acid composition of different presentations of raw and processed foods produced and consumed in Mexico. The amino acid composition was determined using Beckman amino acid analyzers (models 116 and 6300). Tryptophan was determined using the Spies and Chambers method. Of the different foods analyzed, some comments are made on native or basic foods in Mexico: Spirulin, where lysine is the limiting amino acid, with a chemical score of 67%, is a good source of tryptophan (1.16g/16 gN); amaranth contains high levels of sulphur amino acids (4.09 to 5.34 g/16gN), with a protein content of 15 g/100g; and pulque, a Pre-Hispanic beverage that contains high levels of tryptophan (2.58 g/16 gN) and sulphur amino acids (2.72 g/16 gN). Finally, insects are good sources of sulphur amino acids and lysine.

  18. Rumen-protected methionine and lysine: effects on milk production and plasma amino acids of dairy cows with reference to metabolisable protein status.

    Science.gov (United States)

    Awawdeh, Mofleh S

    2016-05-01

    Two experiments were conducted to study the effects of rumen-protected Met (RPM) alone or with rumen-protected Lys (RPL) on milk yield and plasma amino acids of dairy cows. In experiment 1, 24 multiparous Holstein cows (154 DIM) were assigned to one of 3 groups where each cow received 0 g/d of RPM and RPL (C), 30 g/d of RPM (M), or 30 g/d of RPM plus 25 g of RPL (ML). The study lasted for 8 weeks where milk yield and composition were determined weekly. Daily milk yield averaged 28·0, 27·8, and 29·7 kg/cow for the C, M, and ML groups, respectively. Dietary treatments had no effects (P ≥ 0·54) on milk contents of fat, lactose, solid non-fat or total solids. Milk protein content in the ML group was greater (P Plasma levels of all AA were not significantly (P ≥ 0·09) affected by supplemental RPL and/or RPM. In experiment 2, 30 multiparous Holstein cows (100 DIM) were assigned to one of 3 groups where each cow received 0 g/d of RPM and RPL (C), 50 g/d of RPM (M), or 50 g/d of RPM plus 25 g/d of RPL (ML). The study lasted for 5 weeks. Cows in the M (30·5 kg) and ML (31·4 kg) groups produced (P < 0·05) more milk than those of the C group (29·1 kg). Under conditions of this study, RPM plus RPL improved milk yield and protein contents of dairy cows and was better than supplying RPM alone. Response in milk yield to RPM and RPL was affected by the MP status of cows which deserves further investigation.

  19. Ethyl-bridged hybrid column as an efficient alternative for HPLC analysis of plasma amino acids by pre-column derivatization with 6-aminoquinolyl-N-hydroxysuccinimidyl carbamate.

    Science.gov (United States)

    Castellanos, Mar; Van Eendenburg, Cecile Van; Gubern, Carme; Sanchez, Juan M

    2016-09-01

    Conventional C18 silica columns have proven to be useful for the analysis of amino acids (AA) from protein hydrolysates but undesirable peak overlapping is usually found when analyzing body fluids given that a large number of AAs are present in the samples. As an alternative to silica packings, an ethyl-bridged packing for reversed-phase liquid chromatography of derivatized AAs with 6-aminoquinolyl-N-hydroxysuccinimidyl carbamate (AQC) has been evaluated. The new packing material improves the separation efficiency allowing better separations when analyzing biological fluids. Moreover, this packing has advantages for routine AA analysis, such as a decrease in the total running time and an increase in the life-time of the columns. The pH of the mobile phase has a significant effect on the elution behavior of the AQC hydrolysis product (AMQ) and on the AA derivatives. It is not possible to elute AMQ before detecting the first AA derivative, which requires an accurate adjustment of the pH in the range of 5.30-5.35 to obtain good separation and resolution for the most polar compounds. Under the conditions proposed, it is possible to separate all AAs except the Gly-Gln pair, which is not a problem when hydrolyzed samples are analyzed. The AMQ-Ser pair requires either the use of a different mobile phase pH for its baseline separation or the use of fluorescence detection. Two different procedures for protein removal from plasma samples have been evaluated, solvent precipitation and ultrafiltration (UF) and it has been found that UF gives better results as no significant losses of AAs were observed. The validation of the proposed method with UV detection gives method detection limits in the range of 8-12μM, with repeatability values<8% (n=6) and inter-day precision in plasma samples ranging from 4 to 13% (n=4).

  20. Relationship between amino acid usage and amino acid evolution in primates.

    Science.gov (United States)

    Liu, Haoxuan; Xie, Zhengqing; Tan, Shengjun; Zhang, Xiaohui; Yang, Sihai

    2015-02-25

    Amino acid usage varies from species to species. A previous study has found a universal trend in amino acid gain and loss in many taxa and a one-way model of amino acid evolution in which the number of new amino acids increases as the number of old amino acids decreases was proposed. Later studies showed that this pattern of amino acid gain and loss is likely to be compatible with the neutral theory. The present work aimed to further study this problem by investigating the evolutionary patterns of amino acids in 8 primates (the nucleotide and protein alignments are available online http://gattaca.nju.edu.cn/pub_data.html). First, the number of amino acids gained and lost was calculated and the evolution trend of each amino acid was inferred. These values were found to be closely related to the usage of each amino acid. Then we analyzed the mutational trend of amino acid substitution in human using SNPs, this trend is highly correlated with fixation trend only with greater variance. Finally, the trends in the evolution of 20 amino acids were evaluated in human on different time scales, and the increasing rate of 5 significantly increasing amino acids was found to decrease as a function of time elapsed since divergence, and the dS/dN ratio also found to increase as a function of time elapsed since divergence. These results suggested that the observed amino acid substitution pattern is influenced by mutation and purifying selection. In conclusion, the present study shows that usage of amino acids is an important factor capable of influencing the observed pattern of amino acid evolution, and also presented evidences suggesting that the observed universal trend of amino acid gain and loss is compatible with neutral evolution. Copyright © 2014 Elsevier B.V. All rights reserved.

  1. Effect of domoic acid on brain amino acid levels.

    Science.gov (United States)

    Durán, R; Arufe, M C; Arias, B; Alfonso, M

    1995-03-01

    The administration of Domoic Acid (Dom) in a 0.2 mg/kg i.p. dose induces changes in the levels of amino acids of neurochemical interest (Asp, Glu, Gly, Tau, Ala, GABA) in different rat brain regions (hypothalamus, hippocampus, amygdala, striatum, cortex and midbrain). The most affected amino acid is the GABA, the main inhibitory amino acid neurotransmitter, whereas glutamate, the main excitatory amino acid, is not affected. The rat brain regions that seem to be the main target of the Dom action belong to the limbic system (hippocampus, amygdala). The possible implication of the amino acids in the actions of Dom is also discussed.

  2. Effects of amino acid additives during hemodialysis of children.

    Science.gov (United States)

    Abitbol, C L; Mrozinska, K; Mandel, S; McVicar, M; Wapnir, R A

    1984-01-01

    The intradialytic losses into the dialysate of free amino acids (AA) and alpha-amino nitrogen were determined during the dialysis of three children. Variations in plasma AA were determined pre- and postdialysis. The effect of these losses with the addition of an Abbott General Amino Acid Mixture to the dialysate in concentrations of 8.5, 17, and 34 mg/100 ml was studied. The major determinant of AA losses was the plasma concentration of the AA before beginning the dialysis treatment. Dialysance of individual AA varied inversely with their molecular weights. A zero flux of alpha-amino nitrogen occurred at a derived concentration of 22 mg/100 ml of the AA additive in the dialysate. Plasma concentrations of nonessential amino acids were little affected by the dialysate additive. In contrast, total essential amino acid nitrogen which fell during baseline dialyses showed significant improvement when the AA solution was added to the dialysate. This study suggests that the addition of AA to the dialysate bath may be effective in decreasing AA nitrogen losses during dialysis.

  3. Synthesis of Chiral Amino Cyclic Phosphoric Acids

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Chirai amino cyclic phosphoric acids, 5-amino-2-hydroxy-4- (4-nitrophenyl)-l, 3,2-dioxaphospho- rinane 2-oxide and 2-hydroxy-4- (4-methylsulfonylphenyl)-5-phthalimido-1,3,2-dioxaphos phorinane 2-oxide are synthesized in good over yields (64. 2% and 72. 8% respectively) from 2-amino-l-aryl-l,3-propanediols. The different reaction conditions are necessary in hydrolysis reactions of amino cyclic phosphonyl chlorides.

  4. Plasma Free Amino Acid Responses to Intraduodenal Whey Protein, and Relationships with Insulin, Glucagon-Like Peptide-1 and Energy Intake in Lean Healthy Men

    Directory of Open Access Journals (Sweden)

    Natalie D. Luscombe-Marsh

    2016-01-01

    Full Text Available This study determined the effects of increasing loads of intraduodenal (ID dairy protein on plasma amino acid (AA concentrations, and their relationships with serum insulin, plasma glucagon-like peptide-1 (GLP-1 and energy intake. Sixteen healthy men had concentrations of AAs, GLP-1 and insulin measured in response to 60-min ID infusions of hydrolysed whey protein administered, in double-blinded and randomised order, at 2.1 (P2.1, 6.3 (P6.3 or 12.5 (P12.5 kJ/min (encompassing the range of nutrient emptying from the stomach, or saline control (C. Energy intake was quantified immediately afterwards. Compared with C, the concentrations of 19/20 AAs, the exception being cysteine, were increased, and this was dependent on the protein load. The relationship between AA concentrations in the infusions and the area under the curve from 0 to 60 min (AUC0–60 min of each AA profile was strong for essential AAs (R2 range, 0.61–0.67, but more variable for non-essential (0.02–0.54 and conditional (0.006–0.64 AAs. The AUC0–60 min for each AA was correlated directly with the AUC0–60 min of insulin (R2 range 0.3–0.6, GLP-1 (0.2–0.6 and energy intake (0.09–0.3 (p < 0.05, for all, with the strongest correlations being for branched-chain AAs, lysine, methionine and tyrosine. These findings indicate that ID whey protein infused at loads encompassing the normal range of gastric emptying increases plasma concentrations of 19/20 AAs in a load-dependent manner, and provide novel information on the close relationships between the essential AAs, leucine, valine, isoleucine, lysine, methionine, and the conditionally-essential AA, tyrosine, with energy intake, insulin and GLP-1.

  5. Nutritional value of D-amino acids, D-peptides, and amino acid derivatives in mice.

    Science.gov (United States)

    Friedman, Mendel; Levin, Carol E

    2012-01-01

    This paper describes 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 for such determinations may be preferable to protein-based diets.

  6. Microbial production of natural poly amino acid

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Three kinds of poly amino acids, poly-γ-glutamic acid, poly(ε-L-lysine) and multi-L-arginyl-poly (L-aspartic acid) can be synthesized by enzymatic process independently from ribosomal protein biosynthesis pathways in microorganism. These biosynthesized polymers have attracted more and more attentions because of their unique properties and various applications. In this review, the current knowledge on the biosynthesis, biodegradations and applications of these three poly amino acids are summarized.

  7. Amino acids transport in lactic streptococci

    NARCIS (Netherlands)

    Driessen, Arnold Jacob Mathieu

    1987-01-01

    Lactic streptococci are extremely fastidious bacteria. For growth an exogenous source of amino acids and other nutrients is essential. The amino acid requirement in milk is fulfilled by the milk-protein casein, which is degraded by sequential hydrolysis, involving proteases and peptidases. ... Zie:

  8. Crystalline amino acids and nitrogen emission

    NARCIS (Netherlands)

    Verstegen, M.W.A.; Jongbloed, A.W.

    2003-01-01

    Reductions in dietary protein level and supplementation with certain crystalline amino acids is a well-established method of formulating diets to achieve a more ideal amino acid pattern and to reduce nitrogen excretion. Up to 35% reduction in nitrogen excretion may be achieved by supplementing pig

  9. Crystalline amino acids and nitrogen emission

    NARCIS (Netherlands)

    Verstegen, M.W.A.; Jongbloed, A.W.

    2003-01-01

    Reductions in dietary protein level and supplementation with certain crystalline amino acids is a well-established method of formulating diets to achieve a more ideal amino acid pattern and to reduce nitrogen excretion. Up to 35% reduction in nitrogen excretion may be achieved by supplementing pig d

  10. The Apollo Program and Amino Acids

    Science.gov (United States)

    Fox, Sidney W.

    1973-01-01

    Discusses the determination of hydrolyzable amino acid precursors and a group of six amino acids in the returned lunar samples of the Apollo programs. Indicates that molecular evolution is arrested at the precursor stage on the Moon because of lack of water. (CC)

  11. Synthesis of β-Amino Acid Derivatives

    Institute of Scientific and Technical Information of China (English)

    Zhao Yonghua; Ma Zhihua; Jiang Nan; Wang Jianbo

    2004-01-01

    In recent years, β-amino acids and their derivatives have attracted considerable attention due to their occurrence in biologically active natural products, such as dolastatins,cyclohexylnorstatine and Taxol. β-Amino acids also find application in the synthesis of β-lactams,piperidines, indolizidines. Moreover, the peptides consisting of β-amino acids, the so-called β-peptides, have been extensively studied recently. Consequently, considerable efforts have been directed to the synthesis of β-amino acids and their derivatives1. In particular, stereoselective synthesis of β-amino acids has been a challenging project, and there are only limited methods available. In this presentation, we report our efforts in this area.

  12. Alterations in amino acid status in cats with feline dysautonomia.

    Science.gov (United States)

    McGorum, Bruce C; Symonds, Herb W; Knottenbelt, Clare; Cave, Tom A; MacDonald, Susan J; Stratton, Joanna; Leon, Irene; Turner, Judith A; Pirie, R Scott

    2017-01-01

    Feline dysautonomia (FD) is a multiple system neuropathy of unknown aetiology. An apparently identical disease occurs in horses (equine grass sickness, EGS), dogs, rabbits, hares, sheep, alpacas and llamas. Horses with acute EGS have a marked reduction in plasma concentrations of the sulphur amino acids (SAA) cyst(e)ine and methionine, which may reflect exposure to a neurotoxic xenobiotic. The aim of this study was to determine whether FD cats have alterations in amino acid profiles similar to those of EGS horses. Amino acids were quantified in plasma/serum from 14 FD cats, 5 healthy in-contact cats which shared housing and diet with the FD cats, and 6 healthy control cats which were housed separately from FD cats and which received a different diet. The adequacy of amino acids in the cats' diet was assessed by determining the amino acid content of tinned and dry pelleted foods collected immediately after occurrences of FD. Compared with controls, FD cats had increased concentrations of many essential amino acids, with the exception of methionine which was significantly reduced, and reductions in most non-essential amino acids. In-contact cats also had inadequate methionine status. Artefactual loss of cysteine during analysis precluded assessment of the cyst(e)ine status. Food analysis indicated that the low methionine status was unlikely to be attributable to dietary inadequacy of methionine or cystine. Multi-mycotoxin screening identified low concentrations of several mycotoxins in dry food from all 3 premises. While this indicates fungal contamination of the food, none of these mycotoxins appears to induce the specific clinico-pathologic features which characterise FD and equivalent multiple system neuropathies in other species. Instead, we hypothesise that ingestion of another, as yet unidentified, dietary neurotoxic mycotoxin or xenobiotic, may cause both the characteristic disease pathology and the plasma SAA depletion.

  13. Alterations in amino acid status in cats with feline dysautonomia

    Science.gov (United States)

    Symonds, Herb W.; Knottenbelt, Clare; Cave, Tom A.; MacDonald, Susan J.; Stratton, Joanna; Leon, Irene; Turner, Judith A.; Pirie, R. Scott

    2017-01-01

    Feline dysautonomia (FD) is a multiple system neuropathy of unknown aetiology. An apparently identical disease occurs in horses (equine grass sickness, EGS), dogs, rabbits, hares, sheep, alpacas and llamas. Horses with acute EGS have a marked reduction in plasma concentrations of the sulphur amino acids (SAA) cyst(e)ine and methionine, which may reflect exposure to a neurotoxic xenobiotic. The aim of this study was to determine whether FD cats have alterations in amino acid profiles similar to those of EGS horses. Amino acids were quantified in plasma/serum from 14 FD cats, 5 healthy in-contact cats which shared housing and diet with the FD cats, and 6 healthy control cats which were housed separately from FD cats and which received a different diet. The adequacy of amino acids in the cats’ diet was assessed by determining the amino acid content of tinned and dry pelleted foods collected immediately after occurrences of FD. Compared with controls, FD cats had increased concentrations of many essential amino acids, with the exception of methionine which was significantly reduced, and reductions in most non-essential amino acids. In-contact cats also had inadequate methionine status. Artefactual loss of cysteine during analysis precluded assessment of the cyst(e)ine status. Food analysis indicated that the low methionine status was unlikely to be attributable to dietary inadequacy of methionine or cystine. Multi-mycotoxin screening identified low concentrations of several mycotoxins in dry food from all 3 premises. While this indicates fungal contamination of the food, none of these mycotoxins appears to induce the specific clinico-pathologic features which characterise FD and equivalent multiple system neuropathies in other species. Instead, we hypothesise that ingestion of another, as yet unidentified, dietary neurotoxic mycotoxin or xenobiotic, may cause both the characteristic disease pathology and the plasma SAA depletion. PMID:28333983

  14. Modelling the effects of dietary methionine level and form on postprandial plasma essential amino acid profiles in rainbow trout (Oncorhynchus mykiss)

    DEFF Research Database (Denmark)

    Rolland, Marine; Feekings, Jordan P.; Dalsgaard, Anne Johanne Tang

    2016-01-01

    essential amino acid (EAA) in rainbow trout. Twelve diets were formulated with pea and soya protein concentrate or fish meal as the main protein ingredients and were supplemented or not with increasing amount of either crystalline or agar-coated methionine. Fish were acclimatized to one of the 12 diets...

  15. Differential distribution of amino acids in plants.

    Science.gov (United States)

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

    2017-03-15

    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

  16. 静脉输注氨基酸对严重创伤病人血氨基酸谱和氮平衡的影响%Effect of amino acid infusion on free amino acid spectrum in plasma and nitrogen balance in severe trauma patients

    Institute of Scientific and Technical Information of China (English)

    骆建军; 施建国; 方雪玲; 方强; 傅素珍; 姚远

    2011-01-01

    目的:探讨严重创伤病人静脉输注复方氨基酸对血游离氨基酸谱和氮平衡的的影响.方法:将40例严重创伤病人随机分为试验组(输注氨基酸+葡萄糖+脂肪乳剂)和对照组(输注葡萄糖+脂肪乳剂).4 d后测定血游离氨基酸谱和氮平衡. 结果:对照组病人大部分氨基酸(甘氨酸、半胱氨酸、缬氨酸、蛋氨酸、异亮氨酸、亮氨酸、赖氨酸、组氨酸、精氨酸)显著低于试验组(P<0.05);两组苯丙氨酸/酪氨酸(Phe/Tyr)比值显著高于正常值(P<0.05);支链氨基酸/芳香族氨基酸(BCAA/AAA)比值显著低于正常值(P<0.05);试验组病人与对照组比,氮平衡得到明显改善(P<0.05). 结论:严重创伤后病人给予静脉输注1.2 g/(kg·d)氨基酸,可提高血中大部分游离氨基酸的水平,改善氮平衡,但未改善氨基酸代谢障碍.%Objective: To investigate the effect of amino acid infusion on free amino acid spectrum in plasma and nitrogen balance in severe trauma patients. Methods: 40 severe trauma patients were randomly divided into two groups: experiment group( amino acid + glucose + fat emulsion) and control group ( glucose + fat emulsion). Blood samples were taken for determination of plasma levels of free amino acid and nitrogen balancewas was measured after 4 days. Results: The levels of glyeine, cysteine, valine, methionine, isoleueine, leucine, lysine, histidine and arginine in experiment group were significantly higher than those in control group ( ρ < 0.05 ). The ratio of phenylalanine and tyrosine ( Phc/Tyr)and the ratio of branched-chain amino acids and aromatic amino acids(BCAA/AAA) in two groups were not different and clearly higher or lower than the normal value ( ρ < 0.05 ). The nitrogen balance was - (6.6 + 3.8) g/L in control group and - ( 0.7 + 5.0 ) g/L in experiment group ( ρ < 0.05 ).Conclusion: Intravenous infusion of 1.2 g/( kg·d)amino acid can increase the levels of most of free amino acid in severe trauma

  17. Synthesis and anticonvulsant activity of novel bicyclic acidic amino acids

    DEFF Research Database (Denmark)

    Conti, Paola; De Amici, Marco; Joppolo Di Ventimiglia, Samuele

    2003-01-01

    Bicyclic acidic amino acids (+/-)-6 and (+/-)-7, which are conformationally constrained homologues of glutamic acid, were prepared via a strategy based on a 1,3-dipolar cycloaddition. The new amino acids were tested toward ionotropic and metabotropic glutamate receptor subtypes; both of them...

  18. Gemini surfactants from natural amino acids.

    Science.gov (United States)

    Pérez, Lourdes; Pinazo, Aurora; Pons, Ramon; Infante, Mrosa

    2014-03-01

    In this review, we report the most important contributions in the structure, synthesis, physicochemical (surface adsorption, aggregation and phase behaviour) and biological properties (toxicity, antimicrobial activity and biodegradation) of Gemini natural amino acid-based surfactants, and some potential applications, with an emphasis on the use of these surfactants as non-viral delivery system agents. Gemini surfactants derived from basic (Arg, Lys), neutral (Ser, Ala, Sar), acid (Asp) and sulphur containing amino acids (Cys) as polar head groups, and Geminis with amino acids/peptides in the spacer chain are reviewed.

  19. Amino acid analogs for tumor imaging

    Science.gov (United States)

    Goodman, M.M.; Shoup, T.

    1998-09-15

    The invention provides novel amino acid compounds of use in detecting and evaluating brain and body tumors. These compounds combine the advantageous properties of 1-amino-cycloalkyl-1-carboxylic acids, namely, their rapid uptake and prolonged retention in tumors with the properties of halogen substituents, including certain useful halogen isotopes including fluorine-18, iodine-123, iodine-125, iodine-131, bromine-75, bromine-76, bromine-77 and bromine-82. In one aspect, the invention features amino acid compounds that have a high specificity for target sites when administered to a subject in vivo. Preferred amino acid compounds show a target to non-target ratio of at least 5:1, are stable in vivo and substantially localized to target within 1 hour after administration. An especially preferred amino acid compound is [{sup 18}F]-1-amino-3-fluorocyclobutane-1-carboxylic acid (FACBC). In another aspect, the invention features pharmaceutical compositions comprised of an {alpha}-amino acid moiety attached to either a four, five, or a six member carbon-chain ring. In addition, the invention features analogs of {alpha}-aminoisobutyric acid.

  20. Amino acid analogs for tumor imaging

    Energy Technology Data Exchange (ETDEWEB)

    Goodman, Mark M. (Atlanta, GA); Shoup, Timothy (Decatur, GA)

    1998-09-15

    The invention provides novel amino acid compounds of use in detecting and evaluating brain and body tumors. These compounds combine the advantageous properties of 1-amino-cycloalkyl-1-carboxylic acids, namely, their rapid uptake and prolonged retention in tumors with the properties of halogen substituents, including certain useful halogen isotopes including fluorine-18, iodine-123, iodine-125, iodine-131, bromine-75, bromine-76, bromine-77 and bromine-82. In one aspect, the invention features amino acid compounds that have a high specificity for target sites when administered to a subject in vivo. Preferred amino acid compounds show a target to non-target ratio of at least 5:1, are stable in vivo and substantially localized to target within 1 hour after administration. An especially preferred amino acid compound is ›.sup.18 F!-1-amino-3-fluorocyclobutane-1-carboxylic acid (FACBC). In another aspect, the invention features pharmaceutical compositions comprised of an .alpha.-amino acid moiety attached to either a four, five, or a six member carbon-chain ring. In addition, the invention features analogs of .alpha.-aminoisobutyric acid.

  1. Amino acid analogs for tumor imaging

    Energy Technology Data Exchange (ETDEWEB)

    Goodman, Mark M. (Atlanta, GA); Shoup, Timothy (Decatur, GA)

    1998-10-06

    The invention provides novel amino acid compounds of use in detecting and evaluating brain and body tumors. These compounds combine the advantageous properties of 1-amino-cycloalkyl-1-carboxylic acids, namely, their rapid uptake and prolonged retention in tumors with the properties of halogen substituents, including certain useful halogen isotopes including fluorine-18, iodine-123, iodine-125, iodine-131, bromine-75, bromine-76, bromine-77 and bromine-82. In one aspect, the invention features amino acid compounds that have a high specificity for target sites when administered to a subject in vivo. Preferred amino acid compounds show a target to non-target ratio of at least 5:1, are stable in vivo and substantially localized to target within 1 hour after administration. An especially preferred amino acid compound is ›.sup.18 F!-1-amino-3-fluorocyclobutane-1-carboxylic acid (FACBC). In another aspect, the invention features pharmaceutical compositions comprised of an .alpha.-amino acid moiety attached to either a four, five, or a six member carbon-chain ring. In addition, the invention features analogs of .alpha.-aminoisobutyric acid.

  2. Amino acid analogs for tumor imaging

    Energy Technology Data Exchange (ETDEWEB)

    Goodman, M.M.; Shoup, T.

    1998-10-06

    The invention provides novel amino acid compounds of use in detecting and evaluating brain and body tumors. These compounds combine the advantageous properties of 1-amino-cycloalkyl-1-carboxylic acids, namely, their rapid uptake and prolonged retention in tumors with the properties of halogen substituents, including certain useful halogen isotopes including fluorine-18, iodine-123, iodine-125, iodine-131, bromine-75, bromine-76, bromine-77 and bromine-82. In one aspect, the invention features amino acid compounds that have a high specificity for target sites when administered to a subject in vivo. Preferred amino acid compounds show a target to non-target ratio of at least 5:1, are stable in vivo and substantially localized to target within 1 hour after administration. An especially preferred amino acid compound is [{sup 18}F]-1-amino-3-fluorocyclobutane-1-carboxylic acid (FACBC). In another aspect, the invention features pharmaceutical compositions comprised of an {alpha}-amino acid moiety attached to either a four, five, or a six member carbon-chain ring. In addition, the invention features analogs of {alpha}-aminoisobutyric acid.

  3. Amino Acids in the Martian Meteorite Nakhla

    Science.gov (United States)

    Glavin, Daniel P.; Bada, Jeffrey L.; Brinton, Karen L. F.; McDonald, Gene D.

    1999-08-01

    A suite of protein and nonprotein amino acids were detected with high-performance liquid chromatography in the water- and acid-soluble components of an interior fragment of the Martian meteorite Nakhla, which fell in Egypt in 1911. Aspartic and glutamic acids, glycine, alanine, β -alanine, and γ -amino-n-butyric acid (γ -ABA) were the most abundant amino acids detected and were found primarily in the 6 M HCl-hydrolyzed, hot water extract. The concentrations ranged from 20 to 330 parts per billion of bulk meteorite. The amino acid distribution in Nakhla, including the D/L ratios (values range from contamination of Martian meteorites after direct exposure to the terrestrial environment has important implications for Mars sample-return missions and the curation of the samples from the time of their delivery to Earth.

  4. Amino acids analysis during lactic acid fermentation by single strain ...

    African Journals Online (AJOL)

    SAM

    2014-07-09

    Jul 9, 2014 ... of the three LAB strains to utilize amino acids for growth and lactic acid production were employed to ... Lactic acid bacteria (LAB), which are used for the ..... and characterization of potential probiotic lactobacilli from pig feces.

  5. Amino Acid Stability in the Early Oceans

    Science.gov (United States)

    Parker, E. T.; Brinton, K. L.; Burton, A. S.; Glavin, D. P.; Dworkin, J. P.; Bada, J. L.

    2015-01-01

    It is likely that a variety of amino acids existed in the early oceans of the Earth at the time of the origin and early evolution of life. "Primordial soup", hydrothermal vent, and meteorite based processes could have contributed to such an inventory. Several "protein" amino acids were likely present, however, based on prebiotic synthesis experiments and carbonaceous meteorite studies, non-protein amino acids, which are rare on Earth today, were likely the most abundant. An important uncertainty is the length of time these amino acids could have persisted before their destruction by abiotic and biotic processes. Prior to life, amino acid concentrations in the oceans were likely regulated by circulation through hydro-thermal vents. Today, the entire ocean circulates through vent systems every 10(exp 7) years. On the early Earth, this value was likely smaller due to higher heat flow and thus marine amino acid life-time would have been shorter. After life, amino acids in the oceans could have been assimilated by primitive organisms.

  6. Enantiomer-specific selection of amino acids

    Science.gov (United States)

    Ren, Xueying; Tellez, Luis A; de Araujo, Ivan E

    2013-01-01

    Dietary intake of L-amino acids impacts on several physiological functions, including the control of gastrointestinal motility, pancreatic secretion, and appetite. However, the biological mechanisms regulating behavioral predilections for certain amino acid types remain poorly understood. We tested the hypothesis that, in mice, the potency with which a given glucogenic amino acid increases glucose utilization reflects its rewarding properties. We have found that: 1. During long-, but not short-, term preference tests, L-alanine and L-serine were preferred over their D-enantiomer counterparts, while no such effect was observed for L-threonine vs. D-threonine; 2. These behavioral patterns were closely associated with the ability of L-amino acids to promote increases in respiratory exchange ratios such that those, and only those, L-amino acids able to promote increases in respiratory exchange ratios were preferred over their D-isomers; 3. These behavioral preferences were independent of gustatory influences, since taste-deficient Trpm5 knockout mice displayed ingestive responses very similar to those of their wild-type counterparts. We conclude that the ability to promote increases in respiratory exchange ratios enhances the reward value of nutritionally relevant amino acids, and suggest a mechanistic link between substrate utilization and amino acid preferences. PMID:24072505

  7. Distribution of Amino Acids in Lunar Regolith

    Science.gov (United States)

    Elsila, J. E.; Callahan, M. P.; Glavin, D. P.; Dworkin, J. P.; Noble, S. K.; Gibson, E. K., Jr.

    2014-01-01

    One of the most eagerly studied questions upon initial return of lunar samples was whether significant amounts of organic compounds, including amino acids, were present. Analyses during the 1970s produced only tentative and inconclusive identifications of indigenous amino acids. Those analyses were hampered by analytical difficulties including relative insensitivity to certain compounds, the inability to separate chiral enantiomers, and the lack of compound-specific isotopic measurements, which made it impossible to determine whether the detected amino acids were indigenous to the lunar samples or the results of contamination. Numerous advances have been made in instrumentation and methodology for amino acid characterization in extraterrestrial samples in the intervening years, yet the origin of amino acids in lunar regolith samples has been revisited only once for a single lunar sample, (3) and remains unclear. Here, we present initial data from the analyses of amino acid abundances in 12 lunar regolith samples. We discuss these abundances in the context of four potential amino acid sources: (1) terrestrial biological contamination; (2) contamination from lunar module (LM) exhaust; (3) derivation from solar windimplanted precursors; and (4) exogenous delivery from meteorites.

  8. Enantiomer-specific selection of amino acids.

    Science.gov (United States)

    Ren, Xueying; Tellez, Luis A; de Araujo, Ivan E

    2013-12-01

    Dietary intake of L-amino acids impacts on several physiological functions, including the control of gastrointestinal motility, pancreatic secretion, and appetite. However, the biological mechanisms regulating behavioral predilections for certain amino acid types remain poorly understood. We tested the hypothesis that, in mice, the potency with which a given glucogenic amino acid increases glucose utilization reflects its rewarding properties. We have found that: (1) during long-, but not short-, term preference tests, L-alanine and L-serine were preferred over their D-enantiomer counterparts, while no such effect was observed for L-threonine vs. D-threonine; (2) these behavioral patterns were closely associated with the ability of L-amino acids to promote increases in respiratory exchange ratios such that those, and only those, L-amino acids able to promote increases in respiratory exchange ratios were preferred over their D-isomers; (3) these behavioral preferences were independent of gustatory influences, since taste-deficient Trpm5 knockout mice displayed ingestive responses very similar to those of their wild-type counterparts. We conclude that the ability to promote increases in respiratory exchange ratios enhances the reward value of nutritionally relevant amino acids and suggest a mechanistic link between substrate utilization and amino acid preferences.

  9. 肝癌病人血浆氨基酸变化与肝功能的相关性分析%Plasma amino acid changes in patients with liver cancer and liver function in correlation analysis

    Institute of Scientific and Technical Information of China (English)

    范志娟; 刘树业

    2011-01-01

    目的 探讨肝癌病人血浆氨基酸谱变化与肝功能的相关性.方法 对100例肝癌病人进行血浆氨基酸的检测和肝功能的检测,并做两者的相关性分析.结果 氨基酸谱变化显示肝癌患者中有9种氨基酸发生变化,其中6种氨基酸升高,3种氨基酸降低.氨基酸谱与肝功能相关性分析显示:1.苏氨酸(THR)、蛋氨酸(MET)与谷丙转氨酶(ALT)成正相关;2.谷氨酸(GLU)、蛋氨酸、酪氨酸(TYR)、苯丙氨酸(PHE)、赖氨酸(LYS)与总胆红素(TBIL)、结合胆红素(DBIL)、游离胆红素(IBIL)成正相关,且蛋氨酸、酪氨酸与其三者成中度正相关;3、缬氨酸(VAL)和亮氨酸(LEU)与白蛋白(ALB)、前白蛋白(PALB)成正相关,且亮氨酸与总蛋白(TP), 白蛋白、白球比(A/G),胆碱酯酶(CHE), 前白蛋白均成正相关;4、支芳比与ALB,A/G,CHE,PALB成正相关,与TBIL,DBIL,IBIL成负相关.结论 肝癌病人血浆氨基酸谱变化广泛,可直接反映机体的代谢及营养状况;氨基酸变化水平与肝功能密切相关,可间接反映肝细胞破坏及坏死程度,氨基酸与肝功能的联合检测对肝癌患者的诊断,治疗及预后具有重要意义.%Objective To study the spectrum of plasma amino acid changes in patients with liver cancer and liver function correlation.Methods We use 100 cases of liver cancer patients make plasma amino acid testing and liver function testing ,and do analysis of the correlation between the two.Results amino acid changes in liver cancer patients in 9 kinds of amino acids changes ,including six kinds of amino acids increased three kinds of amino acids reduced.Amino acids and liver function correlation analysis showed that :1 ,threonine ,methionine was positively correlated with ALT ;2, glutamic acid ,methionine -tyrosine, phenylalanine, lysine and total bilirubin bilirubin ,free bilirubin was positively correlated ,and methionine ,tyrosine into a moderate positive correlation with the three;3 ,VAL ,and LET with

  10. Amino Acid Degradation after Meteoritic Impact Simulation

    Science.gov (United States)

    Bertrand, M.; Westall, F.; vanderGaast, S.; Vilas, F.; Hoerz, F.; Barnes, G.; Chabin, A.; Brack, A.

    2008-01-01

    Amino acids are among the most important prebiotic molecules as it is from these precursors that the building blocks of life were formed [1]. Although organic molecules were among the components of the planetesimals making up the terrestrial planets, large amounts of primitive organic precursor molecules are believed to be exogenous in origin and to have been imported to the Earth via micrometeorites, carbonaceous meteorites and comets, especially during the early stages of the formation of the Solar System [1,2]. Our study concerns the hypothesis that prebiotic organic matter, present on Earth, was synthesized in the interstellar environment, and then imported to Earth by meteorites or micrometeorites. We are particularly concerned with the formation and fate of amino acids. We have already shown that amino acid synthesis is possible inside cometary grains under interstellar environment conditions [3]. We are now interested in the effects of space conditions and meteoritic impact on these amino acids [4-6]. Most of the extraterrestrial organic molecules known today have been identified in carbonaceous chondrite meteorites [7]. One of the components of these meteorites is a clay with a composition close to that of saponite, used in our experiments. Two American teams have studied the effects of impact on various amino acids [8,9]. [8] investigated amino acids in saturated solution in water with pressure ranges between 5.1 and 21 GPa and temperature ranges between 412 and 870 K. [9] studied amino acids in solid form associated with and without minerals (Murchison and Allende meteorite extracts) and pressure ranges between 3 and 30 GPa. In these two experiments, the amino acids survived up to 15 GPa. At higher pressure, the quantity of preserved amino acids decreases quickly. Some secondary products such as dipeptides and diketopiperazins were identified in the [8] experiment.

  11. Amino acids in the Martian meteorite Nakhla.

    Science.gov (United States)

    Glavin, D P; Bada, J L; Brinton, K L; McDonald, G D

    1999-08-03

    A suite of protein and nonprotein amino acids were detected with high-performance liquid chromatography in the water- and acid-soluble components of an interior fragment of the Martian meteorite Nakhla, which fell in Egypt in 1911. Aspartic and glutamic acids, glycine, alanine, beta-alanine, and gamma-amino-n-butyric acid (gamma-ABA) were the most abundant amino acids detected and were found primarily in the 6 M HCl-hydrolyzed, hot water extract. The concentrations ranged from 20 to 330 parts per billion of bulk meteorite. The amino acid distribution in Nakhla, including the D/L ratios (values range from meteorite soon after its fall to Earth, although it is possible that some of the amino acids are endogenous to the meteorite. The rapid amino acid contamination of Martian meteorites after direct exposure to the terrestrial environment has important implications for Mars sample-return missions and the curation of the samples from the time of their delivery to Earth.

  12. Discovery and History of Amino Acid Fermentation.

    Science.gov (United States)

    Hashimoto, Shin-Ichi

    There has been a strong demand in Japan and East Asia for L-glutamic acid as a seasoning since monosodium glutamate was found to present umami taste in 1907. The discovery of glutamate fermentation by Corynebacterium glutamicum in 1956 enabled abundant and low-cost production of the amino acid, creating a large market. The discovery also prompted researchers to develop fermentative production processes for other L-amino acids, such as lysine. Currently, the amino acid fermentation industry is so huge that more than 5 million metric tons of amino acids are manufactured annually all over the world, and this number continues to grow. Research on amino acid fermentation fostered the notion and skills of metabolic engineering which has been applied for the production of other compounds from renewable resources. The discovery of glutamate fermentation has had revolutionary impacts on both the industry and science. In this chapter, the history and development of glutamate fermentation, including the very early stage of fermentation of other amino acids, are reviewed.

  13. EXAMINATION OF VITAMIN AND AMINO ACID PROFILES OF ...

    African Journals Online (AJOL)

    AGROSEARCH UIL

    content of RGWF. The total essential amino acid (TEAA), percentage total non essential amino acid (%TEAA) ... Key words: Amino acid, vitamin, gmelina, fruit, pulp, livestock, feed. ..... “Lippincott's Illustrated Reviews: Biochemistry.” 4th. Edition ...

  14. An astrophysically-relevant mechanism for amino acid enantiomer enrichment

    NARCIS (Netherlands)

    P. Fletcher, S.; B. C. Jagt, R.; Feringa, B.L.

    2007-01-01

    The sublimation of low ee amino acids was examined while exploring simple mechanisms by which high ee amino acids can be generated under conditions that exist in space; significant enantioenrichment of a variety of amino acids by sublimation was achieved.

  15. Amino acids profile of four Nile fish

    African Journals Online (AJOL)

    juba

    This study was intended to identify contents of amino acids (AAs) of four commercial Nile fishes in. Sudan and to ... and Lysine-rich ingredients (fish meal, blood meal) are often expensive ... However, determination process of tryptophan from ...

  16. AMINO ACIDS APPLICATION TO CREATE OF NANOSTRUCTURES

    Directory of Open Access Journals (Sweden)

    I. S. Chekman

    2014-12-01

    Full Text Available Review is devoted to the amino acids that could be used for nanostructures creation. The investigation of corresponding properties of amino acids is essential for their role definition in creation of nanomedicines. However, amino acid studying as components of nanostructures is insufficient. Study of nanoparticles for medicines creation was initiated by the development of nanotechnology. Amino acids in complexes with the nanoparticles of organic and inorganic nature play an important role for medicines targeting in pathological process. They could reduce toxicity of the nanomaterials used in nanomedicine and are used for creation of biosensors, lab-on-chip and therefore they are a promising material for synthesis of new nanodrugs and diagnostic tools.

  17. Amino Acid Biosynthesis Pathways in Diatoms

    Directory of Open Access Journals (Sweden)

    Mariusz A. Bromke

    2013-04-01

    Full Text Available Amino acids are not only building blocks for proteins but serve as precursors for the synthesis of many metabolites with multiple functions in growth and other biological processes of a living organism. The biosynthesis of amino acids is tightly connected with central carbon, nitrogen and sulfur metabolism. Recent publication of genome sequences for two diatoms Thalassiosira pseudonana and Phaeodactylum tricornutum created an opportunity for extensive studies on the structure of these metabolic pathways. Based on sequence homology found in the analyzed diatomal genes, the biosynthesis of amino acids in diatoms seems to be similar to higher plants. However, one of the most striking differences between the pathways in plants and in diatomas is that the latter possess and utilize the urea cycle. It serves as an important anaplerotic pathway for carbon fixation into amino acids and other N-containing compounds, which are essential for diatom growth and contribute to their high productivity.

  18. Side Chain Cyclized Aromatic Amino Acids

    DEFF Research Database (Denmark)

    Van der Poorten, Olivier; Knuhtsen, Astrid; Sejer Pedersen, Daniel

    2016-01-01

    Constraining the conformation of flexible peptides is a proven strategy to increase potency, selectivity, and metabolic stability. The focus has mostly been on constraining the backbone dihedral angles; however, the correct orientation of the amino acid side chains (χ-space) that constitute...... the peptide pharmacophore is equally important. Control of χ-space utilizes conformationally constrained amino acids that favor, disfavor, or exclude the gauche (-), the gauche (+), or the trans conformation. In this review we focus on cyclic aromatic amino acids in which the side chain is connected...... to the peptide backbone to provide control of χ(1)- and χ(2)-space. The manifold applications for cyclized analogues of the aromatic amino acids Phe, Tyr, Trp, and His within peptide medicinal chemistry are showcased herein with examples of enzyme inhibitors and ligands for G protein-coupled receptors....

  19. Effects of glucose and amino acids on ghrelin secretion in sheep.

    Science.gov (United States)

    Sugino, Toshihisa; Kawakita, Yuko; Fukumori, Rika; Hasegawa, Yoshihisa; Kojima, Masayasu; Kangawa, Kenji; Obitsu, Taketo; Taniguchi, Kohzo

    2010-04-01

    Two experiments were conducted to elucidate the effects of post-ruminal administration of starch and casein (Exp. 1), plasma amino acids concentrations (Exp. 2), and plasma glucose and insulin concentrations (Exp. 2) on plasma ghrelin concentrations in sheep. In Exp. 1, plasma ghrelin concentrations were determined by four infusion treatments (water, cornstarch, casein and cornstarch plus casein) in four wethers. Abomasal infusion of casein increased plasma alpha-amino N (AAN) concentrations. Infusion of starch or casein alone did not affect plasma ghrelin concentrations, but starch plus casein infusion increased plasma levels of ghrelin, glucose and AAN. In Exp 2, we investigated the effects of saline or amino acids on ghrelin secretion in four wethers. Two hours after the initiation of saline or amino acid infusion into the jugular vein, glucose was also continuously infused to investigate the effects of blood glucose and insulin by hyper-glycemic clump on plasma ghrelin concentrations. Infusion of amino acids alone raised plasma levels of ghrelin, but the higher plasma glucose and insulin concentrations had no effect on plasma ghrelin concentrations. These results suggest that high plasma levels of amino acids can stimulate ghrelin secretion, but glucose and insulin do not affect ghrelin secretion in sheep.

  20. Genetically encoded fluorescent coumarin amino acids

    Science.gov (United States)

    Wang, Jiangyun; Xie, Jianming; Schultz, Peter G.

    2010-10-05

    The invention relates to orthogonal pairs of tRNAs and aminoacyl-tRNA synthetases that can incorporate the coumarin unnatural amino acid L-(7-hydroxycoumarin-4-yl) ethylglycine into proteins produced in eubacterial host cells such as E. coli. The invention provides, for example but not limited to, novel orthogonal synthetases, methods for identifying and making the novel synthetases, methods for producing proteins containing the unnatural amino acid L-(7-hydroxycoumarin-4-yl)ethylglycine and related translation systems.

  1. Genetically encoded fluorescent coumarin amino acids

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Jiangyun [San Diego, CA; Xie, Jianming [San Diego, CA; Schultz, Peter G [La Jolla, CA

    2012-06-05

    The invention relates to orthogonal pairs of tRNAs and aminoacyl-tRNA synthetases that can incorporate the coumarin unnatural amino acid L-(7-hydroxycoumarin-4-yl)ethylglycine into proteins produced in eubacterial host cells such as E. coli. The invention provides, for example but not limited to, novel orthogonal synthetases, methods for identifying and making the novel synthetases, methods for producing proteins containing the unnatural amino acid L-(7-hydroxycoumarin-4-yl)ethylglycine and related translation systems.

  2. Evaluation of amino acids as turfgrass nematicides.

    Science.gov (United States)

    Zhang, Yun; Luc, John E; Crow, William T

    2010-12-01

    Laboratory experiments revealed that DL-methionine, sodium methionate, potassium methionate, and methionine hydroxyl analog at rates of 224 and 448 kg amino acid/ha reduced the number of Belonolaimus longicaudatus mixed life-stages and Meloidogyne incognita J2 in soil, whereas L-threonine and lysine were not effective in reducing the number of either nematode. Futhermore, greenhouse experiments demonstrated that DL-methionine, sodium methionate, potassium methionate, and methionine hydroxyl analog were equally effective against B. longicaudatus at rates of 112, 224, and 448 kg amino acid/ha, and the highest rate (448 kg amino acid/ha) of all amino acids was more effective in reducing the number of B. longicaudatus than the lower rate. However, phytotoxicity was observed on creeping bentgrass (Agrostis palustris) treated with 448 kg amino acid/ha of methionine hydroxyl analog and DL methionine. In addition, in one of two field experiments on bermudagrass (Cynodon dactylon × C. transvaalensis) turf percentage green cover was increased and the number of B. longicaudatus was reduced by 224 kg amino acid/ha of DL-methionine and potassium methionate compared to untreated controls in one of two trials.

  3. Effect of a microbial phytase on growth performance, plasma parameters and apparent ileal amino acid digestibility in Youxian Sheldrake fed a low-phosphorus corn-soybean diet

    Directory of Open Access Journals (Sweden)

    Shaoping He

    2017-10-01

    Full Text Available Objective This study investigated the effect of microbial phytase supplementation on growth performance, tibia ash, plasma parameters, apparent ileal digestibility (AID of amino acid (AA and apparent digestibility of nutrients in Youxian Sheldrakes fed with low-phosphorus (P corn-soybean diets. Methods A total of 350 Youxian Sheldrakes (7d old were randomly divided into 5 treatment groups: positive control (PC group has adequate available P diet (0.42% and 0.38%, starter and grower, negative control (NC group were deficient in available P (0.32% and 0.28%, starter and grower and NC diet was supplemented with 3 levels of microbial phytase (500, 750, and 1,000 U/kg. Results Dietary supplementation of phytase in NC diet improved the average daily gain, increased the levels of serum calcium (Ca, tibia Ca and P, AID of AA and apparent digestibility of energy and Ca in starter stage (p<0.05. There was an increased (p<0.001 in the utilization of P from 17.3% to 23.9%. Phytase supplementation (1,000 U/kg has shown that the AID of His, Thr, Val, indispensable AA, Glu, Pro, and dispensable AA was higher (p<0.05 than that of NC. Moreover, phytase supplementation improved (p<0.05 serum and tibia Ca and P, AID of AA and apparent digestibility of dry matter, crude protein, energy, P and Ca, and reduced (p<0.05 feed to gain ratio (F/G and the levels of serum alkaline phosphatase in grower stage. Likewise, an increase (p<0.001 in the utilization of P was noticed from 12.6% to 17.2%. Supplement phytase at 750 U/kg improved the AID of His, Thr, Asp, Cys, Pro, and Ser (p<0.05. Conclusion The microbial phytase supplement could improve growth performance, AID of some AA and apparent utilization of other nutrients in Youxian Sheldrakes, and reduce excreta P load to environment.

  4. Effects of Exogenous Amino Acids on the Contents of Amino Acids in Tobacco Leaves

    Institute of Scientific and Technical Information of China (English)

    WU Xue-ping; LIU Guo-shun; ZHU Kai; PENG Sa; GUO Qiao-yan

    2005-01-01

    The effect of three amino acids on the growth of flue-cured tobacco was studied with water culture. The results showed that the three amino acids improved the growth of flue-cured tobacco and increased the contents of chlorophyll a,chlorophyll b and carotenoid in tobacco. At the same time, the activities of NR (nitrate reductase), INV(invertase) and root growth activity were also significantly enhanced. The exogenous glutamic, aspartate and phenylalanine all increased the amino acid contents of tobacco leaves. Of these three amino acids, glutamic had the greatest effect, the next was aspartate,and phenylalanine had the least effect. These three amino acids all had significantly increased the accumulation of amino acids in the leaves of individual plants of tobacco; and the magnitude of accumulation indicated aspartate > glutamic >phenylalanine.

  5. Incretin effect after oral amino Acid ingestion in humans

    DEFF Research Database (Denmark)

    Lindgren, Ola; Pacini, Giovanni; Tura, Andrea

    2015-01-01

    is also present after amino acid ingestion is not known. OBJECTIVE: The objective of the study was to explore insulin secretion and incretin hormones after oral and iv amino acid administration at matched total amino acid concentrations in healthy subjects. DESIGN: An amino acid mixture (Vaminolac......: Oral amino acid mixture ingestion elicits a stronger insulin secretory response than iv amino acid at matching amino acid levels and this is associated with increased GIP level, suggesting that an incretin effect exists also after oral amino acids, possibly mediated by GIP....

  6. Synthesis of L-2-amino-8-oxodecanoic acid: an amino acid component of apicidins

    OpenAIRE

    Linares de la Morena, María Lourdes; Agejas Chicharro, Francisco Javier; Alajarín Ferrández, Ramón; Vaquero López, Juan José; Álvarez-Builla Gómez, Julio

    2001-01-01

    The synthesis Of L-2-amino-8-oxodecanoic acid (Aoda) is described. This is a rare amino acid component of apicidins, a family of new cyclic tetrapeptides, inhibitors of histone deacetylase. Aoda was synthesised in seven steps from L-glutamic acid along with some derivatives. Universidad de Alcalá Fundación General de la Universidad de Alcalá FEDER

  7. Hybrid gold single crystals incorporating amino acids

    CERN Document Server

    Chen, Linfeng; Weber, Eva; Fitch, Andy N; Pokroy, Boaz

    2016-01-01

    Composite hybrid gold crystals are of profound interest in various research areas ranging from materials science to biology. Their importance is due to their unique properties and potential implementation, for example in sensing or in bio-nanomedicine. Here we report on the formation of hybrid organic-metal composites via the incorporation of selected amino acids histidine, aspartic acid, serine, glutamine, alanine, cysteine, and selenocystine into the crystal lattice of single crystals of gold. We used electron microscopy, chemical analysis and high-resolution synchrotron powder X ray diffraction to examine these composites. Crystal shape, as well as atomic concentrations of occluded amino acids and their impact on the crystal structure of gold, were determined. Concentration of the incorporated amino acid was highest for cysteine, followed by serine and aspartic acid. Our results indicate that the incorporation process probably occurs through a complex interaction of their individual functional groups with ...

  8. Amino acid survival in large cometary impacts

    Science.gov (United States)

    Pierazzo, E.; Chyba, C. F.

    1999-11-01

    A significant fraction of the Earth's prebiotic volatile inventory may have been delivered by asteroidal and cometary impacts during the period of heavy bombardment. The realization that comets are particularly rich in organic material seemed to strengthen this suggestion. Previous modeling studies, however, indicated that most organics would be entirely destroyed in large comet and asteroid impacts. The availability of new kinetic parameters for the thermal degradation of amino acids in the solid phase made it possible to readdress this question. We present the results of new high-resolution hydrocode simulations of asteroid and comet impact coupled with recent experimental data for amino acid pyrolysis in the solid phase. Differences due to impact velocity as well as projectile material have been investigated. Effects of angle of impacts were also addressed. The results suggest that some amino acids would survive the shock heating of large (kilometer-radius) cometary impacts. At the time of the origins of life on Earth, the steady-state oceanic concentration of certain amino acids (like aspartic and glutamic acid) delivered by comets could have equaled or substantially exceeded that due to Miller-Urey synthesis in a carbon dioxide-rich atmosphere. Furthermore, in the unlikely case of a grazing impact (impact angle around 5 degrees from the horizontal) an amount of some amino acids comparable to that due to the background steady-state production or delivery would be delivered to the early Earth.

  9. Interaction of Atmospheric-Pressure Air Microplasmas with Amino Acids as Fundamental Processes in Aqueous Solution.

    Directory of Open Access Journals (Sweden)

    Renwu Zhou

    Full Text Available Plasma medicine is a relatively new field that investigates potential applications of cold atmospheric-pressure plasmas in bioengineering, such as for bacterial inactivation and degradation of organic molecules in water. In order to enunciate mechanisms of bacterial inactivation at molecular or atomic levels, we investigated the interaction of atmospheric-pressure air microplasmas with amino acids in aqueous solution by using high-resolution mass spectrometry (HRMS. Results show that the oxidation effect of plasma-induced species on the side chains of the amino acids can be categorized into four types, namely hydroxylation, nitration, dehydrogenation and dimerization. In addition, relative activities of amino acids resulting from plasma treatment come in descending order as follows: sulfur-containing carbon-chain amino acids > aromatic amino acids > five-membered ring amino acids > basic carbon-chain amino acids. Since amino acids are building blocks of proteins vital to the growth and reproduction of bacteria, these results provide an insight into the mechanism of bacterial inactivation by plasma.

  10. Interaction of Atmospheric-Pressure Air Microplasmas with Amino Acids as Fundamental Processes in Aqueous Solution

    Science.gov (United States)

    Zhou, Renwu; Zhou, Rusen; Zhuang, Jinxing; Zong, Zichao; Zhang, Xianhui; Liu, Dongping; Bazaka, Kateryna; Ostrikov, Kostya

    2016-01-01

    Plasma medicine is a relatively new field that investigates potential applications of cold atmospheric-pressure plasmas in bioengineering, such as for bacterial inactivation and degradation of organic molecules in water. In order to enunciate mechanisms of bacterial inactivation at molecular or atomic levels, we investigated the interaction of atmospheric-pressure air microplasmas with amino acids in aqueous solution by using high-resolution mass spectrometry (HRMS). Results show that the oxidation effect of plasma-induced species on the side chains of the amino acids can be categorized into four types, namely hydroxylation, nitration, dehydrogenation and dimerization. In addition, relative activities of amino acids resulting from plasma treatment come in descending order as follows: sulfur-containing carbon-chain amino acids > aromatic amino acids > five-membered ring amino acids > basic carbon-chain amino acids. Since amino acids are building blocks of proteins vital to the growth and reproduction of bacteria, these results provide an insight into the mechanism of bacterial inactivation by plasma. PMID:27183129

  11. Glucagon and Amino Acids Are Linked in a Mutual Feedback Cycle

    DEFF Research Database (Denmark)

    Holst, Jens J; Wewer Albrechtsen, Nicolai J; Pedersen, Jens

    2017-01-01

    ; neither condition is necessarily associated with disturbed glucose metabolism. In glucagonoma patients, amino acid turnover and ureagenesis are greatly accelerated, and low plasma amino acid levels are probably at least partly responsible for the necrolytic migratory erythema, which resolves after amino...... acid administration. In patients with receptor mutations (and in knockout mice), pancreatic swelling is due to α-cell hyperplasia with gross hypersecretion of glucagon, which according to recent groundbreaking research may result from elevated amino acid levels. Additionally, solid evidence indicates...... that ureagenesis, and thereby amino acid levels, is critically controlled by glucagon. Together, this constitutes a complete endocrine system; feedback regulation involving amino acids regulates α-cell function and secretion, while glucagon, in turn, regulates amino acid turnover....

  12. Branched chain amino acid profile in early chronic kidney disease

    Directory of Open Access Journals (Sweden)

    M Anil Kumar

    2012-01-01

    Full Text Available The nutritional status in chronic kidney disease (CKD patients is a predictor of prognosis during the first period of dialysis. Serum albumin is the most commonly used nutritional marker. Another index is plasma amino acid profile. Of these, the plasma levels of branched chain amino acids (BCAA, especially valine and leucine, correlate well with nutritional status. Plasma BCAAs were evaluated along with albumin and C-reactive protein in 15 patients of early stages of CKD and 15 age- and sex-matched healthy controls. A significant decrease in plasma valine, leucine and albumin levels was observed in CKD patients when compared with the controls (P <0.05. No significant difference in C-reactive protein (CRP levels was observed between the two groups. Malnutrition seen in our CKD patients in the form of hypoalbuminemia and decreased concentrations of BCAA points to the need to evaluate the nutritional status in the early stages itself. Simple measures in the form of amino acid supplementation should be instituted early to decrease the morbidity and mortality before start of dialysis in these patients.

  13. Amino acid uptake in rust fungi.

    Science.gov (United States)

    Struck, Christine

    2015-01-01

    The plant pathogenic rust fungi colonize leaf tissue and feed off their host plants without killing them. Certain economically important species of different genera such as Melampsora, Phakopsora, Puccinia, or Uromyces are extensively studied for resolving the mechanisms of the obligate biotrophy. As obligate parasites rust fungi only can complete their life cycle on living hosts where they grow through the leaf tissue by developing an extended network of intercellular hyphae from which intracellular haustoria are differentiated. Haustoria are involved in key functions of the obligate biotrophic lifestyle: suppressing host defense responses and acquiring nutrients. This review provides a survey of rust fungi nitrogen nutrition with special emphasis on amino acid uptake. A variety of sequences of amino acid transporter genes of rust fungi have been published; however, transport activity of only three in planta highly up-regulated amino acid permeases have been characterized. Functional and immunohistochemical investigations have shown the specificity and localization of these transporters. Sequence data of various genome projects allowed identification of numerous rust amino acid transporter genes. An in silico analysis reveals that these genes can be classified into different transporter families. In addition, genetic and molecular data of amino acid transporters have provided new insights in the corresponding metabolic pathways.

  14. Amino acid "little Big Bang": Representing amino acid substitution matrices as dot products of Euclidian vectors

    Directory of Open Access Journals (Sweden)

    Zimmermann Karel

    2010-01-01

    Full Text Available Abstract Background Sequence comparisons make use of a one-letter representation for amino acids, the necessary quantitative information being supplied by the substitution matrices. This paper deals with the problem of finding a representation that provides a comprehensive description of amino acid intrinsic properties consistent with the substitution matrices. Results We present a Euclidian vector representation of the amino acids, obtained by the singular value decomposition of the substitution matrices. The substitution matrix entries correspond to the dot product of amino acid vectors. We apply this vector encoding to the study of the relative importance of various amino acid physicochemical properties upon the substitution matrices. We also characterize and compare the PAM and BLOSUM series substitution matrices. Conclusions This vector encoding introduces a Euclidian metric in the amino acid space, consistent with substitution matrices. Such a numerical description of the amino acid is useful when intrinsic properties of amino acids are necessary, for instance, building sequence profiles or finding consensus sequences, using machine learning algorithms such as Support Vector Machine and Neural Networks algorithms.

  15. Economic aspects of amino acids production.

    Science.gov (United States)

    Mueller, Udo; Huebner, Susanna

    2003-01-01

    Amino acids represent basic elements of proteins, which as a main source of nutrition themselves serve as a major reserve for maintaining essential functions of humans as well as animals. Taking the recent state of scientific knowledge into account, the industrial sector of amino acids is a priori "suitable" to a specific kind of an ecologically sound way of production, which is based on biotechnology. The following article may point out characteristics of this particular industrial sector and illustrates the applicability of the latest economic methods, founded on development of the discipline of bionics in order to describe economic aspects of amino acids markets. The several biochemical and technological fields of application of amino acids lead to specific market structures in high developed and permanently evolving systems. The Harvard tradition of industrial economics explains how market structures mould the behaviour of the participants and influences market results beyond that. A global increase in intensity of competition confirms the notion that the supply-side is characterised by asymmetric information in contrast to Kantzenbachs concept of "narrow oligopoly" with symmetrical shared knowledge about market information. Departing from this point, certain strategies of companies in this market form shall be derived. The importance of Research and Development increases rapidly and leads to innovative manufacturing methods which replace more polluting manufacturing processes like acid hydrolysis. In addition to these modifications within the production processes the article deals furthermore with the pricing based on product life cycle concept and introduces specific applications of tools like activity based costing and target costing to the field of amino acid production. The authors come to the conclusion that based on a good transferability of latest findings in bionics and ecological compatibility competitors in amino acids manufacturing are well advised

  16. Postprandial fate of amino acids: adaptation to molecular forms

    NARCIS (Netherlands)

    Nolles, J.A.

    2006-01-01

    During the postprandial phase dietary proteins are digested to peptides and amino acids and absorbed. Once absorbed the peptides are further hydrolyzed to amino acids and transported to the tissues. These amino acids are largely incorporated into body proteins. Not all amino acids are, however,

  17. AMINO ACID METABOLISM IN COWS DURING THE TRANSITION PERIOD IN BALANCING DIET ON THE EXCHANGE PROTEIN AND DIGESTIBLE AMINO ACIDS

    Directory of Open Access Journals (Sweden)

    Ryadchikov V. G.

    2014-02-01

    Full Text Available Application of a factorial method for determining the needs in metabolic protein and essential amino acids, helps to deepen knowledge on physiology of protein and amino acid supply and allow to improve the standards for dairy cows during the transition period; in insufficient of metabolic protein and essential amino acids increased coefficients of their transformation into net protein and absorptive amino acids as a result of mobilization of body of cows; with an optimal protein nutrition their transformation in net milk protein, lysine and methionine accordingly amounted to 0.67, 0,83 and 0,82. The most significant changes in the concentration of methionine, proline, glutamate, glutamine, glycine were observed in cows before calving and immediately after birth, stabilization of their level starts with a 24 lactation day, that is connected with the peculiarities of the feeding behavior of the cows and the gradual intensification of the processes of metabolism and milk production. To control the status of protein metabolism we have offered benchmarks compositions of free amino acids in cows’ blood plasma phases: 21-0 days before calving, 0-21 and 22-120 days after calving

  18. Prolonged maternal amino acid infusion in late-gestation pregnant sheep increases fetal amino acid oxidation.

    Science.gov (United States)

    Rozance, Paul J; Crispo, Michelle M; Barry, James S; O'Meara, Meghan C; Frost, Mackenzie S; Hansen, Kent C; Hay, William W; Brown, Laura D

    2009-09-01

    Protein supplementation during human pregnancy does not improve fetal growth and may increase small-for-gestational-age birth rates and mortality. To define possible mechanisms, sheep with twin pregnancies were infused with amino acids (AA group, n = 7) or saline (C group, n = 4) for 4 days during late gestation. In the AA group, fetal plasma leucine, isoleucine, valine, and lysine concentrations were increased (P < 0.05), and threonine was decreased (P < 0.05). In the AA group, fetal arterial pH (7.365 +/- 0.007 day 0 vs. 7.336 +/- 0.012 day 4, P < 0.005), hemoglobin-oxygen saturation (46.2 +/- 2.6 vs. 37.8 +/- 3.6%, P < 0.005), and total oxygen content (3.17 +/- 0.17 vs. 2.49 +/- 0.20 mmol/l, P < 0.0001) were decreased on day 4 compared with day 0. Fetal leucine disposal did not change (9.22 +/- 0.73 vs. 8.09 +/- 0.63 micromol x min(-1) x kg(-1), AA vs. C), but the rate of leucine oxidation increased 43% in the AA group (2.63 +/- 0.16 vs. 1.84 +/- 0.24 micromol x min(-1) x kg(-1), P < 0.05). Fetal oxygen utilization tended to be increased in the AA group (327 +/- 23 vs. 250 +/- 29 micromol x min(-1) x kg(-1), P = 0.06). Rates of leucine incorporation into fetal protein (5.19 +/- 0.97 vs. 5.47 +/- 0.89 micromol x min(-1) x kg(-1), AA vs. C), release from protein breakdown (4.20 +/- 0.95 vs. 4.62 +/- 0.74 micromol x min(-1) x kg(-1)), and protein accretion (1.00 +/- 0.30 vs. 0.85 +/- 0.25 micromol x min(-1) x kg(-1)) did not change. Consistent with these data, there was no change in the fetal skeletal muscle ubiquitin ligases MaFBx1 or MuRF1 or in the protein synthesis regulators 4E-BP1, eEF2, eIF2alpha, and p70(S6K). Decreased concentrations of certain essential amino acids, increased amino acid oxidation, fetal acidosis, and fetal hypoxia are possible mechanisms to explain fetal toxicity during maternal amino acid supplementation.

  19. Ionotropic excitatory amino acid receptor ligands. Synthesis and pharmacology of a new amino acid AMPA antagonist

    DEFF Research Database (Denmark)

    Madsen, U; Sløk, F A; Stensbøl, T B;

    2000-01-01

    We have previously described the potent and selective (RS)-2-amino-3-(3-hydroxy-5-methyl-4-isoxazolyl)propionic acid (AMPA) receptor agonist, (RS)-2-amino-3-(3-carboxy-5-methyl-4-isoxazolyl)propionic acid (ACPA), and the AMPA receptor antagonist (RS)-2-amino-3-[3-(carboxymethoxy)-5-methyl-4......-isoxazolyl]propionic acid (AMOA). Using these AMPA receptor ligands as leads, a series of compounds have been developed as tools for further elucidation of the structural requirements for activation and blockade of AMPA receptors. The synthesized compounds have been tested for activity at ionotropic...... excitatory amino acid (EAA) receptors using receptor binding and electrophysiological techniques, and for activity at metabotropic EAA receptors using second messenger assays. Compounds 1 and 4 were essentially inactive. (RS)-2-Amino-3-[3-(2-carboxyethyl)-5-methyl-4-isoxazolyl]propionic acid (ACMP, 2...

  20. Cytokines: muscle protein and amino acid metabolism

    DEFF Research Database (Denmark)

    van Hall, Gerrit

    2012-01-01

    raises TNF-α and IL-6 to moderate levels, has only identified IL-6 as a potent cytokine, decreasing systemic amino acid levels and muscle protein metabolism. The marked decrease in circulatory and muscle amino acid concentrations was observed with a concomitant reduction in both the rates of muscle...... of IL-6 on the regulation of muscle protein metabolism but indirectly via IL-6 reducing amino acid availability. SUMMARY: Recent studies suggest that the best described cytokines TNF-α and IL-6 are unlikely to be the major direct mediators of muscle protein loss in inflammatory diseases. However...... protein synthesis and breakdown, that is, reduced turnover with a minor increase in net muscle degradation. Very similar observations have been made in models of acute inflammation, induced by high-dose endotoxin injection. However, these changes were suggested not to be attributed to a direct effect...

  1. Cytokines: muscle protein and amino acid metabolism

    DEFF Research Database (Denmark)

    van Hall, Gerrit

    2012-01-01

    raises TNF-α and IL-6 to moderate levels, has only identified IL-6 as a potent cytokine, decreasing systemic amino acid levels and muscle protein metabolism. The marked decrease in circulatory and muscle amino acid concentrations was observed with a concomitant reduction in both the rates of muscle...... protein synthesis and breakdown, that is, reduced turnover with a minor increase in net muscle degradation. Very similar observations have been made in models of acute inflammation, induced by high-dose endotoxin injection. However, these changes were suggested not to be attributed to a direct effect...... of IL-6 on the regulation of muscle protein metabolism but indirectly via IL-6 reducing amino acid availability. SUMMARY: Recent studies suggest that the best described cytokines TNF-α and IL-6 are unlikely to be the major direct mediators of muscle protein loss in inflammatory diseases. However...

  2. Cometary Amino Acids from the STARDUST Mission

    Science.gov (United States)

    Cook, Jamie Elsila

    2009-01-01

    NASA's Stardust spacecraft returned samples from comet 81 P/WiId 2 to Earth in January 2006. Examinations of the organic compounds in cometary samples can reveal information about the prebiotic organic inventory present on the early Earth and within the early Solar System, which may have contributed to the origin of life. Preliminary studies of Stardust material revealed the presence of a suite of organic compounds including several amines and amino acids, but the origin of these compounds (cometary vs. terrestrial contamination) could not be identified. We have recently measured the carbon isotopic ratios of these amino acids to determine their origin, leading to the first detection of a cometary amino acid.

  3. Metal induced amino acid adsorption on nanotubes

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Chia M., E-mail: abinitio@dragon.nchu.edu.t [Research Center for the Remediation of Soil and Ground Water Pollution, Department of Soil and Environmental Sciences, National Chung Hsing University, Taichung 402, Taiwan (China); Jalbout, Abraham F. [Departamento de Investigacion en Fisica, Universidad de Sonora, Hermosillo, Sonora C.P., 83000 Mexico (Mexico)

    2010-02-01

    In this work we detail the mechanism by which alkali metal encapsulation inside an armchair (9,9) single walled carbon nanotube (SWNT) can affect external amino acid interactions. Based on our analysis, several configurations revealed that the physical properties of the SWNT systems are modified by using an internally situated Li atom. Density-functional theory calculations reveal that the most favorable interactions of the SWNT system is with tryptophan, threonine and proline that can be directly correlated to the backbone geometry of the amino acid species.

  4. Microbial degradation of poly(amino acid)s.

    Science.gov (United States)

    Obst, Martin; Steinbüchel, Alexander

    2004-01-01

    Natural poly(amino acid)s are a group of poly(ionic) molecules (ionomers) with various biological functions and putative technical applications and play, therefore, an important role both in nature and in human life. Because of their biocompatibility and their synthesis from renewable resources, poly(amino acid)s may be employed for many different purposes covering a broad spectrum of medical, pharmaceutical, and personal care applications as well as the domains of agriculture and of environmental applications. Biodegradability is one important advantage of naturally occurring poly(amino acid)s over many synthetic polymers. The intention of this review is to give an overview about the enzyme systems catalyzing the initial steps in poly(amino acid) degradation. The focus is on the naturally occurring poly(amino acid)s cyanophycin, poly(epsilon-L-lysine) and poly(gamma-glutamic acid); but biodegradation of structurally related synthetic polyamides such as poly(aspartic acid) and nylons, which are known from various technical applications, is also included.

  5. Defective intestinal amino acid absorption in Ace2 null mice.

    Science.gov (United States)

    Singer, Dustin; Camargo, Simone M R; Ramadan, Tamara; Schäfer, Matthias; Mariotta, Luca; Herzog, Brigitte; Huggel, Katja; Wolfer, David; Werner, Sabine; Penninger, Josef M; Verrey, François

    2012-09-15

    Mutations in the main intestinal and kidney luminal neutral amino acid transporter B(0)AT1 (Slc6a19) lead to Hartnup disorder, a condition that is characterized by neutral aminoaciduria and in some cases pellagra-like symptoms. These latter symptoms caused by low-niacin are thought to result from defective intestinal absorption of its precursor L-tryptophan. Since Ace2 is necessary for intestinal B(0)AT1 expression, we tested the impact of intestinal B(0)AT1 absence in ace2 null mice. Their weight gain following weaning was decreased, and Na(+)-dependent uptake of B(0)AT1 substrates measured in everted intestinal rings was defective. Additionally, high-affinity Na(+)-dependent transport of L-proline, presumably via SIT1 (Slc6a20), was absent, whereas glucose uptake via SGLT1 (Slc5a1) was not affected. Measurements of small intestine luminal amino acid content following gavage showed that more L-tryptophan than other B(0)AT1 substrates reach the ileum in wild-type mice, which is in line with its known lower apparent affinity. In ace2 null mice, the absorption defect was confirmed by a severalfold increase of L-tryptophan and of other neutral amino acids reaching the ileum lumen. Furthermore, plasma and muscle levels of glycine and L-tryptophan were significantly decreased in ace2 null mice, with other neutral amino acids displaying a similar trend. A low-protein/low-niacin diet challenge led to differential changes in plasma amino acid levels in both wild-type and ace2 null mice, but only in ace2 null mice to a stop in weight gain. Despite the combination of low-niacin with a low-protein diet, plasma niacin concentrations remained normal in ace2 null mice and no pellagra symptoms, such as photosensitive skin rash or ataxia, were observed. In summary, mice lacking Ace2-dependent intestinal amino acid transport display no total niacin deficiency nor clear pellagra symptoms, even under a low-protein and low-niacin diet, despite gross amino acid homeostasis alterations.

  6. Amino acid nutrition of fishes: requirements and supplementation of diets

    Science.gov (United States)

    Ketola, H.G.

    1982-01-01

    The purpose of this paper is: (1) to make a concise review of the published dietary requirements of fishes for amino acids, (2) to describe recent findings at the Tunison Laboratory concerning amino acid nutrition of trout, (3) to review specific signs of deficiency of amino acids, and (4) to discuss use of the fish egg amino acid pattern as a guideline to formulating new feeds or studying amino acid requirements of fishes for which there is limited information on their quantitative requirements.

  7. Cerebral net exchange of large neutral amino acids after lipopolysaccharide infusion in healthy humans

    DEFF Research Database (Denmark)

    Berg, Ronan Mg; Taudorf, Sarah; Bailey, Damian M;

    2010-01-01

    Alterations in circulating large neutral amino acids (LNAAs), leading to a decrease in the plasma ratio between branched-chain and aromatic amino acids (BCAA/AAA ratio), may be involved in sepsis-associated encephalopathy. We hypothesised that a decrease in the BCAA/AAA ratio occurs along with a ...

  8. Cerebral net exchange of large neutral amino acids after lipopolysaccharide infusion in healthy humans

    DEFF Research Database (Denmark)

    2010-01-01

    Alterations in circulating large neutral amino acids (LNAAs), leading to a decrease in the plasma ratio between branched-chain and aromatic amino acids (BCAA/AAA ratio), may be involved in sepsis-associated encephalopathy. We hypothesised that a decrease in the BCAA/AAA ratio occurs along...

  9. Amino acid derived 1,4-dialkyl substituted imidazolones

    DEFF Research Database (Denmark)

    Diness, Frederik; Meldal, Morten Peter

    2010-01-01

    A general method for synthesis of 1,4-substituted imidazolones from amino acids on solid support or in solution has been developed. Amino acid derived 3-Boc-(1,3)-oxazinane (Box) protected amino aldehyde building blocks were coupled through urea bonds to the amino terminal of dipeptides or amino ...

  10. Quantitative amino acid profiling and stable isotopically labeled amino acid tracer enrichment used for in vivo human systemic and tissue kinetics measurements.

    Science.gov (United States)

    Bornø, Andreas; van Hall, Gerrit

    2014-03-01

    An important area within clinical functional metabolomics is in vivo amino acid metabolism and protein turnover measurements for which accurate amino acid concentrations and stable isotopically labeled amino acid enrichments are mandatory not the least when tissue metabolomics is determined. The present study describes a new sensitive liquid chromatography tandem mass-spectrometry method quantifying 20 amino acids and their tracer(s) ([ring-(13)C6]/D5Phenylalanine) in human plasma and skeletal muscle specimens. Before analysis amino acids were extracted and purified via deprotonization/ion exchange, derivatized using a phenylisothiocyanate reagent and each amino acid was quantitated with its own stable isotopically labeled internal standard (uniformly labeled-(13)C/(15)N). The method was validated according to general recommendations for chromatographic analytical methods. The calibration curve correlations for amino acids were on average; r(2)=0.998. Interday accuracy for amino acids determined in spiked plasma was on average 97.3% and the coefficient of variation (CV) was 2.6%. The ([ring-(13)C6]/D5Phenylalanine) enrichment CV's for machine reproducibility in muscle tissue fluid and plasma were 4.4 and 0.8%, and the interday variability was 3.4% and the recovery was 90.5%, respectively. In conclusion, we have developed and validated a method for quantitative amino acid profiling that meets the requirements for systemic and tissue human in vivo amino acid and protein turnover kinetics measurements. Moreover, citrulline, ornithine, π-methyl-histidine, τ-methyl-l-histidine, hydroxy-proline and carnitine were analysed but when similar precision and accuray are required an additional stable istopically labeled internal standard for these meatablites should be be added.

  11. Polymerization of amino acids containing nucleotide bases

    Science.gov (United States)

    Ben Cheikh, Azzouz; Orgel, Leslie E.

    1990-01-01

    The nucleoamino acids 1-(3'-amino,3'-carboxypropyl)uracil (3) and 9-(3'-amino,3'-carboxypropyl)adenine (4) have been prepared as (L)-en-antiomers and as racemic mixtures. When 3 or 4 is suspended in water and treated with N,N'-carbon-yldiimidazole, peptides are formed in good yield. The products formed from the (L)-enantiomers are hydrolyzed to the monomeric amino acids by pronase. Attempts to improve the efficiency of these oligomerizations by including a polyuridylate template in the reaction mixture were not successful. Similarly, oligomers derived from the (L)-enantiomer of 3 did not act as templates to facilitate the oligomerization of 4.

  12. Comparison of different analyzing methods for detection of free amino acids in plasma%不同方法检测血浆游离氨基酸结果比较

    Institute of Scientific and Technical Information of China (English)

    张文辉; 何桂珍; 林韶辉; 喻长远

    2016-01-01

    Objective To evaluate the accuracy of different methods in detecting free amino acids in plasma.Method 40 blood samples from healthy volunteers were analyzed by an automatic amino acid analyzer ( Li+system) and the results compared with previous reports using other analyzers.Results The results ob-tained by this analyzer for major amino acids [asparagine (Asn), glutamic acid (Glu), glutamine (Gln), valine (Val), tyrosine (Tyr), phenylalanine (Phe), ornithine (Orn), arginine (Arg)] were similar with those previously reported using other amino acid analyzers ( all P>0.05 ) and liquid chromatography tandem-mass spectrometry (LC-MS/MS) (all P>0.05).Except for Glu and Tyr, the results for major amino acids showed large deviation compared to the results from high performance liquid chromatography ( HPLC) ( all P<0.05).Conclusion The amino acid analyzer (Li+) and LC-MS/MS (iTRAQ kit) could accurately detect free amino acids in plasma.%目的:比较不同方法检测血浆游离氨基酸的准确性。方法应用全自动氨基酸分析仪( Li+系统)测定40例健康志愿者血浆游离氨基酸,与中外文献不同方法健康志愿者氨基酸测定结果进行对比分析。结果本研究氨基酸分析仪( Li+系统)测定40例健康志愿者血浆游离氨基酸结果中,天冬酰胺(Asn)、谷氨酸(Glu)、谷氨酰胺(Gln)、缬氨酸(Val)、酪氨酸(Tyr)、苯丙氨酸( Phe)、鸟氨酸( Orn)、精氨酸( Arg)等主要氨基酸的正常值与国内外氨基酸分析仪测定结果相近(均P>0.05),且与液相色谱-质谱联用法(LC-MS/MS)测定结果较为相近(均P>0.05),除Glu、Tyr外,其他氨基酸测定结果与高效液相色谱法(HPLC)测定结果偏差大(均P<0.05)。结论采用氨基酸分析仪法( Li+系统)和液相色谱-质谱联用法( iTRAQ试剂)检测的结果较为客观和准确,适用于分析血浆游离氨基酸。

  13. Effects of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) on liver phosphoenolpyruvate carboxykinase (PEPCK) activity, glucose homeostasis and plasma amino acid concentrations in the most TCDD-susceptible and the most TCDD-resistant rat strains

    Energy Technology Data Exchange (ETDEWEB)

    Viluksela, M.; Pohjanvirta, R.; Tuomisto, J.T.; Tuomisto, J. (National Public Health Inst., Laboratory of Toxicology, Kuopio (Finland)); Unkila, M. (Department of Pharmacology and Toxicology, Univ. of Kuopio (Finland)); Stahl, B.U.; Rozman, K.K. (Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, Kansas City, KS (United States) Section of Environmental Toxicology, GSF-Institut fuer Toxikologie, Neuherberg (Germany))

    1999-08-01

    Reduced gluconeogenesis due to decreased activity of key gluconeogenic enzymes in liver, together with feed refusal, has been suggested to play an important role in 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD)-induced lethality in rats. This study was carried out to further analyse the toxicological significance of reduced gluconeogenesis by comparing dose-responses and time-courses of effects of TCDD on the activity of phosphoenolpyruvate carboxykinase (PEPCK) in liver, liver glycogen concentration as well as plasma concentrations of glucose and amino acids in both genders of TCDD-sensitive Long-Evans (L-E) rats and TCDD-resistant Han/Wistar (H/W) rats. A dose-dependent decrease in PEPCK activity was observed in H/W rats, but in L-E rats the activity was not decreased. However, TCDD impaired the strong increase in liver PEPCK activity observed in pair-fed controls of the L-E strain. Liver glycogen concentrations were severely decreased in L-E rats and moderately in H/W rats. This effect seems to be secondary to reduced feed intake, since a similar decrease was seen in pair-fed controls. Decreases in plasma glucose concentrations were also more profound in L-E rats than in H/W rats, but pair-fed controls were generally less affected. Circulating concentrations of amino acids were markedly increased in TCDD-treated L-E rats, which is likely to reflect increased mobilization of amino acids and their decreased metabolism in liver. Reduction of liver PEPCK activity cannot account for the sensitivity difference of these two strains of rats in terms of mortality. Nevertheless, the response of both strains of TCDD-treated rats regarding gluconeogenesis is different from that seen in pair-fed controls and suggesting that impairment of this pathway contributes to the development of the wasting syndrome. (orig.) With 7 figs., 2 tabs., 47 refs.

  14. Dietary Supplements and Sports Performance: Amino Acids

    Directory of Open Access Journals (Sweden)

    Williams Melvin

    2005-12-01

    Full Text Available Abstract This is the third in a series of six articles to discuss the major classes of dietary supplements (vitamins; minerals; amino acids; herbs or botanicals; metabolites, constituents/extracts, or combinations. The major focus is on efficacy of such dietary supplements to enhance exercise or sport performance.

  15. [Sublicons containing amino acids and nucleotides].

    Science.gov (United States)

    Kaĭmakov, E A

    1979-01-01

    Sublicons have been obtained. Sublicons are threadlike structures appearing during sublimation of frozen solutions of small concentrations, containing racemate mixture of amino acids and nucleotides. It is suggested that close location of chains and their zonal distribution by the section of helix spire forming sublicon wall, should provide the formation of stereohomogenous and complementary successions of biomonomers of different clases.

  16. Amino Acid Formation on Interstellar Dust Particles

    Science.gov (United States)

    Meierhenrich, U. J.; Munoz Caro, G. M.; Barbier, B.; Brack, A.; Thiemann, W.; Goesmann, F.; Rosenbauer, H.

    2003-04-01

    In the dense interstellar medium dust particles accrete ice layers of known molecular composition. In the diffuse interstellar medium these ice layers are subjected to energetic UV-irradiation. Here, photoreactions form complex organic molecules. The interstellar processes were recently successfully simulated in two laboratories. At NASA Ames Research Center three amino acids were detected in interstellar ice analogues [1], contemporaneously, our European team reported on the identification of 16 amino acids therein [2]. Amino acids are the molecular building blocks of proteins in living organisms. The identification of amino acids on the simulated icy surface of interstellar dust particles strongly supports the assumption that the precursor molecules of life were delivered from interstellar and interplanetary space via (micro-) meteorites and/or comets to the earyl Earth. The results shall be verified by the COSAC experiment onboard the ESA cometary mission Rosetta [3]. [1] M.P. Bernstein, J.P. Dworkin, S.A. Sandford, G.W. Cooper, L.J. Allamandola: itshape Nature \\upshape 416 (2002), 401-403. [2] G.M. Muñoz Caro, U.J. Meierhenrich, W.A. Schutte, B. Barbier, A. Arcones Sergovia, H. Rosenbauer, W.H.-P. Thiemann, A. Brack, J.M. Greenberg: itshape Nature \\upshape 416 (2002), 403-406. [3] U. Meierhenrich, W.H.-P. Thiemann, H. Rosenbauer: itshape Chirality \\upshape 11 (1999), 575-582.

  17. Amino acid modifications on tRNA

    Institute of Scientific and Technical Information of China (English)

    Jing Yuan; Kelly Sheppard; Dieter S(o)ll

    2008-01-01

    The accurate formation of cognate aminoacyl-transfer RNAs (aa-tRNAs) is essential for the fidelity of translation.Most amino acids are esterified onto their cognate tRNA isoacceptors directly by aa.tRNA synthetases.However,in the case of four amino acids (Gin,Asn,Cys and Sec),aminoacyl-tRNAs are made through indirect pathways in many organisms across all three domains of life.The process begins with the charging ofnoncognate amino acids to tRNAs by a specialized synthetase in the case of Cys-tRNAcys formation or by synthetases with relaxed specificity,such as the non-discriminating glutamyl-tRNA,non-discriminating aspartyl-tRNA and seryl-tRNA synthetases.The resulting misacylated tRNAs are then converted to cognate pairs through transformation of the amino acids on the tRNA,which is catalyzed by a group of tRNA-dependent modifying enzymes,such as tRNA-dependent amidotransferases,Sep-tRNA:Cys-tRNA synthase,O-phosphoseryi-tRNA kinase and Sep-tRNA:Sec-tRNA synthase.The majority of these indirect pathways are widely spread in all domains of life and thought to be part of the evolutionary process.

  18. Estimate of Amino Acid Balance in Nutrition

    Institute of Scientific and Technical Information of China (English)

    SunWenzhi

    1995-01-01

    A new chemical index-imbalance degree(IBD),was proposed on the basis of cluster analysis in multivariate statistical analysis to estimate the extent of amino acid balance in protein.The range of IBD is between 0 and 1,successively corresponding to complete baance and entire imbalance for the amino acid profile of a sample.The amino acid increment model of IBD belongs to an asymmetrical maximum-type,and there is a high correlation between IBD and coefficient of variation(CV),The nutritional Value of individual feed can be ranked and clustered according to its IBD;and by calculating the IBD of amixed sample with two or more feedstuffs,it is possible theoretically to predict whether a synergetic phenomenon exists and when an optimal mutual complement can happen.If the conceptive frame of IBD extended,it can be used to study the balance of plement can happen.If the conceptive frame of IBD extended,it can be used to study the balance of nutrients besides amino acids,and is helpful to realize the automatic distinction and selection in diet formulating.

  19. 21 CFR 172.320 - Amino acids.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Amino acids. 172.320 Section 172.320 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 §...

  20. Amino acid quality indices of the leaves of Clerodendrum volubile

    Directory of Open Access Journals (Sweden)

    Ochuko Lucky Erukainure

    2016-04-01

    Full Text Available Objective: To evaluate the amino acid profile and quality indices of Clerodendrum volubile (C. volubile leaves. Methods: Dried leaves of C. volubile were blended, defatted and subjected to amino acid analysis using the technicon sequential multi-sample amino acid analyzer. The amino acid quality indices which covers for chemical score, essential amino acid index, nutritional index, true digestibility, protein digestibility corrected amino acid score, and digestible indispensable amino acid score were evaluated using standard formulas. Results: Amino acid analysis revealed glutamic acid to have the highest concentration, with cysteine having the least. Aspartic acid had the highest chemical score, this was followed by glycine, histidine and arginine, respectively. The least scores were observed in serine and methionine. Glutamic acid had the highest value for true digestibility and protein digestibility corrected amino acid score, with the least observed in cysteine. Digestible indispensable amino acid score evaluation showed histidine to have the highest value for infants (birth to 6 months, threonine for children (6 months to 3 years, while isoleucine was observed to have the highest value for older children, adolescents and adults. The essential amino acid index value was less than 4, while nutritional index value was less than 0.5. Conclusions: These results indicated the leaves of C. volubile as a potential source of amino acids in the human diet as portrayed by its amino acids profile and qualities.

  1. Biosynthesis of natural products containing β-amino acids.

    Science.gov (United States)

    Kudo, Fumitaka; Miyanaga, Akimasa; Eguchi, Tadashi

    2014-08-01

    Covering: up to January, 2014. We focus here on β-amino acids as components of complex natural products because the presence of β-amino acids produces structural diversity in natural products and provides characteristic architectures beyond those of ordinary α-L-amino acids, thus generating significant and unique biological functions in nature. In this review, we first survey the known bioactive β-amino acid-containing natural products including nonribosomal peptides, macrolactam polyketides, and nucleoside-β-amino acid hybrids. Next, the biosynthetic enzymes that form β-amino acids from α-amino acids and the de novo synthesis of β-amino acids are summarized. Then, the mechanisms of β-amino acid incorporation into natural products are reviewed. Because it is anticipated that the rational swapping of the β-amino acid moieties with various side chains and stereochemistries by biosynthetic engineering should lead to the creation of novel architectures and bioactive compounds, the accumulation of knowledge regarding β-amino acid-containing natural product biosynthetic machinery could have a significant impact in this field. In addition, genome mining of characteristic β-amino acid biosynthetic genes and unique β-amino acid incorporation machinery could lead to the discovery of new β-amino acid-containing natural products.

  2. Permeability of membranes to amino acids and modified amino acids: mechanisms involved in translocation

    Science.gov (United States)

    Chakrabarti, A. C.; Deamer, D. W. (Principal Investigator); Miller, S. L. (Principal Investigator)

    1994-01-01

    The amino acid permeability of membranes is of interest because they are one of the key solutes involved in cell function. Membrane permeability coefficients (P) for amino acid classes, including neutral, polar, hydrophobic, and charged species, have been measured and compared using a variety of techniques. Decreasing lipid chain length increased permeability slightly (5-fold), while variations in pH had only minor effects on the permeability coefficients of the amino acids tested in liposomes. Increasing the membrane surface charge increased the permeability of amino acids of the opposite charge, while increasing the cholesterol content decreased membrane permeability. The permeability coefficients for most amino acids tested were surprisingly similar to those previously measured for monovalent cations such as sodium and potassium (approximately 10(-12)-10(-13) cm s-1). This observation suggests that the permeation rates for the neutral, polar and charged amino acids are controlled by bilayer fluctuations and transient defects, rather than partition coefficients and Born energy barriers. Hydrophobic amino acids were 10(2) more permeable than the hydrophilic forms, reflecting their increased partition coefficient values. External pH had dramatic effects on the permeation rates for the modified amino acid lysine methyl ester in response to transmembrane pH gradients. It was established that lysine methyl ester and other modified short peptides permeate rapidly (P = 10(-2) cm s-1) as neutral (deprotonated) molecules. It was also shown that charge distributions dramatically alter permeation rates for modified di-peptides. These results may relate to the movement of peptides through membranes during protein translocation and to the origin of cellular membrane transport on the early Earth.

  3. Microbial Production of Amino Acid-Related Compounds.

    Science.gov (United States)

    Wendisch, Volker F

    2016-11-22

    Corynebacterium glutamicum is the workhorse of the production of proteinogenic amino acids used in food and feed biotechnology. After more than 50 years of safe amino acid production, C. glutamicum has recently also been engineered for the production of amino acid-derived compounds, which find various applications, e.g., as synthons for the chemical industry in several markets including the polymer market. The amino acid-derived compounds such as non-proteinogenic ω-amino acids, α,ω-diamines, and cyclic or hydroxylated amino acids have similar carbon backbones and functional groups as their amino acid precursors. Decarboxylation of amino acids may yield ω-amino acids such as β-alanine, γ-aminobutyrate, and δ-aminovalerate as well as α,ω-diamines such as putrescine and cadaverine. Since transamination is the final step in several amino acid biosynthesis pathways, 2-keto acids as immediate amino acid precursors are also amenable to production using recombinant C. glutamicum strains. Approaches for metabolic engineering of C. glutamicum for production of amino acid-derived compounds will be described, and where applicable, production from alternative carbon sources or use of genome streamline will be referred to. The excellent large-scale fermentation experience with C. glutamicum offers the possibility that these amino acid-derived speciality products may enter large-volume markets.

  4. 乳腺癌患者血浆、尿液中氨基酸谱的变化%Change in the spectrum of free amino acids in plasma and urine of patients with breast cancer

    Institute of Scientific and Technical Information of China (English)

    高翠红

    2014-01-01

    Objective To investigate the characteristics of amino acids metabolism in breast cancer patients so as to provide theoretic evidence for nutrition support.Method The levels of free amino acids in plasma and urine were examined in 55 breast cancer patients and 50 normal controls with Hitachi L-8900 amino acid analyzer.Results Compared with the normal controls,the plasma level of methionine increased significantly in breast cancer patients [(48.22 ± 12.90) μmol/L,P =0.04),while the levels of 7 amino acids decreased,ineluding isoleucine [(43.07 ± 14.88) μmol/L,P =0.04],leucine [(93.22 ± 18.29) μmol/L,P =0.01],valine [(200.86 ± 42.11) μmol/L,P =0.04],arginine [(46.49 ± 11.79) μmol/L,P =0.00],lysine [(107.37 ±32.61) μmol/L,P=0.01],tyrosine [(29.51 ±18.09) μmol/L,P=0.02] and phenylalanine [(57.39 ± 17.03) μmol/L,P =0.00],and branched chain amino acids/aromatic amino acid decreased to 1.81 ± 0.81 (P =0.04).Compared with the normal controls,the urine levels of phenylalanine [(22.01 ± 4.37) μmol/L,P=0.01],tyrosine [(12.13 ±5.72) μmol/L,P=0.02] and lysine [(107.37 ± 32.61) μmol/L,P =0.00] increased significantly in breast cancer patients,while the urine levels of leucine [(0.84 ±0.21) μmol/L,P =0.04] and valine [(0.50 ± 1.10) μmol/L,P =0.01] decreased significantly,and the ratio of branched chain amino acids/aromatic amino acid dropped to 1.91 ± 0.60 (P =0.03).Conclusions There is metabolic disorders of amino acids in patients who breast cancer.The focus of the amino acid imbalance treatment for breast cancer patients are supplementation of branch amino acids and arginine.%目的 了解乳腺癌患者体内氨基酸代谢特点,以便更合理地给予营养支持.方法 采用日立L-8900型氨基酸自动分析仪,检测55例乳腺癌患者及50例正常人血浆、尿液中游离氨基酸的含量.结果 乳腺癌患者血浆中蛋氨酸含量(48.22±12.90)μmol/L较正常人升高(P=0.04);异亮氨酸(43.07±14.88) μmol/L、亮氨酸(93.22

  5. Quantitative amino acid profiling and stable isotopically labeled amino acid tracer enrichment used for in vivo human systemic and tissue kinetics measurements

    DEFF Research Database (Denmark)

    Bornø, Andreas; van Hall, Gerrit

    2014-01-01

    /ion exchange, derivatized using a phenylisothiocyanate reagent and each amino acid was quantitated with its own stable isotopically labeled internal standard (uniformly labeled-(13)C/(15)N). The method was validated according to general recommendations for chromatographic analytical methods. The calibration...... and plasma were 4.4 and 0.8%, and the interday variability was 3.4% and the recovery was 90.5%, respectively. In conclusion, we have developed and validated a method for quantitative amino acid profiling that meets the requirements for systemic and tissue human in vivo amino acid and protein turnover...

  6. Fish oil and the pan-PPAR agonist tetradecylthioacetic acid affect the amino acid and carnitine metabolism in rats.

    Directory of Open Access Journals (Sweden)

    Bodil Bjørndal

    Full Text Available Peroxisome proliferator-activated receptors (PPARs are important in the regulation of lipid and glucose metabolism. Recent studies have shown that PPARα-activation by WY 14,643 regulates the metabolism of amino acids. We investigated the effect of PPAR activation on plasma amino acid levels using two PPARα activators with different ligand binding properties, tetradecylthioacetic acid (TTA and fish oil, where the pan-PPAR agonist TTA is a more potent ligand than omega-3 polyunsaturated fatty acids. In addition, plasma L-carnitine esters were investigated to reflect cellular fatty acid catabolism. Male Wistar rats (Rattus norvegicus were fed a high-fat (25% w/w diet including TTA (0.375%, w/w, fish oil (10%, w/w or a combination of both. The rats were fed for 50 weeks, and although TTA and fish oil had hypotriglyceridemic effects in these animals, only TTA lowered the body weight gain compared to high fat control animals. Distinct dietary effects of fish oil and TTA were observed on plasma amino acid composition. Administration of TTA led to increased plasma levels of the majority of amino acids, except arginine and lysine, which were reduced. Fish oil however, increased plasma levels of only a few amino acids, and the combination showed an intermediate or TTA-dominated effect. On the other hand, TTA and fish oil additively reduced plasma levels of the L-carnitine precursor γ-butyrobetaine, as well as the carnitine esters acetylcarnitine, propionylcarnitine, valeryl/isovalerylcarnitine, and octanoylcarnitine. These data suggest that while both fish oil and TTA affect lipid metabolism, strong PPARα activation is required to obtain effects on amino acid plasma levels. TTA and fish oil may influence amino acid metabolism through different metabolic mechanisms.

  7. Recent advances in amino acid production by microbial cells.

    Science.gov (United States)

    Hirasawa, Takashi; Shimizu, Hiroshi

    2016-12-01

    Amino acids have been utilized for the production of foods, animal feeds and pharmaceuticals. After the discovery of the glutamic acid-producing bacterium Corynebacterium glutamicum by Japanese researchers, the production of amino acids, which are primary metabolites, has been achieved using various microbial cells as hosts. Recently, metabolic engineering studies on the rational design of amino acid-producing microbial cells have been successfully conducted. Moreover, the technology of systems biology has been applied to metabolic engineering for the creation of amino acid-producing microbial cells. Currently, new technologies including synthetic biology, single-cell analysis, and evolutionary engineering have been utilized to create amino acid-producing microbial cells. In addition, useful compounds from amino acids have been produced by microbial cells. Here, current researches into the metabolic engineering of microbial cells toward production of amino acids and amino acid-related compounds are reviewed.

  8. Biosynthesis of 'essential' amino acids by scleractinian corals.

    Science.gov (United States)

    Fitzgerald, L M; Szmant, A M

    1997-02-15

    Animals rely on their diet for amino acids that they are incapable either of synthesizing or of synthesizing in sufficient quantities to meet metabolic needs. These are the so-called 'essential amino acids'. This set of amino acids is similar among the vertebrates and many of the invertebrates. Previously, no information was available for amino acid synthesis by the most primitive invertebrates, the Cnidaria. The purpose of this study was to examine amino acid synthesis by representative cnidarians within the Order Scleractinia. Three species of zooxanthellate reef coral, Montastraea faveolata, Acropora cervicornis and Porites divaricata, and two species of non-zooxanthellate coral, Tubastrea coccinea and Astrangia poculata, were incubated with 14C-labelled glucose or with the 14C-labelled amino acids glutamic acid, lysine or valine. Radiolabel tracer was followed into protein amino acids. A total of 17 amino acids, including hydroxyproline, were distinguishable by the techniques used. Of these, only threonine was not found radiolabelled in any of the samples. We could not detect tryptophan or cysteine, nor distinguish between the amino acid pairs glutamic acid and glutamine, or aspartic acid and asparagine. Eight amino acids normally considered essential for animals were made by the five corals tested, although some of them were made only in small quantities. These eight amino acids are valine, isoleucine, leucine, tyrosine, phenylalanine histidine, methionine and lysine. The ability of cnidarians to synthesize these amino acids could be yet another indicator of a separate evolutionary history of the cnidarians from the rest of the Metazoa.

  9. Role of amino acids as additives on sperm motility, plasma membrane integrity and lipid peroxidation levels at pre-freeze and post-thawed ram semen.

    Science.gov (United States)

    Sangeeta, Sharon; Arangasamy, A; Kulkarni, S; Selvaraju, S

    2015-10-01

    The possibility of including amino acids for cryopreservation of ram semen to improve the quality of frozen semen was explored in this study in sheep model. 24 samples were collected in triplicate from 8 rams of 2-3 year old Bannur cross bred rams maintained at the Institute Experimental Livestock Unit. Semen was diluted in tris-egg yolk glycerol diluent and made into 7 aliquots as follows: aliquot 1 served as control, "l-alanine" was added at 100 and 135mM in the aliquots 2 and 3, "l-glutamine" was added at 20 and 25mM in the aliquots 4 and 5 and "l-proline" was added at 25 and 50mM in the aliquots 6 and 7, respectively. Diluted semen was filled in 0.25ml French straws and frozen in LN2. Inclusion of "l-proline" and "l-glutamine" in the diluent increased the percent live sperm (Pram semen as they prevented cryoinjuries to sperm and improved the pre-freeze and post-thaw semen characteristics.

  10. Direct amino acid analyses of mozzarella cheese.

    Science.gov (United States)

    Hoskins, M N

    1985-12-01

    The amino acid content of mozzarella (low moisture, part skim milk) and asadero cheeses was determined by the column chromatographic method. Data from the direct analyses of the mozzarella cheeses were compared with the calculated amino acid composition reported in tables in Agriculture Handbook No. 8-1. Phenylalanine and tyrosine contents were found to be higher in the direct analyses than in the calculated data in Handbook No. 8-1 (1.390 gm and 1.127 gm for phenylalanine, and 1.493 gm and 1.249 gm for tyrosine per 100 gm edible portion, respectively). That is of particular concern in the dietary management of phenylketonuria, in which accuracy in computing levels of phenylalanine and tyrosine is essential.

  11. Intermolecular Vibrations of Hydrophobic Amino Acids

    Science.gov (United States)

    Williams, Michael Roy Casselman

    Hydrophobic amino acids interact with their chemical environment through a combination of electrostatic, hydrogen bonding, dipole, induced dipole, and dispersion forces. These interactions all have their own characteristic energy scale and distance dependence. The low-frequency (0.1-5 THz, 5-150 cm-1) vibrational modes of amino acids in the solid state are a direct indicator of the interactions between the molecules, which include interactions between an amino acid functional group and its surroundings. This information is central to understanding the dynamics and morphology of proteins. The alpha-carbon is a chiral center for all of the hydrophobic amino acids, meaning that they exist in two forms, traditionally referred to as L- and D-enantiomers. This nomenclature indicates which direction the molecule rotates plane-polarized visible light (levorotory and dextrorotory). Chiral a-amino acids in proteins are exclusively the L-variety In the solid state, the crystal lattice of the pure L-enantiomer is the mirror image of the D-enantiomer crystal lattice. These solids are energetically identical. Enantiomers also have identical spectroscopic properties except when the measurement is polarization sensitive. A mixture of equal amounts D- and L-amino acid enantiomers can crystallize into a racemic (DL-) structure that is different from that of the pure enantiomers. Whether a solution of both enantiomers will crystallize into a racemic form or spontaneously resolve into a mixture of separate D- and L-crystals largely depends on the interactions between molecules available in the various possible configurations. This is an active area of research. Low-frequency vibrations with intermolecular character are very sensitive to changes in lattice geometry, and consequently the vibrational spectra of racemic crystals are usually quite distinct from the spectra of the crystals of the corresponding pure enantiomers in the far-infrared (far-IR). THz time-domain spectroscopy (THz

  12. Rotational Study of Natural Amino Acid Glutamine

    Science.gov (United States)

    Varela, Marcelino; Cabezas, Carlos; Alonso, José L.

    2014-06-01

    Recent improvements in laser ablation molecular beam Fourier transform microwave spectroscopy (LA-MB-FTMW) have allowed the investigation of glutamine (COOH-CH(NH2)-CH2-CH2-CONH2), a natural amino acid with a long polar side chain. One dominant structure has been detected in the rotational spectrum. The nuclear quadrupole hyperfine structure of two 14N nuclei has been totally resolved allowing the conclusive identification of the observed species.

  13. Alimentary proteins, amino acids and cholesterolemia.

    Science.gov (United States)

    Blachier, François; Lancha, Antonio H; Boutry, Claire; Tomé, Daniel

    2010-01-01

    Numerous data from both epidemiological and experimental origins indicate that some alimentary proteins and amino acids in supplements can modify the blood LDL cholesterol, HDL cholesterol and total cholesterol. After an initial approval of the health claim for soy protein consumption for the prevention of coronary heart disease, more recently it has been concluded from an overall analysis of literature that isolated soy protein with isoflavones only slightly decrease LDL and total cholesterol. Other plant extracts and also some proteins from animal origin have been reported to exert a lowering effect on blood cholesterol when compared with a reference protein (often casein). The underlying mechanisms are still little understood. Individual amino acids and mixture of amino acids have also been tested (mostly in animal studies) for their effects on cholesterol parameters and on cholesterol metabolism. Methionine, lysine, cystine, leucine, aspartate and glutamate have been tested individually and in combination in different models of either normo or hypercholesterolemic animals and found to be able to modify blood cholesterol and/or LDL cholesterol and/or HDL cholesterol. It is however not known if these results are relevant to human nutrition.

  14. the amino acid composition of selected south african feed ingredients

    African Journals Online (AJOL)

    ook, om die balans van die aminosure te kan bepaal, is elkeen aangetoon as'n persentasie .... lent to the free amino acid less the one molecule of .... AMINO ACID PERCENT (a) PERCENT FACTORS (c) PERCENT (d) PERCENT OF PROTEIN.

  15. Single amino acid supplementation in aminoacidopathies: a systematic review

    Science.gov (United States)

    2014-01-01

    Aminoacidopathies are a group of rare and diverse disorders, caused by the deficiency of an enzyme or transporter involved in amino acid metabolism. For most aminoacidopathies, dietary management is the mainstay of treatment. Such treatment includes severe natural protein restriction, combined with protein substitution with all amino acids except the amino acids prior to the metabolic block and enriched with the amino acid that has become essential by the enzymatic defect. For some aminoacidopathies, supplementation of one or two amino acids, that have not become essential by the enzymatic defect, has been suggested. This so-called single amino acid supplementation can serve different treatment objectives, but evidence is limited. The aim of the present article is to provide a systematic review on the reasons for applications of single amino acid supplementation in aminoacidopathies treated with natural protein restriction and synthetic amino acid mixtures. PMID:24422943

  16. A Green Synthesis of Diisopropyl Phosphoryl Amino Acid

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    In this paper, we report that diisopropyl phosphoryl amino acid could be prepared with reasonable yields under solvent-free condition by adding amino acid to the mixture of diisopropyl phosphite and N-chlorodiisopropylamine.

  17. Quantitative detection of single amino acid polyrnorphisms by targeted proteornics

    Institute of Scientific and Technical Information of China (English)

    Zhi-Duan Su; Jia-Rui Wu; Liang Sun; Dan-Xia Yu; Rong-Xia Li; Huai-Xing Li; Zhi-Jie Yu; Quan-Hu Sheng; Xu Lin; RongZeng

    2011-01-01

    Single-nucleotide polymorphisms (SNPs) are recognized as one kind of major genetic variants in population scale. However, polymorphisms at the proteome level in population scale remain elusive. In the present study, we named amino acid variances derived from SNPs within coding regions as single amino acid polymorphisms (SAPs) at the proteome level, and developed a pipeline of non-targeted and targeted proteomics to identify and quantify SAP peptides in human plasma. The absolute concentrations of three selected SAP-peptide pairs among 290 Asian individuals were measured by selected reaction monitoring (SRM) approach, and their associations with both obesity and diabetes were further analyzed. This work revealed that heterozygotes and homozygotes with various SAPs in a population could have different associations with particular traits. In addition, the SRM approach allows us for the first time to separately measure the absolute concentration of each SAP peptide in the heterozygotes, which also shows different associations with particular traits.%Single-nucleotide polymorphisms (SNPs) are recognized as one kind of major genetic variants in population scale.However,polymorphisms at the proteome level in population scale remain elusive.In the present study,we named amino acid variances derived from SNPs within coding regions as single amino acid polymorphisms (SAPs) at the proteome level,and developed a pipeline of non-targeted and targeted proteomics to identify and quantify SAP peptides in human plasma.The absolute concentrations of three selected SAP-peptide pairs among 290 Asian individuals were measured by selected reaction monitoring (SRM) approach,and their associations with both obesity and diabetes were further analyzed.This work revealed that heterozygotes and homozygotes with various SAPs in a population could have different associations with particular traits.In addition,the SRM approach allows us for the first time to separately measure the absolute

  18. Origin, Microbiology, Nutrition, and Pharmacology of D-Amino Acids

    Science.gov (United States)

    Exposure of food proteins to certain processing conditions induces two major chemical changes: racemization of all L-amino acids (LAA) to D-amino acids (DAA) and concurrent formation of crosslinked amino acids such as lysinoalanine (LAL). The diet contains both processing-induced and naturally-form...

  19. Differential diagnosis of (inherited) amino acid metabolism or transport disorders

    NARCIS (Netherlands)

    W. Blom (W.); J.G.M. Huijmans (Jan)

    1992-01-01

    markdownabstract__Abstract__ Disorders of amino acid metabolism or transport are most clearly expressed in urine. Nevertheless the interpretation of abnormalities in urinary amino acid excretion remains difficult. An increase or decrease of almost every amino acid in urine can be due to various eti

  20. A Convenient Synthesis of Amino Acid Methyl Esters

    Directory of Open Access Journals (Sweden)

    Yaowu Sha

    2008-05-01

    Full Text Available A series of amino acid methyl ester hydrochlorides were prepared in good toexcellent yields by the room temperature reaction of amino acids with methanol in thepresence of trimethylchlorosilane. This method is not only compatible with natural aminoacids, but also with other aromatic and aliphatic amino acids.

  1. Metabolism of amino acid amides in Pseudomonas putida ATCC 12633

    NARCIS (Netherlands)

    Hermes, H.F.M.; Croes, L.M.; Peeters, W.P.H.; Peters, P.J.H.; Dijkhuizen, L.

    1993-01-01

    The metabolism of the natural amino acid L-valine, the unnatural amino acids D-valine, and D-, L-phenylglycine (D-, L-PG), and the unnatural amino acid amides D-, L-phenylglycine amide (D, L-PG-NH2) and L-valine amide (L-Val-NH2) was studied in Pseudomonas putida ATCC 12633. The organism possessed c

  2. Metabolism of amino acid amides in Pseudomonas putida ATCC 12633

    NARCIS (Netherlands)

    Hermes, H.F.M.; Croes, L.M.; Peeters, W.P.H.; Peters, P.J.H.; Dijkhuizen, L.

    1993-01-01

    The metabolism of the natural amino acid L-valine, the unnatural amino acids D-valine, and D-, L-phenylglycine (D-, L-PG), and the unnatural amino acid amides D-, L-phenylglycine amide (D, L-PG-NH2) and L-valine amide (L-Val-NH2) was studied in Pseudomonas putida ATCC 12633. The organism possessed

  3. Effects of pre-meal drinks with protein and amino acids on glycemic and metabolic responses at a subsequent composite meal

    DEFF Research Database (Denmark)

    Gunnerud, Ulrika J; Heinzle, Cornelia; Holst, Jens Juul

    2012-01-01

    Whey proteins have insulinogenic properties and the effect appears to originate from a specific postprandial plasma amino acid pattern. The insulinogenic effect can be mimicked by a specific mixture of the five amino acids iso, leu, lys, thr and val.......Whey proteins have insulinogenic properties and the effect appears to originate from a specific postprandial plasma amino acid pattern. The insulinogenic effect can be mimicked by a specific mixture of the five amino acids iso, leu, lys, thr and val....

  4. Computational model of abiogenic amino acid condensation to obtain a polar amino acid profile.

    Science.gov (United States)

    Polanco, Carlos; Buhse, Thomas; Samaniego, José Lino; Castañón González, Jorge Alberto; Arias Estrada, Miguel

    2014-01-01

    In accordance with the second law of thermodynamics, the Universe as a whole tends to higher entropy. However, the sequence of far-from-equilibrium events that led to the emergence of life on Earth could have imposed order and complexity during the course of chemical reactions in the so-called primordial soup of life. Hence, we may expect to find characteristic profiles or biases in the prebiotic product mixtures, as for instance among the first amino acids. Seeking to shed light on this hypothesis, we have designed a high performance computer program that simulates the spontaneous formation of the amino acid monomers in closed environments. The program was designed in reference to a prebiotic scenario proposed by Sydney W. Fox. The amino acid abundances and their polarities as the two principal biases were also taken into consideration. We regarded the computational model as exhaustive since 200,000 amino acid dimers were formed by simulation, subsequently expressed in a vector and compared with the corresponding amino acid dimers that were experimentally obtained by Fox. We found a very high similarity between the experimental results and our simulations.

  5. Induction of amino acid transporters expression by endurance exercise in rat skeletal muscle

    Energy Technology Data Exchange (ETDEWEB)

    Murakami, Taro, E-mail: tamuraka@sgk.ac.jp; Yoshinaga, Mariko

    2013-10-04

    Highlights: •Regulation of amino acid transporter expression in working muscle remains unclear. •Expression of amino acid transporters for leucine were induced by a bout of exercise. •Requirement of leucine in muscle cells might regulate expression of its transporters. •This information is beneficial for understanding the muscle remodeling by exercise. -- Abstract: We here investigated whether an acute bout of endurance exercise would induce the expression of amino acid transporters that regulate leucine transport across plasma and lysosomal membranes in rat skeletal muscle. Rats ran on a motor-driven treadmill at a speed of 28 m/min for 90 min. Immediately after the exercise, we observed that expression of mRNAs encoding L-type amino acid transporter 1 (LAT1) and CD98 was induced in the gastrocnemius, soleus, and extensor digitorum longus (EDL) muscles. Sodium-coupled neutral amino acid transporter 2 (SNAT2) mRNA was also induced by the exercise in those three muscles. Expression of proton-assisted amino acid transporter 1 (PAT1) mRNA was slightly but not significantly induced by a single bout of exercise in soleus and EDL muscles. Exercise-induced mRNA expression of these amino acid transporters appeared to be attenuated by repeated bouts of the exercise. These results suggested that the expression of amino acid transporters for leucine may be induced in response to an increase in the requirement for this amino acid in the cells of working skeletal muscles.

  6. Methionine and Choline Supply during the Periparturient Period Alter Plasma Amino Acid and One-Carbon Metabolism Profiles to Various Extents: Potential Role in Hepatic Metabolism and Antioxidant Status

    Directory of Open Access Journals (Sweden)

    Zheng Zhou

    2016-12-01

    Full Text Available The objective of this study was to profile plasma amino acids (AA and derivatives of their metabolism during the periparturient period in response to supplemental rumen-protected methionine (MET or rumen-protected choline (CHOL. Forty cows were fed from −21 through 30 days around parturition in a 2 × 2 factorial design a diet containing MET or CHOL. MET supply led to greater circulating methionine and proportion of methionine in the essential AA pool, total AA, and total sulfur-containing compounds. Lysine in total AA also was greater in these cows, indicating a better overall AA profile. Sulfur-containing compounds (cystathionine, cystine, homocystine, and taurine were greater in MET-fed cows, indicating an enriched sulfur-containing compound pool due to enhanced transsulfuration activity. Circulating essential AA and total AA concentrations were greater in cows supplied MET due to greater lysine, arginine, tryptophan, threonine, proline, asparagine, alanine, and citrulline. In contrast, CHOL supply had no effect on essential AA or total AA, and only tryptophan and cystine were greater. Plasma 3-methylhistidine concentration was lower in response to CHOL supply, suggesting less tissue protein mobilization in these cows. Overall, the data revealed that enhanced periparturient supply of MET has positive effects on plasma AA profiles and overall antioxidant status.

  7. Nutritional and medicinal aspects of D-amino acids.

    Science.gov (United States)

    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.

  8. Neighbor Preferences of Amino Acids and Context-Dependent Effects of Amino Acid Substitutions in Human, Mouse, and Dog

    Directory of Open Access Journals (Sweden)

    Mingchuan Fu

    2014-09-01

    Full Text Available Amino acids show apparent propensities toward their neighbors. In addition to preferences of amino acids for their neighborhood context, amino acid substitutions are also considered to be context-dependent. However, context-dependence patterns of amino acid substitutions still remain poorly understood. Using relative entropy, we investigated the neighbor preferences of 20 amino acids and the context-dependent effects of amino acid substitutions with protein sequences in human, mouse, and dog. For 20 amino acids, the highest relative entropy was mostly observed at the nearest adjacent site of either N- or C-terminus except C and G. C showed the highest relative entropy at the third flanking site and periodic pattern was detected at G flanking sites. Furthermore, neighbor preference patterns of amino acids varied greatly in different secondary structures. We then comprehensively investigated the context-dependent effects of amino acid substitutions. Our results showed that nearly half of 380 substitution types were evidently context dependent, and the context-dependent patterns relied on protein secondary structures. Among 20 amino acids, P elicited the greatest effect on amino acid substitutions. The underlying mechanisms of context-dependent effects of amino acid substitutions were possibly mutation bias at a DNA level and natural selection. Our findings may improve secondary structure prediction algorithms and protein design; moreover, this study provided useful information to develop empirical models of protein evolution that consider dependence between residues.

  9. Neighbor preferences of amino acids and context-dependent effects of amino acid substitutions in human, mouse, and dog.

    Science.gov (United States)

    Fu, Mingchuan; Huang, Zhuoran; Mao, Yuanhui; Tao, Shiheng

    2014-09-10

    Amino acids show apparent propensities toward their neighbors. In addition to preferences of amino acids for their neighborhood context, amino acid substitutions are also considered to be context-dependent. However, context-dependence patterns of amino acid substitutions still remain poorly understood. Using relative entropy, we investigated the neighbor preferences of 20 amino acids and the context-dependent effects of amino acid substitutions with protein sequences in human, mouse, and dog. For 20 amino acids, the highest relative entropy was mostly observed at the nearest adjacent site of either N- or C-terminus except C and G. C showed the highest relative entropy at the third flanking site and periodic pattern was detected at G flanking sites. Furthermore, neighbor preference patterns of amino acids varied greatly in different secondary structures. We then comprehensively investigated the context-dependent effects of amino acid substitutions. Our results showed that nearly half of 380 substitution types were evidently context dependent, and the context-dependent patterns relied on protein secondary structures. Among 20 amino acids, P elicited the greatest effect on amino acid substitutions. The underlying mechanisms of context-dependent effects of amino acid substitutions were possibly mutation bias at a DNA level and natural selection. Our findings may improve secondary structure prediction algorithms and protein design; moreover, this study provided useful information to develop empirical models of protein evolution that consider dependence between residues.

  10. [Bound amino acids in local strains of Trichomonas vaginalis].

    Science.gov (United States)

    Tsvetkova, A; Osinovski, E; Vasilevska, M

    1990-01-01

    Amino acid composition of water-soluble and water-insoluble proteins of 8 strains of Tr. vaginalis is studied. 17 amino acids are found in both protein hydrolyzates. Despite the complete coincidence of their qualitative compositions there are reliable differences in the quantitative contents of some amino acids. Differences in the contents of main amino acids of water-soluble proteins of different strains reflect the belonging of the latter to different sero-groups. No reliable differences in the quantitative contents of amino acids of both water-soluble and water-insoluble proteins in strains belonging to one sero-group are recognised.

  11. Ligands targeting the excitatory amino acid transporters (EAATs).

    Science.gov (United States)

    Dunlop, John; Butera, John A

    2006-01-01

    This review provides an overview of ligands for the excitatory amino acid transporters (EAATs), a family of high-affinity glutamate transporters localized to the plasma membrane of neurons and astroglial cells. Ligand development from the perspective of identifying novel and more selective tools for elucidating transporter subtype function, and the potential of transporter ligands in a therapeutic setting are discussed. Acute pharmacological modulation of EAAT activity in the form of linear and conformationally restricted glutamate and aspartate analogs is presented, in addition to recent strategies aimed more toward modulating transporter expression levels, the latter of particular significance to the development of transporter based therapeutics.

  12. The Hip Functional Retrieval after Elective Surgery May Be Enhanced by Supplemented Essential Amino Acids

    Directory of Open Access Journals (Sweden)

    Eleonora Baldissarro

    2016-01-01

    Full Text Available It is not known whether postsurgery systemic inflammation and plasma amino acid abnormalities are still present during rehabilitation of individuals after elective hip arthroplasty (EHA. Sixty subjects (36 females; age 66.58±8.37 years were randomized to receive 14-day oral EAAs (8 g/day or a placebo (maltodextrin. At admission to and discharge from the rehabilitation center, serum C-reactive protein (CRP and venous plasma amino acid concentrations were determined. Post-EHA hip function was evaluated by Harris hip score (HHS test. Ten matched healthy subjects served as controls. At baseline, all patients had high CRP levels, considerable reduction in several amino acids, and severely reduced hip function (HHS 40.78±2.70 scores. After treatment, inflammation decreased both in the EAA group and in the placebo group. Only EAA patients significantly improved their levels of glycine, alanine, tyrosine, and total amino acids. In addition, they enhanced the rate of hip function recovery (HHS (from baseline 41.8±1.15 to 76.37±6.6 versus baseline 39.78±4.89 to 70.0±7.1 in placebo one; p=0.006. The study documents the persistence of inflammation and plasma amino acid abnormalities in post-EHA rehabilitation phase. EAAs enhance hip function retrieval and improve plasma amino acid abnormalities.

  13. The Hip Functional Retrieval after Elective Surgery May Be Enhanced by Supplemented Essential Amino Acids

    Science.gov (United States)

    Baldissarro, Eleonora; Aquilani, Roberto; Boschi, Federica; Baiardi, Paola; Iadarola, Paolo; Fumagalli, Marco; Pasini, Evasio; Verri, Manuela; Dossena, Maurizia; Gambino, Arianna; Cammisuli, Sharon; Viglio, Simona

    2016-01-01

    It is not known whether postsurgery systemic inflammation and plasma amino acid abnormalities are still present during rehabilitation of individuals after elective hip arthroplasty (EHA). Sixty subjects (36 females; age 66.58 ± 8.37 years) were randomized to receive 14-day oral EAAs (8 g/day) or a placebo (maltodextrin). At admission to and discharge from the rehabilitation center, serum C-reactive protein (CRP) and venous plasma amino acid concentrations were determined. Post-EHA hip function was evaluated by Harris hip score (HHS) test. Ten matched healthy subjects served as controls. At baseline, all patients had high CRP levels, considerable reduction in several amino acids, and severely reduced hip function (HHS 40.78 ± 2.70 scores). After treatment, inflammation decreased both in the EAA group and in the placebo group. Only EAA patients significantly improved their levels of glycine, alanine, tyrosine, and total amino acids. In addition, they enhanced the rate of hip function recovery (HHS) (from baseline 41.8 ± 1.15 to 76.37 ± 6.6 versus baseline 39.78 ± 4.89 to 70.0 ± 7.1 in placebo one; p = 0.006). The study documents the persistence of inflammation and plasma amino acid abnormalities in post-EHA rehabilitation phase. EAAs enhance hip function retrieval and improve plasma amino acid abnormalities. PMID:27110573

  14. Characterization of amino acids using Raman spectroscopy

    Science.gov (United States)

    Jenkins, Amanda L.; Larsen, Richard A.; Williams, Timothy B.

    2005-05-01

    A key process in the development of new drugs is elucidation of the interaction between the drug molecule and the target protein. Such knowledge then makes it possible to make systematic structural modifications of the drug molecule to optimize the interaction. Many analytical techniques can be applied to proteins in solution such as circular dichroism, ultraviolet, and fluorescence spectroscopy but these all have limitations. In this paper, we investigate the feasibility of using relatively simple, visible light Raman spectroscopic methods to investigate amino acids and related biopolymers.

  15. Photoinduced dynamics in protonated aromatic amino acid

    CERN Document Server

    Grégoire, Gilles; Barat, Michel; Fayeton, Jacqueline; Dedonder-Lardeux, Claude; Jouvet, Christophe

    2008-01-01

    UV photoinduced fragmentation of protonated aromatics amino acids have emerged the last few years, coming from a situation where nothing was known to what we think a good understanding of the optical properties. We will mainly focus this review on the tryptophan case. Three groups have mostly done spectroscopic studies and one has mainly been involved in dynamics studies of the excited states in the femtosecond/picosecond range and also in the fragmentation kinetics from nanosecond to millisecond. All these data, along with high level ab initio calculations, have shed light on the role of the different electronic states of the protonated molecules upon the fragmentation mechanisms.

  16. Extraterrestrial Amino Acids in the Almahata Sitta Meteorite

    Science.gov (United States)

    Glavin, Daniel P.; Aubrey, Andrew D.; Callahan, Michael P.; Dworkin, Jason P.; Elsila, Jamie E.; Parker, Eric T.; Bada, Jeffrey L.

    2010-01-01

    Amino acid analysis of a meteorite fragment of asteroid 2008 TC3 called Almahata Sitta was carried out using reverse-phase liquid chromatography coupled with UV fluorescence detection and time-of-flight mass spectrometry (LC-FD/ToF-MS) as part of a sample analysis consortium. LC-FD/ToF-MS analyses of hot-water extracts from the meteorite revealed a complex distribution of two- to seven-carbon aliphatic amino acids and one- to three-carbon amines with abundances ranging from 0.5 to 149 parts-per-billion (ppb). The enantiomeric ratios of the amino acids alanine, R-amino-n-butyric acid (beta-ABA), 2-amino-2-methylbutanoic acid (isovaline), and 2-aminopentanoic acid (norvaline) in the meteorite were racemic (D/L approximately 1), indicating that these amino acids are indigenous to the meteorite and not terrestrial contaminants. Several other non-protein amino acids were also identified in the meteorite above background levels including alpha-aminoisobutyric acid (alpha-AIB), 4-amino-2- methylbutanoic acid, 4-amino-3-methylbutanoic acid, and 3-, 4-, and 5-aminopentanoic acid. The total abundances of isovaline and alpha-AIB in Almahata Sitta are 1000 times lower than the abundances of these amino acids found in the CM carbonaceous chondrite Murchison. The extremely low abundances and unusual distribution of five carbon amino acids in Almahata Sitta compared to Cl, CM, and CR carbonaceous chondrites may reflect extensive thermal alteration of amino acids on the parent asteroid by partial melting during formation or subsequent impact shock heating. It is also possible that amino acids were synthesized by catalytic reactions on the parent body after asteroid 2008 TC3 cooled to lower temperatures.

  17. Ribosomal Synthesis of Peptides with Multiple β-Amino Acids.

    Science.gov (United States)

    Fujino, Tomoshige; Goto, Yuki; Suga, Hiroaki; Murakami, Hiroshi

    2016-02-17

    The compatibility of β-amino acids with ribosomal translation was studied for decades, but it has been still unclear whether the ribosome can accept various β-amino acids, and whether the ribosome can introduce multiple β-amino acids in a peptide. In the present study, by using the Escherichia coli reconstituted cell-free translation system with a reprogramed genetic code, we screened β-amino acids that give high single incorporation efficiency and used them to synthesize peptides containing multiple β-amino acids. The experiments of single β-amino acid incorporation into a peptide revealed that 13 β-amino acids are compatible with ribosomal translation. Six of the tested β-amino acids (βhGly, l-βhAla, l-βhGln, l-βhPhg, l-βhMet, and d-βhPhg) showed high incorporation efficiencies, and seven (l-βhLeu, l-βhIle, l-βhAsn, l-βhPhe, l-βhLys, d-βhAla, and d-βhLeu) showed moderate incorporation efficiencies; whereas no full-length peptide was produced using other β-amino acids (l-βhPro, l-βhTrp, and l-βhGlu). Subsequent double-incorporation experiments using β-amino acids with high single incorporation efficiency revealed that elongation of peptides with successive β-amino acids is prohibited. Efficiency of the double-incorporation of the β-amino acids was restored by the insertion of Tyr or Ile between the two β-amino acids. On the basis of these experiments, we also designed mRNA sequences of peptides, and demonstrated the ribosomal synthesis of peptides containing different types of β-amino acids at multiple positions.

  18. Evolutionary systems biology of amino acid biosynthetic cost in yeast.

    Directory of Open Access Journals (Sweden)

    Michael D Barton

    Full Text Available Every protein has a biosynthetic cost to the cell based on the synthesis of its constituent amino acids. In order to optimise growth and reproduction, natural selection is expected, where possible, to favour the use of proteins whose constituents are cheaper to produce, as reduced biosynthetic cost may confer a fitness advantage to the organism. Quantifying the cost of amino acid biosynthesis presents challenges, since energetic requirements may change across different cellular and environmental conditions. We developed a systems biology approach to estimate the cost of amino acid synthesis based on genome-scale metabolic models and investigated the effects of the cost of amino acid synthesis on Saccharomyces cerevisiae gene expression and protein evolution. First, we used our two new and six previously reported measures of amino acid cost in conjunction with codon usage bias, tRNA gene number and atomic composition to identify which of these factors best predict transcript and protein levels. Second, we compared amino acid cost with rates of amino acid substitution across four species in the genus Saccharomyces. Regardless of which cost measure is used, amino acid biosynthetic cost is weakly associated with transcript and protein levels. In contrast, we find that biosynthetic cost and amino acid substitution rates show a negative correlation, but for only a subset of cost measures. In the economy of the yeast cell, we find that the cost of amino acid synthesis plays a limited role in shaping transcript and protein expression levels compared to that of translational optimisation. Biosynthetic cost does, however, appear to affect rates of amino acid evolution in Saccharomyces, suggesting that expensive amino acids may only be used when they have specific structural or functional roles in protein sequences. However, as there appears to be no single currency to compute the cost of amino acid synthesis across all cellular and environmental

  19. EFFECT OF MICROORGANISMS ON FREE AMINO ACID AND FREE D-AMINO ACID CONTENTS OF VARIOUS DAIRY PRODUCTS

    OpenAIRE

    Csilla Albert; Gabriella Pohn; Katalin Lóki; Szidónia Salamon; Beáta Albert; P. Sára; Z. Mándoki; Jánosné Csapó; Csapó, J.

    2007-01-01

    Free amino acid and free D-amino acid contents of milk samples with different microorganism numbers and composition of dairy products produced from them were examined. Total microorganism number of milk samples examined varied from 1.25x106 to 2.95x106. It was established that concentration of both free D-amino acids and free L-amino acids increased with an increase in microorganism number. However, increase in D-amino acid contents was higher considering its proportion. There was a particula...

  20. Effects of alkali or acid treatment on the isomerization of amino acids.

    Science.gov (United States)

    Ohmori, Taketo; Mutaguchi, Yuta; Doi, Katsumi; Ohshima, Toshihisa

    2012-10-01

    The effect of alkali treatment on the isomerization of amino acids was investigated. The 100×D/(D+L) values of amino acids from peptide increased with increase in the number of constituent amino acid residues. Furthermore, the N-terminal amino acid of a dipeptide was isomerized to a greater extent than the C-terminal residue.

  1. Amino acids in healthy aging skeletal muscle.

    Science.gov (United States)

    Riddle, Emily S; Stipanuk, Martha H; Thalacker-Mercer, Anna E

    2016-01-01

    Life expectancy in the U.S. and globally continues to increase. Despite increased life expectancy quality of life is not enhanced, and older adults often experience chronic age-related disease and functional disability, including frailty. Additionally, changes in body composition such as the involuntary loss of skeletal muscle mass (i.e. sarcopenia) and subsequent increases in adipose tissue can augment disease and disability in this population. Furthermore, increased oxidative stress and decreased antioxidant concentrations may also lead to metabolic dysfunction in older adults. Specific amino acids, including leucine, cysteine and its derivative taurine, and arginine can play various roles in healthy aging, especially in regards to skeletal muscle health. Leucine and arginine play important roles in muscle protein synthesis and cell growth while cysteine and arginine play important roles in quenching oxidative stress. Evidence suggests that supplemental doses of each of these amino acids may improve the aging phenotype. However, additional research is required to establish the doses required to achieve positive outcomes in humans.

  2. Conformational properties of oxazoline-amino acids

    Science.gov (United States)

    Staś, Monika; Broda, Małgorzata A.; Siodłak, Dawid

    2016-04-01

    Oxazoline-amino acids (Xaa-Ozn) occur in natural peptides of potentially important bioactivity. The conformations of the model compounds: Ac-(S)-Ala-Ozn(4R-Me), Ac-(S)-Ala-Ozn(4S-Me), and (gauche+, gauche-, anti) Ac-(S)-Val-Ozn(4R-Me) were studied at meta-hybrid M06-2X/6-311++G(d,p) method including solvent effect. Boc-L-Ala-L-Ozn-4-COOMe and Boc-L-Val-L-Ozn-4-COOMe were synthesized and studied by FT-IR and NMR-NOE methods. The conformations in crystal state were gathered from the Cambridge Structural Data Base. The main conformational feature of the oxazoline amino acids is the conformation β2 (ϕ,ψ ∼ -161°, -6°), which predominates in weakly polar environment and still is accessible in polar surrounding. The changes of the conformational preferences towards the conformations αR (ϕ,ψ ∼ -70°, -15°) and then β (ϕ,ψ ∼ -57°, -155°) are observed with increase of the environment polarity.

  3. Formation and transformation of amino acids and amino acid precursors by high-velocity impacts

    Science.gov (United States)

    Kaneko, T.; Kobayashi, K.; Yamori, A.

    A wide variety of organic compounds have been found in extraterrestrial bodies such as comets and carbonaceous chondrites. It is plausible that these extraterrestrial bodies carried organic compounds such as amino acids or their precursors to the early Earth. It is claimed, however, that these extraterrestrial organics were destroyed during impacts to the Earth. We therefore examined possible transformation of amino acids and their precursors during high-velocity impacts by using a rail gun "HYPAC" in ISAS. Starting materials used in the impact experiments were (i) aqueous solution of glycine (10 mM or 1.0 M), and (ii) a mixture of ammonia, methanol and water. The target materials were sealed in stainless steel capsules, and shocked by impact with a polycarbonate projectile accelerated with "HYPAC" to the velocities of 2.5 - 7.0 km/s. A part of the products was acid-hydrolyzed. Both hydrolyzed an unhydrolyzed products were analyzed by mass spectrometry, high performance liquid chromatography and capillary electrophoresis and chromatography. When an aqueous solution containing ammonia, methanol and water was shocked by impact at the velocity of 6.4 km/s, a number of amino acids (e.g., serine and glycine) were detected after hydrolysis. The present results suggest that amino acid precursors could be formed during cometary impacts. When glycine solution was used as a starting material, about 40 % of glycine was recovered even after 6 km/s impact. Methylamine and ammonia, which are known as pyrolytic products of glycine, were detected, besides them, diketopiperazine and an unidentified product whose molecular weight was 134, were detected, while no glycine peptides were identified in them. It was shown that the impact processes resulted in the formation of amino acid condensates. Thermal stability of glycine precursor is comparable with glycine. The present results suggest that organic material could survive and/or formed during an impact process. Most of organic

  4. Inadequacy of prebiotic synthesis as origin of proteinous amino acids.

    Science.gov (United States)

    Wong, J T; Bronskill, P M

    1979-07-18

    The production of some nonproteinous, and lack of production of other proteinous, amino acids in model prebiotic synthesis, along with the instability of glutamine and asparagine, suggest that not all of the 20 present day proteinous amino acids gained entry into proteins directly from the primordial soup. Instead, a process of active co-evolution of the genetic code and its constituent amino acids would have to precede the final selection of these proteinous amono acids.

  5. Ist2 in the yeast cortical endoplasmic reticulum promotes trafficking of the amino acid transporter Bap2 to the plasma membrane.

    Directory of Open Access Journals (Sweden)

    Wendelin Wolf

    Full Text Available The equipment of the plasma membrane in Saccharomyces cerevisiae with specific nutrient transporters is highly regulated by transcription, translation and protein trafficking allowing growth in changing environments. The activity of these transporters depends on a H(+ gradient across the plasma membrane generated by the H(+-ATPase Pma1. We found that the polytopic membrane protein Ist2 in the cortical endoplasmic reticulum (ER is required for efficient leucine uptake during the transition from fermentation to respiration. Experiments employing tandem fluorescence timer protein tag showed that Ist2 was necessary for efficient trafficking of newly synthesized leucine transporter Bap2 from the ER to the plasma membrane. This finding explains the growth defect of ist2Δ mutants during nutritional challenges and illustrates the important role of physical coupling between cortical ER and plasma membrane.

  6. Chiral amino acid metabolomics for novel biomarker screening in the prognosis of chronic kidney disease

    Science.gov (United States)

    Kimura, Tomonori; Hamase, Kenji; Miyoshi, Yurika; Yamamoto, Ryohei; Yasuda, Keiko; Mita, Masashi; Rakugi, Hiromi; Hayashi, Terumasa; Isaka, Yoshitaka

    2016-01-01

    D-Amino acids, the enantiomers of L-amino acids, are increasingly recognized as novel biomarkers. Although the amounts of D-amino acids are usually very trace in human, some of them have sporadically been detected in blood from patients with kidney diseases. This study examined whether multiple chiral amino acids would be associated with kidney functions, comorbidities, and prognosis of chronic kidney disease (CKD) by enantioselective analyses of all chiral amino acids with a micro-two-dimensional high-performance liquid chromatograph (2D-HPLC)-based analytical platform. 16 out of 21 D-amino acids were detected in plasma from 108 CKD patients in a longitudinal cohort. The levels of D-Ser, D-Pro, and D-Asn were strongly associated with kidney function (estimated glomerular filtration ratio), the levels of D-Ala and D-Pro were associated with age, and the level of D-Asp and D-Pro were associated with the presence of diabetes mellitus. D-Ser and D-Asn were significantly associated with the progression of CKD in mutually-adjusted Cox regression analyses; the risk of composite end point (developing to ESKD or death before ESKD) was elevated from 2.7- to 3.8-fold in those with higher levels of plasma D-Ser and D-Asn. These findings identified chiral amino acids as potential biomarkers in kidney diseases. PMID:27188851

  7. Unprecedented concentrations of indigenous amino acids in primitive CR meteorites

    Science.gov (United States)

    Ehrenfreund, Pascale; Martins, Zita; Alexander, Conel; Orzechowska, Grazyna; Fogel, Marylin

    CR meteorites are among the most primitive meteorites. We have performed pioneering work determining the compositional characteristics of amino acids in this type of carbonaceous chondrites. We report the first measurements of amino acids in Antarctic CR meteorites, two of which show the highest amino acid concentrations ever found in a chondrite. We have analyzed the amino acid content of the Antarctic CRs EET92042, GRA95229 and GRO95577 using high performance liquid chromatography with UV fluorescence detection (HPLC-FD) and gas chromatography-mass spectrometry (GC-MS). Additionally, compound-specific carbon isotopic measurements for most of the individual amino acids from the EET92042 and GRA95229 meteorites were achieved by gas chromatography-combustion-isotope ratio mass spectrometry (GC-C-IRMS). Our data show that EET92042 and GRA95229 are the most amino acid-rich chondrites ever analyzed, with total amino acid concentrations of 180 and 249 parts-per-million (ppm), respectively. GRO95577, however, is depleted in amino acids (determined for most amino acids indicate that primitive organic matter was preserved in these meteorites. In addition, the relative abundances of α-AIB and β-alanine amongst Antarctic CR meteorites appear to correspond to the degree of aqueous alteration on their respective parent body. Investigating the abundances and isotopic composition of amino acids in primitive chondrites helps to understand the role of meteorites as a source of extraterrestrial prebiotic organic compounds to the early Earth.

  8. The prebiotic synthesis of amino acids - interstellar vs. atmospheric mechanisms

    Science.gov (United States)

    Meierhenrich, U. J.; Muñoz Caro, G. M.; Schutte, W. A.; Barbier, B.; Arcones Segovia, A.; Rosenbauer, H.; Thiemann, W. H.-P.; Brack, A.

    2002-11-01

    Until very recently, prebiotic amino acids were believed to have been generated in the atmosphere of the early Earth, as successfully simulated by the Urey-Miller experiments. Two independent studies now identified ice photochemistry in the interstellar medium as a possible source of prebiotic amino acids. Ultraviolet irradiation of ice mixtures containing identified interstellar molecules (such as H2O, CO2, CO, CH3OH, and NH3) in the conditions of vacuum and low temperature found in the interstellar medium generated amino acid structures including glycine, alanine, serine, valine, proline, and aspartic acid. After warmup, hydrolysis and derivatization, our team was able to identify 16 amino acids as well as furans and pyrroles. Enantioselective analyses of the amino acids showed racemic mixtures. A prebiotic interstellar origin of amino acid structures is now discussed to be a plausible alternative to the Urey-Miller mechanism.

  9. Transfer of Asymmetry between Proteinogenic Amino Acids under Harsh Conditions.

    Science.gov (United States)

    Tarasevych, Arkadii V; Vives, Thomas; Snytnikov, Valeriy N; Guillemin, Jean-Claude

    2017-03-31

    The heating above 400 °C of serine, cysteine, selenocysteine and threonine leads to a complete decomposition of the amino acids and to the formation in low yields of alanine for the three formers and of 2-aminobutyric acid for the latter. At higher temperature, this amino acid is observed only when sublimable α-alkyl-α-amino acids are present, and with an enantiomeric excess dependent on several parameters. Enantiopure or enantioenriched Ser, Cys, Sel or Thr is not able to transmit its enantiomeric excess to the amino acid formed during its decomposition. The presence during the sublimation-decomposition of enantioenriched valine or isoleucine leads to the enantioenrichment of all sublimable amino acids independently of the presence of many decomposition products coming from the unstable derivative. All these studies give information on a potentially prebiotic key-reaction of abiotic transformations between α-amino acids and their evolution to homochirality.

  10. Extraterrestrial Amino Acids in the Almahata Sitta Meteorite

    Science.gov (United States)

    Glavin, Daniel P.; Aubrey, Andrew D.; Callahan, Michael P.; Dworkin, Jason P.; Elsila, Jamie E.; Parker, Eric T.; Bada, Jeffrey L.

    2009-01-01

    Amino acid analysis of a meteorite fragment of asteroid 2008 TC(sub 3) called Almahata Sitta was carried out using reverse-phase high-perfo rmance liquid chromatography coupled with UV fluorescence detection a nd time-of-flight mass spectrometry (HPLC-FD/ToF-MS) as part of a sam ple analysis consortium. HPLC analyses of hot-water extracts from the meteorite revealed a complex distribution of two- to six-carbon aliph atic amino acids and one- to three carbon amines with abundances rang ing from 0.5 to 149 parts-per-billion (ppb). The enantiomeric ratios of the amino acids alanine, Beta-amino-n-butyric acid (Beta-ABA), 2-amino-2- methylbutanoic acid (isovaline), and 2-aminopentanoic acid (no rvaline) in the meteorite were racemic (D/L approximately 1), indicat ing that these amino acids are indigenous to the meteorite and not te rrestrial contaminants. Several other non-protein amino acids were also identified in the meteorite above background levels including alpha -aminoisobutyric acid (alpha-AIB), 4-amino-2- methybutanoic acid, 4-a mino-3-methylbutanoic acid, and 3-, 4-, and 5-aminopentanoic acid. Th e total abundances of isovaline and AlB in Almahata Sitta are approximately 1000 times lower than the abundances of these amino acids found in the CM carbonaceous meteorite Murchison. The extremely love abund ances and unusual distribution of five carbon amino acids in Almahata Sitta compared to Cl, CM, and CR carbonaceous meteorites and may be due to extensive thermal alteration of amino acids on the parent aster oid by partial melting during formation or impact shock heating.

  11. Stereoselective synthesis of stable-isotope-labeled amino acids

    Energy Technology Data Exchange (ETDEWEB)

    Unkefer, C.J.; Martinez, R.A.; Silks, L.A. III [Los Alamos National Laboratory, NM (United States); Lodwig, S.N. [Centralia College, WA (United States)

    1994-12-01

    For magnetic resonance and vibrational spectroscopies to reach their full potential, they must be used in combination with sophisticated site-specific stable isotope labeling of biological macromolecules. Labeled amino acids are required for the study of the structure and function of enzymes and proteins. Because there are 20 common amino acids, each with its own distinguishing chemistry, they remain a synthetic challenge. The Oppolzer chiral auxiliary provides a general tool with which to approach the synthesis of labeled amino acids. By using the Oppolzer auxiliary, amino acids can be constructed from several small molecules, which is ideal for stable isotope labeling. In addition to directing the stereochemistry at the {alpha}-carbon, the camphorsultam can be used for stereo-specific isotope labeling at prochiral centers in amino acids. By using the camphorsultam auxiliary we have the potential to synthesize virtually any isotopomer of all of the common amino acids.

  12. Twenty natural amino acids identification by a photochromic sensor chip.

    Science.gov (United States)

    Qin, Meng; Li, Fengyu; Huang, Yu; Ran, Wei; Han, Dong; Song, Yanlin

    2015-01-20

    All 20 natural amino acids identification shows crucial importance in biochemistry and clinical application while it is still a challenge due to highly similarity in molecular configuration of the amino acids. Low efficiency, complicated sensing molecules and environment hindered the successful identification. Here, we developed a facile sensor chip composed of one photochromic molecule with metal ions spotted to form spirooxazine-metallic complexes, and successfully recognized all the 20 natural amino acids as well as their mixtures. The sensor chip gives distinct fluorescent fingerprint pattern of each amino acid, based on multistate of spirooxazine under different light stimulations and discriminated interaction between various metal ions and amino acids. The sensor chip demonstrates powerful capability of amino acids identification, which promotes sensing of biomolecules.

  13. Nectar amino acids enhance reproduction in male butterflies.

    Science.gov (United States)

    Cahenzli, Fabian; Erhardt, Andreas

    2013-01-01

    After over 30 years of research, it was recently shown that nectar amino acids increase female butterfly fecundity. However, little attention has been paid to the effect of nectar amino acids on male butterfly reproduction. Here, we show that larval food conditions (nitrogen-rich vs. nitrogen-poor host plants) and adult diet quality (nectar with or without amino acids) affected the amount of consumed nectar in Coenonympha pamphilus males. Furthermore, amino acids in the nectar diet of males increased progeny's larval hatching mass, irrespective of paternal larval reserves. Our study takes the whole reproductive cycle of male butterflies into account, and also considers the role of females in passing male nutrients to offspring, as males' realized reproduction was examined indirectly via nuptial gifts, by female performance. With this comprehensive approach, we demonstrate for the first time that nectar amino acids can improve male butterfly reproduction, supporting the old postulate that nectar amino acids generally enhance butterfly fitness.

  14. Surface Propensity of Atmospherically Relevant Amino Acids Studied by XPS.

    Science.gov (United States)

    Mocellin, Alexandra; Gomes, Anderson Herbert de Abreu; Araújo, Oscar Cardoso; de Brito, Arnaldo Naves; Bjorneholm, Olle

    2017-03-30

    Amino acids constitute an important fraction of the water-soluble organic nitrogen (WSON) compounds in aerosols and are involved in many processes in the atmosphere. In this work, we applied XPS to study aqueous solutions of four amino acids: glycine, alanine, valine and methionine, in their zwitterionic forms. We found that amino acids with hydrophilic side chains and smaller size, GLY and ALA, tend to stay in the bulk of the liquid, while the hydrophobic and bigger amino acids, VAL and MET, are found to concentrate more on the surface. We found experimental evidences that the amino acids have preferential orientation relative to the surface, with the hydrophobic side chain being closer to the surface than the hydrophilic carboxylate group. The observed amino acid surface propensity has implications in atmospheric science as the surface interaction play a central role in cloud droplet formation, and they should be considered in climate models.

  15. Distribution and Origin of Amino Acids in Lunar Regolith Samples

    Science.gov (United States)

    Elsila, J. E.; Callahan, M. P.; Glavin, D. P.; Dworkin, J. P.; McLain, H. L.; Noble, S. K.; Gibson, E. K., Jr.

    2015-01-01

    The existence of organic compounds on the lunar surface has been a question of interest from the Apollo era to the present. Investigations of amino acids immediately after collection of lunar samples yielded inconclusive identifications, in part due to analytical limitations including insensitivity to certain compounds, an inability to separate enantiomers, and lack of compound-specific isotopic measurements. It was not possible to determine if the detected amino acids were indigenous to the lunar samples or the result of terrestrial contamination. Recently, we presented initial data from the analysis of amino acid abundances in 12 lunar regolith samples and discussed those results in the context of four potential amino acid sources [5]. Here, we expand on our previous work, focusing on amino acid abundances and distributions in seven regolith samples and presenting the first compound-specific carbon isotopic ratios measured for amino acids in a lunar sample.

  16. Diversity of amino acids in a typical chernozem of Moldova

    Science.gov (United States)

    Frunze, N. I.

    2014-12-01

    The content and composition of the amino acids in typical chernozems were studied. The objects of the study included a reference soil under an old fallow and three variants under fodder crop rotations: not fertilized, with mineral fertilizers, and with organic fertilizers. The contents of 18 amino acids were determined in these soils. The amino acids were extracted by the method of acid hydrolysis and identified by the method of ion-exchange chromatography. The total content of most of the amino acids was maximal in the reference soil; it was much lower in the cultivated soils and decreased in the following sequence: organic background > mineral background > no fertilization. The diversity of amino acids was evaluated quantitatively using different parameters applied in ecology for estimating various aspects of the species composition of communities (Simpson, Margalef, Menhinick, and Shannon's indices). The diversity and contribution of different amino acids to the total pool of amino acids also varied significantly in the studied variants. The maximum diversity of amino acids and maximum evenness of their relative abundance indices were typical of the reference chernozem; these parameters were lower in the cultivated soils. It was concluded that the changes in the structure of the amino acids under the impact of agricultural loads are similar to those that are usually observed under stress conditions.

  17. Preference for and learning of amino acids in larval Drosophila

    Directory of Open Access Journals (Sweden)

    Nana Kudow

    2017-03-01

    Full Text Available Relative to other nutrients, less is known about how animals sense amino acids and how behaviour is organized accordingly. This is a significant gap in our knowledge because amino acids are required for protein synthesis − and hence for life as we know it. Choosing Drosophila larvae as a case study, we provide the first systematic analysis of both the preference behaviour for, and the learning of, all 20 canonical amino acids in Drosophila. We report that preference for individual amino acids differs according to the kind of amino acid, both in first-instar and in third-instar larvae. Our data suggest that this preference profile changes across larval instars, and that starvation during the third instar also alters this profile. Only aspartic acid turns out to be robustly attractive across all our experiments. The essentiality of amino acids does not appear to be a determinant of preference. Interestingly, although amino acids thus differ in their innate attractiveness, we find that all amino acids are equally rewarding. Similar discrepancies between innate attractiveness and reinforcing effect have previously been reported for other tastants, including sugars, bitter substances and salt. The present analyses will facilitate the ongoing search for the receptors, sensory neurons, and internal, homeostatic amino acid sensors in Drosophila.

  18. Preference for and learning of amino acids in larval Drosophila.

    Science.gov (United States)

    Kudow, Nana; Miura, Daisuke; Schleyer, Michael; Toshima, Naoko; Gerber, Bertram; Tanimura, Teiichi

    2017-03-15

    Relative to other nutrients, less is known about how animals sense amino acids and how behaviour is organized accordingly. This is a significant gap in our knowledge because amino acids are required for protein synthesis - and hence for life as we know it. Choosing Drosophila larvae as a case study, we provide the first systematic analysis of both the preference behaviour for, and the learning of, all 20 canonical amino acids in Drosophila We report that preference for individual amino acids differs according to the kind of amino acid, both in first-instar and in third-instar larvae. Our data suggest that this preference profile changes across larval instars, and that starvation during the third instar also alters this profile. Only aspartic acid turns out to be robustly attractive across all our experiments. The essentiality of amino acids does not appear to be a determinant of preference. Interestingly, although amino acids thus differ in their innate attractiveness, we find that all amino acids are equally rewarding. Similar discrepancies between innate attractiveness and reinforcing effect have previously been reported for other tastants, including sugars, bitter substances and salt. The present analyses will facilitate the ongoing search for the receptors, sensory neurons, and internal, homeostatic amino acid sensors in Drosophila.

  19. The Origin of Amino Acids in Lunar Regolith Samples

    Science.gov (United States)

    Cook, Jamie E.; Callahan, Michael P.; Dworkin, Jason P.; Glavin, Daniel P.; McLain, Hannah L.; Noble, Sarah K.; Gibson, Everett K., Jr.

    2016-01-01

    We analyzed the amino acid content of seven lunar regolith samples returned by the Apollo 16 and Apollo 17 missions and stored under NASA curation since collection using ultrahigh-performance liquid chromatography with fluorescence detection and time-of-flight mass spectrometry. Consistent with results from initial analyses shortly after collection in the 1970s, we observed amino acids at low concentrations in all of the curated samples, ranging from 0.2 parts-per-billion (ppb) to 42.7 ppb in hot-water extracts and 14.5 ppb to 651.1 ppb in 6M HCl acid-vapor-hydrolyzed, hot-water extracts. Amino acids identified in the Apollo soil extracts include glycine, D- and L-alanine, D- and L-aspartic acid, D- and L-glutamic acid, D- and L-serine, L-threonine, and L-valine, all of which had previously been detected in lunar samples, as well as several compounds not previously identified in lunar regoliths: -aminoisobutyric acid (AIB), D-and L-amino-n-butyric acid (-ABA), DL-amino-n-butyric acid, -amino-n-butyric acid, -alanine, and -amino-n-caproic acid. We observed an excess of the L enantiomer in most of the detected proteinogenic amino acids, but racemic alanine and racemic -ABA were present in some samples.

  20. Interactions between homopolymeric amino acids (HPAAs).

    Science.gov (United States)

    Oma, Yoko; Kino, Yoshihiro; Toriumi, Kazuya; Sasagawa, Noboru; Ishiura, Shoichi

    2007-10-01

    Many human proteins contain consecutive amino acid repeats, known as homopolymeric amino acid (HPAA) tracts. Some inherited diseases are caused by proteins in which HPAAs are expanded to an excessive length. To this day, nine polyglutamine-related diseases and nine polyalanine-related diseases have been reported, including Huntington's disease and oculopharyngeal muscular dystrophy. In this study, potential HPAA-HPAA interactions were examined by yeast two-hybrid assays using HPAAs of approximately 30 residues in length. The results indicate that hydrophobic HPAAs interact with themselves and with other hydrophobic HPAAs. Previously, we reported that hydrophobic HPAAs formed large aggregates in COS-7 cells. Here, those HPAAs were shown to have significant interactions with each other, suggesting that hydrophobicity plays an important role in aggregation. Among the observed HPAA-HPAA interactions, the Ala28-Ala29 interaction was notable because polyalanine tracts of these lengths have been established to be pathogenic in several polyalanine-related diseases. By testing several constructs of different lengths, we clarified that polyalanine self-interacts at longer lengths (>23 residues) but not at shorter lengths (six to approximately 23 residues) in a yeast two-hybrid assay and a GST pulldown assay. This self-interaction was found to be SDS sensitive in SDS-PAGE and native-PAGE assays. Moreover, the intracellular localization of these long polyalanine tracts was also observed to be disturbed. Our results suggest that long tracts of polyalanine acquire SDS-sensitive self-association properties, which may be a prerequisite event for their abnormal folding. The misfolding of these tracts is thought to be a common molecular aspect underlying the pathogenesis of polyalanine-related diseases.

  1. Relationship between insulin resistance and amino acids in women and men

    OpenAIRE

    Seibert, Ryan; Abbasi, Fahim; Hantash, Feras M.; Caulfield, Michael P; Reaven, Gerald; Sun H. Kim

    2015-01-01

    Insulin resistance has been associated with higher plasma amino acid (AA) concentrations, but majority of studies have used indirect measures of insulin resistance. Our main objective was to define the relationship between plasma AA concentrations and a direct measure of insulin resistance in women and men. This was a cross-sectional study of 182 nondiabetic individuals (118 women and 64 men) who had measurement of 24 AAs and steady-state plasma glucose (SSPG) concentration (insulin resistanc...

  2. A new synthetic protocol for coumarin amino acid

    Directory of Open Access Journals (Sweden)

    Xinyi Xu

    2013-02-01

    Full Text Available The hydrochloride of the racemic amino acid (2-(7-hydroxycoumarin-4-ylethylglycine, which can serve as a fluorescent probe in proteins, and two halogen derivatives of it, were synthesized by using a new synthetic protocol in five steps. It is less costly and relatively easy to prepare this kind of fluorescent amino acid with the new synthetic method. Furthermore, it can be applied to synthesize other derivatives of the coumarin amino acid with some specific properties.

  3. PHARMACOLOGICAL EFFECTS OF SNAKE VENOM L- AMINO ACID OXIDASES

    OpenAIRE

    Joseph Baby; Rajan Sheeja S; M.V Jeevitha; S.U Ajisha

    2011-01-01

    L-Amino acid oxidases are flavoenzymes which catalyze the stereospecific oxidative deamination of an L-amino acid substrate to a corresponding a-ketoacid with hydrogen peroxide and ammonia production. These enzymes, which are widely distributed in many different organisms, exhibit a marked affinity for hydrophobic amino acids, including phenylalanine, tryptophan, tyrosine, and leucine. Snake venom LAAO induces platelet aggregation and cytotoxicity in various cancer cell lines. The enzyme has ...

  4. SIFT: predicting amino acid changes that affect protein function

    OpenAIRE

    Ng, Pauline C.; Henikoff, Steven

    2003-01-01

    Single nucleotide polymorphism (SNP) studies and random mutagenesis projects identify amino acid substitutions in protein-coding regions. Each substitution has the potential to affect protein function. SIFT (Sorting Intolerant From Tolerant) is a program that predicts whether an amino acid substitution affects protein function so that users can prioritize substitutions for further study. We have shown that SIFT can distinguish between functionally neutral and deleterious amino acid changes in...

  5. A Novel Synthesis of β-Hydroxy-α-amino Acids

    Institute of Scientific and Technical Information of China (English)

    ZHANG Zhi-Hui; LI Shuo; XU Pen-gFei

    2003-01-01

    @@ β-hydroxy-α-amino acids constitute an important class of compounds as naturally occurring amino acids and as components of many complex natural products possessing a wide range of biological activities. [1] As a consequence of the essential role played by these amino acids in the biological systems and their utility as synthetic building blocks, a number of useful strategies have been devised for their preparation. [2

  6. Gas-Phase Acidities of Phosphorylated Amino Acids.

    Science.gov (United States)

    Stover, Michele L; Plummer, Chelsea E; Miller, Sean R; Cassady, Carolyn J; Dixon, David A

    2015-11-19

    Gas-phase acidities and heats of formation have been predicted at the G3(MP2)/SCRF-COSMO level of theory for 10 phosphorylated amino acids and their corresponding amides, including phospho-serine (pSer), -threonine (pThr), and -tyrosine (pTyr), providing the first reliable set of these values. The gas-phase acidities (GAs) of the three named phosphorylated amino acids and their amides have been determined using proton transfer reactions in a Fourier transform ion cyclotron mass spectrometer. Excellent agreement was found between the experimental and predicted GAs. The phosphate group is the deprotonation site for pSer and pThr and deprotonation from the carboxylic acid generated the lowest energy anion for pTyr. The infrared spectra were calculated for six low energy anions of pSer, pThr, and pTyr. For deprotonated pSer and pThr, good agreement is found between the experimental IRMPD spectra and the calculated spectra for our lowest energy anion structure. For pTyr, the IR spectra for a higher energy phosphate deprotonated structure is in good agreement with experiment. Additional experiments tested electrospray ionization (ESI) conditions for pTyr and determined that variations in solvent, temperature, and voltage can result in a different experimental GA value, indicating that ESI conditions affect the conformation of the pTyr anion.

  7. Design and characterization of auxotrophy-based amino acid biosensors.

    Directory of Open Access Journals (Sweden)

    Felix Bertels

    Full Text Available Efficient and inexpensive methods are required for the high-throughput quantification of amino acids in physiological fluids or microbial cell cultures. Here we develop an array of Escherichia coli biosensors to sensitively quantify eleven different amino acids. By using online databases, genes involved in amino acid biosynthesis were identified that - upon deletion - should render the corresponding mutant auxotrophic for one particular amino acid. This rational design strategy suggested genes involved in the biosynthesis of arginine, histidine, isoleucine, leucine, lysine, methionine, phenylalanine, proline, threonine, tryptophan, and tyrosine as potential genetic targets. A detailed phenotypic characterization of the corresponding single-gene deletion mutants indeed confirmed that these strains could neither grow on a minimal medium lacking amino acids nor transform any other proteinogenic amino acid into the focal one. Site-specific integration of the egfp gene into the chromosome of each biosensor decreased the detection limit of the GFP-labeled cells by 30% relative to turbidometric measurements. Finally, using the biosensors to determine the amino acid concentration in the supernatants of two amino acid overproducing E. coli strains (i.e. ΔhisL and ΔtdcC both turbidometrically and via GFP fluorescence emission and comparing the results to conventional HPLC measurements confirmed the utility of the developed biosensor system. Taken together, our study provides not only a genotypically and phenotypically well-characterized set of publicly available amino acid biosensors, but also demonstrates the feasibility of the rational design strategy used.

  8. Amino acids in the cultivation of mammalian cells.

    Science.gov (United States)

    Salazar, Andrew; Keusgen, Michael; von Hagen, Jörg

    2016-05-01

    Amino acids are crucial for the cultivation of mammalian cells. This importance of amino acids was realized soon after the development of the first cell lines, and a solution of a mixture of amino acids has been supplied to cultured cells ever since. The importance of amino acids is further pronounced in chemically defined mammalian cell culture media, making the consideration of their biological and chemical properties necessary. Amino acids concentrations have been traditionally adjusted to their cellular consumption rates. However, since changes in the metabolic equilibrium of amino acids can be caused by changes in extracellular concentrations, metabolomics in conjunction with flux balance analysis is being used in the development of culture media. The study of amino acid transporters is also gaining importance since they control the intracellular concentrations of these molecules and are influenced by conditions in cell culture media. A better understanding of the solubility, stability, dissolution kinetics, and interactions of these molecules is needed for an exploitation of these properties in the development of dry powdered chemically defined media for mammalian cells. Due to the complexity of these mixtures however, this has proven to be challenging. Studying amino acids in mammalian cell culture media will help provide a better understanding of how mammalian cells in culture interact with their environment. It would also provide insight into the chemical behavior of these molecules in solutions of complex mixtures, which is important in the understanding of the contribution of individual amino acids to protein structure.

  9. Amino Acid transport in protoplasts isolated from soybean leaves.

    Science.gov (United States)

    Vernooy, C D; Lin, W

    1986-05-01

    We isolated large quantities of mesophyll protoplasts from source and sink leaves of soybean plants and examined them for amino acid uptake. Accumulation of amino acids in isolated protoplasts was linear for at least 40 minutes. Uptake kinetics revealed the presence of both saturable and linear components. Increasing external pH decreases the uptake. The uncoupler, carbonyl cyanide p-trifluoromethoxyphenylhydrazone at 15 micromolar inhibited and fusicoccin at 10 micromolar stimulated amino acid uptake. Our data are consistent with a proton-cotransport mechanism for the uptake of l-glutamine and alpha-amino isobutyric acid into soybean mesophyll cells.

  10. Abiotic racemization kinetics of amino acids in marine sediments

    DEFF Research Database (Denmark)

    Steen, Andrew; Jørgensen, Bo Barker; Lomstein, Bente Aagaard

    2013-01-01

    Enantiomeric ratios of amino acids can be used to infer the sources and composition of sedimentary organic matter. Such inferences, however, rely on knowing the rates at which amino acids in sedimentary organic racemize abiotically. Based on a heating experiment, we report Arrhenius parameters...... between different amino acids or depths. These results can be used in conjunction with measurements of sediment age to predict the ratio of D:L amino acids due solely to abiotic racemization of the source material, deviations from which can indicate the abundance and turnover of active microbial...

  11. Continuous Enteral Administration Can Enable Normal Amino Acid Absorption in Rats with Methotrexate-Induced Gastrointestinal Mucositis

    NARCIS (Netherlands)

    Fijlstra, Margot; Schierbeek, Henk; Voortman, Gardi; Dorst, Kristien Y.; van Goudoever, Johannes B.; Rings, Edmond H. H. M.; Tissings, Wim J. E.

    2012-01-01

    It is unknown what feeding strategy to use during chemotherapy-induced gastrointestinal mucositis, which causes weight loss and possibly malabsorption. To study the absorptive capacity of amino acids during mucositis, we determined the plasma availability of enterally administered amino acids (AA),

  12. Synthesis of novel fullerene α-amino acid conjugates

    Institute of Scientific and Technical Information of China (English)

    Jing Zhang; Yan Xia Wang; Feng Kang; Ying Ya Shao; Zong Jie Li; Xin Lin Yang

    2008-01-01

    Aspartie acid and glutamic acid with protected α-amino and α-carboxyl groups had been used to react with the activated hydroxyl group of N-substituted 3,4-fuUero pyrrolidine.The products were deprotected,affording two monofullerene α-amino acids,monofullerene aspartic acid(mFas)and monofullerene glutamic acid(mFgu).Then a bifullerene glutamic acid conjugate (bFguC)was synthesized by reaction of mFgu containing protected amino group with N-subsfimted 3,4-fullero pyrrolidine.

  13. Synthesis, Characterization and Structure of Chiral Amino Acids and Their Corresponding Amino Alcohols with Camphoric Backbone

    Institute of Scientific and Technical Information of China (English)

    QIAN Hui-Fen; HUANG Wei; LI Hui-Hui; YAO Cheng

    2006-01-01

    Chiral amino acids and their corresponding amino alcohols bearing camphoric backbone were prepared from D-(+)-camphoric imide and characterized by infrared, elemental analysis, ESI-MS, and NMR measurements. Among them, one intermediate (lS,3R)-3-amino-2,2,3-trimethyl cyclopentane-1-carboxylic acid hydrochloride 3 was structurally elucidated by X-ray diffraction techniques. Versatile intermolecular hydrogen bonding interactions observed in its packing structure result in a two-dimensional framework.

  14. Amino Acid Transporters and Release of Hydrophobic Amino Acids in the Heterocyst-Forming Cyanobacterium Anabaena sp. Strain PCC 7120

    Directory of Open Access Journals (Sweden)

    Rafael Pernil

    2015-04-01

    Full Text Available Anabaena sp. strain PCC 7120 is a filamentous cyanobacterium that can use inorganic compounds such as nitrate or ammonium as nitrogen sources. In the absence of combined nitrogen, it can fix N2 in differentiated cells called heterocysts. Anabaena also shows substantial activities of amino acid uptake, and three ABC-type transporters for amino acids have been previously characterized. Seven new loci encoding predicted amino acid transporters were identified in the Anabaena genomic sequence and inactivated. Two of them were involved in amino acid uptake. Locus alr2535-alr2541 encodes the elements of a hydrophobic amino acid ABC-type transporter that is mainly involved in the uptake of glycine. ORF all0342 encodes a putative transporter from the dicarboxylate/amino acid:cation symporter (DAACS family whose inactivation resulted in an increased uptake of a broad range of amino acids. An assay to study amino acid release from Anabaena filaments to the external medium was set up. Net release of the alanine analogue α-aminoisobutyric acid (AIB was observed when transport system N-I (a hydrophobic amino acid ABC-type transporter was engaged in the uptake of a specific substrate. The rate of AIB release was directly proportional to the intracellular AIB concentration, suggesting leakage from the cells by diffusion.

  15. Sequential-injection on-line preconcentration using chitosan resin functionalized with 2-amino-5-hydroxy benzoic acid for the determination of trace elements in environmental water samples by inductively coupled plasma-atomic emission spectrometry.

    Science.gov (United States)

    Sabarudin, Akhmad; Lenghor, Narong; Oshima, Mitsuko; Hakim, Lukman; Takayanagi, Toshio; Gao, Yun-Hua; Motomizu, Shoji

    2007-07-31

    A new chelating resin using chitosan as a base material was synthesized. Functional moiety of 2-amino-5-hydroxy benzoic acid (AHBA) was chemically bonded to the amino group of cross-linked chitosan (CCTS) through the arm of chloromethyloxirane (CCTS-AHBA resin). Several elements, such as Ag, Be, Cd, Co, Cu, Ni, Pb, U, V, and rare earth elements (REEs), could be adsorbed on the resin. To use the resin for on-line pretreatment, the resin was packed in a mini-column and installed into a sequential-injection/automated pretreatment system (Auto-Pret System) coupled with inductively coupled plasma-atomic emission spectrometry (ICP-AES). The sequential-injection/automated pretreatment system was a laboratory-assembled, and the program was written using Visual Basic software. This system can provide easy operation procedures, less reagent consumption, as well as less waste production. Experimental variables considered as effective factors in the improvement sensitivity, such as an eluent concentration, a sample and an eluent flow rate, pH of samples, and air-sandwiched eluent were carefully optimized. The proposed system provides excellent on-line collection efficiency, as well as high concentration factors of analytes in water samples, which results in highly sensitive detection of ultra-trace and trace analysis. Under the optimal conditions, the detection limits of 24 elements examined are in the range from ppt to sub-ppb levels. The proposed method was validated by using the standard reference material of a river water, SLRS-4, and the applicability was further demonstrated to the on-line collection/concentration of trace elements, such as Ag, Be, Cd, Co, Cu, Ni, Pb, U, V, and REEs in water samples.

  16. Albumin dialysis has a favorable effect on amino acid profile in hepatic encephalopathy.

    Science.gov (United States)

    Koivusalo, Anna-Maria; Teikari, Taru; Höckerstedt, Krister; Isoniemi, Helena

    2008-12-01

    According to one popular theory, hepatic encephalopathy (HE) is partly caused by an imbalance in plasma amino acid levels. The Fischer's ratio between branched chain amino acids (BCAAs) and aromatic amino acids (AAAs) correlates with the degree of HE; the lower Fischer's ratio, the higher the grade of HE. Extra-corporeal liver support systems, like MARS(R)-albumin dialysis (Molecular Adsorbents Recirculating System), can improve HE. The MARS(R) system uses a hyperosmolar albumin circuit to remove both water-soluble and albumin-bound substances. Plasma levels of neuroactive amino acids were analyzed in 82 consecutive patients with life-threatening liver failure admitted to our ICU. All patients fulfilled our indications for MARS treatment and most also fulfilled the criteria for liver transplantation (LTx). In patients with acute liver failure (ALF), as compared to those with acute decompensation of chronic liver failure (AcOChr), levels of leucine and isoleucine were significantly higher before MARS(R) treatment. In all patients, before MARS(R) treatment the higher the grade of HE grade the lower was the Fischer's ratio and higher were the levels of inhibitory neuroactive amino acids. During MARS(R) treatments the Fischer's ratio increased, and the grade of HE decreased. The increase in Fischer's ratio was mainly due to the decrease in AAAs. The plasma levels of neuroactive amino acids, methionine, glutamine, glutamate, histidine and taurine decreased during MARS(R)-treatment. In this study MARS(R)-albumin dialysis had a favorable effect on the plasma amino acid profile of patients with HE.

  17. Breast milk composition in Ethiopian and Swedish mothers. III. Amino acids and other nitrogenous substances.

    Science.gov (United States)

    Svanberg, U; Gebre-Medhin, M; Ljungqvist, B; Olsson, M

    1977-04-01

    The content of amino acids and other nitrogenous substances was determined in milk samples from Ethiopian and Swedish mothers. The Ethiopian mothers were divided into two groups, one with children having low weight for age and one with children having standard weight for age. All children were in the age range 2 to 5 months, and there were eight in each group. The main findings were as follows: 1) The mean daily milk volumes and total daily nitrogen content in the milk were found to be similar in all three groups. The Swedish group had a significantly lower nitrogen content per milliliter than did the Ethiopian group with low weight for age. 2) The total amino acid composition of the milk was almost identical in the three groups studied except for the tyrosine value, which was significantly lower in the Ethiopian standard group than in the low weight for age group. The composition corresponded well with previous findings. 3) The protein fraction constituted 90 to 92% of the total amino acids, the peptide fraction 4 to 5%, and the free amino acids 5%. 4) The concentrations of free amino acids in milk were lower (2 to 6 times) than in plasma, except for glutamic and aspartic acid. The taurine concentration was much higher in milk than in plasma. Only the urea levels in milk and plasma were significantly correlated. The implications of these findings in child health are discussed.

  18. Host defense--a role for the amino acid taurine?

    Science.gov (United States)

    Stapleton, P P; O'Flaherty, L; Redmond, H P; Bouchier-Hayes, D J

    1998-01-01

    Taurine (2-aminoethane sulphonic acid), a ubiquitous beta-amino acid is conditionally essential in man. It is not utilized in protein synthesis but found free or in some simple peptides. Derived from methionine and cysteine metabolism, taurine is known to play a pivotal role in numerous physiological functions. Some of the roles with which taurine has been associated include osmoregulation, antioxidation, detoxification and stimulation of glycolysis and glycogenesis. Intracellular taurine is maintained at high concentrations in a variety of cell types and alteration of cell taurine levels is difficult. The role of taurine within the cell appears to be determined by the cell type. Recent research has determined a regulatory role for taurinechloramine, the product formed by the reaction between taurine and neutrophil derived hypochlorous acid on macrophage function. Plasma taurine levels are also high, although decreases are observed in response to surgical injury and numerous pathological conditions including cancer and sepsis. Supplementary taurine replenishes decreased plasma taurine. Although commonly used as a dietary supplement in the Far East, the potential advantages of dietary taurine supplementation have not as yet been fully recognized in the Western World; this is an area which could prove to be beneficial in the clinical arena.

  19. Abc Amino Acids: Design, Synthesis, and Properties of New Photoelastic Amino Acids

    Energy Technology Data Exchange (ETDEWEB)

    Standaert, Robert F [ORNL; Park, Dr Seung Bum [Seoul National University

    2006-01-01

    Photoisomerizable amino acids provide a direct avenue to the experimental manipulation of bioactive polypeptides, potentially allowing real-time, remote control of biological systems and enabling useful applications in nanobiotechnology. Herein, we report a new class of photoisomerizable amino acids intended to cause pronounced expansion and contraction in the polypeptide backbone, i.e., to be photoelastic. These compounds, termed Abc amino acids, employ a photoisomerizable azobiphenyl chromophore to control the relative disposition of aminomethyl and carboxyl substituents. Molecular modeling of nine Abc isomers led to the identification of one with particularly attractive properties, including the ability to induce contractions up to 13A in the backbone upon transa?cis photoisomerization. This isomer, designated mpAbc, has substituents at meta and para positions on the inner (azo-linked) and outer rings, respectively. An efficient synthesis of Fmoc-protected mpAbc was executed in which the biaryl components were formed via Suzuki couplings and the azo linkage was formed via amine/nitroso condensation; protected forms of three other Abc isomers were prepared similarly. A decapeptide incorporating mpAbc was synthesized by conventional solid-phase methods and displayed characteristic azobenzene photochemical behavior with optimal conversion to the cis isomer at 360 nm and a thermal cisa?trans half life of 100 min. at 80 AoC.

  20. Gas-phase Acidities of Aspartic Acid, Glutamic Acid, and their Amino Acid Amides.

    Energy Technology Data Exchange (ETDEWEB)

    Li, Zhong; Matus, Myrna H; Velazquez, Hector A; Dixon, David A; Cassady, Carolyn J

    2007-02-14

    Gas-phase acidities (GA or ΔGacid) for the two most acidic common amino acids, aspartic acid and glutamic acid, have been determined for the first time. Because of the amide linkage’s importance in peptides and as an aid in studying side chain versus main chain deprotonation, aspartic acid amide and glutamic acid amide were also studied. Experimental GA values were measured by proton transfer reactions in an electrospray ionization/Fourier transform ion cyclotron resonance mass spectrometer. Calculated GAs were obtained by density functional and molecular orbital theory approaches. The best agreement with experiment was found at the G3MP2 level; the MP2/CBS and B3LYP/aug-cc-pVDZ results are 3–4 kcal/mol more acidic than the G3MP2 results. Experiment shows that aspartic acid is more acidic than glutamic acid by ca. 3 kcal/mol whereas the G3MP2 results show a smaller acidity difference of 0.2 kcal/mol. Similarly, aspartic acid amide is experimentally observed to be ca. 2 kcal/mol more acidic than glutamic acid amide whereas the G3MP2 results show a correspondingly smaller energy difference of 0.7 kcal/mol. The computational results clearly show that the anions are all ring-like structures with strong hydrogen bonds between the OH or NH2 groups and the CO2- group from which the proton is removed. The two amino acids are main-chain deprotonated. In addition, use of the COSMO model for the prediction of the free energy differences in aqueous solution gave values in excellent agreement with the most recent experimental values for pKa. Glutamic acid is predicted to be more acidic than aspartic acid in aqueous solution due to differential solvation effects.

  1. EFFECT OF MICROORGANISMS ON FREE AMINO ACID AND FREE D-AMINO ACID CONTENTS OF VARIOUS DAIRY PRODUCTS

    Directory of Open Access Journals (Sweden)

    Csilla Albert

    2007-06-01

    Full Text Available Free amino acid and free D-amino acid contents of milk samples with different microorganism numbers and composition of dairy products produced from them were examined. Total microorganism number of milk samples examined varied from 1.25x106 to 2.95x106. It was established that concentration of both free D-amino acids and free L-amino acids increased with an increase in microorganism number. However, increase in D-amino acid contents was higher considering its proportion. There was a particularly significant growth in the microorganism number range from 1.5x106 to 2.9x106. Based on analysis of curds and cheese samples produced using different technologies we have come to the conclusion that for fresh dairy products and for those matured over a short time there was a close relation between total microorganism number and free D-amino acid and free L-amino acid contents. At the same time it was found that the ratio of the enantiomers was not affected by the total microorganism number. For dairy products, however, where amino acid production capability of the microbial cultures considerably exceeds, production of microorganisms originally present in the milk raw material, free amino acid contents of the milk product (both D- and L-enantiomers seem to be independent of the composition of milk raw material.

  2. Specificity of amino acid regulated gene expression: analysis of genes subjected to either complete or single amino acid deprivation

    Science.gov (United States)

    Palii, S. S.; Kays, C. E.; Deval, C.; Bruhat, A.; Fafournoux, P.

    2013-01-01

    Amino acid deprivation activates the amino acid response (AAR) pathway that enhances transcription of genes containing an amino acid response element (AARE). The present data reveal a quantitative difference in the response to deprivation of individual amino acids. The AAR leads to increased eukaryotic initiation factor 2α (eIF2α) phosphorylation and ATF4 translation. When HepG2 cells were deprived of an individual essential amino acid, p-eIF2α and activating transcription factor 4 were increased, but the correlation was relatively weak. Complete amino acid starvation in either Earle’s balanced salt solution or Krebs–Ringer bicarbonate buffer (KRB) resulted in activation of transcription driven by a SNAT2 genomic fragment that contained an AARE. However, for the KRB, a proportion of the transcription was AARE-independent suggesting that amino acid-independent mechanisms were responsible. Therefore, activation of AARE-driven transcription is triggered by a deficiency in any one of the essential amino acids, but the response is not uniform. Furthermore, caution must be exercised when using a medium completely devoid of amino acids. PMID:19009228

  3. Vibrational and photoionization spectroscopy of biomolecules: aliphatic amino acid structures.

    Science.gov (United States)

    Hu, Yongjun; Bernstein, Elliot R

    2008-04-28

    The aliphatic amino acids glycine, valine, leucine, and isoleucine are thermally placed into the gas phase and expanded into a vacuum system for access by time of flight mass spectroscopy and infrared (IR) spectroscopy in the energy range of 2500-4000 cm(-1) (CH, NH, OH, and stretching vibrations). The isolated neutral amino acids are ionized by a single photon of 10.5 eV energy (118 nm), which exceeds by less than 2 eV their reported ionization thresholds. As has been reported for many hydrogen bonded acid-base systems (e.g., water, ammonia, alcohol, acid clusters, and acid molecules), the amino acids undergo a structural rearrangement in the ion state (e.g., in simplest form, a proton transfer) that imparts sufficient excess vibrational energy to the ion to completely fragment it. No parent ions are observed. If the neutral ground state amino acids are exposed to IR radiation prior to ionization, an IR spectrum of the individual isomers for each amino acid can be determined by observation of the ion intensity of the different fragment mass channels. Both the IR spectrum and fragmentation patterns for individual isomers can be qualitatively identified and related to a particular isomer in each instance. Thus, each fragment ion detected presents an IR spectrum of its particular parent amino acid isomer. In some instances, the absorption of IR radiation by the neutral amino acid parent isomer increases a particular fragmentation mass channel intensity, while other fragmentation mass channel intensities decrease. This phenomenon can be rationalized by considering that with added energy in the molecule, the fragmentation channel populations can be modulated by the added vibrational energy in the rearranged ions. This observation also suggests that the IR absorption does not induce isomerization in the ground electronic state of these amino acids. These data are consistent with theoretical predictions for isolated amino acid secondary structures and can be related to

  4. Utilization of acidic α-amino acids as acyl donors: an effective stereo-controllable synthesis of aryl-keto α-amino acids and their derivatives.

    Science.gov (United States)

    Wang, Lei; Murai, Yuta; Yoshida, Takuma; Okamoto, Masashi; Tachrim, Zetryana Puteri; Hashidoko, Yasuyuki; Hashimoto, Makoto

    2014-05-16

    Aryl-keto-containing α-amino acids are of great importance in organic chemistry and biochemistry. They are valuable intermediates for the construction of hydroxyl α-amino acids, nonproteinogenic α-amino acids, as well as other biofunctional components. Friedel-Crafts acylation is an effective method to prepare aryl-keto derivatives. In this review, we summarize the preparation of aryl-keto containing α-amino acids by Friedel-Crafts acylation using acidic α-amino acids as acyl-donors and Lewis acids or Brönsted acids as catalysts.

  5. Amino acid adsorption on mesoporous materials: influence of types of amino acids, modification of mesoporous materials, and solution conditions.

    Science.gov (United States)

    Gao, Qiang; Xu, Wujun; Xu, Yao; Wu, Dong; Sun, Yuhan; Deng, Feng; Shen, Wanling

    2008-02-21

    In order to disclose the dominant interfacial interaction between amino acids and ordered mesoporous materials, the adsorption behaviors of five amino acids on four mesoporous materials were investigated in aqueous solutions with adjustable amino acid concentration, ion strength, and pH. The selected amino acids were acidic amino acid glutamic acid (Glu), basic amino acid arginine (Arg), and neutral amino acids phenylalanine (Phe), leucine (Leu), and alanine (Ala), and the selected mesoporous materials were SBA-15, Al-SBA-15, CH3(10%)-SBA-15, and CH3(20%)-SBA-15. The adsorption capacities of Glu and Arg were strongly dependent on pH and surface charge of the mesoporous adsorbent. The adsorption of Phe showed pH insensitivity but depended on the surface organic functionalization of mesoporous adsorbent. On the basis of the theoretical analysis about the interaction between amino acid and adsorbent, such a remarkable difference was attributed to the different nature of the interaction between amino acid and adsorbent. Arg could be readily adsorbed on the surface of SBA-15, especially Al-SBA-15, under appropriate pH in which the electrostatic interaction was predominant. The driving force of Phe adsorption on mesoporous adsorbent mainly came from the hydrophobic interaction. Therefore, the adsorption capability of Arg decreased with increasing ion strength of solution, while the adsorption capability of Phe increased with the increasing degree of CH3 functionalization on SBA-15. For neutral amino acid Phe, Ala, and Leu, the adsorption capability increased with the increase of the length of their side chains, which was another evidence of hydrophobic effect. Thus, all the adsorption of amino acids on mesoporous silica materials can be decided by the combined influence of two fundamental interactions: electrostatic attraction and hydrophobic effect.

  6. Plasmodium falciparum malaria elicits inflammatory responses that dysregulate placental amino acid transport.

    Directory of Open Access Journals (Sweden)

    Philippe Boeuf

    2013-02-01

    Full Text Available Placental malaria (PM can lead to poor neonatal outcomes, including low birthweight due to fetal growth restriction (FGR, especially when associated with local inflammation (intervillositis or IV. The pathogenesis of PM-associated FGR is largely unknown, but in idiopathic FGR, impaired transplacental amino acid transport, especially through the system A group of amino acid transporters, has been implicated. We hypothesized that PM-associated FGR could result from impairment of transplacental amino acid transport triggered by IV. In a cohort of Malawian women and their infants, the expression and activity of system A (measured by Na⁺-dependent ¹⁴C-MeAIB uptake were reduced in PM, especially when associated with IV, compared to uninfected placentas. In an in vitro model of PM with IV, placental cells exposed to monocyte/infected erythrocytes conditioned medium showed decreased system A activity. Amino acid concentrations analyzed by reversed phase ultra performance liquid chromatography in paired maternal and cord plasmas revealed specific alterations of amino acid transport by PM, especially with IV. Overall, our data suggest that the fetoplacental unit responds to PM by altering its placental amino acid transport to maintain adequate fetal growth. However, IV more profoundly compromises placental amino acid transport function, leading to FGR. Our study offers the first pathogenetic explanation for FGR in PM.

  7. Acute supplementation of amino acids increases net protein accretion in IUGR fetal sheep.

    Science.gov (United States)

    Brown, Laura D; Rozance, Paul J; Thorn, Stephanie R; Friedman, Jacob E; Hay, William W

    2012-08-01

    Placental insufficiency decreases fetal amino acid uptake from the placenta, plasma insulin concentrations, and protein accretion, thus compromising normal fetal growth trajectory. We tested whether acute supplementation of amino acids or insulin into the fetus with intrauterine growth restriction (IUGR) would increase net fetal protein accretion rates. Late-gestation IUGR and control (CON) fetal sheep received acute, 3-h infusions of amino acids (with euinsulinemia), insulin (with euglycemia and euaminoacidemia), or saline. Fetal leucine metabolism was measured under steady-state conditions followed by a fetal muscle biopsy to quantify insulin signaling. In CON, increasing amino acid delivery rates to the fetus by 100% increased leucine oxidation rates by 100%. In IUGR, amino acid infusion completely suppressed fetal protein breakdown rates but increased leucine oxidation rate by only 25%, resulting in increased protein accretion rates by 150%. Acute insulin infusion, however, had very little effect on amino acid delivery rates, fetal leucine disposal rates, or fetal protein accretion rates in CON or IUGR fetuses despite robust signaling of the fetal skeletal muscle insulin-signaling cascade. These results indicate that, when amino acids are given directly into the fetal circulation independently of changes in insulin concentrations, IUGR fetal sheep have suppressed protein breakdown rates, thus increasing net fetal protein accretion.

  8. Synthesis of gold nanoparticles using various amino acids.

    Science.gov (United States)

    Maruyama, Tatsuo; Fujimoto, Yuhei; Maekawa, Tetsuya

    2015-06-01

    Gold nanoparticles (4-7nm) were synthesized from tetraauric acid using various amino acids as reducing and capping agents. The gold nanoparticles were produced from the incubation of a AuCl4(-) solution with an amino acid at 80°C for 20min. Among the twenty amino acids tested, several amino acids produced gold nanoparticles. The color of the nanoparticle solutions varied with the amino acids used for the reduction. We adopted l-histidine as a reducing agent and investigated the effects of the synthesis conditions on the gold nanoparticles. The His and AuCl4(-) concentrations affected the size of the gold nanoparticles and their aggregates. The pH of the reaction solution also affected the reaction yields and the shape of the gold nanoparticles.

  9. Polysulfone affinity membranes for the treatment of amino acid mixtures.

    Science.gov (United States)

    Rodemann, K; Staude, E

    1995-06-20

    Affinity membranes for the treatment of solutions containing amino acids were obtained via lithiating polysulfone that was subsequently converted with glycidylether. From this polymer asymmetric ultrafiltration membranes were cast. The membranes were reacted with iminodiacetic acid yielding membranes fitted out with bidentate chelates. The same reaction path was applied to commercially available symmetric microfiltration membranes. The chelate-bearing membranes were complexed with Cu, Ni, and Zn ions. For the experiments with amino acids only the Cu-complexed membranes were used. The complexation constants for histidine and tryptophan for six different membranes were determined. Because of the affinity of these two amino acids for the complexed Cu ions, they could easily be separated from solutions containing amino acids such as alanine, glycine, and valine. Also, concentrating very dilute amino acid solutions was carried out successfully.

  10. Free amino acids in botanicals and botanical preparations.

    Science.gov (United States)

    Carratù, B; Boniglia, C; Giammarioli, S; Mosca, M; Sanzini, E

    2008-06-01

    Numerous studies were carried out about aminoacidic composition of vegetable proteins, but information about the free amino acid pool and the role of these substances is very incomplete. The aim of this paper was to contribute to the scarce knowledge concerning the composition of free amino acids in botanicals and botanical preparations widely used as food, in dietary supplements, and in pharmaceutical products. This work studied the composition of free amino acids, identified the major components of 19 species of plants, and evaluated the influence of different types of extraction on the amino acid profile. Amino acids were determined using an automatic precolumn derivatization with fluorenylmethyl-chloroformate and reversed-phase liquid chromatography with fluorescence and ultraviolet detection. The amounts of total free amino acids varied widely between plants, from approximately 12 g in 100 g of Echinacea pallida extract to less than 60 mg in the same amount of Coleus forskohlii, Garcinia cambogia, and Glycine max. In 13 plants arginine, asparagine, glutamine, proline, and gamma-aminobutyric acid were the free amino acids found in preponderant quantities. The levels of free amino acids above the quantification limit in 36 assayed samples of botanicals, extracts, and supplements are shown.

  11. Enzymatic tRNA acylation by acid and alpha-hydroxy acid analogues of amino acids.

    Science.gov (United States)

    Owczarek, Alina; Safro, Mark; Wolfson, Alexey D

    2008-01-08

    Incorporation of unnatural amino acids with unique chemical functionalities has proven to be a valuable tool for expansion of the functional repertoire and properties of proteins as well as for structure-function analysis. Incorporation of alpha-hydroxy acids (primary amino group is substituted with hydroxyl) leads to the synthesis of proteins with peptide bonds being substituted by ester bonds. Practical application of this modification is limited by the necessity to prepare corresponding acylated tRNA by chemical synthesis. We investigated the possibility of enzymatic incorporation of alpha-hydroxy acid and acid analogues (lacking amino group) of amino acids into tRNA using aminoacyl-tRNA synthetases (aaRSs). We studied direct acylation of tRNAs by alpha-hydroxy acid and acid analogues of amino acids and corresponding chemically synthesized analogues of aminoacyl-adenylates. Using adenylate analogues we were able to enzymatically acylate tRNA with amino acid analogues which were otherwise completely inactive in direct aminoacylation reaction, thus bypassing the natural mechanisms ensuring the selectivity of tRNA aminoacylation. Our results are the first demonstration that the use of synthetic aminoacyl-adenylates as substrates in tRNA aminoacylation reaction may provide a way for incorporation of unnatural amino acids into tRNA, and consequently into proteins.

  12. Gas-phase acidities of aspartic acid, glutamic acid, and their amino acid amides

    Science.gov (United States)

    Li, Zhong; Matus, Myrna H.; Velazquez, Hector Adam; Dixon, David A.; Cassady, Carolyn J.

    2007-09-01

    Gas-phase acidities (GA or [Delta]Gacid) for the two most acidic common amino acids, aspartic acid and glutamic acid, have been determined for the first time. Because of the amide linkage's importance in peptides and as an aid in studying side chain versus main chain deprotonation, aspartic acid amide and glutamic acid amide were also studied. Experimental GA values were measured by proton transfer reactions in an electrospray ionization/Fourier transform ion cyclotron resonance mass spectrometer. Calculated GAs were obtained by density functional and molecular orbital theory approaches. The best agreement with experiment was found at the G3MP2 level; the MP2/CBS and B3LYP/aug-cc-pVDZ results are 3-4 kcal/mol more acidic than the G3MP2 results. Experiment shows that aspartic acid is more acidic than glutamic acid by ca. 3 kcal/mol whereas the G3MP2 results show a smaller acidity difference of 0.2 kcal/mol. Similarly, aspartic acid amide is experimentally observed to be ca. 2 kcal/mol more acidic than glutamic acid amide whereas the G3MP2 results show a correspondingly smaller energy difference of 0.7 kcal/mol. The computational results clearly show that the anions are all ring-like structures with strong hydrogen bonds between the OH or NH2 groups and the CO2- group from which the proton is removed. The two amino acids are main-chain deprotonated. In addition, use of the COSMO model for the prediction of the free energy differences in aqueous solution gave values in excellent agreement with the most recent experimental values for pKa. Glutamic acid is predicted to be more acidic than aspartic acid in aqueous solution due to differential solvation effects.

  13. Effect of sunlight shielding on leaf structure and amino acids ...

    African Journals Online (AJOL)

    zino

    2013-09-04

    Sep 4, 2013 ... acids concentration of light sensitive albino tea plant ... Key words: Camellia sinensis, leaf albinism, light intensity, photosynthetic pigments, amino acids, chloroplast. .... tructive reaction or photodamage which occurs in the.

  14. The Path of Carbon in Photosynthesis II. Amino Acids

    Science.gov (United States)

    Stepka, W.; Benson, A. A.; Calvin, M.

    1948-05-25

    The radioactive amino acid's synthesized from C{sup 14}O{sub 2} by green algae both in the light and in the dark after CO{sub 2}-free preillumination have been separated and identified using paper chromatography and radioautography. The radioactive amino acids identified were aspartic acid, alanine and smaller amounts of 3- and 4-carbon amino acids. This finding as well as the total absence of radioactive glutamic acid substantiates the mechanism for reduction of CO{sub 2} previously postulated by members of this laboratory.

  15. Terrestrial evolution of polymerization of amino acids - Heat to ATP

    Science.gov (United States)

    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.

  16. Accelerated protein digestion and amino acid absorption after Roux-en-Y gastric bypass

    DEFF Research Database (Denmark)

    Bojsen-Møller, Kirstine N; Jacobsen, Siv H; Dirksen, Carsten;

    2015-01-01

    . CONCLUSIONS: RYGB accelerates caseinate digestion and amino acid absorption, resulting in faster and higher but more transient postprandial elevation of plasma amino acids. Changes are likely mediated by accelerated intestinal nutrient entry and clearly demonstrate that protein digestion is not impaired after......BACKGROUND: Roux-en-Y gastric bypass (RYGB) involves exclusion of major parts of the stomach and changes in admixture of gastro-pancreatic enzymes, which could have a major impact on protein digestion and amino acid absorption. OBJECTIVE: We investigated the effect of RYGB on amino acid appearance...... in the systemic circulation from orally ingested protein and from endogenous release. DESIGN: Nine obese glucose-tolerant subjects, with a mean body mass index (in kg/m(2)) of 39.2 (95% CI: 35.2, 43.3) and mean glycated hemoglobin of 5.3% (95% CI: 4.9%, 5.6%), were studied before and 3 mo after RYGB. Leucine...

  17. Amino acid determination in some edible Mexican insects.

    Science.gov (United States)

    Ladrón de Guevara, O; Padilla, P; García, L; Pino, J M; Ramos-Elorduy, J

    1995-06-01

    The amino acid contents of edible insects from different provinces of Mexico and reference proteins were analysed by reversed-phase high-performance liquid chromatography and ion exchange chromatography. The insect amino acid contents were higher than the adult requirements indicated by the WHO/FAO pattern.

  18. Ileal recovery of endogenous amino acids in pigs

    NARCIS (Netherlands)

    Caine, W.

    1997-01-01

    Ileal recovery of endogenous amino acids is important for determining balanced homeostasis of protein metabolism in pigs and the true digestibility of dietary protein. In this context, the ileal recoveries of endogenous amino acids were determined in growing pigs fed guanidinated Nutrisoy protein

  19. Site specific incorporation of keto amino acids into proteins

    Science.gov (United States)

    Schultz, Peter G [La Jolla, CA; Wang, Lei [San Diego, CA

    2012-02-14

    Compositions and methods of producing components of protein biosynthetic machinery that include orthogonal tRNAs, orthogonal aminoacyl-tRNA synthetases, and orthogonal pairs of tRNAs/synthetases, which incorporate keto amino acids into proteins are provided. Methods for identifying these orthogonal pairs are also provided along with methods of producing proteins with keto amino acids using these orthogonal pairs.

  20. Physiological and biochemical studies of bacterial amino acid amide metabolism

    NARCIS (Netherlands)

    Hermes, Hubertus Franciscus Maria

    2008-01-01

    Amino acids represent a class of versatile chiral building blocks for a whole range of fine chemicals, used in the pharmaceutical and agro-chemical industry. Considerable experience currently is available with a wide variety of chemo-enzymatic processes for the synthesis of amino acids, which is app

  1. Nitrogen and amino acid metabolism in dairy cows

    NARCIS (Netherlands)

    Tamminga, S.

    1981-01-01

    For the process of milk production, the dairy cow requires nutrients of which energy supplying nutrients and protein or amino acid supplying nutrients are the most important. Amino acid supplying nutrients have to be absorbed from the small intestine and the research reported in this thesis mainly c

  2. Origin of Homochirality of Amino Acids in the Biosphere

    Directory of Open Access Journals (Sweden)

    Shosuke Kojo

    2010-05-01

    Full Text Available Discussions are made concerning realistic mechanisms for the origin of L-amino acids in the biosphere. As the most plausible mechanism, it is proposed that a mixture of racemic amino acids in the prebiotic sea caused spontaneous and effective optical resolution through self crystallization, even if asymmetric synthesis of a single amino acid has never occurred without the aid of an optically active molecule. This hypothesis is based on recrystallization of a mixture of D,L-amino acids in the presence of excess of D,L-asparagine (Asn. The enantiomeric excess (ee of each amino acid in the resulting crystals indicates that crystallization of co-existing amino acids with the configuration same as that of Asn took place, although it was incidental whether the enrichment occurred in L- or D-amino acids. In addition, the resulting ee was sufficiently high (up to 100% to account for the predominance of L-amino acids on the earth.

  3. Nitrogen and amino acid metabolism in dairy cows

    NARCIS (Netherlands)

    Tamminga, S.

    1981-01-01

    For the process of milk production, the dairy cow requires nutrients of which energy supplying nutrients and protein or amino acid supplying nutrients are the most important. Amino acid supplying nutrients have to be absorbed from the small intestine and the research reported in this thesis mainly

  4. Natural toxins that affect plant amino acid metabolism

    Science.gov (United States)

    A diverse range of natural compounds interfere with the synthesis and other aspects of amino acid metabolism. Some are amino acid analogues, but most are not. This review covers a number of specific natural phytotoxic compounds by molecular target site. Inhibition of glutamine synthetase is of part...

  5. CO2 sorption by supported amino acid ionic liquids

    DEFF Research Database (Denmark)

    2014-01-01

    The present invention concerns the absorption and desorption behaviour of carbon dioxide (CO2) using ionic liquids derived from amino acids adsorbed on porous carrier materials.......The present invention concerns the absorption and desorption behaviour of carbon dioxide (CO2) using ionic liquids derived from amino acids adsorbed on porous carrier materials....

  6. Representation of protein-sequence information by amino acid subalphabets

    DEFF Research Database (Denmark)

    Andersen, C.A.F.; Brunak, Søren

    2004-01-01

    -sequence information, using machine learning strategies, where the primary goal is the discovery of novel powerful representations for use in AI techniques. In the case of proteins and the 20 different amino acids they typically contain, it is also a secondary goal to discover how the current selection of amino acids...

  7. Determining Amino Acid Chirality in the Supernova Neutrino Processing Model

    Directory of Open Access Journals (Sweden)

    Michael Famiano

    2014-11-01

    Full Text Available A model is described that can be used to estimate the bulk polarization of largerotating meteoroids in the magnetic field of a neutron star. The results of this model areapplicable to the Supernova Neutrino Amino Acid Processing model, which describes onepossible way in which the amino acids, known in nearly all cases to exhibit supramolecularchirality, could have become enantiomeric.

  8. Site specific incorporation of keto amino acids into proteins

    Energy Technology Data Exchange (ETDEWEB)

    Schultz, Peter G [La Jolla, CA; Wang, Lei [San Diego, CA

    2012-02-14

    Compositions and methods of producing components of protein biosynthetic machinery that include orthogonal tRNAs, orthogonal aminoacyl-tRNA synthetases, and orthogonal pairs of tRNAs/synthetases, which incorporate keto amino acids into proteins are provided. Methods for identifying these orthogonal pairs are also provided along with methods of producing proteins with keto amino acids using these orthogonal pairs.

  9. Site specific incorporation of keto amino acids into proteins

    Energy Technology Data Exchange (ETDEWEB)

    Schultz, Peter G. (La Jolla, CA); Wang, Lei (San Diego, CA)

    2011-03-22

    Compositions and methods of producing components of protein biosynthetic machinery that include orthogonal tRNAs, orthogonal aminoacyl-tRNA synthetases, and orthogonal pairs of tRNAs/synthetases, which incorporate keto amino acids into proteins are provided. Methods for identifying these orthogonal pairs are also provided along with methods of producing proteins with keto amino acids using these orthogonal pairs.

  10. Site specific incorporation of keto amino acids into proteins

    Energy Technology Data Exchange (ETDEWEB)

    Schultz, Peter G [La Jolla, CA; Wang, Lei [San Diego, CA

    2011-12-06

    Compositions and methods of producing components of protein biosynthetic machinery that include orthogonal tRNAs, orthogonal aminoacyl-tRNA synthetases, and orthogonal pairs of tRNAs/synthetases, which incorporate keto amino acids into proteins are provided. Methods for identifying these orthogonal pairs are also provided along with methods of producing proteins with keto amino acids using these orthogonal pairs.

  11. Amino acids: metabolism, functions, and nutrition.

    Science.gov (United States)

    Wu, Guoyao

    2009-05-01

    Recent years have witnessed the discovery that amino acids (AA) are not only cell signaling molecules but are also regulators of gene expression and the protein phosphorylation cascade. Additionally, AA are key precursors for syntheses of hormones and low-molecular weight nitrogenous substances with each having enormous biological importance. Physiological concentrations of AA and their metabolites (e.g., nitric oxide, polyamines, glutathione, taurine, thyroid hormones, and serotonin) are required for the functions. However, elevated levels of AA and their products (e.g., ammonia, homocysteine, and asymmetric dimethylarginine) are pathogenic factors for neurological disorders, oxidative stress, and cardiovascular disease. Thus, an optimal balance among AA in the diet and circulation is crucial for whole body homeostasis. There is growing recognition that besides their role as building blocks of proteins and polypeptides, some AA regulate key metabolic pathways that are necessary for maintenance, growth, reproduction, and immunity. They are called functional AA, which include arginine, cysteine, glutamine, leucine, proline, and tryptophan. Dietary supplementation with one or a mixture of these AA may be beneficial for (1) ameliorating health problems at various stages of the life cycle (e.g., fetal growth restriction, neonatal morbidity and mortality, weaning-associated intestinal dysfunction and wasting syndrome, obesity, diabetes, cardiovascular disease, the metabolic syndrome, and infertility); (2) optimizing efficiency of metabolic transformations to enhance muscle growth, milk production, egg and meat quality and athletic performance, while preventing excess fat deposition and reducing adiposity. Thus, AA have important functions in both nutrition and health.

  12. Electronic coupling through natural amino acids

    Energy Technology Data Exchange (ETDEWEB)

    Berstis, Laura; Beckham, Gregg T., E-mail: michael.crowley@nrel.gov, E-mail: gregg.beckham@nrel.gov; Crowley, Michael F., E-mail: michael.crowley@nrel.gov, E-mail: gregg.beckham@nrel.gov [National Renewable Energy Laboratory, National Bioenergy Center, 15013 Denver West Pkwy, Golden, Colorado 80401 (United States)

    2015-12-14

    Myriad scientific domains concern themselves with biological electron transfer (ET) events that span across vast scales of rate and efficiency through a remarkably fine-tuned integration of amino acid (AA) sequences, electronic structure, dynamics, and environment interactions. Within this intricate scheme, many questions persist as to how proteins modulate electron-tunneling properties. To help elucidate these principles, we develop a model set of peptides representing the common α-helix and β-strand motifs including all natural AAs within implicit protein-environment solvation. Using an effective Hamiltonian strategy with density functional theory, we characterize the electronic coupling through these peptides, furthermore considering side-chain dynamics. For both motifs, predictions consistently show that backbone-mediated electronic coupling is distinctly sensitive to AA type (aliphatic, polar, aromatic, negatively charged and positively charged), and to side-chain orientation. The unique properties of these residues may be employed to design activated, deactivated, or switch-like superexchange pathways. Electronic structure calculations and Green’s function analyses indicate that localized shifts in the electron density along the peptide play a role in modulating these pathways, and further substantiate the experimentally observed behavior of proline residues as superbridges. The distinct sensitivities of tunneling pathways to sequence and conformation revealed in this electronic coupling database help improve our fundamental understanding of the broad diversity of ET reactivity and provide guiding principles for peptide design.

  13. Functional amino acids in nutrition and health.

    Science.gov (United States)

    Wu, Guoyao

    2013-09-01

    The recent years have witnessed growing interest in biochemistry, physiology and nutrition of amino acids (AA) in growth, health and disease of humans and other animals. This results from the discoveries of AA in cell signaling involving protein kinases, G protein-coupled receptors, and gaseous molecules (i.e., NO, CO and H2S). In addition, nutritional studies have shown that dietary supplementation with several AA (e.g., arginine, glutamine, glutamate, leucine, and proline) modulates gene expression, enhances growth of the small intestine and skeletal muscle, or reduces excessive body fat. These seminal findings led to the new concept of functional AA, which are defined as those AA that participate in and regulate key metabolic pathways to improve health, survival, growth, development, lactation, and reproduction of the organisms. Functional AA hold great promise in prevention and treatment of metabolic diseases (e.g., obesity, diabetes, and cardiovascular disorders), intrauterine growth restriction, infertility, intestinal and neurological dysfunction, and infectious disease (including viral infections).

  14. Amino Acid Analyses of Acid Hydrolysates in Desert Varnish

    Science.gov (United States)

    Perry, Randall S.; Staley, James T.; Dworkin, Jason P.; Engel, Mike

    2001-01-01

    There has long been a debate as to whether rock varnish deposits are microbially mediated or are deposited by inorganic processes. Varnished rocks are found throughout the world primarily in arid and semi-arid regions. The varnish coats are typically up to 200 microns thick and are composed of clays and alternating layers enriched in manganese and iron oxides. The individual layers range in thickness from 1 micron to greater than 10 microns and may continue laterally for more than a 100 microns. Overlapping botryoidal structures are visible in thin section and scanning electron micrographs. The coatings also include small amounts of organic mater and detrital grains. Amino-acid hydrolysates offer a means of assessing the organic composition of rock varnish collected from the Sonoran Desert, near Phoenix, AZ. Chromatographic analyses of hydrolysates from powdered samples of rock varnish suggest that the interior of rock varnish is relatively enriched in amino acids and specifically in d-alanine and glutamic acid. Peptidoglycan (murein) is the main structural component of gram-positive bacterial cell walls. The d-enantiomer of alanine and glutamic acid are specific to peptidoglycan and are consequently an indicator for the presence of bacteria. D-alanine is also found in teichoic acid which is only found in gram-positive bacteria. Several researchers have cultured bacteria from the surface of rock varnish and most have been gram-positive, suggesting that gram-positive bacteria are intimately associated with varnish coatings and may play a role in the formation of varnish coatings.

  15. Interaction of metal ions and amino acids - Possible mechanisms for the adsorption of amino acids on homoionic smectite clays

    Science.gov (United States)

    Gupta, A.; Loew, G. H.; Lawless, J.

    1983-01-01

    A semiempirical molecular orbital method is used to characterize the binding of amino acids to hexahydrated Cu(2+) and Ni(2+), a process presumed to occur when they are adsorbed in the interlamellar space of homoionic smectite clays. Five alpha-amino acids, beta-alanine, and gamma-aminobutyric acid were used to investigate the metal ion and amino acid specificity in binding. It was assumed that the alpha, beta, and gamma-amino acids would bind as bidentate anionic ligands, forming either 1:1 or 1:2 six-coordinated five, six, and seven-membered-ring chelate complexes, respectively. Energies of complex formation, optimized geometries, and electron and spin distribution were determined; and steric constraints of binding of the amino acids to the ion-exchanged cations in the interlamellar spacing of a clay were examined. Results indicate that hexahydrated Cu(2+) forms more stable complexes than hexahydrated Ni(2+) with all the amino acids studied. However, among these amino acids, complex formation does not favor the adsorption of the biological subset. Calculated energetics of complex formation and steric constraints are shown to predict that 1:1 rather than 1:2 metal-amino acid complexes are generally favored in the clay.

  16. Interaction of metal ions and amino acids - Possible mechanisms for the adsorption of amino acids on homoionic smectite clays

    Science.gov (United States)

    Gupta, A.; Loew, G. H.; Lawless, J.

    1983-01-01

    A semiempirical molecular orbital method is used to characterize the binding of amino acids to hexahydrated Cu(2+) and Ni(2+), a process presumed to occur when they are adsorbed in the interlamellar space of homoionic smectite clays. Five alpha-amino acids, beta-alanine, and gamma-aminobutyric acid were used to investigate the metal ion and amino acid specificity in binding. It was assumed that the alpha, beta, and gamma-amino acids would bind as bidentate anionic ligands, forming either 1:1 or 1:2 six-coordinated five, six, and seven-membered-ring chelate complexes, respectively. Energies of complex formation, optimized geometries, and electron and spin distribution were determined; and steric constraints of binding of the amino acids to the ion-exchanged cations in the interlamellar spacing of a clay were examined. Results indicate that hexahydrated Cu(2+) forms more stable complexes than hexahydrated Ni(2+) with all the amino acids studied. However, among these amino acids, complex formation does not favor the adsorption of the biological subset. Calculated energetics of complex formation and steric constraints are shown to predict that 1:1 rather than 1:2 metal-amino acid complexes are generally favored in the clay.

  17. Independence divergence-generated binary trees of amino acids.

    Science.gov (United States)

    Tusnády, G E; Tusnády, G; Simon, I

    1995-05-01

    The discovery of the relationship between amino acids is important in terms of the replacement ability, as used in protein engineering homology studies, and gaining a better understanding of the roles which various properties of the residues play in the creation of a unique, stable, 3-D protein structure. Amino acid sequences of proteins edited by evolution are anything but random. The measure of nonrandomness, i.e. the level of editing, can be characterized by an independence divergence value. This parameter is used to generate binary tree relationships between amino acids. The relationships of residues presented in this paper are based on protein building features and not on the physico-chemical characteristics of amino acids. This approach is not biased by the tautology present in all sequence similarity-based relationship studies. The roles which various physico-chemical characteristics play in the determination of the relationships between amino acids are also discussed.

  18. Supernovae, Neutrinos and the Chirality of Amino Acids

    Directory of Open Access Journals (Sweden)

    Toshitaka Kajino

    2011-05-01

    Full Text Available A mechanism for creating an enantioenrichment in the amino acids, the building blocks of the proteins, that involves global selection of one handedness by interactions between the amino acids and neutrinos from core-collapse supernovae is defined. The chiral selection involves the dependence of the interaction cross sections on the orientations of the spins of the neutrinos and the 14N nuclei in the amino acids, or in precursor molecules, which in turn couple to the molecular chirality. It also requires an asymmetric distribution of neutrinos emitted from the supernova. The subsequent chemical evolution and galactic mixing would ultimately populate the Galaxy with the selected species. The resulting amino acids could either be the source thereof on Earth, or could have triggered the chirality that was ultimately achieved for Earth’s proteinaceous amino acids.

  19. Amino Acids Are an Ineffective Fertilizer for Dunaliella spp. Growth

    Directory of Open Access Journals (Sweden)

    Colin A. Murphree

    2017-05-01

    Full Text Available Autotrophic microalgae are a promising bioproducts platform. However, the fundamental requirements these organisms have for nitrogen fertilizer severely limit the impact and scale of their cultivation. As an alternative to inorganic fertilizers, we investigated the possibility of using amino acids from deconstructed biomass as a nitrogen source in the genus Dunaliella. We found that only four amino acids (glutamine, histidine, cysteine, and tryptophan rescue Dunaliella spp. growth in nitrogen depleted media, and that supplementation of these amino acids altered the metabolic profile of Dunaliella cells. Our investigations revealed that histidine is transported across the cell membrane, and that glutamine and cysteine are not transported. Rather, glutamine, cysteine, and tryptophan are degraded in solution by a set of oxidative chemical reactions, releasing ammonium that in turn supports growth. Utilization of biomass-derived amino acids is therefore not a suitable option unless additional amino acid nitrogen uptake is enabled through genetic modifications of these algae.

  20. Adaptive amino acid composition in collagens of parasitic nematodes.

    Science.gov (United States)

    Hughes, Austin L

    2015-04-01

    Amino acid composition was analyzed in the glycine-rich repeat region of 306 collagens belonging to three major families of collagens from both parasitic and free-living nematodes. The collagens of parasitic species showed a tendency toward decreased usage of the hydrophilic residues A, D, and Q and increased usage of the hydrophobic resides I, L, and M; and this trend was seen in parasitic species of both the order Rhabdita and the order Spirurida. The amino acid composition of collagens of parasitic Rhabdita thus tended to resemble those of Spirurida more than that of free-living Rhabdita, suggesting an association between amino acid composition and a parasitic lifestyle. Computer predictions suggested that the more hydrophobic amino acid composition was associated with a reduction of the propensity towards B-cell epitope formation, suggesting that evasion of host immune responses may be a major selective factor responsible for the parasite-specific trend in collagen amino acid composition.

  1. Amino acid biogeo- and stereochemistry in coastal Chilean sediments

    DEFF Research Database (Denmark)

    Lomstein, Bente Aagaard; Jørgensen, Bo Barker; Schubert, Carsten J.;

    2006-01-01

    The spatial distribution of total hydrolysable amino acids (THAA) and amino acid enantiomers (D- and L-forms) was investigated in sediments underlying two contrasting Chilean upwelling regions,: at ~23°S off Antofagasta and at ~36°S off Concepcion. The contribution of amino acids to total organic...... carbon (%TAAC: 7-14%) and total nitrogen (%TAAN: 23-38%) in surface sediments decreased with increasing water depth (from 126 to 1350 m) indicating that organic matter becomes increasingly decomposed in surface sediments at greater water depth. Changes in the ratio between the protein amino acid...... aspartate and its non-protein degradation product β-alanine confirmed this observation. Furthermore, estimates of THAA mineralization showed that sedimentary amino acid reactivity decreased with both increasing water depth as well as progressive degradation status of the organic matter that was incorporated...

  2. Stardust, Supernovae and the Chirality of the Amino Acids

    Energy Technology Data Exchange (ETDEWEB)

    Boyd, R N; Kajino, T; Onaka, T

    2011-03-09

    A mechanism for creating enantiomerism in the amino acids, the building blocks of the proteins, that involves global selection of one chirality by interactions between the amino acids and neutrinos from core-collapse supernovae is described. The selection involves the dependence of the interaction cross sections on the orientations of the spins of the neutrinos and the 14N nuclei in the amino acids, or in precursor molecules, which in turn couple to the molecular chirality. The subsequent chemical evolution and galactic mixing would ultimately populate the Galaxy with the selected species. The resulting amino acids could either be the source thereof on Earth, or could have triggered the chirality that was ultimately achieved for Earth's amino acids.

  3. Supernovae, Neutrinos, and the Chirality of the Amino Acids

    CERN Document Server

    Boyd, R N; Onaka, T

    2011-01-01

    A mechanism for creating an enantioenrichment in the amino acids, the building blocks of the proteins, that involves global selection of one handedness by interactions between the amino acids and neutrinos from core-collapse supernovae is described. The chiral selection involves the dependence of the interaction cross sections on the orientations of the spins of the neutrinos and the 14N nuclei in the amino acids, or in precursor molecules, which in turn couple to the molecular chirality. It also requires an asymmetric distribution of neutrinos emitted from the supernova. The subsequent chemical evolution and galactic mixing would ultimately populate the Galaxy with the selected species. The resulting amino acids could either be the source thereof on Earth, or could have triggered the chirality that was ultimately achieved for Earth's proteinaceous amino acids.

  4. Regulation of intestinal protein metabolism by amino acids.

    Science.gov (United States)

    Bertrand, Julien; Goichon, Alexis; Déchelotte, Pierre; Coëffier, Moïse

    2013-09-01

    Gut homeostasis plays a major role in health and may be regulated by quantitative and qualitative food intake. In the intestinal mucosa, an intense renewal of proteins occurs, at approximately 50% per day in humans. In some pathophysiological conditions, protein turnover is altered and may contribute to intestinal or systemic diseases. Amino acids are key effectors of gut protein turnover, both as constituents of proteins and as regulatory molecules limiting intestinal injury and maintaining intestinal functions. Many studies have focused on two amino acids: glutamine, known as the preferential substrate of rapidly dividing cells, and arginine, another conditionally essential amino acid. The effects of glutamine and arginine on protein synthesis appear to be model and condition dependent, as are the involved signaling pathways. The regulation of gut protein degradation by amino acids has been minimally documented until now. This review will examine recent data, helping to better understand how amino acids regulate intestinal protein metabolism, and will explore perspectives for future studies.

  5. Amino Acid Profile of Some New Vartieties of Oil Seeds

    Directory of Open Access Journals (Sweden)

    Satish Ingale and S.K. Shrivastava

    2011-04-01

    Full Text Available There are large varieties of oil seeds and legumes in India, which are part of traditional food system but whose nutritional and economic values have not been completely determine and are far less exploited for both human and livestock utilization. The objective of this study was to evaluate Sunflower (Helianths annuus LSF-11, Sunflower (Helianths annuus LSF-8, Safflower (Carthamus tinctorius PBNS-12, Safflower (Carthamus tinctorius PBNS-40, and Ground nut (Arachis hypogaea JL-24 seeds with the aim of qualifying and quantifying chemical information that might serve as a guide to exploit its potentials and benefits for human and animal nutrition. The amino acid profile of these oil seed were carried out using standard methods. Amino acid analysis using technical sequential multisampling amino acid analyzer detected all essential and non essential amino acids. The seeds are rich in four amino acids (EAA and NEAA (g/16g N Glutamic acid (5.083, Aspartic acid (3.459, Proline (6.412 and Methionine (3.001%, respectively. The other amino acids compared well with the FAO reference protein, Serine appeared to be the most limiting amino acid percent. Based on results of this study, the lesser known and under-utilized oil seeds, they can be a potential source and energy supplements in livestock feed.

  6. The amino acid transporter SLC6A14 in cancer and its potential use in chemotherapy

    Directory of Open Access Journals (Sweden)

    Yangzom D. Bhutia

    2014-12-01

    Full Text Available Tumor cells have an increased demand for glucose and amino acids to support their rapid growth, and also exhibit alterations in biochemical pathways that metabolize these nutrients. Transport across the plasma membrane is essential to feed glucose and amino acids into these tumor cell-selective metabolic pathways. Transfer of amino acids across biological membranes occurs via a multitude of transporters; tumor cells must upregulate one or more of these transporters to satisfy their increased demand for amino acids. Among the amino acid transporters, SLC6A14 stands out with specific functional features uniquely suited for the biological needs of the tumor cells. This transporter is indeed upregulated in tumors of epithelial origin, including colon cancer, cervical cancer, breast cancer, and pancreatic cancer. Since normal cells express this transporter only at low levels, blockade of this transporter should lead to amino acid starvation selectively in tumor cells, thus having little effect on normal cells. This offers a novel, yet logical, strategy for the treatment of cancers that are associated with upregulation of SLC6A14. In addition, a variety of amino acid-based prodrugs are recognized as substrates by SLC6A14, thus raising the possibility that anticancer drugs can be delivered into tumor cells selectively via this transporter in the form of amino acid prodrugs. This strategy allows exposure of SLC6A14-positive tumor cells to chemotherapy with minimal off-target effects. In conclusion, the amino acid transporter SLC6A14 holds great potential not only as a direct drug target for cancer therapy but also for tumor cell-selective delivery of anticancer drugs.

  7. Hydration of amino acids: FTIR spectra and molecular dynamics studies.

    Science.gov (United States)

    Panuszko, Aneta; Adamczak, Beata; Czub, Jacek; Gojło, Emilia; Stangret, Janusz

    2015-11-01

    The hydration of selected amino acids, alanine, glycine, proline, valine, isoleucine and phenylalanine, has been studied in aqueous solutions by means of FTIR spectra of HDO isotopically diluted in H2O. The difference spectra procedure and the chemometric method have been applied to remove the contribution of bulk water and thus to separate the spectra of solute-affected HDO. To support interpretation of obtained spectral results, molecular dynamics simulations of amino acids were performed. The structural-energetic characteristic of these solute-affected water molecules shows that, on average, water affected by amino acids forms stronger and shorter H-bonds than those in pure water. Differences in the influence of amino acids on water structure have been noticed. The effect of the hydrophobic side chain of an amino acid on the solvent interactions seems to be enhanced because of the specific cooperative coupling of water strong H-bond chain, connecting the carboxyl and amino groups, with the clathrate-like H-bond network surrounding the hydrocarbon side chain. The parameter derived from the spectral data, which corresponds to the contributions of the population of weak hydrogen bonds of water molecules which have been substituted by the stronger ones in the hydration sphere of amino acids, correlated well with the amino acid hydrophobicity indexes.

  8. Fatty acid-amino acid conjugates diversification in lepidopteran caterpillars.

    Science.gov (United States)

    Yoshinaga, Naoko; Alborn, Hans T; Nakanishi, Tomoaki; Suckling, David M; Nishida, Ritsuo; Tumlinson, James H; Mori, Naoki

    2010-03-01

    Fatty acid amino acid conjugates (FACs) have been found in noctuid as well as sphingid caterpillar oral secretions; in particular, volicitin [N-(17-hydroxylinolenoyl)-L-glutamine] and its biochemical precursor, N-linolenoyl-L-glutamine, are known elicitors of induced volatile emissions in corn plants. These induced volatiles, in turn, attract natural enemies of the caterpillars. In a previous study, we showed that N-linolenoyl-L-glutamine in larval Spodoptera litura plays an important role in nitrogen assimilation which might be an explanation for caterpillars synthesizing FACs despite an increased risk of attracting natural enemies. However, the presence of FACs in lepidopteran species outside these families of agricultural interest is not well known. We conducted FAC screening of 29 lepidopteran species, and found them in 19 of these species. Thus, FACs are commonly synthesized through a broad range of lepidopteran caterpillars. Since all FAC-containing species had N-linolenoyl-L-glutamine and/or N-linoleoyl-L-glutamine in common, and the evolutionarily earliest species among them had only these two FACs, these glutamine conjugates might be the evolutionarily older FACs. Furthermore, some species had glutamic acid conjugates, and some had hydroxylated FACs. Comparing the diversity of FACs with lepidopteran phylogeny indicates that glutamic acid conjugates can be synthesized by relatively primitive species, while hydroxylation of fatty acids is limited mostly to larger and more developed macrolepidopteran species.

  9. Excretion of amino acids by humans during space flight

    Science.gov (United States)

    Stein, T. P.; Schluter, M. D.

    1998-01-01

    We measured the urine amino acid distribution patterns before, during and after space flight on the Space Shuttle. The urine samples were collected on two separate flights of the space shuttle. The first flight lasted 9.5 days and the second flight 15 days. Urine was collected continuously on 8 subjects for the period beginning 10 d before launch to 6 d after landing. Results: In contrast to the earlier Skylab missions where a pronounced amino aciduria was found, on shuttle the urinary amino acids showed little change with spaceflight except for a marked decrease in all of the amino acids on FD (flight day) 1 (pvaline on FD3 and FD4 (p<0.05). Conclusions: (i) Amino aciduria is not an inevitable consequence of space flight. (ii) The occurrence of amino aciduria, like muscle protein breakdown is a mission specific effect rather than part of the general human response to microgravity.

  10. Non-protein amino acids in peptide design

    Indian Academy of Sciences (India)

    S Aravinda; N Shamala; Rituparna S Roy; P Balaram

    2003-10-01

    An overview of the use of non-protein amino acids in the design of conformationally well-defined peptides, based on work from the author’s laboratory, is discussed. The crystal structures of several designed oligopeptides illustrate the use -aminoisobutyric acid (Aib) in the construction of helices, D-amino acids in the design of helix termination segments and DPro-Xxx segments for nucleating of -hairpin structures. - and -amino acid residues have been used to expand the range of designed polypeptide structures.

  11. Enantioseparation of Amino Acids by Micelle-Enhanced Ultrafiltration : Experimental and Theoretical Studies of Copper(II) Amino Acid Interactions

    NARCIS (Netherlands)

    Bruin, de T.J.M.

    2000-01-01

    A micelle-enhanced ultrafiltration system, which can potentially be used for large scale separations, has been used to investigate the resolution of amino acid enantiomers. For this purpose amino acid derivatives were synthesized, which in combination with copper(II) ions were used as chiral selecto

  12. D-Amino acids in the brain and mutant rodents lacking D-amino-acid oxidase activity.

    Science.gov (United States)

    Yamanaka, Masahiro; Miyoshi, Yurika; Ohide, Hiroko; Hamase, Kenji; Konno, Ryuichi

    2012-11-01

    D-Amino acids are stereoisomers of L-amino acids. They are often called unnatural amino acids, but several D-amino acids have been found in mammalian brains. Among them, D-serine is abundant in the forebrain and functions as a co-agonist of NMDA receptors to enhance neurotransmission. D-Amino-acid oxidase (DAO), which degrades neutral and basic D-amino acids, is mainly present in the hindbrain. DAO catabolizes D-serine and, therefore, modulates neurotransmission. In the brains of mutant mice and rats lacking DAO activity, the amounts of D-serine and other D-amino acids are markedly increased. Mutant mice manifested behavioral changes characteristic of altered NMDA receptor activity, likely due to increased levels of D-serine. D-Serine and DAO have been demonstrated to play important roles in cerebellar development and synaptic plasticity. They have also implicated in amyotrophic lateral sclerosis and pain response. There have also been several lines of evidence correlating DAO with schizophrenia. Taken together, the experiments indicate that D-amino acids and DAO have pivotal functions in the central nervous system.

  13. Quantitative analysis of 17 amino acids in tobacco leaves using an amino acid analyzer and chemometric resolution.

    Science.gov (United States)

    Zeng, Yihang; Cai, Wensheng; Shao, Xueguang

    2015-06-01

    A method was developed for quantifying 17 amino acids in tobacco leaves by using an A300 amino acid analyzer and chemometric resolution. In the method, amino acids were eluted by the buffer solution on an ion-exchange column. After reacting with ninhydrin, the derivatives of amino acids were detected by ultraviolet detection. Most amino acids are separated by the elution program. However, five peaks of the derivatives are still overlapping. A non-negative immune algorithm was employed to extract the profiles of the derivatives from the overlapping signals, and then peak areas were adopted for quantitative analysis of the amino acids. The method was validated by the determination of amino acids in tobacco leaves. The relative standard deviations (n = 5) are all less than 2.54% and the recoveries of the spiked samples are in a range of 94.62-108.21%. The feasibility of the method was proved by analyzing the 17 amino acids in 30 tobacco leaf samples.

  14. Overall renal and tubular function during infusion of amino acids in normal man

    DEFF Research Database (Denmark)

    Olsen, Niels Vidiendal; Hansen, J M; Ladefoged, S D

    1990-01-01

    1. Amino acids have been used to test renal reserve filtration capacity. Previous studies suggest that amino acids increase glomerular filtration rate (GFR) by reducing distal tubular flow and tubuloglomerular feedback activity. 2. Glomerular function and the renal tubular handling of sodium during...... infusion of amino acids was studied in 12 normal volunteers. 3. Clearance of sodium (CNa) was unchanged. Effective renal plasma flow increased slightly, but significantly, by 9% (P less than 0.05). GFR was increased by 13% (P less than 0.001). Clearance of lithium (CLi) (used as an index of proximal...... tubular outflow) increased by 38% (P less than 0.001). Calculated absolute proximal reabsorption (GFR-CLi) remained unchanged. Fractional proximal reabsorption [1-(CLi/GFR)] was decreased by 10% (P less than 0.001). Calculated absolute distal sodium reabsorption [(CLi-CNa) x PNa, where PNa is plasma...

  15. Overall renal and tubular function during infusion of amino acids in normal man

    DEFF Research Database (Denmark)

    Olsen, Niels Vidiendal; Hansen, J M; Ladefoged, S D

    1990-01-01

    1. Amino acids have been used to test renal reserve filtration capacity. Previous studies suggest that amino acids increase glomerular filtration rate (GFR) by reducing distal tubular flow and tubuloglomerular feedback activity. 2. Glomerular function and the renal tubular handling of sodium during...... infusion of amino acids was studied in 12 normal volunteers. 3. Clearance of sodium (CNa) was unchanged. Effective renal plasma flow increased slightly, but significantly, by 9% (P less than 0.05). GFR was increased by 13% (P less than 0.001). Clearance of lithium (CLi) (used as an index of proximal...... tubular outflow) increased by 38% (P less than 0.001). Calculated absolute proximal reabsorption (GFR-CLi) remained unchanged. Fractional proximal reabsorption [1-(CLi/GFR)] was decreased by 10% (P less than 0.001). Calculated absolute distal sodium reabsorption [(CLi-CNa) x PNa, where PNa is plasma...

  16. 早期断奶仔猪血浆氨基酸代谢谱动态变化研究%Dynamic Change of Plasma Amino Acid Profiles in Early Weaned Piglets

    Institute of Scientific and Technical Information of China (English)

    肖英平; 陈安国; 代兵; 陈镜刚; 李开锋; 杨华

    2015-01-01

    本试验旨在研究仔猪早期断奶过程中血浆氨基酸代谢谱的动态变化. 选取8头21日龄"杜×长×大"断奶仔猪,在断奶后0、1、3、5、7、10、15、30 d采集血液样本用于氨基酸分析. 结果表明,仔猪血浆精氨酸、瓜氨酸和鸟氨酸含量在断奶后1~5 d内显著下降(P0.05). 主成分分析显示,随着断奶后时间的延长,仔猪血浆氨基酸代谢谱与断奶后0d的代谢谱差异逐渐变大,然后逐渐向断奶后0d代谢谱位置靠拢,并趋于稳定,其中断后3~5d血浆氨基酸代谢谱变化幅度最大.偏最小二乘法判别分析模型表明,谷氨酸在NRC ( 1998 )饲养标准下区分断奶后各时间点血浆代谢谱最重要的氨基酸. 由此可见,仔猪在早期断奶阶段机体的蛋白质或者氨基酸代谢发生明显变化,且在断奶后3~5d变化幅度最为显著.%The time-course of plasma amino acid ( AA) following response to early weaning was investigated over a 30 d period in weaned piglets using AA analyzer. Eight 21-day-old "Duroc × Landrace × Large York-shire" weaned piglets were selected and their blood samples were collected on days 0, 1, 3, 5, 7, 10, 15, and 30 post-weaning. The results showed as follows: plasma contents of arginine and its immediate precursors ( citrulline and ornithine) decreased ( P0.05) . In score plot of principal component analysis, the profiles of AA were gradually away from the profile of AA on day 0 post-weaning, and then were closed to that, and tended to be stable. On days 3 and 5 post-weaning, the profiles of AA were robustly altered. The pattern of partial least-square discriminant analysis demonstrated that glutamic acid played the most important role in differentiating the profiles of AA at different time points post-weaning. It is concluded that early weaning changes the metabolism of protein and amino acid in the body of piglets, especially on days 3 and 5 post-weaning.

  17. Subcritical Water Extraction of Amino Acids from Atacama Desert Soils

    Science.gov (United States)

    Amashukeli, Xenia; Pelletier, Christine C.; Kirby, James P.; Grunthaner, Frank J.

    2007-01-01

    Amino acids are considered organic molecular indicators in the search for extant and extinct life in the Solar System. Extraction of these molecules from a particulate solid matrix, such as Martian regolith, will be critical to their in situ detection and analysis. The goals of this study were to optimize a laboratory amino acid extraction protocol by quantitatively measuring the yields of extracted amino acids as a function of liquid water temperature and sample extraction time and to compare the results to the standard HCl vapor- phase hydrolysis yields for the same soil samples. Soil samples from the Yungay region of the Atacama Desert ( Martian regolith analog) were collected during a field study in the summer of 2005. The amino acids ( alanine, aspartic acid, glutamic acid, glycine, serine, and valine) chosen for analysis were present in the samples at concentrations of 1 - 70 parts- per- billion. Subcritical water extraction efficiency was examined over the temperature range of 30 - 325 degrees C, at pressures of 17.2 or 20.0 MPa, and for water- sample contact equilibration times of 0 - 30 min. None of the amino acids were extracted in detectable amounts at 30 degrees C ( at 17.2 MPa), suggesting that amino acids are too strongly bound by the soil matrix to be extracted at such a low temperature. Between 150 degrees C and 250 degrees C ( at 17.2 MPa), the extraction efficiencies of glycine, alanine, and valine were observed to increase with increasing water temperature, consistent with higher solubility at higher temperatures, perhaps due to the decreasing dielectric constant of water. Amino acids were not detected in extracts collected at 325 degrees C ( at 20.0 MPa), probably due to amino acid decomposition at this temperature. The optimal subcritical water extraction conditions for these amino acids from Atacama Desert soils were achieved at 200 degrees C, 17.2 MPa, and a water- sample contact equilibration time of 10 min.

  18. Organometallic and Bioorganometallic Chemistry – Ferrocene Amino Acids

    Directory of Open Access Journals (Sweden)

    Barišić, L.

    2012-01-01

    Full Text Available This article is the second part of a series dealing with organometallic and bioorganometallic chemistry. In the first part of this series a short review on the history and development of these disciplines was given, emphasizing the importance and scope of bioorganometallic chemistry as a new field dealing with conjugates of organometallics and biomolecules (DNA, PNA, amino acids, peptides.... From the variety of biorganometallics, syntheses and properties of simple conjugates of ferrocene with natural amino acids/peptides were elaborated inter alia. This material is the basis for the second part in which ferrocene amino acids are described. The introduction presents nonproteinogenic alicyclic and aromatic amino acids as the models for the title compounds. Naturally occurring amino acids labelled with ferrocene moiety mostly retain properties of the biomolecules included. Contrary to these ω-ferrocenylamino acids, one could imagine specific amino acids with inserted ferrocene core belonging to either homo- or heterodisubstituted type. The central part of this article is devoted to our investigations of the second type - H2N-(CH2m-Fn-(CH2n-COOH. The general rational procedure for synthesis of these compounds and of their N- and/or C-protected derivatives via the azide intermediates N3-CO-(CH2m- Fn-(CH2n-COOMe has been described. In the solid state derivatives of ferrocene amino acids contain intermolecular hydrogen bonds giving dimeric structures, three-dimensional networks or endless helical chains. The solutions of homologues Ac-NH-(CH2m-Fn-(CH2n-COOMe in nonpolar solvents are dominated by open form conformers. Compounds containing 2–3 ferrocene cores connected by amide, imide and oxalamide spacers were prepared by oligomerization of 1'-aminoferrocene-1-carboxylic acid (Fca or by its condensation with the appropriate reagents. Similar to natural amino acids, ferrocene amino acids are water-soluble substances with high melting points

  19. Subcritical Water Extraction of Amino Acids from Atacama Desert Soils

    Science.gov (United States)

    Amashukeli, Xenia; Pelletier, Christine C.; Kirby, James P.; Grunthaner, Frank J.

    2007-01-01

    Amino acids are considered organic molecular indicators in the search for extant and extinct life in the Solar System. Extraction of these molecules from a particulate solid matrix, such as Martian regolith, will be critical to their in situ detection and analysis. The goals of this study were to optimize a laboratory amino acid extraction protocol by quantitatively measuring the yields of extracted amino acids as a function of liquid water temperature and sample extraction time and to compare the results to the standard HCl vapor- phase hydrolysis yields for the same soil samples. Soil samples from the Yungay region of the Atacama Desert ( Martian regolith analog) were collected during a field study in the summer of 2005. The amino acids ( alanine, aspartic acid, glutamic acid, glycine, serine, and valine) chosen for analysis were present in the samples at concentrations of 1 - 70 parts- per- billion. Subcritical water extraction efficiency was examined over the temperature range of 30 - 325 degrees C, at pressures of 17.2 or 20.0 MPa, and for water- sample contact equilibration times of 0 - 30 min. None of the amino acids were extracted in detectable amounts at 30 degrees C ( at 17.2 MPa), suggesting that amino acids are too strongly bound by the soil matrix to be extracted at such a low temperature. Between 150 degrees C and 250 degrees C ( at 17.2 MPa), the extraction efficiencies of glycine, alanine, and valine were observed to increase with increasing water temperature, consistent with higher solubility at higher temperatures, perhaps due to the decreasing dielectric constant of water. Amino acids were not detected in extracts collected at 325 degrees C ( at 20.0 MPa), probably due to amino acid decomposition at this temperature. The optimal subcritical water extraction conditions for these amino acids from Atacama Desert soils were achieved at 200 degrees C, 17.2 MPa, and a water- sample contact equilibration time of 10 min.

  20. Amino acid profiles and digestible indispensable amino acid scores of proteins from the prioritized key foods in Bangladesh.

    Science.gov (United States)

    Shaheen, Nazma; Islam, Saiful; Munmun, Sarah; Mohiduzzaman, Md; Longvah, Thingnganing

    2016-12-15

    Concentrations of standard amino acids were determined in the composite samples (representing 30 agro-ecological zones of Bangladesh) of six prioritized key dietary protein sources: Oryza sativa (rice), Triticum aestivum (wheat flour), Lens culinaris (lentils), Pangusius pangusius (pangas), Labeo rohita (rohu) and Oreochromis mossambicus (tilapia). Digestible indispensable amino acid scores (DIAAS) was calculated using published data on amino acids' digestibility to evaluate the protein quality of these foods. Indispensable amino acid (IAA) contents (mg IAA/g protein), found to be highest in pangas (430) and lowest in wheat (336), of all these analyzed foods exceeded the FAO recommended daily allowance (277mg IAA/g protein) and contributed on average 40% to total amino acid contents. Untruncated DIAAS values ranged from 51% (lysine) in wheat to 106% (histidine) in pangas and distinguished pangas, rohu, and tilapia containing 'excellent quality' protein (DIAAS>100%) with potential to complement lower quality protein of cereals, fruits, and vegetables.

  1. Evaluation of methods to estimate the essential amino acids requirements of fish from the muscle amino acid profile

    Directory of Open Access Journals (Sweden)

    Álvaro José de Almeida Bicudo

    2014-03-01

    Full Text Available Many methods to estimate amino acid requirement based on amino acid profile of fish have been proposed. This study evaluates the methodology proposed by Meyer & Fracalossi (2005 and by Tacon (1989 to estimate amino acids requirement of fish, which do exempt knowledge on previous nutritional requirement of reference amino acid. Data on amino acid requirement of pacu, Piaractus mesopotamicus, were used to validate de accuracy of those methods. Meyer & Fracalossi's and Tacon's methodology estimated the lysine requirement of pacu, respectively, at 13 and 23% above requirement determined using dose-response method. The values estimated by both methods lie within the range of requirements determined for other omnivorous fish species, the Meyer & Fracalossi (2005 method showing better accuracy.

  2. Rapid determination of amino acids in biological samples using a monolithic silica column.

    Science.gov (United States)

    Song, Yanting; Funatsu, Takashi; Tsunoda, Makoto

    2012-05-01

    A high-performance liquid chromatography method in which fluorescence detection is used for the simultaneous determination of 21 amino acids is proposed. Amino acids were derivatized with 4-fluoro-7-nitro-2,1,3-benzoxadiazole (NBD-F) and then separated on a monolithic silica column (MonoClad C18-HS, 150 mm×3 mm i.d.). A mixture of 25 mM citrate buffer containing 25 mM sodium perchlorate (pH 5.5) and acetonitrile was used as the mobile phase. We found that the most significant factor in the separation was temperature, and a linear temperature gradient from 30 to 49°C was used to control the column temperature. The limits of detection and quantification for all amino acids ranged from 3.2 to 57.2 fmol and 10.8 to 191 fmol, respectively. The calibration curves for the NBD-amino acid had good linearity within the range of 40 fmol to 40 pmol when 6-aminocaproic acid was used as an internal standard. Using only conventional instruments, the 21 amino acids could be analyzed within 10 min. This method was found to be suitable for the quantification of the contents of amino acids in mouse plasma and adrenal gland samples.

  3. Amino Acid Synthesis in a Supercritical Carbon Dioxide - Water System

    Directory of Open Access Journals (Sweden)

    Akiyoshi Hoshino

    2009-06-01

    Full Text Available Mars is a CO2-abundant planet, whereas early Earth is thought to be also CO2-abundant. In addition, water was also discovered on Mars in 2008. From the facts and theory, we assumed that soda fountains were present on both planets, and this affected amino acid synthesis. Here, using a supercritical CO2/liquid H2O (10:1 system which mimicked crust soda fountains, we demonstrate production of amino acids from hydroxylamine (nitrogen source and keto acids (oxylic acid sources. In this research, several amino acids were detected with an amino acid analyzer. Moreover, alanine polymers were detected with LC-MS. Our research lights up a new pathway in the study of life’s origin.

  4. Amino Acid and Peptide Immobilization on Oxidized Nanocellulose: Spectroscopic Characterization

    Directory of Open Access Journals (Sweden)

    Claude Daneault

    2012-06-01

    Full Text Available In this work, oxidized nanocellulose (ONC was synthesized and chemically coupled with amino acids and peptides using a two step coupling method at room temperature. First, ONC was activated by N-ethyl-N’-(3-dimethylaminopropyl carbodiimide hydrochloride, forming a stable active ester in the presence of N-hydroxysuccinimide. Second, the active ester was reacted with the amino group of the amino acid or peptide, forming an amide bond between ONC and the grafted molecule. Using this method, the intermolecular interaction of amino acids and peptides was avoided and uniform coupling of these molecules on ONC was achieved. The coupling reaction was very fast in mild conditions and without alteration of the polysaccharide. The coupling products (ONC-amino acids and ONC-peptides were characterized by transmission electron microscopy and by the absorption, emission, Fourier transform infrared spectroscopy (FTIR and X-ray photoelectron spectroscopy (XPS spectroscopic techniques.

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

    Science.gov (United States)

    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.

  6. L-citrulline-malate influence over branched chain amino acid utilization during exercise.

    Science.gov (United States)

    Sureda, Antoni; Córdova, Alfredo; Ferrer, Miguel D; Pérez, Gerardo; Tur, Josep A; Pons, Antoni

    2010-09-01

    Exhaustive exercise induces disturbances in metabolic homeostasis which can result in amino acid catabolism and limited L-arginine availability. Oral L-citrulline supplementation raises plasma L-arginine concentration and augments NO-dependent signalling. Our aim was to evaluate the effects of diet supplementation with L-citrulline-malate prior to intense exercise on the metabolic handle of plasma amino acids and on the products of metabolism of arginine as creatinine, urea and nitrite and the possible effects on the hormonal levels. Seventeen voluntary male pre-professional cyclists were randomly assigned to one of two groups: control or supplemented (6 g L-citrulline-malate 2 h prior exercise) and participated in a 137-km cycling stage. Blood samples were taken in basal conditions, 15 min after the race and 3 h post race (recovery). Most essential amino acids significantly decreased their plasma concentration as a result of exercise; however, most non-essential amino acids tended to significantly increase their concentration. Citrulline-malate ingestion significantly increased the plasma concentration of citrulline, arginine, ornithine, urea, creatinine and nitrite (p urea.

  7. Differential diagnosis of (inherited) amino acid metabolism or transport disorders.

    Science.gov (United States)

    Blom, W; Huijmans, J G

    1992-02-01

    Disorders of amino acid metabolism or transport are most clearly expressed in urine. Nevertheless the interpretation of abnormalities in urinary amino acid excretion remains difficult. An increase or decrease of almost every amino acid in urine can be due to various etiology. To differentiate between primary and secondary aminoacido-pathies systematic laboratory investigation is necessary. Early diagnosis of disorders of amino acid metabolism or transport is very important, because most of them can be treated, leading to the prevention of (further) clinical abnormalities. In those disorders, which cannot be treated, early diagnosis in an index-patient may prevent the birth of other siblings by means of genetic counseling and prenatal diagnosis.Primary aminoacidopathies can be due to genetically determined transport disorders and enzyme deficiencies in amino acid metabolism or degradation. Secondary aminoacidopathies are the result of abnormal or deficient nutrition, intestinal dysfunction, organ pathology or other metabolic diseases like organic acidurias.A survey of amino acid metabolism and transport abnormalities will be given, illustrated with metabolic pathways and characteristic abnormal amino acid chromatograms.

  8. Metabolism of amino acids, dipeptides and tetrapeptides by Lactobacillus sakei.

    Science.gov (United States)

    Sinz, Quirin; Schwab, Wilfried

    2012-04-01

    The microbial degradation of proteins, peptides and amino acids generates volatiles involved in the typical flavor of dry fermented sausage. The ability of three Lactobacillus sakei strains to form aroma compounds was investigated. Whole resting cells were fermented in phosphate buffer with equimolar amounts of substrates consisting of dipeptides, tetrapeptides and free amino acids, respectively. Dipeptides disappeared quickly from the solutions whereas tetrapeptides were only partially degraded. In both approaches the concentration of free amino acids increased in the reaction mixture but did not reach the equimolar amount of the initial substrates. When free amino acids were fed to the bacteria their levels decreased only slightly. Although peptides were more rapidly degraded and/or transported into the cells, free amino acids produced higher amounts of volatiles. It is suggested, that after transport into the cell peptides are only partially hydrolyzed to their amino acids, while the rest is metabolized via alternative metabolic pathways. The three L. sakei strains differed to some extend in their ability to metabolize the substrates to volatile compounds. In a few cases this was due to the position of the amino acids within the peptides. Compared to other starter cultures used for the production of dry fermented sausages, the metabolic impact of the L. sakei strains on the formation of volatiles was very low.

  9. New Functions and Potential Applications of Amino Acids.

    Science.gov (United States)

    Uneyama, Hisayuki; Kobayashi, Hisamine; Tonouchi, Naoto

    Currently, several types of amino acids are being produced and used worldwide. Nevertheless, several new functions of amino acids have been recently discovered that could result in other applications. For example, oral stimulation by glutamate triggers the cephalic phase response to prepare for food digestion. Further, the stomach and intestines have specific glutamate-recognizing systems in their epithelial mucosa. Regarding clinical applications, addition of monosodium glutamate to the medicinal diet has been shown to markedly enhance gastric secretion in a vagus-dependent manner. Branched-chain amino acids (BCAAs) are the major components of muscles, and ingestion of BCAAs has been found to be effective for decreasing muscle pain. BCAAs are expected to be a solution for the serious issue of aging. Further, ingestion of specific amino acids could be beneficial. Glycine can be ingested for good night's sleep: glycine ingestion before bedtime significantly improved subjective sleep quality. Ingestion of alanine and glutamine effectively accelerates alcohol metabolism, and ingestion of cystine and theanine effectively prevents colds. Finally, amino acids could be used in a novel clinical diagnostic method: the balance of amino acids in the blood could be an indicator of the risk of diseases such as cancer. These newly discovered functions of amino acids are expected to contribute to the resolution of various issues.

  10. Aromatic amino acids in high selectivity bismuth(III) recognition.

    Science.gov (United States)

    Ghatak, Sumanta Kumar; Dey, Debarati; Sen, Souvik; Sen, Kamalika

    2013-04-21

    The three aromatic amino acids, tyrosine, tryptophan and phenylalanine, play different physiological roles in life processes. Metal ions capable of binding these amino acids may aid in the reduction of effective concentration of these amino acids in any physiological system. Here we have studied the efficacy of some heavy metals for their complexation with these three amino acids. Bismuth has been found to bind selectively with these aromatic amino acids and this was confirmed using spectrofluorimetric, spectrophotometric and cyclic voltammetric studies. The series of heavy metals has been chosen because each of these metals remains associated with the others at very low concentration levels and Bi(III) is the least toxic amongst the other elements. So, selective recognition for Bi(III) would also mean no response for the other heavy elements if contaminants are present even at low concentration levels. The affinity towards these amino acids has been found to be in the order tryptophan phenylalanine amino acids have been calculated using Benesi-Hildebrand equations and the corresponding free energy change has also been calculated. The values of the association constants obtained from BH equations using absorbance values corroborate with the Stern-Volmer constants obtained from fluorimetric studies. The evidence for complexation is also supported by the results of cyclic voltammetry.

  11. Distribution of soluble amino acids in maize endosperm mutants

    Directory of Open Access Journals (Sweden)

    Toro Alejandro Alberto

    2003-01-01

    Full Text Available For human nutrition the main source of vegetable proteins are cereal and legume seeds. The content of total soluble amino acids in mature endosperm of wild-type, opaque and floury maize (Zea mays L. mutants were determined by HPLC. The total absolute concentration of soluble amino acids among the mutants varied depending on the mutant. The o11 and o13 mutants exhibited the highest average content, whereas o10, fl3 and fl1 exhibited the lowest average content. In general, the mutants exhibited similar concentrations of total soluble amino acids when compared to the wild-type lines, with the clear exception of mutants o11 and fl1, with the o11 mutant exhibiting a higher concentration of total soluble amino acids when compared to its wild-type counterpart W22 and the fl1 mutant a lower concentration when compared to its wild-type counterpart Oh43. For methionine, the mutants o2 and o11 and wild-type Oh43 exhibited the highest concentrations of this amino acid. Significant differences were not observed between mutants for other amino acids such as lysine and threonine. The high lysine concentrations obtained originally for these mutants may be due to the amino acids incorporated into storage proteins, but not those present in the soluble form.

  12. Amino Acid Catabolism in Alzheimer's Disease Brain: Friend or Foe?

    Science.gov (United States)

    2017-01-01

    There is a dire need to discover new targets for Alzheimer's disease (AD) drug development. Decreased neuronal glucose metabolism that occurs in AD brain could play a central role in disease progression. Little is known about the compensatory neuronal changes that occur to attempt to maintain energy homeostasis. In this review using the PubMed literature database, we summarize evidence that amino acid oxidation can temporarily compensate for the decreased glucose metabolism, but eventually altered amino acid and amino acid catabolite levels likely lead to toxicities contributing to AD progression. Because amino acids are involved in so many cellular metabolic and signaling pathways, the effects of altered amino acid metabolism in AD brain are far-reaching. Possible pathological results from changes in the levels of several important amino acids are discussed. Urea cycle function may be induced in endothelial cells of AD patient brains, possibly to remove excess ammonia produced from increased amino acid catabolism. Studying AD from a metabolic perspective provides new insights into AD pathogenesis and may lead to the discovery of dietary metabolite supplements that can partially compensate for alterations of enzymatic function to delay AD or alleviate some of the suffering caused by the disease. PMID:28261376

  13. Roux-en-Y Gastric Bypass Surgery, but Not Calorie Restriction, Reduces Plasma Branched-Chain Amino Acids in Obese Women Independent of Weight Loss or the Presence of Type 2 Diabetes

    NARCIS (Netherlands)

    Lips, M.A.; Klinken, J.B. van; Harmelen, V. van; Dharuri, H.K.; Hoen, P.A.C. 't; Laros, J.F.; Ommen, G.J.B. van; Janssen, I.M; Ramshorst, B. van; Wagensveld, B.A. van; Swank, D.J.; Dielen, F. Van; Dane, A.; Harms, A.; Vreeken, R.; Hankemeier, T.; Smit, J.W.A.; Pijl, H.; Dijk, K van

    2014-01-01

    OBJECTIVE: Obesity and type 2 diabetes mellitus (T2DM) have been associated with increased levels of circulating branched-chain amino acids (BCAAs) that may be involved in the pathogenesis of insulin resistance. However, weight loss has not been consistently associated with the reduction of BCAA

  14. Roux-en-Y Gastric Bypass Surgery, but Not Calorie Restriction, Reduces Plasma Branched-Chain Amino Acids in Obese Women Independent of Weight Loss or the Presence of Type 2 Diabetes

    NARCIS (Netherlands)

    Lips, M.A.; Klinken, J.B. van; Harmelen, V. van; Dharuri, H.K.; Hoen, P.A.C. 't; Laros, J.F.; Ommen, G.J.B. van; Janssen, I.M; Ramshorst, B. van; Wagensveld, B.A. van; Swank, D.J.; Dielen, F. Van; Dane, A.; Harms, A.; Vreeken, R.; Hankemeier, T.; Smit, J.W.A.; Pijl, H.; Dijk, K van

    2014-01-01

    OBJECTIVE: Obesity and type 2 diabetes mellitus (T2DM) have been associated with increased levels of circulating branched-chain amino acids (BCAAs) that may be involved in the pathogenesis of insulin resistance. However, weight loss has not been consistently associated with the reduction of BCAA lev

  15. Whey protein supplementation does not alter plasma branched-chained amino acid profiles but results in unique metabolomics patterns in obese women enrolled in an 8-week weight loss trial

    Science.gov (United States)

    Background: It has been suggested that perturbations in branched-chain amino acid (BCAA) catabolism are associated with insulin resistance and contribute to elevated systemic BCAAs. Evidence in rodents suggests dietary protein rich in BCAAs can increase BCAA catabolism, but there is limited evidence...

  16. A common periodic table of codons and amino acids.

    Science.gov (United States)

    Biro, J C; Benyó, B; Sansom, C; Szlávecz, A; Fördös, G; Micsik, T; Benyó, Z

    2003-06-27

    A periodic table of codons has been designed where the codons are in regular locations. The table has four fields (16 places in each) one with each of the four nucleotides (A, U, G, C) in the central codon position. Thus, AAA (lysine), UUU (phenylalanine), GGG (glycine), and CCC (proline) were placed into the corners of the fields as the main codons (and amino acids) of the fields. They were connected to each other by six axes. The resulting nucleic acid periodic table showed perfect axial symmetry for codons. The corresponding amino acid table also displaced periodicity regarding the biochemical properties (charge and hydropathy) of the 20 amino acids and the position of the stop signals. The table emphasizes the importance of the central nucleotide in the codons and predicts that purines control the charge while pyrimidines determine the polarity of the amino acids. This prediction was experimentally tested.

  17. Exhaustive Database Searching for Amino Acid Mutations in Proteomes

    Energy Technology Data Exchange (ETDEWEB)

    Hyatt, Philip Douglas [ORNL; Pan, Chongle [ORNL

    2012-01-01

    Amino acid mutations in proteins can be found by searching tandem mass spectra acquired in shotgun proteomics experiments against protein sequences predicted from genomes. Traditionally, unconstrained searches for amino acid mutations have been accomplished by using a sequence tagging approach that combines de novo sequencing with database searching. However, this approach is limited by the performance of de novo sequencing. The Sipros algorithm v2.0 was developed to perform unconstrained database searching using high-resolution tandem mass spectra by exhaustively enumerating all single non-isobaric mutations for every residue in a protein database. The performance of Sipros for amino acid mutation identification exceeded that of an established sequence tagging algorithm, Inspect, based on benchmarking results from a Rhodopseudomonas palustris proteomics dataset. To demonstrate the viability of the algorithm for meta-proteomics, Sipros was used to identify amino acid mutations in a natural microbial community in acid mine drainage.

  18. The origin of amino acids in lunar regolith samples

    Science.gov (United States)

    Elsila, Jamie E.; Callahan, Michael P.; Dworkin, Jason P.; Glavin, Daniel P.; McLain, Hannah L.; Noble, Sarah K.; Gibson, Everett K.

    2016-01-01

    We analyzed the amino acid content of seven lunar regolith samples returned by the Apollo 16 and Apollo 17 missions and stored under NASA curation since collection using ultrahigh-performance liquid chromatography with fluorescence detection and time-of-flight mass spectrometry. Consistent with results from initial analyses shortly after collection in the 1970s, we observed amino acids at low concentrations in all of the curated samples, ranging from 0.2 parts-per-billion (ppb) to 42.7 ppb in hot-water extracts and 14.5-651.1 ppb in 6 M HCl acid-vapor-hydrolyzed, hot-water extracts. Amino acids identified in the Apollo soil extracts include glycine, D- and L-alanine, D- and L-aspartic acid, D- and L-glutamic acid, D- and L-serine, L-threonine, and L-valine, all of which had previously been detected in lunar samples, as well as several compounds not previously identified in lunar regoliths: α-aminoisobutyric acid (AIB), D- and L-β-amino-n-butyric acid (β-ABA), DL-α-amino-n-butyric acid, γ-amino-n-butyric acid, β-alanine, and ε-amino-n-caproic acid. We observed an excess of the L enantiomer in most of the detected proteinogenic amino acids, but racemic alanine and racemic β-ABA were present in some samples. We also examined seven samples from Apollo 15, 16, and 17 that had been previously allocated to a non-curation laboratory, as well as two samples of terrestrial dunite from studies of lunar module engine exhaust that had been stored in the same laboratory. The amino acid content of these samples suggested that contamination had occurred during non-curatorial storage. We measured the compound-specific carbon isotopic ratios of glycine, β-alanine, and L-alanine in Apollo regolith sample 70011 and found values of -21‰ to -33‰. These values are consistent with those seen in terrestrial biology and, together with the enantiomeric compositions of the proteinogenic amino acids, suggest that terrestrial biological contamination is a primary source of the

  19. Metabolic Response of Pakchoi Leaves to Amino Acid Nitrogen

    Institute of Scientific and Technical Information of China (English)

    WANG Xiao-li; YU Wen-juan; ZHOU Qian; HAN Rui-feng; HUANG Dan-feng

    2014-01-01

    Different nitrogen (N) forms may cause changes in the metabolic profiles of plants. However, few studies have been conducted on the effects of amino acid-N on plant metabolic proifles. The main objective of this study was to identify primary metabolites associated with amino acid-N (Gly, Gln and Ala) through metabolic proifle analysis using gas chromatography-mass spectrometry (GC-MS). Plants of pakchoi (Brassica campestris L. ssp. chinensis L.), Huawang and Wuyueman cultivars, were grown with different nitrogen forms (i.e., Gly, Gln, Ala, NO3--N, and N starvation) applied under sterile hydroponic conditions. The fresh weight and plant N accumulation of Huawang were greater than those of Wuyueman, which indicates that the former exhibited better N-use efficiency than the latter. The physiological performances of the applied N forms were generally in the order of NO3--N>Gln>Gly>Ala. The metabolic analysis of leaf polar extracts revealed 30 amino acid N-responsive metabolites in the two pakchoi cultivars, mainly consisting of sugars, amino acids, and organic acids. Changes in the carbon metabolism of pakchoi leaves under amino acid treatments occurred via the accumulation of fructose, glucose, xylose, and arabinose. Disruption of amino acid metabolism resulted in accumulation of endogenous Gly in Gly treatment, Pro in Ala treatment, and Asn in three amino acid (Gly, Gln and Ala) treatments. By contrast, the levels of endogenous Gln and Leu decreased. However, this reduction varied among cultivars and amino acid types. Amino acid-N supply also affected the citric acid cycle, namely, the second stage of respiration, where leaves in Gly, Gln and Ala treatments contained low levels of malic, citric and succinic acids compared with leaves in NO3--N treatments. No signiifcant difference in the metabolic responses was observed between the two cultivars which differed in their capability to use N. The response of primary metabolites in pakchoi leaves to amino acid-N supply

  20. SIFT: Predicting amino acid changes that affect protein function.

    Science.gov (United States)

    Ng, Pauline C; Henikoff, Steven

    2003-07-01

    Single nucleotide polymorphism (SNP) studies and random mutagenesis projects identify amino acid substitutions in protein-coding regions. Each substitution has the potential to affect protein function. SIFT (Sorting Intolerant From Tolerant) is a program that predicts whether an amino acid substitution affects protein function so that users can prioritize substitutions for further study. We have shown that SIFT can distinguish between functionally neutral and deleterious amino acid changes in mutagenesis studies and on human polymorphisms. SIFT is available at http://blocks.fhcrc.org/sift/SIFT.html.

  1. PROTEINS, PEPTIDES AND AMINO ACIDS AS MARKERS OF BRONCHOPULMONARY DISEASES

    Directory of Open Access Journals (Sweden)

    V. I. Fyodorov

    2013-01-01

    Full Text Available The article is a review of current literature on a content of proteins, peptides and amino acids in human exhaled breath. The results of proteomics and metabolomics applying for selective detection of individual proteins, peptides and amino acids are described. The study of exhaled breath condensate and exhaled endogenous particles contained lung proteins are considered. The peculiarities of protein, peptide and amino acid content in exhaled breath at various respiratory diseases are described. It is shown that the detectable substances may be specific markers of individual diseases.

  2. Hybride magnetic nanostructure based on amino acids functionalized polypyrrole

    Science.gov (United States)

    Nan, Alexandrina; Bunge, Alexander; Turcu, Rodica

    2015-12-01

    Conducting polypyrrole is especially promising for many commercial applications because of its unique optical, electric, thermal and mechanical properties. We report the synthesis and characterization of novel pyrrole functionalized monomers and core-shell hybrid nanostructures, consisting of a conjugated polymer layer (amino acids functionalized pyrrole copolymers) and a magnetic nanoparticle core. For functionalization of the pyrrole monomer we used several amino acids: tryptophan, leucine, phenylalanine, serine and tyrosine. These amino acids were linked via different types of hydrophobic linkers to the nitrogen atom of the pyrrole monomer. The magnetic core-shell hybrid nanostructures are characterized by various methods such as FTIR spectroscopy, transmission electron microscopy (TEM) and magnetic measurements.

  3. Hybride magnetic nanostructure based on amino acids functionalized polypyrrole

    Energy Technology Data Exchange (ETDEWEB)

    Nan, Alexandrina, E-mail: alexandrina.nan@itim-cj.ro; Bunge, Alexander; Turcu, Rodica [National Institute for Research and Development of Isotopic and Molecular Technologies, 67-103 Donat, 400293 Cluj-Napoca (Romania)

    2015-12-23

    Conducting polypyrrole is especially promising for many commercial applications because of its unique optical, electric, thermal and mechanical properties. We report the synthesis and characterization of novel pyrrole functionalized monomers and core-shell hybrid nanostructures, consisting of a conjugated polymer layer (amino acids functionalized pyrrole copolymers) and a magnetic nanoparticle core. For functionalization of the pyrrole monomer we used several amino acids: tryptophan, leucine, phenylalanine, serine and tyrosine. These amino acids were linked via different types of hydrophobic linkers to the nitrogen atom of the pyrrole monomer. The magnetic core-shell hybrid nanostructures are characterized by various methods such as FTIR spectroscopy, transmission electron microscopy (TEM) and magnetic measurements.

  4. Amino acid metabolism during total parenteral nutrition in healthy volunteers: evaluation of a new amino acid solution.

    Science.gov (United States)

    Berard, M P; Hankard, R; Cynober, L

    2001-10-01

    The aim of this study was to determine the metabolism and the tolerance of a new amino acid (AA) solution administered under conditions mimicking cyclical parenteral nutrition (PN) in humans. Eight healthy volunteers received peripheral PN for 10 h providing 10.5 mg N x kg(-1) x h(-1) and 2.0 kcal x kg(-1) x h(-1) (glucose-to-lipids ratio: 70/30%). For adaptation, a non-protein energy intake was increased progressively for 90 min; thereafter, AA infusion was started and maintained at a constant rate for 10 h. Plasma and urine concentrations of all the AAs were measured before, during and after the PN. For each given AA, the relation between plasma variations at the steady-state and infusion rate, plasma clearance (Cl), renal clearance (Clr), re-absorption rate (Reab) and, retention rate (Reten) were determined. The nitrogen balance (DeltaN) was calculated during the PN period. The results are presented as means+/-sem. All plasma AA concentrations decreased during the starting period of non-protein energy intake. The plasma AA concentrations reached a steady-state within 3 h upon AA infusion, except for glycine and lysine (6 h). At the steady state, the plasma concentrations of the infused AAs were closely correlated to their infusion rate (y= -18.3+1.5x, r(2)=0.92). The plasma glutamine concentration was maintained during the PN, which indicates that the solution might stimulate the de novo synthesis of this AA. When the PN was stopped, plasma levels of the AAs decreased, most of them returning to their basal levels, or significantly below for lysine (Por= 99%, Reten >or=99% and for non-essential AAs: Cl or= 98% except glycine (95+/-1), aspartate (94+/-2) and histidine (94+/-1), Reten >or=97% except histidine (94+/-1), glycine (95+/-3). These results indicate that in healthy subjects, the amounts of AAs provided by the new solution were well balanced for an intravenous administration, and so were well utilized without excessive urinary excretion. The present study

  5. Exploring the Lean Phenotype of Glutathione-Depleted Mice: Thiol, Amino Acid and Fatty Acid Profiles

    Science.gov (United States)

    Elshorbagy, Amany K.; Jernerén, Fredrik; Scudamore, Cheryl L.; McMurray, Fiona; Cater, Heather; Hough, Tertius; Cox, Roger; Refsum, Helga

    2016-01-01

    Background Although reduced glutathione (rGSH) is decreased in obese mice and humans, block of GSH synthesis by buthionine sulfoximine (BSO) results in a lean, insulin-sensitive phenotype. Data is lacking about the effect of BSO on GSH precursors, cysteine and glutamate. Plasma total cysteine (tCys) is positively associated with stearoyl-coenzyme A desaturase (SCD) activity and adiposity in humans and animal models. Objective To explore the phenotype, amino acid and fatty acid profiles in BSO-treated mice. Design Male C3H/HeH mice aged 11 weeks were fed a high-fat diet with or without BSO in drinking water (30 mmol/L) for 8 weeks. Amino acid and fatty acid changes were assessed, as well as food consumption, energy expenditure, locomotor activity, body composition and liver vacuolation (steatosis). Results Despite higher food intake, BSO decreased particularly fat mass but also lean mass (both P<0.001), and prevented fatty liver vacuolation. Physical activity increased during the dark phase. BSO decreased plasma free fatty acids and enhanced insulin sensitivity. BSO did not alter liver rGSH, but decreased plasma total GSH (tGSH) and rGSH (by ~70%), and liver tGSH (by 82%). Glutamate accumulated in plasma and liver. Urine excretion of cysteine and its precursors was increased by BSO. tCys, rCys and cystine decreased in plasma (by 23–45%, P<0.001 for all), but were maintained in liver, at the expense of decreased taurine. Free and total plasma concentrations of the SCD products, oleic and palmitoleic acids were decreased (by 27–38%, P <0.001 for all). Conclusion Counterintuitively, block of GSH synthesis decreases circulating tCys, raising the question of whether the BSO-induced obesity-resistance is linked to cysteine depletion. Cysteine-supplementation of BSO-treated mice is warranted to dissect the effects of cysteine and GSH depletion on energy metabolism. PMID:27788147

  6. Esterification by the Plasma Acidic Water: Novel Application of Plasma Acid

    Science.gov (United States)

    Gu, Ling

    2014-03-01

    This work explores the possibility of plasma acid as acid catalyst in organic reactions. Plasma acidic water was prepared by dielectric barrier discharge and used to catalyze esterification of n-heptanioc acid with ethanol. It is found that the plasma acidic water has a stable and better performance than sulfuric acid, meaning that it is an excellent acid catalyst. The plasma acidic water would be a promising alternative for classic mineral acid as a more environment friendly acid.

  7. Transport of amino acids and GABA analogues via the human proton-coupled amino acid transporter, hPAT1

    DEFF Research Database (Denmark)

    Larsen, Mie; Larsen, Birger Brodin; Frølund, Bente

    2008-01-01

    The objective of this study was to investigate transepithelial amino acid transport as a function of Caco-2 cell culture time. Furthermore, the objective was to investigate apical uptake characteristics of hPAT1-mediated transport under various experimental conditions. Apical amino acid uptake......, which has been shown to function as a carboxylic acid bioisostere for substrates of the GABA receptor and transport systems....

  8. Method Development for Efficient Incorporation of Unnatural Amino Acids

    KAUST Repository

    Harris, Paul D.

    2014-04-01

    The synthesis of proteins bearing unnatural amino acids has the potential to enhance and elucidate many processes in biochemistry and molecular biology. There are two primary methods for site specific unnatural amino acid incorporation, both of which use the cell’s native protein translating machinery: in vitro chemical acylation of suppressor tRNAs and the use of orthogonal amino acyl tRNA synthetases. Total chemical synthesis is theoretically possible, but current methods severely limit the maximum size of the product protein. In vivo orthogonal synthetase methods suffer from the high cost of the unnatural amino acid. In this thesis I sought to address this limitation by increasing cell density, first in shake flasks and then in a bioreactor in order to increase the yield of protein per amount of unnatural amino acid used. In a parallel project, I used the in vitro chemical acylation system to incorporate several unnatural amino acids, key among them the fluorophore BODIPYFL, with the aim of producing site specifically fluorescently labeled protein for single molecule FRET studies. I demonstrated successful incorporation of these amino acids into the trial protein GFP, although incorporation was not demonstrated in the final target, FEN1. This also served to confirm the effectiveness of a new procedure developed for chemical acylation.

  9. Protective effect of squalene on certain lysosomal hydrolases and free amino acids in isoprenaline-induced myocardial infarction in rats

    DEFF Research Database (Denmark)

    Farvin, Sabeena; Surendraraj, A.; Anandan, R.

    2010-01-01

    This study was aimed to evaluate the preventive role of squalene on free amino acids and lysosomal alterations in experimentally induced myocardial infarction in rats. The levels of lysosomal enzymes (beta-glucuronidase, beta-galactosidase, beta-glucosidase, acid phosphatase and cathepsin D......) in plasma and lysosomal fractions, hydroxyproline content and free amino acids in heart tissue were determined. Isoprenaline administration to rats resulted in decreased stability of the membranes which was reflected by significantly (p...

  10. Polymers with complexing properties. Simple poly(amino acids)

    Science.gov (United States)

    Roque, J. M.

    1978-01-01

    The free amino (0.3 equiv/residue) and carboxyl (0.5 equiv/residue) groups of thermal polylysine increased dramatically on treatment with distilled water. The total hydrolysis of such a polymer was abnormal in that only about 50% of the expected amino acids were recovered. Poly (lysine-co-alanine-co-glycine) under usual conditions hydrolyzed completely in 8 hours; whereas, when it was pretreated with diazomethane, a normal period of 24 hours was required to give (nearly) the same amounts of each free amino acid as compared with those obtained from the untreated polymer. The amino groups of the basic thermal poly(amino acids) were sterically hindered. The existence of nitrogen atoms linking two or three chains and reactive groups (anhydride, imine) were proposed.

  11. Profiling analysis of amino acids from hyperlipidaemic rats treated with Gynostemma pentaphyllum and atorvastatin.

    Science.gov (United States)

    Wang, Yinan; Zhao, Min; Wang, Miao; Zhao, Chunjie

    2016-10-01

    Context Gynostemma pentaphyllum (Thunb.) Makino has been used in traditional medicine for the treatment of hyperlipidaemic with a long history. The objective of this study was to evaluate the influence of Gynostemma pentaphyllum (GP) and atorvastatin on amino acids from the plasma and liver tissue of hyperlipidaemic rats. Materials and methods The rats were fed a high-fat diet continuously for 11 weeks for the construction of hyperlipidaemic model. The hyperlipidaemic rats were treated with Gynostemma pentaphyllum (120 mg/kg) and atorvastatin (1.8 mg/kg) for 4 weeks, and the rats were intragastric administration one time every day. Chromatographic separation was performed on a Shim-pack XR-ODSIII C18 analytical column (75 mm × 2.0 mm i.d., 1.6 μm, Shmadazu Corp., Tokyo, Japan). The biomarkers of amino acids were identified by principal component analysis (PCA) and partial least squares discriminant analysis (PLS-DA). Results After feeding with a high-fat diet, the TC and LDL-C values of the hyperlipidaemic mode rats increased dramatically (p < 0.01). The established method allowed a target analysis of 12 kinds of amino acids. PCA studies showed that the plasma amino acids had not returned to normal after GP treatment, but those had recovered slightly after atorvastatin treatment. GP has almost no impact on the metabolism of amino acids, while atorvastatin can modify the metabolism of amino acids via self-regulatory mechanisms. Discussion and conclusion UPLC/DAD combined with SCX-SPE can be successfully used for profiling analysis of amino acids. By the comparison of biomarkers following treatment with GP and atorvastatin, the influence of the two drugs on biomarkers is revealed.

  12. Continuous enteral administration can enable normal amino acid absorption in rats with methotrexate-induced gastrointestinal mucositis

    NARCIS (Netherlands)

    M. Fijlstra (Margot); H. Schierbeek (Henk); G.J. Voortman (Gardi); K.Y. Dorst (Kristien); J.B. van Goudoever (Hans); E.H.H.M. Rings (Edmond); W.J.E. Tissing (Wim)

    2012-01-01

    textabstractIt is unknown what feeding strategy to use during chemotherapy-induced gastrointestinal mucositis, which causes weight loss and possibly malabsorption. To study the absorptive capacity of amino acids during mucositis, we determined the plasma availability of enterally administered amino

  13. Searching for Extraterrestrial Amino Acids in a Contaminated Meteorite: Amino Acid Analyses of the Canakkale L6 Chondrite

    Science.gov (United States)

    Burton, A. S.; Elsila, J. E.; Glavin, D. P.; Dworkin, J. P.; Ornek, C. Y.; Esenoglu, H. H.; Unsalan, O.; Ozturk, B.

    2016-01-01

    Amino acids can serve as important markers of cosmochemistry, as their abundances and isomeric and isotopic compositions have been found to vary predictably with changes in parent body chemistry and alteration processes. Amino acids are also of astrobiological interest because they are essential for life on Earth. Analyses of a range of meteorites, including all groups of carbonaceous chondrites, along with H, R, and LL chondrites, ureilites, and a martian shergottite, have revealed that amino acids of plausible extraterrestrial origin can be formed in and persist after a wide range of parent body conditions. However, amino acid analyses of L6 chondrites to date have not provided evidence for indigenous amino acids. In the present study, we performed amino acid analysis on larger samples of a different L6 chondite, Canakkale, to determine whether or not trace levels of indigenous amino acids could be found. The Canakkale meteor was an observed fall in late July, 1964, near Canakkale, Turkey. The meteorite samples (1.36 and 1.09 g) analyzed in this study were allocated by C. Y. Ornek, along with a soil sample (1.5 g) collected near the Canakkale recovery site.

  14. Molecular cloning of mouse amino acid transport system B0, a neutral amino acid transporter related to Hartnup disorder.

    Science.gov (United States)

    Bröer, Angelika; Klingel, Karin; Kowalczuk, Sonja; Rasko, John E J; Cavanaugh, Juleen; Bröer, Stefan

    2004-06-04

    Resorption of amino acids in kidney and intestine is mediated by transporters, which prefer groups of amino acids with similar physico-chemical properties. It is generally assumed that most neutral amino acids are transported across the apical membrane of epithelial cells by system B(0). Here we have characterized a novel member of the Na(+)-dependent neurotransmitter transporter family (B(0)AT1) isolated from mouse kidney, which shows all properties of system B(0). Flux experiments showed that the transporter is Na(+)-dependent, electrogenic, and actively transports most neutral amino acids but not anionic or cationic amino acids. Superfusion of mB(0)AT1-expressing oocytes with neutral amino acids generated inward currents, which were proportional to the fluxes observed with labeled amino acids. In situ hybridization showed strong expression in intestinal microvilli and in the proximal tubule of the kidney. Expression of mouse B(0)AT1 was restricted to kidney, intestine, and skin. It is generally assumed that mutations of the system B(0) transporter underlie autosomal recessive Hartnup disorder. In support of this notion mB(0)AT1 is located on mouse chromosome 13 in a region syntenic to human chromosome 5p15, the locus of Hartnup disorder. Thus, the human homologue of this transporter is an excellent functional and positional candidate for Hartnup disorder.

  15. Sequential-injection on-line preconcentration using chitosan resin functionalized with 2-amino-5-hydroxy benzoic acid for the determination of trace elements in environmental water samples by inductively coupled plasma-atomic emission spectrometry

    OpenAIRE

    2007-01-01

    A new chelating resin using chitosan as a base material was synthesized. Functional moiety of 2-amino-5-hydroxy benzoic acid (AHBA) was chemically bonded to the amino group of cross-linked chitosan (CCTS) through the arm of chloromethyloxirane (CCTS-AHBA resin). Several elements, such as Ag, Be, Cd, Co, Cu, Ni, Ph, U, V, and rare earth elements (REEs), could be adsorbed on the resin. To use the resin for on-line pretreatment, the resin was packed in a mini-column and installed into a sequenti...

  16. Comparison of the amino acid and peptide composition and postprandial response of beef, hydrolyzed chicken, and whey protein nutritional preparations

    Directory of Open Access Journals (Sweden)

    Christopher J. Detzel

    2016-10-01

    Full Text Available Background: Increasing dietary protein intake synergistically improves the effect of exercise to stimulate muscle protein synthesis. The purpose of this study was to evaluate the plasma amino acid response of two novel protein nutritional preparations, beef protein isolate (BeefISO™ and hydrolyzed chicken protein isolate (MyoCHX™. Methods: The postprandial plasma amino acid response over 3 hours was monitored in young adults (n=6 following consumption of 23 grams of WPC, BeefISO™, or MyoCHX™. Amino acid compositional analysis and molecular weight distributions of each protein were performed by HPLC. Statistical analyses were performed using one-way or two-way ANOVA where appropriate and corrected for multiple comparisons to account for the cross-over design. Results: Compositional evaluations revealed similar levels of essential and branched-chain amino acids for WPC and MyoCHX™. While the results of this study predictably demonstrated plasma amino acids levels increased following consumption of the different proteins, the kinetics of the postprandial response was unique to each protein source. WPC and MyoCHX™ were rapidly absorbed with maximum plasma amino acid concentrations observed at 30 and 15 min, respectively. The slightly faster absorption of MyoCHX™ was associated with the increased peptide content of MyoCHX™ (greater than 76% of protein is <2kDa. BeefISO™ exhibited sustained release characteristics as evidenced by increased post prandial amino acid concentrations after 3 hours. Conclusions: The protein preparations studied each had different amino acid profiles and absorption kinetics. WPC and MyoCHX™ contained a higher essential amino acid content and were rapidly absorbed with plasma amino acid concentrations peaking within 30 minutes following consumption. BeefISO™ contained a higher proportion of conditionally essential amino acids that steadily increased in plasma over 3 hours, indicating a sustained release

  17. The Amino Acid Composition of the Sutter's Mill Carbonaceous Chondrite

    Science.gov (United States)

    Glavin, D. P.; Burton, A. S.; Elsila, J. E.; Dworkin, J. P.; Yin, Q. Z.; Cooper, G.; Jenniskens, P.

    2012-01-01

    In contrast to the Murchison meteorite which had a complex distribution of amino acids with a total C2 to Cs amino acid abundance of approx.14,000 parts-per-billion (ppb) [2], the Sutters Mill meteorite was found to be highly depleted in amino acids. Much lower abundances (approx.30 to 180 ppb) of glycine, beta-alanine, L-alanine and L-serine were detected in SM2 above procedural blank levels indicating that this meteorite sample experienced only minimal terrestrial amino acid contamination after its fall to Earth. Carbon isotope measurements will be necessary to establish the origin of glycine and beta-alanine in SM2. Other non-protein amino acids that are rare on Earth, yet commonly found in other CM meteorites such as aaminoisobutyric acid (alpha-AIB) and isovaline, were not identified in SM2. However, traces of beta-AIB (approx.1 ppb) were detected in SM2 and could be" extraterrestrial in origin. The low abundances of amino acids in the Sutter's Mill meteorite is consistent with mineralogical evidence that at least some parts of the Sutter's Mill meteorite parent body experienced extensive aqueous and/or thermal alteration.

  18. Updates on industrial production of amino acids using Corynebacterium glutamicum.

    Science.gov (United States)

    Wendisch, Volker F; Jorge, João M P; Pérez-García, Fernando; Sgobba, Elvira

    2016-06-01

    L-Amino acids find various applications in biotechnology. L-Glutamic acid and its salts are used as flavor enhancers. Other L-amino acids are used as food or feed additives, in parenteral nutrition or as building blocks for the chemical and pharmaceutical industries. L-amino acids are synthesized from precursors of central carbon metabolism. Based on the knowledge of the biochemical pathways microbial fermentation processes of food, feed and pharma amino acids have been developed. Production strains of Corynebacterium glutamicum, which has been used safely for more than 50 years in food biotechnology, and Escherichia coli are constantly improved using metabolic engineering approaches. Research towards new processes is ongoing. Fermentative production of L-amino acids in the million-ton-scale has shaped modern biotechnology and its markets continue to grow steadily. This review focusses on recent achievements in strain development for amino acid production including the use of CRISPRi/dCas9, genome-reduced strains, biosensors and synthetic pathways to enable utilization of alternative carbon sources.

  19. Covalently functionalized graphene sheets with biocompatible natural amino acids

    Energy Technology Data Exchange (ETDEWEB)

    Mallakpour, Shadpour, E-mail: mallak@cc.iut.ac.ir [Organic Polymer Chemistry Research Laboratory, Department of Chemistry, Isfahan University of Technology, Isfahan, 84156-83111, Islamic Republic of Iran (Iran, Islamic Republic of); Nanotechnology and Advanced Materials Institute, Isfahan University of Technology, Isfahan, 84156-83111, Islamic Republic of Iran (Iran, Islamic Republic of); Abdolmaleki, Amir, E-mail: abdolmaleki@cc.iut.ac.ir [Organic Polymer Chemistry Research Laboratory, Department of Chemistry, Isfahan University of Technology, Isfahan, 84156-83111, Islamic Republic of Iran (Iran, Islamic Republic of); Nanotechnology and Advanced Materials Institute, Isfahan University of Technology, Isfahan, 84156-83111, Islamic Republic of Iran (Iran, Islamic Republic of); Borandeh, Sedigheh [Organic Polymer Chemistry Research Laboratory, Department of Chemistry, Isfahan University of Technology, Isfahan, 84156-83111, Islamic Republic of Iran (Iran, Islamic Republic of)

    2014-07-01

    Graphene sheets were covalently functionalized with aromatic–aliphatic amino acids (phenylalanine and tyrosine) and aliphatic amino acids (alanine, isoleucine, leucine, methionine and valine) by simple and green procedure. For this aim, at first natural graphite was converted into graphene oxide (GO) through strong oxidation procedure; then, based on the surface-exposed epoxy and carboxylic acid groups in GO solid, its surface modification with naturally occurring amino acids, occurred easily throughout the corresponding nucleophilic substitution and condensation reactions. Amino acid functionalized graphene demonstrates stable dispersion in water and common organic solvents. Fourier transform infrared, Raman and X-ray photoelectron spectroscopies, X-ray diffraction, field emission scanning electron microscopy and transmission electron microscopy were used to investigate the nanostructures and properties of prepared materials. Each amino acid has different considerable effects on the structure and morphology of the pure graphite, from increasing the layer spacing to layer scrolling, based on their structures, functional groups and chain length. In addition, therogravimetric analysis was used for demonstrating a successful grafting of amino acid molecules to the surface of graphene.

  20. Profile of Fatty Acids, Amino Acids, Carotenoid Total, and α-Tocopherol from Flying Fish Eggs

    Directory of Open Access Journals (Sweden)

    Aulia Azka

    2015-12-01

    Full Text Available Flying fish are found in waters of eastern Indonesia, which until now is still limited information about nutritional content. The purpose of this research was determine the composition of fatty acids, amino acids, total carotenoids, α-tocopherol flying fish eggs (Hyrundicthys sp.. The composition of fatty acid was measured by gas chromatography (GC, while amino acids, total carotenoids, α-tocopherol was measured by High performanced Liquid Chromatography (HPLC. Egg contained 22 fatty acids such as saturated fatty acid 29.71%, monounsaturated fatty acid 7.86%, and polysaturated fatty acid 13.64%. The result showed that eggs flying fish contained 17 amino acids, such as essential amino acid 14.96% and non-essential amino acids 20.27%. Eggs contained a total carotenoid of 245.37 ppm. α-tocopherol content of flying fish eggs by 1.06 ppm.

  1. Sugar amino acids and related molecules: Some recent developments

    Indian Academy of Sciences (India)

    Tushar Kanti Chakraborty; Pothukanuri Srinivasu; Subhasish Tapadar; Bajjuri Krishna Mohan

    2004-06-01

    To meet the growing demands for the development of new molecular entities for discovering new drugs and materials, organic chemists have started working on many new concepts that can help to assimilate knowledge-based structural diversities more efficiently than ever before. Emulating the basic principles followed by Nature to build its vast repertoire of biomolecules, organic chemists are developing many novel multifunctional building blocks and using them to create `nature-like’ and yet unnatural organic molecules. Sugar amino acids constitute an important class of such polyfunctional scaffolds where the carboxyl, amino and hydroxyl termini provide an excellent opportunity to organic chemists to create structural diversities akin to Nature’s molecular arsenal. In recent years, sugar amino acids have been used extensively in the area of peptidomimetic studies. Advances made in the area of combinatorial chemistry can provide the necessary technological support for rapid compilations of sugar amino acidbased libraries exploiting the diversities of their carbohydrate frameworks and well-developed solidphase peptide synthesis methods. This perspective article chronicles some of the recent applications of various sugar amino acids, furan amino acids, pyrrole amino acids etc. and many other related building blocks in wide-ranging peptidomimetic studies.

  2. Swarming modulatory effects of some amino acids on Proteus ...

    African Journals Online (AJOL)

    TonukariJ

    Key words: Proteus strains, swarming motility, amino acids, Lagos. INTRODUCTION ... motility on nutrient and blood agar media were recruited for study. They were ... determine the concentration of total protein secreted by the Proteus strains ...

  3. Amino acid requirements of South African Mutton Merino lambs

    African Journals Online (AJOL)

    1998-11-15

    Nov 15, 1998 ... Duodenal and whole empty body essential amino acid profile ... determining growth requirements of the South African Mutton ... to only a limited extent in the liver and thus their concentration in the extra hepatic blood circula-.

  4. Enzymatic stereoselective synthesis of B-amino acids

    CSIR Research Space (South Africa)

    Chhiba, V

    2014-06-01

    Full Text Available , antimicrobials, and as nonstandard amino acids in therapeutic peptides or peptidomimetics. Access to these compounds can be achieved through diverse synthetic routes with enantioselective steps catalyzed in different ways, including by means of nitrile hydrolysis...

  5. Amino acids production focusing on fermentation technologies – A review

    DEFF Research Database (Denmark)

    D'Este, Martina; Alvarado-Morales, Merlin; Angelidaki, Irini

    2017-01-01

    Amino acids are attractive and promising biochemicals with market capacity requirements constantly increasing. Their applicability ranges from animal feed additives, flavour enhancers and ingredients in cosmetic to specialty nutrients in pharmaceutical and medical fields. This review gives...... an overview of the processes applied for amino acids production and points out the main advantages and disadvantages of each. Due to the advances made in the genetic engineering techniques, the biotechnological processes, and in particular the fermentation with the aid of strains such as Corynebacterium...... glutamicum or Escherichia coli, play a significant role in the industrial production of amino acids. Despite the numerous advantages of the fermentative amino acids production, the process still needs significant improvements leading to increased productivity and reduction of the production costs. Although...

  6. Amyloid Aggregates Arise from Amino Acid Condensations under Prebiotic Conditions.

    Science.gov (United States)

    Greenwald, Jason; Friedmann, Michael P; Riek, Roland

    2016-09-12

    Current theories on the origin of life reveal significant gaps in our understanding of the mechanisms that allowed simple chemical precursors to coalesce into the complex polymers that are needed to sustain life. The volcanic gas carbonyl sulfide (COS) is known to catalyze the condensation of amino acids under aqueous conditions, but the reported di-, tri-, and tetra-peptides are too short to support a regular tertiary structure. Here, we demonstrate that alanine and valine, two of the proteinogenic amino acids believed to have been among the most abundant on a prebiotic earth, can polymerize into peptides and subsequently assemble into ordered amyloid fibers comprising a cross-β-sheet quaternary structure following COS-activated continuous polymerization of as little as 1 mm amino acid. Furthermore, this spontaneous assembly is not limited to pure amino acids, since mixtures of glycine, alanine, aspartate, and valine yield similar structures.

  7. Protein evolution via amino acid and codon elimination

    DEFF Research Database (Denmark)

    Goltermann, Lise; Larsen, Marie Sofie Yoo; Banerjee, Rajat;

    2010-01-01

    BACKGROUND: Global residue-specific amino acid mutagenesis can provide important biological insight and generate proteins with altered properties, but at the risk of protein misfolding. Further, targeted libraries are usually restricted to a handful of amino acids because there is an exponential...... correlation between the number of residues randomized and the size of the resulting ensemble. Using GFP as the model protein, we present a strategy, termed protein evolution via amino acid and codon elimination, through which simplified, native-like polypeptides encoded by a reduced genetic code were obtained...... simultaneously), while retaining varying levels of activity. Combination of these substitutions to generate a Phe-free variant of GFP abolished fluorescence. Combinatorial re-introduction of five Phe residues, based on the activities of the respective single amino acid replacements, was sufficient to restore GFP...

  8. Comparing Amino Acid Abundances and Distributions Across Carbonaceous Chondrite Groups

    Science.gov (United States)

    Burton, Aaron S.; Callahan, Michael P.; Glavin, Daniel P.; Elsila, Jamie E.; Dworkin, Jason P.

    2012-01-01

    Meteorites are grouped according to bulk properties such as chemical composition and mineralogy. These parameters can vary significantly among the different carbonaceous chondrite groups (CI, CM, CO, CR, CH, CB, CV and CK). We have determined the amino acid abundances of more than 30 primary amino acids in meteorites from each of the eight groups, revealing several interesting trends. There are noticeable differences in the structural diversity and overall abundances of amino acids between meteorites from the different chondrite groups. Because meteorites may have been an important source of amino acids to the prebiotic Earth and these organic compounds are essential for life as we know it, the observed variations of these molecules may have been important for the origins of life.

  9. Excitatory amino acid transporters as potential drug targets

    DEFF Research Database (Denmark)

    Bunch, Lennart; Erichsen, Mette Navy; Jensen, Anders Asbjørn

    2009-01-01

    BACKGROUND: Excitatory amino acid transporters (EAATs) are transmembrane proteins responsible for the uptake of (S)-glutamate (Glu) from the synaptic cleft, thereby terminating the glutamatergic neurotransmitter signal. Today five subtypes have been identified. Except for EAAT2, their individual...

  10. Detection of COL III in Parchment by Amino Acid Analysis

    DEFF Research Database (Denmark)

    Vestergaard Poulsen Sommer, Dorte; Larsen, René

    2016-01-01

    Cultural heritage parchments made from the reticular dermis of animals have been subject to studies of deterioration and conservation by amino acid analysis. The reticular dermis contains a varying mixture of collagen I and III (COL I and III). When dealing with the results of the amino acid...... analyses, till now the COL III content has not been taken into account. Based on the available amino acid sequences we present a method for determining the amount of COL III in the reticular dermis of new and historical parchments calculated from the ratio of Ile/Val. We find COL III contents between 7...... and 32 % in new parchments and between 0.2 and 40 % in the historical parchments. This is consistent with results in the literature. The varying content of COL III has a significant influence on the uncertainty of the amino acid analysis. Although we have not found a simple correlation between the COL...

  11. Determination of Proximate Composition and Amino Acid Profile of ...

    African Journals Online (AJOL)

    Johnny

    essential amino acids needed for enhanced nutrition. ... Edible seeds are important sources of nutrients and energy especially among the ... Likewise, edible seeds can sustain livestock production by ensuring the availability of various sources ...

  12. NMR analysis of unnatural amino acids in natural antibiotics.

    Science.gov (United States)

    Castiglione, Franca

    2012-01-01

    A large number of modified amino acids other than the canonical amino acid residues can be found in natural products, especially antibiotics. The structure of these peptide-based compounds is investigated using modern two-dimensional NMR techniques. The automatic assignment of the 2D NMR proton spectra and consequent determination of the primary and 3D structure of peptides or small size proteins containing natural amino acids is nowadays routine. However, a deficiency in the ability to readily sequence peptides containing unnatural amino acids still remains and a great human effort and time is required. The experimental methods and the protocols of manual analysis of the data are described in the following sections.

  13. Azide- and alkyne-derivatised α-amino acids

    DEFF Research Database (Denmark)

    Johansson, Karl Henrik; Pedersen, D.S.

    2012-01-01

    With the emergence of the copper-catalysed Huisgen cycloaddition the use of azide- and alkyne-derivatised α-amino acids has found widespread use within most chemistry disciplines. Despite a growing interest in these building blocks researchers are struggling to identify the best way...... for their synthesis. In this review we have compiled available methods for synthesising optically active azide- and alkyne-derivatised α-amino acids that can be prepared from readily available α-amino acids. We highlight a number of commonly overlooked problems associated with existing methods and direct attention...... to unexplored possibilities. Azide- and alkyne-derivatised α-amino acids are finding widespread use within most chemistry disciplines. However, it is far from clear what the best way for the synthesis of these useful building blocks is. Herein we show the available methods for synthesis of optically active...

  14. Chemical Approaches to Studying Labile Amino Acid Phosphorylation.

    Science.gov (United States)

    Marmelstein, Alan M; Moreno, Javier; Fiedler, Dorothea

    2017-04-01

    Phosphorylation of serine, threonine, and tyrosine residues is the archetypal posttranslational modification of proteins. While phosphorylation of these residues has become standard textbook knowledge, phosphorylation of other amino acid side chains is underappreciated and minimally characterized by comparison. This disparity is rooted in the relative instability of these chemically distinct amino acid side chain moieties, namely phosphoramidates, acyl phosphates, thiophosphates, and phosphoanhydrides. In the case of the O-phosphorylated amino acids, synthetic constructs were critical to assessing their stability and developing tools for their study. As the chemical biology community has become more aware of these alternative phosphorylation sites, methodology has been developed for the synthesis of well-characterized standards and close mimics of these phosphorylated amino acids as well. In this article, we review the synthetic chemistry that is a prerequisite to progress in this field.

  15. Disturbed amino acid metabolism in HIV: association with neuropsychiatric symptoms

    Directory of Open Access Journals (Sweden)

    Johanna M Gostner

    2015-07-01

    Full Text Available Blood levels of the amino acid phenylalanine, as well as of the tryptophan breakdown product kynurenine, are found to be elevated in human immunodeficiency virus type 1 (HIV-1-infected patients. Both essential amino acids, tryptophan and phenylalanine are important precursor molecules for neurotransmitter biosynthesis. Thus, dysregulated amino acid metabolism may be related to disease-associated neuropsychiatric symptoms such as development of depression, fatigue, and cognitive impairment.Increased phenylalanine/tyrosine and kynurenine/tryptophan ratios are associated with immune activation in patients with HIV-1 infection and decrease upon effective antiretroviral therapy. Recent large-scale metabolic studies have confirmed the crucial involvement of tryptophan and phenylalanine metabolism in HIV-associated disease. Herein, we summarize the current status of the role of tryptophan and phenylalanine metabolism in HIV disease and discuss how inflammatory stress-associated dysregulation of amino acid metabolism may be part of the pathophysiology of common HIV-associated neuropsychiatric conditions.

  16. Synthesis and catalytic application of amino acid based dendritic macromolecules

    NARCIS (Netherlands)

    Koten, G. van; Gossage, R.A.; Jastrzebski, J.T.B.H.; Ameijde, J. van; Mulders, S.J.E.; Brouwer, Arwin J.; Liskamp, R.M.J.

    1999-01-01

    The use of amino acid based dendrimers as molecular scaffolds for the attachment of catalytically active organometallic Ni ''pincer'' complexes, via a urea functionality, is described; the dendrimer catalysts have comparable activity to their mononuclear (NCN)NiX analogues.

  17. Astrobionibbler: In Situ Microfluidic Subcritical Water Extraction of Amino Acids

    Science.gov (United States)

    Noell, A. C.; Fisher, A. M.; Takano, N.; Fors-Francis, K.; Sherrit, S.; Grunthaner, F.

    2016-10-01

    A fluidic-chip based instrument for subcritical water extraction (SCWE) of amino acids and other organics from powder samples has been developed. A variety of soil analog extractions have been performed to better understand SCWE capabilities.

  18. Comparison of amino acids interaction with gold nanoparticle.

    Science.gov (United States)

    Ramezani, Fatemeh; Amanlou, Massoud; Rafii-Tabar, Hashem

    2014-04-01

    The study of nanomaterial/biomolecule interface is an important emerging field in bionanoscience, and additionally in many biological processes such as hard-tissue growth and cell-surface adhesion. To have a deeper understanding of the amino acids/gold nanoparticle assemblies, the adsorption of these amino acids on the gold nanoparticles (GNPs) has been investigated via molecular dynamics simulation. In these simulations, all the constituent atoms of the nanoparticles were considered to be dynamic. The geometries of amino acids, when adsorbed on the nanoparticle, were studied and their flexibilities were compared with one another. The interaction of each of 20 amino acids was considered with 3 and 8 nm gold GNPs.

  19. Inhibitors of amino acids biosynthesis as antifungal agents.

    Science.gov (United States)

    Jastrzębowska, Kamila; Gabriel, Iwona

    2015-02-01

    Fungal microorganisms, including the human pathogenic yeast and filamentous fungi, are able to synthesize all proteinogenic amino acids, including nine that are essential for humans. A number of enzymes catalyzing particular steps of human-essential amino acid biosynthesis are fungi specific. Numerous studies have shown that auxotrophic mutants of human pathogenic fungi impaired in biosynthesis of particular amino acids exhibit growth defect or at least reduced virulence under in vivo conditions. Several chemical compounds inhibiting activity of one of these enzymes exhibit good antifungal in vitro activity in minimal growth media, which is not always confirmed under in vivo conditions. This article provides a comprehensive overview of the present knowledge on pathways of amino acids biosynthesis in fungi, with a special emphasis put on enzymes catalyzing particular steps of these pathways as potential targets for antifungal chemotherapy.

  20. Expression of heteromeric amino acid transporters along the murine intestine.

    Science.gov (United States)

    Dave, Mital H; Schulz, Nicole; Zecevic, Marija; Wagner, Carsten A; Verrey, Francois

    2004-07-15

    Members of the new heterodimeric amino acid transporter family are composed of two subunits, a catalytic multitransmembrane spanning protein (light chain) and a type II glycoprotein (heavy chain). These transporters function as exchangers and thereby extend the transmembrane amino acid transport selectivity to specific amino acids. The heavy chain rBAT associates with the light chain b degrees (,+)AT to form a cystine and cationic amino acid transporter. The other heavy chain, 4F2hc, can interact with seven different light chains to form various transporters corresponding to systems L, y(+)L, asc or x(-)(c). The importance of some of these transporters in intestinal and renal (re)absorption of amino acids is highlighted by the fact that mutations in either the rBAT or b degrees (,+)AT subunit result in cystinuria whereas a defect in the y(+)-LAT1 light chain causes lysinuric protein intolerance. Here we investigated the localization of these transporters in intestine since both diseases are also characterized by altered intestinal amino acid absorption. Real time PCR showed organ-specific expression patterns for all transporter subunit mRNAs along the intestine and Western blotting confirmed these findings on the protein level. Immunohistochemistry demonstrated basolateral coexpression of 4F2hc, LAT2 and y(+)-LAT1 in stomach and small intestine, whereas rBAT and b degrees (,+)AT were found colocalizing on the apical side of small intestine epithelium. In stomach, 4F2hc and LAT2 were localized in H(+)/K(+)-ATPase-expressing parietal cells. The abundant expression of several members of the heterodimeric transporter family along the murine small intestine suggests their involvement in amino acids absorption. Furthermore, strong expression of rBAT, b degrees (,+)AT and y(+)-LAT1 in the small intestine explains the reduced intestinal absorption of some amino acid in patients with cystinuria or lysinuric protein intolerance.

  1. Genetic code correlations - Amino acids and their anticodon nucleotides

    Science.gov (United States)

    Weber, A. L.; Lacey, J. C., Jr.

    1978-01-01

    The data here show direct correlations between both the hydrophobicity and the hydrophilicity of the homocodonic amino acids and their anticodon nucleotides. While the differences between properties of uracil and cytosine derivatives are small, further data show that uracil has an affinity for charged species. Although these data suggest that molecular relationships between amino acids and anticodons were responsible for the origin of the code, it is not clear what the mechanism of the origin might have been.

  2. Co2 chemosorption by functionalized amino acid derivatives

    DEFF Research Database (Denmark)

    2015-01-01

    The absorption and desorption behaviour of carbon dioxide (CO2) using a composition comprising an ionic compound comprising a cation [A+] and an anion [B-] is described, wherein the anion [B-] is a mono-amine functionalized amino acid.......The absorption and desorption behaviour of carbon dioxide (CO2) using a composition comprising an ionic compound comprising a cation [A+] and an anion [B-] is described, wherein the anion [B-] is a mono-amine functionalized amino acid....

  3. Stereoselective synthesis of unsaturated α-amino acids.

    Science.gov (United States)

    Fanelli, Roberto; Jeanne-Julien, Louis; René, Adeline; Martinez, Jean; Cavelier, Florine

    2015-06-01

    Stereoselective synthesis of unsaturated α-amino acids was performed by asymmetric alkylation. Two methods were investigated and their enantiomeric excess measured and compared. The first route consisted of an enantioselective approach induced by the Corey-Lygo catalyst under chiral phase transfer conditions while the second one involved the hydroxypinanone chiral auxiliary, both implicating Schiff bases as substrate. In all cases, the use of a prochiral Schiff base gave higher enantiomeric excess and yield in the final desired amino acid.

  4. Amino acid modifiers in guayule rubber compounds

    Science.gov (United States)

    Tire producers are increasingly interested in biobased materials, including rubber but also as compounding chemicals. An alternative natural rubber for tire use is produced by guayule, a woody desert shrub native to North America. Alternative compounding chemicals include naturally-occurring amino a...

  5. Did Evolution Select a Nonrandom "Alphabet" of Amino Acids?

    Science.gov (United States)

    Philip, Gayle K.; Freeland, Stephen J.

    2011-04-01

    The last universal common ancestor of contemporary biology (LUCA) used a precise set of 20 amino acids as a standard alphabet with which to build genetically encoded protein polymers. Considerable evidence indicates that some of these amino acids were present through nonbiological syntheses prior to the origin of life, while the rest evolved as inventions of early metabolism. However, the same evidence indicates that many alternatives were also available, which highlights the question: what factors led biological evolution on our planet to define its standard alphabet? One possibility is that natural selection favored a set of amino acids that exhibits clear, nonrandom properties - a set of especially useful building blocks. However, previous analysis that tested whether the standard alphabet comprises amino acids with unusually high variance in size, charge, and hydrophobicity (properties that govern what protein structures and functions can be constructed) failed to clearly distinguish evolution's choice from a sample of randomly chosen alternatives. Here, we demonstrate unambiguous support for a refined hypothesis: that an optimal set of amino acids would spread evenly across a broad range of values for each fundamental property. Specifically, we show that the standard set of 20 amino acids represents the possible spectra of size, charge, and hydrophobicity more broadly and more evenly than can be explained by chance alone.

  6. D-Amino Acids in the Nervous and Endocrine Systems

    Directory of Open Access Journals (Sweden)

    Yoshimitsu Kiriyama

    2016-01-01

    Full Text Available Amino acids are important components for peptides and proteins and act as signal transmitters. Only L-amino acids have been considered necessary in mammals, including humans. However, diverse D-amino acids, such as D-serine, D-aspartate, D-alanine, and D-cysteine, are found in mammals. Physiological roles of these D-amino acids not only in the nervous system but also in the endocrine system are being gradually revealed. N-Methyl-D-aspartate (NMDA receptors are associated with learning and memory. D-Serine, D-aspartate, and D-alanine can all bind to NMDA receptors. H2S generated from D-cysteine reduces disulfide bonds in receptors and potentiates their activity. Aberrant receptor activity is related to diseases of the central nervous system (CNS, such as Alzheimer’s disease, amyotrophic lateral sclerosis, and schizophrenia. Furthermore, D-amino acids are detected in parts of the endocrine system, such as the pineal gland, hypothalamus, pituitary gland, pancreas, adrenal gland, and testis. D-Aspartate is being investigated for the regulation of hormone release from various endocrine organs. Here we focused on recent findings regarding the synthesis and physiological functions of D-amino acids in the nervous and endocrine systems.

  7. Release of selected amino acids from zinc carriers

    Directory of Open Access Journals (Sweden)

    Dyja Renata

    2016-06-01

    Full Text Available The paper deals with the results of an investigation of the release of selected amino acids (histidine, tryptophan, tyrosine from model suspensions prepared by co-precipitation with zinc chloride. It has been proven that the influence of the Zn(II/amino acid molar ratio on dissolution profiles of the tested amino acids and dissolution half-life (t1/2 of histidine or tryptophan is significant. The amount of amino acid in the dispersed phase (supporting dose is a determinant of the amino acid release profile. There is a minimal supporting dose (30.0 μmol of histidine or 17.4 μmol of tryptophan that provides release of similar amounts of amino acid (4.1–4.6 μmol of histidine or 8.7–9.9 μmol of tryptophan after the same time intervals. The tyrosine release profiles follow first order kinetics since the supporting dose (0.9–11.2 μmol is limited by the tyrosine low solubility in water.

  8. Computational protein design quantifies structural constraints on amino acid covariation.

    Directory of Open Access Journals (Sweden)

    Noah Ollikainen

    Full Text Available Amino acid covariation, where the identities of amino acids at different sequence positions are correlated, is a hallmark of naturally occurring proteins. This covariation can arise from multiple factors, including selective pressures for maintaining protein structure, requirements imposed by a specific function, or from phylogenetic sampling bias. Here we employed flexible backbone computational protein design to quantify the extent to which protein structure has constrained amino acid covariation for 40 diverse protein domains. We find significant similarities between the amino acid covariation in alignments of natural protein sequences and sequences optimized for their structures by computational protein design methods. These results indicate that the structural constraints imposed by protein architecture play a dominant role in shaping amino acid covariation and that computational protein design methods can capture these effects. We also find that the similarity between natural and designed covariation is sensitive to the magnitude and mechanism of backbone flexibility used in computational protein design. Our results thus highlight the necessity of including backbone flexibility to correctly model precise details of correlated amino acid changes and give insights into the pressures underlying these correlations.

  9. Cytokinin producing bacteria stimulate amino acid deposition by wheat roots.

    Science.gov (United States)

    Kudoyarova, Guzel R; Melentiev, Alexander I; Martynenko, Elena V; Timergalina, Leila N; Arkhipova, Tatiana N; Shendel, Galina V; Kuz'mina, Ludmila Yu; Dodd, Ian C; Veselov, Stanislav Yu

    2014-10-01

    Phytohormone production is one mechanism by which rhizobacteria can stimulate plant growth, but it is not clear whether the bacteria gain from this mechanism. The hypothesis that microbial-derived cytokinin phytohormones stimulate root exudation of amino acids was tested. The rhizosphere of wheat plants was drenched with the synthetic cytokinin trans-zeatin or inoculated with Bacillus subtilis IB-22 (which produces zeatin type cytokinins) or B. subtilis IB-21 (which failed to accumulate cytokinins). Growing plants in a split root system allowed spatial separation of zeatin application or rhizobacterial inoculation to one compartment and analyses of amino acid release from roots (rhizodeposition) into the other compartment (without either microbial inoculation or treatment with exogenous hormone). Supplying B. subtilis IB-22 or zeatin to either the whole root system or half of the roots increased concentrations of amino acids in the soil solution although the magnitude of the increase was greater when whole roots were treated. There was some similarity in amino acid concentrations induced by either bacterial or zeatin treatment. Thus B. subtilis IB-22 increased amino acid rhizodeposition, likely due to its ability to produce cytokinins. Furthermore, B. subtilis strain IB-21, which failed to accumulate cytokinins in culture media, did not significantly affect amino acid concentrations in the wheat rhizosphere. The ability of rhizobacteria to produce cytokinins and thereby stimulate rhizodeposition may be important in enhancing rhizobacterial colonization of the rhizoplane.

  10. On the physical basis of the amino acid polar requirement.

    Science.gov (United States)

    Mathew, Damien C; Luthey-Schulten, Zaida

    2008-05-01

    Understanding how codons became associated with their specific amino acids is fundamental to deriving a theory for the origin of the genetic code. Carl Woese and coworkers designed a series of experiments to test associations between amino acids and nucleobases that may have played a role in establishing the genetic code. Through these experiments it was found that a property of amino acids called the polar requirement (PR) is correlated with the organization of the codon table. No other property of amino acids has been found that correlates with the codon table as well as PR, indicating that PR is uniquely related to the modern genetic code. Using molecular dynamics simulations of amino acids in solutions of water and dimethylpyridine used to experimentally measure PR, we show that variations in the partitioning between the two phases as described by radial distribution functions correlate well with the measured PRs. Partition coefficients based on probability densities of the amino acids in each phase have the linear behavior with base concentration as suggested by PR experiments.

  11. The preferences of orientations between the Pairs of amino acids

    Institute of Scientific and Technical Information of China (English)

    Chen Ying; Wang Jun; Wang Wei

    2007-01-01

    In this work,we make an investigation on the preferences of orientations between amino acids using the orientation defined based on the local geometry of the amino acids concerned.It is found that there are common preferences of orientations (70°,30°,140°) and (110°,340°,100°) for various pairs of amino acids.Different side chains may strengthen or weaken the common preferences,which is related to the effect of packing.Some amino acids having specific local flexibility may possess some preferences of orientations besides the common ones,such as (10°,280°,210°) .Another analysis on the pairs of the amino acids with different secondary-structure preferences shows that the directional interaction may affect the distribution of orientation more effectively than the packing or local flexibility.All these results provide us some insight of the organization of amino acids in protein,and their relation with some related interactions.

  12. Extraterrestrial Amino Acids in Ureilites Including Almahata Sitta

    Science.gov (United States)

    Burton, A. S.; Glavin, D. P.; Callahan, M. P.; Dworkin, J. P.

    2011-01-01

    Ureilites are a class of meteorites that lack chondrules (achondrites) but have relatively high carbon abundances, averaging approx.3 wt %. Using highly sensitive liquid chromatography coupled with UV fluorescence and time-of-flight mass spectrometry (LC-FD/ToF-MS), it was recently determined that there are amino acids in. fragment 94 of the Almahata Sitta ureilite[l]. Based on the presence of amino acids that are rare in the Earth's biosphere, as well as the near-racemic enantiomeric ratios of marry of the more common amino acids, it was concluded that most of the detected amino acids were indigenous to the meteorite. Although the composition of the Almahata Sitta ureilite appears to be unlike other recovered ureilites, the discovery of amino acids in this meteorite raises the question of whether other ureilites rnav also contain amino acids. Herein we present the results of LC-FDlTo.F-MS analyses of: a sand sample from the Almahata Sitta strewn held, Almahata Sitta fragments 425 (an ordinary H5 chondrite) and 427 (ureilite), as well as an Antarctic ureilite (Allan lulls, ALHA 77257).

  13. Amino acids in the rhizosphere: from plants to microbes.

    Science.gov (United States)

    Moe, Luke A

    2013-09-01

    Often referred to as the "building blocks of proteins", the 20 canonical proteinogenic amino acids are ubiquitous in biological systems as the functional units in proteins. Sometimes overlooked are their varying additional roles that include serving as metabolic intermediaries, playing structural roles in bioactive natural products, acting as cosubstrates in enzymatic transformations, and as key regulators of cellular physiology. Amino acids can also serve as biological sources of both carbon and nitrogen and are found in the rhizosphere as a result of lysis or cellular efflux from plants and microbes and proteolysis of existing peptides. While both plants and microbes apparently prefer to take up nitrogen in its inorganic form, their ability to take up and use amino acids may confer a selective advantage in certain environments where organic nitrogen is abundant. Further, certain amino acids (e.g., glutamate and proline) and their betaines (e.g., glycine betaine) serve as compatible solutes necessary for osmoregulation in plants and microbes and can undergo rapid cellular flux. This ability is of particular importance in an ecological niche such as the rhizosphere, which is prone to significant variations in solute concentrations. Amino acids are also shown to alter key phenotypes related to plant root growth and microbial colonization, symbiotic interactions, and pathogenesis in the rhizosphere. This review will focus on the sources, transport mechanisms, and potential roles of the 20 canonical proteinogenic amino acids in the rhizosphere.

  14. 肠道缺血再灌注损伤对血浆游离氨基酸水平的影响%Impact of intestinal ischemia/reperfusion on free amino acid levels in plasma

    Institute of Scientific and Technical Information of China (English)

    王玉康; 何桂珍; 张睿

    2013-01-01

    /R组谷氨酸浓度明显高于假手术组(P<0.05).结论 大鼠肠道缺血再灌注损伤引起肠道黏膜损伤和血浆游离氨基酸变化,肠道屏障损伤可能与谷氨酰胺浓度下降、蛋白分解增加相关.%Objective To investigate intestinal mucosal injury and the change of free amino acid levels in plasma with intestinal ischemia/reperfusion.Methods Twenty-four Sprague-Dawley (SD) male rats (SPF grade) were randomly divided into 3 groups with 8 rats in each group:Blank group,Sham group and ischemia/reperfusion (I/R) group.The rats in I/R group were subjected to 60 min ischemia by clamping the superior mesenteric artery (SMA),followed by 120 min repeffusion.All rats were sacrificed with blood withdraw through inferior vena cava.The plasma was precipitated with Sulfosalicylic acid and the supernatant free amino acid levels were measured and the intestinal mucosal thickness and villus length were also assayed.Results In the I/R group the total free amino acids,essential amino acids (EAA),glutamine and branched-chain amino acids (BCCA) were remarkably lower [the total free amino acids:I/R vs Blank vs Sham:(4585.1 326.1) vs (5661.5 ±581.9) vs (5337.9±998.7) μmol/L (F=5.075,P=0.016); EAA:I/Rvs Blank vs Sham:(1401.3 ±183.4) vs (2147.6 ± 265.1) vs (1796.2 ± 440.8) μmol/L (F =1 1.216,P =0.000) ; glutamine:I/R vs Blank vs Sham:(646.1 ± 34.7) vs (895.7 ± 258.8) vs (839.1 ± 163.7) μmol/L (F =4.326,P =0.027) ; BCCA:I/R vs Blank vs Sham:(507.8 ± 119.0) vs (912.2 ± 165.8) vs (671.9 ± 79.8) μmol/L (F =10.662,P =0.001)]and the jejunum and ileum mucosal thickness and villus height were decreased compared to Blank and Sham groups [jejunum mucosal thickness:I/R vs Blank vs Sham:(401.50 ± 117.79) vs (529.22 ±54.73) vs (499.54 ±64.48) μm (F=31.869,P =0.000) ; jejunum villus height:I/R vs Blank vs Sham:(271.37 ± 84.29) vs (365.26 ± 46.98) vs (349.67 ± 56.11) μm (F =30.472,P =0.000) ; ileum mucosal thickness:I/R vs Blank vs Sham:(254.20 ± 43.56) vs (324.70 ± 30.56) vs

  15. Amino Acid Synthesis in a Supercritical Carbon Dioxide - Water System

    OpenAIRE

    2009-01-01

    Mars is a CO2-abundant planet, whereas early Earth is thought to be also CO2-abundant. In addition, water was also discovered on Mars in 2008. From the facts and theory, we assumed that soda fountains were present on both planets, and this affected amino acid synthesis. Here, using a supercritical CO2/liquid H2O (10:1) system which mimicked crust soda fountains, we demonstrate production of amino acids from hydroxylamine (nitrogen source) and keto acids (oxylic acid sources). In this research...

  16. Abiotic Racemization Kinetics of Amino Acids in Marine Sediments

    OpenAIRE

    Steen, Andrew D.; Bo Barker Jørgensen; Bente Aa Lomstein

    2013-01-01

    The ratios of d- versus l-amino acids can be used to infer the sources and composition of sedimentary organic matter. Such inferences, however, rely on knowing the rates at which amino acids in sedimentary organic matter racemize abiotically between the d- and the l-forms. Based on a heating experiment, we report kinetic parameters for racemization of aspartic acid, glutamic acid, serine, and alanine in bulk sediment from Aarhus Bay, Denmark, taken from the surface, 30 cm, and 340 cm depth be...

  17. 77 FR 65537 - Requirements for Patent Applications Containing Nucleotide Sequence and/or Amino Acid Sequence...

    Science.gov (United States)

    2012-10-29

    ... Amino Acid Sequence Disclosures ACTION: Proposed collection; comment request. SUMMARY: The United States....'' SUPPLEMENTARY INFORMATION: I. Abstract Patent applications that contain nucleotide and/or amino acid...

  18. Digestible indispensable amino acid score and digestible amino acids in eight cereal grains.

    Science.gov (United States)

    Cervantes-Pahm, Sarah K; Liu, Yanhong; Stein, Hans H

    2014-05-01

    To determine values for the digestible indispensable amino acid score (DIAAS), it is recommended that ileal amino acid (AA) digestibility values obtained in growing pigs are used to characterise protein quality in different foods. Therefore, an experiment was conducted to determine the standardised ileal digestibility (SID) of AA in eight cereal grains (yellow dent maize, Nutridense maize, dehulled barley, dehulled oats, polished white rice, rye, sorghum and wheat) fed to pigs, where SID values in pigs can be used to calculate approximate DIAAS values in humans. In the present experiment, twenty-four barrows with a T-cannula inserted in the distal ileum were allotted to eight diets and fed for three periods to give a total of nine replicate pigs per diet. Each period lasted 14 d, and ileal digesta samples were collected on days 13 and 14. Among the SID values obtained for all cereal grains, values for total indispensable AA were greatest (P< 0·05) in rice and lowest (P< 0·05) in rye and sorghum. The concentrations of SID indispensable AA in rice were less (P< 0·05) than in dehulled oats, but greater (P< 0·05) than in the other cereal grains, and the concentrations of SID indispensable AA in Nutridense maize were greater (P< 0·05) than in yellow dent maize and sorghum, but less (P< 0·05) than in the other cereal grains, except rye. In conclusion, results indicate that to meet dietary requirements for AA in humans, diets based on yellow dent maize or sorghum require more AA supplementation than diets based on other cereal grains.

  19. A Sulfur Amino Acid–Free Meal Increases Plasma Lipids in Humans123

    Science.gov (United States)

    Park, Youngja; Le, Ngoc-Anh; Yu, Tianwei; Strobel, Fred; Gletsu-Miller, Nana; Accardi, Carolyn J.; Lee, Kichun S.; Wu, Shaoxiong; Ziegler, Thomas R.; Jones, Dean P.

    2011-01-01

    The content of sulfur amino acid (SAA) in a meal affects postprandial plasma cysteine concentrations and the redox potential of cysteine/cystine. Because such changes can affect enzyme, transporter, and receptor activities, meal content of SAA could have unrecognized effects on metabolism during the postprandial period. This pilot study used proton NMR (1H-NMR) spectroscopy of human plasma to test the hypothesis that dietary SAA content changes macronutrient metabolism. Healthy participants (18–36 y, 5 males and 3 females) were equilibrated for 3 d to adequate SAA, fed chemically defined meals without SAA for 5 d (depletion), and then fed isoenergetic, isonitrogenous meals containing 56 mg·kg−1·d−1 SAA for 4.5 d (repletion). On the first and last day of consuming the chemically defined meals, a morning meal containing 60% of the daily food intake was given and plasma samples were collected over an 8-h postprandial time course for characterization of metabolic changes by 1H-NMR spectroscopy. SAA-free food increased peak intensity in the plasma 1H-NMR spectra in the postprandial period. Orthogonal signal correction/partial least squares-discriminant analysis showed changes in signals associated with lipids, some amino acids, and lactate, with notable increases in plasma lipid signals (TG, unsaturated lipid, cholesterol). Conventional lipid analyses confirmed higher plasma TG and showed an increase in plasma concentration of the lipoprotein lipase inhibitor, apoC-III. The results show that plasma 1H-NMR spectra can provide useful macronutrient profiling following a meal challenge protocol and that a single meal with imbalanced SAA content alters postprandial lipid metabolism. PMID:21677075

  20. Abiotic racemization kinetics of amino acids in marine sediments.

    Science.gov (United States)

    Steen, Andrew D; Jørgensen, Bo Barker; Lomstein, Bente Aa

    2013-01-01

    The ratios of d- versus l-amino acids can be used to infer the sources and composition of sedimentary organic matter. Such inferences, however, rely on knowing the rates at which amino acids in sedimentary organic matter racemize abiotically between the d- and the l-forms. Based on a heating experiment, we report kinetic parameters for racemization of aspartic acid, glutamic acid, serine, and alanine in bulk sediment from Aarhus Bay, Denmark, taken from the surface, 30 cm, and 340 cm depth below seafloor. Extrapolation to a typical cold deep sea sediment temperature of 3°C suggests racemization rate constants of 0.50×10(-5)-11×10(-5) yr(-1). These results can be used in conjunction with measurements of sediment age to predict the ratio of d:l amino acids due solely to abiotic racemization of the source material, deviations from which can indicate the abundance and turnover of active microbial populations.

  1. The interaction of amino acids, peptides, and proteins with DNA.

    Science.gov (United States)

    Solovyev, Andrey Y; Tarnovskaya, Svetlana I; Chernova, Irina A; Shataeva, Larisa K; Skorik, Yury A

    2015-01-01

    Amino acids that carry charges on their side groups can bind to double stranded DNA (dsDNA) and change the strength of the double helix. Measurement of the DNA melting temperature (Tm) confirmed that acidic amino acids (Glu, Asp) weaken the H-bonds between DNA strands, whereas basic amino acids (Arg, Lys) strengthen the interaction between the strands. A rank correlation exists between the amino acid isoelectric points and the observed changes in Tm. A similar dependence of the hyperchromic effect on the isoelectric point of a protein (pepsin, insulin, cortexin, and protamine) was observed for DNA-protein complexes at room temperature. Short peptides (KE, AEDG, and KEDP) containing a mixture of acidic and basic amino acid residues also affect Tm and the stability of the double helix. A model for binding Glu and Lys to dsDNA was explored by a docking simulation. The model shows that Glu, in an untwisted shape, binds to dsDNA in its major groove and disrupts three H-bonds between the strands, thereby destabilizing the double helix. Lys, in an untwisted shape, binds to the external side of the dsDNA and forms two bonds with O atoms of neighboring phosphodiester groups, thereby strengthening the DNA helix.

  2. Raman spectra of amino acids and their aqueous solutions

    Science.gov (United States)

    Zhu, Guangyong; Zhu, Xian; Fan, Qi; Wan, Xueliang

    2011-03-01

    Amino acids are the basic "building blocks" that combine to form proteins and play an important physiological role in all life-forms. Amino acids can be used as models for the examination of the importance of intermolecular bonding in life processes. Raman spectra serve to obtain information regarding molecular conformation, giving valuable insights into the topology of more complex molecules (peptides and proteins). In this paper, amino acids and their aqueous solution have been studied by Raman spectroscopy. Comparisons of certain values for these frequencies in amino acids and their aqueous solutions are given. Spectra of solids when compared to those of the solute in solution are invariably much more complex and almost always sharper. We present a collection of Raman spectra of 18 kinds of amino acids ( L-alanine, L-arginine, L-aspartic acid, cystine, L-glutamic acid, L-glycine, L-histidine, L-isoluecine, L-leucine, L-lysine, L-phenylalanine, L-methionone, L-proline, L-serine, L-threonine, L-tryptophan, L-tyrosine, L-valine) and their aqueous solutions that can serve as references for the interpretation of Raman spectra of proteins and biological materials.

  3. A novel method for simultaneous measurement of concentration and enrichment of NO synthesis-specific amino acids in human plasma using stable isotopes and LC/MS ion trap analysis.

    Science.gov (United States)

    Oosterink, J Efraim; Buijs, Nikki; van Goudoever, Johannes B; Schierbeek, Henk

    2014-05-01

    Stable isotope studies offer the opportunity to study the in-depth metabolic pathway of glutamine, citrulline, and arginine amino acids involved in NO synthesis. The use of multiple stable isotopes can be used to elucidate the exact transformation of glutamine to citrulline and arginine de novo synthesis. This novel method provides a purification step using cation exchange resin in combination with a rapid and easy derivatization procedure for a precise and robust measurement of the concentration and isotopic enrichments of NO synthesis-specific amino acids using a liquid chromatography mass spectrometry (LC/MS) ion trap system with high sensitivity and selectivity. The ethyl chloroformate derivatization procedure is beneficial in terms of robustness, velocity, simplicity, and derivative stability. In addition, the ethyl chloroformate derivatization can be performed at room temperature in an aqueous environment without incubation and the isolation of the derivatives from the reaction mixture also serves as a purification step. The concentration and enrichment of NO synthesis-specific amino acids as well as phenylalanine and tyrosine to determine protein turnover, were measured with good inter-day precision for the concentration (glutamine-citrulline-arginine pathway by using stable isotope studies.

  4. Energetics of Amino Acid Synthesis in Alkaline Hydrothermal Environments

    Science.gov (United States)

    Kitadai, Norio

    2015-12-01

    Alkaline hydrothermal systems have received considerable attention as candidates for the origin and evolution of life on the primitive Earth. Nevertheless, sufficient information has not yet been obtained for the thermodynamic properties of amino acids, which are necessary components for life, at high temperatures and alkaline pH. These properties were estimated using experimental high-temperature volume and heat capacity data reported in the literature for several amino acids, together with correlation algorithms and the revised Helgeson-Kirkham-Flowers (HKF) equations of state. This approach enabled determination of a complete set of the standard molal thermodynamic data and the revised HKF parameters for the 20 protein amino acids in their zwitterionic and ionization states. The obtained dataset was then used to evaluate the energetics of amino acid syntheses from simple inorganic precursors (CO2, H2, NH3 and H2S) in a simulated alkaline hydrothermal system on the Hadean Earth. Results show that mixing between CO2-rich seawater and the H2-rich hydrothermal fluid can produce energetically favorable conditions for amino acid syntheses, particularly in the lower-temperature region of such systems. Together with data related to the pH and temperature dependences of the energetics of amino acid polymerizations presented in earlier reports, these results suggest the following. Hadean alkaline hydrothermal settings, where steep pH and temperature gradients may have existed between cool, slightly acidic Hadean ocean water and hot, alkaline hydrothermal fluids at the vent-ocean interface, may be energetically the most suitable environment for the synthesis and polymerization of amino acids.

  5. The 2007 ESPEN Sir David Cuthbertson Lecture: amino acids between and within organs. The glutamate-glutamine-citrulline-arginine pathway.

    Science.gov (United States)

    Deutz, Nicolaas E P

    2008-06-01

    In daily practice, the plasma concentration of amino acids is usually viewed as a parameter of production. However, both a high production and/or a reduced disposal capacity can result in an increased plasma concentration. In this presentation, I will discuss my research on interorgan relationships of the amino acids glutamate, glutamine, citrulline and arginine to explain the regulation of the plasma arginine level. The reduced glutamine disposal during liver failure is related to enhanced plasma glutamine level without any change in muscle and gut production or consumption rate. In contrast during sepsis, a small reduction in plasma glutamine is related to a substantially enhanced organ glutamate and glutamine production or consumption rate. These observations are a good example that plasma levels are directly related to production or consumption rates. Because glutamine breakdown in the gut produces citrulline, there is a good relation between the amount of metabolically active gut tissue and gut and whole body citrulline production. Arginine is produces from citrulline in the kidney and a reduced gut glutamine to citrulline conversion during sepsis explains the reduced de novo arginine production that is related to the reduced plasma arginine level. The interorgan route between muscle, gut, liver and kidney of the amino acids glutamate, glutamine, citrulline and arginine is a very good example of how complicated the regulation of plasma amino acid levels can be. However, in-depth research is necessary and will give us important clues to new nutritional strategies.

  6. Administering different levels of parenteral phosphate and amino acids did not influence growth in extremely preterm infants

    DEFF Research Database (Denmark)

    Thomsen, Katrine Moe; Beck-Nielsen, Signe Sparre; Lando, Ane

    2015-01-01

    AIM: When a new high amino acid parenteral nutrition (PN) solution was introduced to our hospital, a design error led to decreased phosphate levels. This prompted us to examine the effect of three different PN solutions on plasma phosphate, plasma calcium and weight increases on extremely preterm...

  7. Synthesis and Biological Activity of Novel Amino Acid-(N'-Benzoyl Hydrazide and Amino Acid-(N'-Nicotinoyl Hydrazide Derivatives

    Directory of Open Access Journals (Sweden)

    Sherine N. Khattab

    2005-09-01

    Full Text Available The coupling reaction of benzoic acid and nicotinic acid hydrazides with N- protected L-amino acids including valine, leucine, phenylalanine, glutamic acid and tyrosine is reported. The target compounds, N-Boc-amino acid-(N`-benzoyl- and N- Boc-amino acid-(N`-nicotinoyl hydrazides 5a-5e and 6a-6e were prepared in very high yields and purity using N-[(dimethylamino-1H-1,2,3-triazolo[4,5-b]pyridin-1-yl- methylene]-N-methyl-methanaminium hexafluorophosphate N-oxide (HATU as coupling reagent. The antimicrobial activity of the Cu and Cd complexes of the designed compounds was tested. The products were deprotected affording the corresponding amino acid-(N`-benzoyl hydrazide hydrochloride salts (7a-7e and amino acid-(N`- nicotinoyl hydrazide hydrochloride salts (8a-8e. These compounds and their Cu and Cd complexes were also tested for their antimicrobial activity. Several compounds showed comparable activity to that of ampicillin against S. aureus and E. coli.

  8. Effect of carbohydrate ingestion on brain exchange of amino acids during sustained exercise in human subjects

    DEFF Research Database (Denmark)

    Blomstrand, E.; Møller, K.; Secher, Niels Henry

    2005-01-01

    AIM: This study investigated the effect of prolonged exercise with and without carbohydrate intake on the brain exchange of amino acids, especially focussing on tryptophan and branched-chain amino acids (BCAA). METHODS: Five male subjects exercised for 3 h on a cycle ergometer at 200 +/- 7 W on two...... occasions; either supplemented with a 6% carbohydrate solution or with flavoured water (placebo). Catheters were inserted into the right internal jugular vein and the radial artery of the non-dominant arm. The brain exchange of amino acids during exercise was calculated from the arterial-jugular venous...... concentration difference multiplied by plasma flow. RESULTS: About 106 micromol (22 mg) of tryptophan was taken up by the brain during exercise in the placebo trial, whereas no significant uptake was observed in the carbohydrate trial. In accordance, the arterial concentration of free tryptophan increased from...

  9. Revised sections F7.5 (quantitative amino acid analysis) and F7.6 (qualitative amino acid analysis): American College of Medical Genetics Standards and Guidelines for Clinical Genetics Laboratories, 2003.

    Science.gov (United States)

    Grier, Robert E; Gahl, William A; Cowan, Tina; Bernardini, Isa; McDowell, Geraldine A; Rinaldo, Piero

    2004-01-01

    Determination of plasma amino acid levels has become a key piece of information in the diagnosis and clinical management of a group of metabolic genetic disorders. Appropriate laboratory methodologies have been published for amino acid analysis, yet there is a need for direction for the laboratory in performing this testing. The following guidelines were generated by a working group of the American College of Medical Genetics Laboratory Quality Assurance Committee. Based upon a body of knowledge and professional experience, these guidelines and standards are to be the benchmark for performance of amino acid analysis for clinical interpretation.

  10. Deorphanization of GPRC6A: a promiscuous L-alpha-amino acid receptor with preference for basic amino acids

    DEFF Research Database (Denmark)

    Wellendorph, Petrine; Hansen, Kasper B; Balsgaard, Anders

    2005-01-01

    . To identify agonists at this orphan receptor, we faced the challenges of achieving surface expression in mammalian cell lines and establishing an appropriate functional assay. Generating a chimeric receptor construct, h6A/5.24, containing the ligand binding amino-terminal domain (ATD) of hGPRC6A...... and was employed to rationally select potential ligands. Measurement of Ca2+-dependent chloride currents in Xenopus laevis oocytes facilitated the deorphanization of h6A/5.24 and identification of L-alpha-amino acids as agonists. The most active agonists were basic L-alpha-amino acids, L-Arg, L-Lys, and L...

  11. The impact of chronic imipramine treatment on amino acid concentrations in the hippocampus of mice.

    Science.gov (United States)

    Nagasawa, Mao; Murakami, Tatsuro; Tomonaga, Shozo; Furuse, Mitsuhiro

    2012-09-01

    The relationship between antidepressants and monoamine concentrations in the brain has been well investigated, but few studies have investigated the relationship between antidepressants and amino acid concentrations in the brain. The purpose of the present study was therefore to investigate the effect of the chronic antidepressant imipramine on amino acid and monoamine concentrations in the mouse brain and plasma. Chronic imipramine treatment decreased the concentration of 5-hydroxyindoleaceticacid/5-hydroxytryptamine in the cerebral cortex and increased that of norepinephrine (NE) in the hippocampus. Since these changes were conspicuous effects of the antidepressant, we concluded that imipramine acts on the central nervous system. No change in amino acid concentrations in plasma was induced by chronic imipramine treatment, but several changes were confirmed in the cerebral cortex, the hypothalamus and the hippocampus. Chronic imipramine treatment caused increases in L-methionine, L-tyrosine, and L-lysine in the cerebral cortex, and an increase in L-aspartate in the hypothalamus. Contrary to this, the concentrations of L-aspartate, L-serine, L-asparagine, glycine, L-glutamine, gamma-aminobutyric acid, L-threonine, L-arginine, L-proline, L-valine, and L-methionine in the hippocampus were decreased by chronic imipramine treatment. The present results demonstrate that the metabolism of several amino acids in the brain, but not of those in plasma, was altered by chronic imipramine treatment. The findings in the present study may help to further elucidate the relationship between amino acids and the effects and side effects of antidepressants.

  12. Amino acids in dew - origin and seasonal variation

    Science.gov (United States)

    Scheller, Edwin

    At two sites in the Armenhof district, 10 km east of Fulda, Germany, dew samples were collected from June 1996 to June 1997 and investigated for free and protein-bound amino acids. On account of the high pollen content, at the beginning of June 1996 and in May 1997 total amino acid concentrations were 53-390 μmol l -1, in one sample 922 μmol l -1. At other times the concentration in dew was 8-164 μmol l -1. On 4 and 5 June 1996 the diluted free amino acid fraction (DFAA) of the total hydrolysed amino acids (THAA) at both sites amounted to 35-44% and was predominantly arginine, proline and glutamine/glutamate. Likewise on 11 March 1997 the fraction of DFAA was found to be 39.5% with extremely high arginine and proline fractions. At other times the DFAA-fraction was in the range 14-26%. From July 1996 to June 1997 the amino acid concentrations in the vapours rising from a meadow were also measured and it ranged from 8 to 51 μmol l -1. From July to October 1996 the amino acid composition in the hydrolysates of dew samples and meadow vapours collected overnight were almost identical. The DFAA fraction in the condensation water collected overnight from the meadow varied from 18 to 40%. From 4 to 6 June 1996, on 11 and 13 March 1997 and in the period 16-20 May 1997, the amino acid distribution in dew showed much variation. The percentage fraction of arginine and proline in the hydrolysate increased greatly, whereas that of glycine and serine decreased. The large increase in proline and arginine in hydrolysate is attributable solely to the large amounts of free arginine and proline. This effect occurred in both 1996 and 1997 over several days at both sites at any one time and therefore appears confirmed.

  13. Branched-chain amino acid supplementation during bed rest: effect on recovery

    Science.gov (United States)

    Stein, T. P.; Donaldson, M. R.; Leskiw, M. J.; Schluter, M. D.; Baggett, D. W.; Boden, G.

    2003-01-01

    Bed rest is associated with a loss of protein from the weight-bearing muscle. The objectives of this study are to determine whether increasing dietary branched-chain amino acids (BCAAs) during bed rest improves the anabolic response after bed rest. The study consisted of a 1-day ambulatory period, 14 days of bed rest, and a 4-day recovery period. During bed rest, dietary intake was supplemented with either 30 mmol/day each of glycine, serine, and alanine (group 1) or with 30 mmol/day each of the three BCAAs (group 2). Whole body protein synthesis was determined with U-(15)N-labeled amino acids, muscle, and selected plasma protein synthesis with l-[(2)H(5)]phenylalanine. Total glucose production and gluconeogenesis from alanine were determined with l-[U-(13)C(3)]alanine and [6,6-(2)H(2)]glucose. During bed rest, nitrogen (N) retention was greater with BCAA feeding (56 +/- 6 vs. 26 +/- 12 mg N. kg(-1). day(-1), P BCAA supplementation on either whole body, muscle, or plasma protein synthesis or the rate of 3-MeH excretion. Muscle tissue free amino acid concentrations were increased during bed rest with BCAA (0.214 +/- 0.066 vs. 0.088 +/- 0.12 nmol/mg protein, P BCAA group in the recovery phase. In conclusion, the improved N retention during bed rest is due, at least in part, to accretion of amino acids in the tissue free amino acid pools. The amount accreted is not enough to impact protein kinetics in the recovery phase but does improve N retention by providing additional essential amino acids in the early recovery phase.

  14. Age-Related Changes in Sulfur Amino Acid Metabolism in Male C57bl/6 Mice.

    Science.gov (United States)

    Jeon, Jang Su; Oh, Jeong-Ja; Kwak, Hui Chan; Yun, Hwi-Yeol; Kim, Hyoung Chin; Kim, Young-Mi; Oh, Soo Jin; Kim, Sang Kyum

    2017-06-14

    Alterations in sulfur amino acid metabolism are associated with an increased risk of a number of common late-life diseases, which raises the possibility that metabolism of sulfur amino acids may change with age. The present study was conducted to understand the age-related changes in hepatic metabolism of sulfur amino acids in 2-, 6-, 18- and 30-month-old male C57BL/6 mice. For this purpose, metabolite profiling of sulfur amino acids from methionine to taurine or glutathione (GSH) was performed. The levels of sulfur amino acids and their metabolites were not significantly different among 2-, 6- and 18-month-old mice, except for plasma GSH and hepatic homocysteine. Plasma total GSH and hepatic total homocysteine levels were significantly higher in 2-month-old mice than those in the other age groups. In contrast, 30-month-old mice exhibited increased hepatic methionine and cysteine, compared with all other groups, but decreased hepatic S-adenosylmethionine (SAM), S-adenosylhomocysteine and homocysteine, relative to 2-month-old mice. No differences in hepatic reduced GSH, GSH disulfide, or taurine were observed. The hepatic changes in homocysteine and cysteine may be attributed to upregulation of cystathionine β-synthase and down-regulation of γ-glutamylcysteine ligase in the aged mice. The elevation of hepatic cysteine levels may be involved in the maintenance of hepatic GSH levels. The opposite changes of methionine and SAM suggest that the regulatory role of SAM in hepatic sulfur amino acid metabolism may be impaired in 30-month-old mice.

  15. Taste preference for amino acids is dependent on internal nutritional state in Drosophila melanogaster.

    Science.gov (United States)

    Toshima, Naoko; Tanimura, Teiichi

    2012-08-15

    Like mammals, insects need to ingest proteins from foods because they cannot synthesise several amino acids. Amino acids are also essential nutrients for Drosophila melanogaster, especially for female egg production, but how flies detect amino acids and how the feeding response to amino acids is regulated are unknown. In this study, the two-choice preference test, the proboscis extension reflex test and a CAFE assay were performed to explore the ability of D. melanogaster to detect and discriminate amino acids. To determine whether D. melanogaster change their feeding preference to amino acids after being deprived of them, as previously reported in the locust, two groups of flies raised on the usual medium or on glucose medium were compared. Amino-acid-deprived flies demonstrated enhanced preference to an amino acid mixture and to several amino acids. These flies ingested amino acids even when they were replete with glucose. The proboscis extension reflex to particular amino acids was induced only in amino-acid-deprived flies. Our findings indicate that the sensitivity of labellar taste cells to amino acids may change when flies are deficient in amino acid supply, and also reveal that the detection pathways for individual amino acids may differ. We suggest the existence of an amino acid receptor and a monitoring system regulating the feeding responses to amino acids.

  16. Thyroid peroxidase activity is inhibited by amino acids

    Directory of Open Access Journals (Sweden)

    D.P. Carvalho

    2000-03-01

    Full Text Available Normal in vitro thyroid peroxidase (TPO iodide oxidation activity was completely inhibited by a hydrolyzed TPO preparation (0.15 mg/ml or hydrolyzed bovine serum albumin (BSA, 0.2 mg/ml. A pancreatic hydrolysate of casein (trypticase peptone, 0.1 mg/ml and some amino acids (cysteine, tryptophan and methionine, 50 µM each also inhibited the TPO iodide oxidation reaction completely, whereas casamino acids (0.1 mg/ml, and tyrosine, phenylalanine and histidine (50 µM each inhibited the TPO reaction by 54% or less. A pancreatic digest of gelatin (0.1 mg/ml or any other amino acid (50 µM tested did not significantly decrease TPO activity. The amino acids that impair iodide oxidation also inhibit the TPO albumin iodination activity. The inhibitory amino acids contain side chains with either sulfur atoms (cysteine and methionine or aromatic rings (tyrosine, tryptophan, histidine and phenylalanine. Among the amino acids tested, only cysteine affected the TPO guaiacol oxidation reaction, producing a transient inhibition at 25 or 50 µM. The iodide oxidation inhibitory activity of cysteine, methionine and tryptophan was reversed by increasing iodide concentrations from 12 to 18 mM, while no such effect was observed when the cofactor (H2O2 concentration was increased. The inhibitory substances might interfere with the enzyme activity by competing with its normal substrates for their binding sites, binding to the free substrates or reducing their oxidized form.

  17. A set of amino acids found to occur more frequently in human and fly than in plant and yeast proteomes consists of non-essential amino acids

    OpenAIRE

    2007-01-01

    We investigated the hypothesis that essential amino acids are being replaced in proteins by non-essential amino acids.We compared the amino acid composition in human, worm and fly proteomes, organisms that cannot synthesize all amino acids, with the amino acids of the proteomes of plant, bakers yeast and budding yeast, which are capable of synthesizing them. The analysis covered 460,737 proteins (212,197,907 amino acids). The data suggest a bias towards the usage of non-essential ami...

  18. (-)-Hydroxycitric Acid Nourishes Protein Synthesis via Altering Metabolic Directions of Amino Acids in Male Rats.

    Science.gov (United States)

    Han, Ningning; Li, Longlong; Peng, Mengling; Ma, Haitian

    2016-08-01

    (-)-Hydroxycitric acid (HCA), a major active ingredient of Garcinia Cambogia extracts, had shown to suppress body weight gain and fat accumulation in animals and humans. While, the underlying mechanism of (-)-HCA has not fully understood. Thus, this study was aimed to investigate the effects of long-term supplement with (-)-HCA on body weight gain and variances of amino acid content in rats. Results showed that (-)-HCA treatment reduced body weight gain and increased feed conversion ratio in rats. The content of hepatic glycogen, muscle glycogen, and serum T4 , T3 , insulin, and Leptin were increased in (-)-HCA treatment groups. Protein content in liver and muscle were significantly increased in (-)-HCA treatment groups. Amino acid profile analysis indicated that most of amino acid contents in serum and liver, especially aromatic amino acid and branched amino acid, were higher in (-)-HCA treatment groups. However, most of the amino acid contents in muscle, especially aromatic amino acid and branched amino acid, were reduced in (-)-HCA treatment groups. These results indicated that (-)-HCA treatment could reduce body weight gain through promoting energy expenditure via regulation of thyroid hormone levels. In addition, (-)-HCA treatment could promote protein synthesis by altering the metabolic directions of amino acids. Copyright © 2016 John Wiley & Sons, Ltd.

  19. Valuable biomolecules from nine North Atlantic red macroalgae: Amino acids, fatty acids, carotenoids, minerals and metals

    DEFF Research Database (Denmark)

    Razi Parjikolaei, Behnaz; Bruhn, Annette; Eybye, Karin Loft

    2016-01-01

    , glutamic acid, and arginine, respectively. The amino acid score of the nine algae varied from 44% to 92%, the most commonly first limiting amino acid being histidine. Lutein, β-carotene, and zeaxanthin were the identified carotenoids. Contents of all macro and trace minerals, with the exception...

  20. Valuable biomolecules from nine North Atlantic red macroalgae: Amino acids, fatty acids, carotenoids, minerals and metals

    DEFF Research Database (Denmark)

    Razi Parjikolaei, Behnaz; Bruhn, Annette; Eybye, Karin Loft

    2016-01-01

    , glutamic acid, and arginine, respectively. The amino acid score of the nine algae varied from 44% to 92%, the most commonly first limiting amino acid being histidine. Lutein, β-carotene, and zeaxanthin were the identified carotenoids. Contents of all macro and trace minerals, with the exception...

  1. Facile synthesis of α-hydroxy carboxylic acids from the corresponding α-amino acids

    DEFF Research Database (Denmark)

    Stuhr-Hansen, Nicolai; Padrah, Shahrokh; Strømgaard, Kristian

    2014-01-01

    An effective and improved procedure is developed for the synthesis of α-hydroxy carboxylic acids by treatment of the corresponding protonated α-amino acid with tert-butyl nitrite in 1,4-dioxane-water. The amino moiety must be protonated and located α to a carboxylic acid function in order...

  2. Absolute quantitation of proteins by Acid hydrolysis combined with amino Acid detection by mass spectrometry

    DEFF Research Database (Denmark)

    Mirgorodskaya, Olga A; Körner, Roman; Kozmin, Yuri P;

    2012-01-01

    Amino acid analysis is among the most accurate methods for absolute quantification of proteins and peptides. Here, we combine acid hydrolysis with the addition of isotopically labeled standard amino acids and analysis by mass spectrometry for accurate and sensitive protein quantitation...

  3. Promiscuous Seven Transmembrane Receptors Sensing L-α-amino Acids

    DEFF Research Database (Denmark)

    Smajilovic, Sanela; Wellendorph, Petrine; Bräuner-Osborne, Hans

    2014-01-01

    A number of nutrient sensing seven trans-membrane (7TM) receptors have been identified and characterized over the past few years. While the sensing mechanisms to carbohydrates and free fatty acids are well understood, the molecular basis of amino acid sensing has recently come to the limelight. T....... The present review describes the current status of promiscuous L-α-amino acid sensors, the calcium sensing receptor (CaSR), the GPRC6A receptor, the T1R1/T1R3 receptor and also their molecular pharmacology, expression pattern and physiological significance....

  4. Fungal Peptaibiotics: Assessing Potential Meteoritic Amino Acid Contamination

    Science.gov (United States)

    Elsila, J. E.; Callahan, M. P.; Glavin, D. P.; Dworkin, J. P.; Bruckner, H.

    2010-01-01

    The presence of non-protein alpha-dialkyl-amino acids such as alpha-aminoisobutyric acid (alpha-A1B) and isovaline (Iva), which are relatively rare in the terrestrial biosphere, has long been used as an indication of the indigeneity of meteoritic amino acids, however, the discovery of alpha-AIB in peptides producers by a widespread group of filamentous fungi indicates the possibility of a terrestrial biotic source for the alpha-AIB observed in some meteorites. The alpha-AIB-containing peptides produced by these fungi are dubbed peptaibiotics. We measured the molecular distribution and stable carbon and nitrogen isotopic ratios for amino acids found in the total hydrolysates of four biologically synthesized peptaibiotics. We compared these aneasurenetts with those from the CM2 carbonaceous chondrite Murchison and from three Antarctic CR2 carbonaceous chondrites in order to understand the peptaibiotics as a potential source of meteoritic contamination.

  5. RESEARCH ON THE POLYCONDENSATION KINETICS OF ω-AMINO-ACIDS

    Institute of Scientific and Technical Information of China (English)

    WANG Baoren; SHI Manli; QIAN Chunqing

    1983-01-01

    In our previous report, it was discovered that the polycondensation of 9-amino-nonanoic acid follows second order from the beginning up to the extent of reaction, p, around 99%, and after which the reaction changes rapidly to third order. In this paper, we wish to report that this change of the reaction order from second to third occurred also in the polycondensation of 6aminocaproic acid and 11-amino-undecanoic acid. The transition region lay again at p around 99%.It may be concluded that this is a general rule in the polycondensation of the ω-amino-acids (monomers of the A-B type), and the controversial results that appeared in the literature may be cleared up by our experiments.

  6. Complete amino acid sequence of the Aspergillus cytotoxin mitogillin

    Energy Technology Data Exchange (ETDEWEB)

    Fernandez-Luna, J.L.; Lopez-Otin, C.; Soriano, F.; Mendez, E.

    1985-02-12

    The complete amino acid sequence of the cytotoxin mitogillin has been determined by sequencing the intact chain and peptide fragments produced by cleavage at methionyl, arginyl, lysyl, and tryptophanyl residues and at one aspartic acid-proline bond. The protein consists of 149 amino acid residues with alanine at the NH/sub 2/ terminus and histidine at the COOH terminus. The calculated Mr of the native mitogillin was 16,867. The native molecule presents two disulfide bridges, one between cysteine residues at positions 5 and 147 and another one between cysteine residues at positions 75 and 131. The amino acid sequence of mitogillin shows 86% homology with another cytotoxic protein called alpha-sarcin.

  7. Suppression of muscle protein turnover and amino acid degradation by dietary protein deficiency

    Science.gov (United States)

    Tawa, N. E. Jr; Goldberg, A. L.

    1992-01-01

    To define the adaptations that conserve amino acids and muscle protein when dietary protein intake is inadequate, rats (60-70 g final wt) were fed a normal or protein-deficient (PD) diet (18 or 1% lactalbumin), and their muscles were studied in vitro. After 7 days on the PD diet, both protein degradation and synthesis fell 30-40% in skeletal muscles and atria. This fall in proteolysis did not result from reduced amino acid supply to the muscle and preceded any clear decrease in plasma amino acids. Oxidation of branched-chain amino acids, glutamine and alanine synthesis, and uptake of alpha-aminoisobutyrate also fell by 30-50% in muscles and adipose tissue of PD rats. After 1 day on the PD diet, muscle protein synthesis and amino acid uptake decreased by 25-40%, and after 3 days proteolysis and leucine oxidation fell 30-45%. Upon refeeding with the normal diet, protein synthesis also rose more rapidly (+30% by 1 day) than proteolysis, which increased significantly after 3 days (+60%). These different time courses suggest distinct endocrine signals for these responses. The high rate of protein synthesis and low rate of proteolysis during the first 3 days of refeeding a normal diet to PD rats contributes to the rapid weight gain ("catch-up growth") of such animals.

  8. Amino acid analogs IV:4-fluoroisoleucine.

    Science.gov (United States)

    Gershon, H; Shanks, L; Clarke, D D

    1978-05-01

    4-Fluoroisoleucine was produced by ammonolysis of 2-bromo-4-fluoro-3-methylpentanoic acid, which resulted from the bromofluorination of 4-methyl-2-pentenoic acid. It did not inhibit Plasmodium berghei in mice at 640 mg/kg and was not toxic to the animals. The fluoroamino acid inhibited Aspergillus niger, Trichoderma viride, Myrothecium verrucaria, Trichophyton mentagrophytes, and Mucor mucedo in Czapek solution agar at a concentration between 10(4) and 10(3) microgram/ml. Growth of Escherichia coli was inhibited 25% at 900 microgram/ml in a defined medium.

  9. Association of Branched and Aromatic Amino Acids Levels with Metabolic Syndrome and Impaired Fasting Glucose in Hypertensive Patients

    Science.gov (United States)

    Weng, Liming; Quinlivan, Eoin; Gong, Yan; Beitelshees, Amber L.; Shahin, Mohamed H.; Turner, Stephen T.; Chapman, Arlene B.; Gums, John G.; Johnson, Julie A.; Frye, Reginald F.; Garrett, Timothy J.

    2015-01-01

    Abstract Background: The three branched amino acids (valine, leucine, and isoleucine) and two aromatic amino acids (tyrosine and phenylalanine) have been associated with many adverse metabolic pathways, including diabetes. However, these associations have been identified primarily in otherwise healthy Caucasian populations. We aimed to investigate the association of this five-amino-acid signature with metabolic syndrome and impaired fasting glucose (IFG) in a hypertensive cohort of Caucasian and African Americans. Methods: We analyzed data from the Pharmacogenomic Evaluation of Antihypertensive Responses (PEAR) studies PEAR and PEAR2 conducted between 2005 and 2014. Subjects were enrolled at the University of Florida (Gainesville, FL), Emory University (Atlanta, GA), and Mayo Clinic (Rochester, MN). A total of 898 patients with essential hypertension were included in this study. Presence of metabolic syndrome and IFG at baseline were determined on the basis of measurements of demographic and biochemical data. Levels of the five amino acids were quantified by liquid chromatography–tandem mass spectroscopy (LC-MS/MS). Results: With a multiple logistic regression model, we found that all five amino acids were significantly associated with metabolic syndrome in both Caucasian and African Americans. IFG and the five amino acids were associated in the Caucasian Americans. Only valine was significantly associated with IFG in African Americans. Conclusion: In both Caucasian and African Americans with uncomplicated hypertension, plasma levels of the five-amino-acid signature are associated with metabolic syndrome. Additionally, in Caucasians we have confirmed the five-amino-acid signature was associated with IFG. PMID:25664967

  10. Improvement of pea biomass and seed productivity by simultaneous increase of phloem and embryo loading with amino acids.

    Science.gov (United States)

    Zhang, Lizhi; Garneau, Matthew G; Majumdar, Rajtilak; Grant, Jan; Tegeder, Mechthild

    2015-01-01

    The development of sink organs such as fruits and seeds strongly depends on the amount of nitrogen that is moved within the phloem from photosynthetic-active source leaves to the reproductive sinks. In many plant species nitrogen is transported as amino acids. In pea (Pisum sativum L.), source to sink partitioning of amino acids requires at least two active transport events mediated by plasma membrane-localized proteins, and these are: (i) amino acid phloem loading; and (ii) import of amino acids into the seed cotyledons via epidermal transfer cells. As each of these transport steps might potentially be limiting to efficient nitrogen delivery to the pea embryo, we manipulated both simultaneously. Additional copies of the pea amino acid permease PsAAP1 were introduced into the pea genome and expression of the transporter was targeted to the sieve element-companion cell complexes of the leaf phloem and to the epidermis of the seed cotyledons. The transgenic pea plants showed increased phloem loading and embryo loading of amino acids resulting in improved long distance transport of nitrogen, sink development and seed protein accumulation. Analyses of root and leaf tissues further revealed that genetic manipulation positively affected root nitrogen uptake, as well as primary source and sink metabolism. Overall, the results suggest that amino acid phloem loading exerts regulatory control over pea biomass production and seed yield, and that import of amino acids into the cotyledons limits seed protein levels.

  11. How Amino Acids and Peptides Shaped the RNA World

    Directory of Open Access Journals (Sweden)

    Peter T.S. van der Gulik

    2015-01-01

    Full Text Available The “RNA world” hypothesis is seen as one of the main contenders for a viable theory on the origin of life. Relatively small RNAs have catalytic power, RNA is everywhere in present-day life, the ribosome is seen as a ribozyme, and rRNA and tRNA are crucial for modern protein synthesis. However, this view is incomplete at best. The modern protein-RNA ribosome most probably is not a distorted form of a “pure RNA ribosome” evolution started out with. Though the oldest center of the ribosome seems “RNA only”, we cannot conclude from this that it ever functioned in an environment without amino acids and/or peptides. Very small RNAs (versatile and stable due to basepairing and amino acids, as well as dipeptides, coevolved. Remember, it is the amino group of aminoacylated tRNA that attacks peptidyl-tRNA, destroying the bond between peptide and tRNA. This activity of the amino acid part of aminoacyl-tRNA illustrates the centrality of amino acids in life. With the rise of the “RNA world” view of early life, the pendulum seems to have swung too much towards the ribozymatic part of early biochemistry. The necessary presence and activity of amino acids and peptides is in need of highlighting. In this article, we try to bring the role of the peptide component of early life back into focus. We argue that an RNA world completely independent of amino acids never existed.

  12. Differential regulation of placental amino acid transport by saturated and unsaturated fatty acids.

    Science.gov (United States)

    Lager, Susanne; Jansson, Thomas; Powell, Theresa L

    2014-10-15

    Fatty acids are critical for normal fetal development but may also influence placental function. We have previously reported that oleic acid (OA) stimulates amino acid transport in primary human trophoblasts (PHTs). In other tissues, saturated and unsaturated fatty acids have distinct effects on cellular signaling, for instance, palmitic acid (PA) but not OA reduces IκBα expression. We hypothesized that saturated and unsaturated fatty acids differentially affect trophoblast amino acid transport and cellular signaling. To test this hypothesis, PHTs were cultured in docosahexaenoic acid (DHA; 50 μM), OA (100 μM), or PA (100 μM). DHA and OA were also combined to test whether DHA could counteract the OA stimulatory effect on amino acid transport. The effects of fatty acids were compared against a vehicle control. Amino acid transport was measured by isotope-labeled tracers. Activation of inflammatory-related signaling pathways and the mechanistic target of rapamycin (mTOR) pathway were determined by Western blot analysis. Exposure of PHTs to DHA for 24 h reduced amino acid transport and phosphorylation of p38 MAPK, STAT3, mTOR, eukaryotic initiation factor 4E-binding protein 1, and ribosomal protein (rp)S6. In contrast, OA increased amino acid transport and phosphorylation of ERK, mTOR, S6 kinase 1, and rpS6. The combination of DHA with OA increased amino acid transport and rpS6 phosphorylation. PA did not affect amino acid transport but reduced IκBα expression. In conclusion, these fatty acids differentially regulated placental amino acid transport and cellular signaling. Taken together, these findings suggest that dietary fatty acids could alter the intrauterine environment by modifying placental function, thereby having long-lasting effects on the developing fetus.

  13. Enzymatic-fluorometric analyses for glutamine, glutamate and free amino groups in protein-free plasma and milk

    DEFF Research Database (Denmark)

    Larsen, Torben; Fernández, Carlos J.

    2017-01-01

    This Technical Research Communication describes new analytical methods for free, unbound glutamic acid and glutamine in protein-free blood plasma and milk and introduces the use of quantitation of free amino groups in the same matrices for descriptive and analytical purposes. The present enzymatic...

  14. Amino acid containing glass-ionomer cement for orthopedic applications

    Science.gov (United States)

    Wu, Wei

    Amino acid containing glass-ionomer cements were synthesized, formulated, and evaluated for orthopedic application. The formulation of different amino acid containing glass-ionomer bone cements was optimized, and conventional and resin-modified glass-ionomer bone cements were compared. Properties of interest included handling characteristics, physical and chemical properties, and mechanical strength of the bone cement. The study was based on the synthesis of different vinyl containing amino acids, different polyelectrolytes containing these amino acid residues, and different resin-modified polyelectrolytes, as well as formulation and evaluation of conventional and resin-modified glass-ionomer bone cements using these polyelectrolytes. Systematic preparation of polyelectrolytes and formulation of glass-ionomer bone cements were essential features of this work, since we anticipated that the mechanical properties of the glass-ionomer bone cements could be strongly affected by the nature of the polyelectrolytes and formulation. Mechanical properties were evaluated in a screw driven mechanical testing machine, and structure-property relationships were determined by scanning electron microscopic (SEM) observation of the fracture surface of the specimens. How the structure of polyelectrolytes, such as different amino acid residues, molecular weight, different modifying resin, and formulation of glass-ionomer bone cement, affected the mechanical properties was also studied.

  15. Molecular evolution of plant AAP and LHT amino acid transporters

    Directory of Open Access Journals (Sweden)

    Mechthild eTegeder