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Sample records for acids proteins carbohydrates

  1. Ruminal protein metabolism and intestinal amino acid utilization as affected by dietary protein and carbohydrate sources in sheep.

    PubMed

    Hussein, H S; Jordan, R M; Stern, M D

    1991-05-01

    Eight wether lambs fitted with ruminal, duodenal, and ileal cannulas were used in a replicated 4 x 4 Latin square design to study the effects of carbohydrate and protein sources on ruminal protein metabolism and carbohydrate fermentation and intestinal amino acid (AA) absorption. Treatments were arranged as a 2 x 2 factorial. Carbohydrate sources were corn and barley; protein sources were soybean meal (SBM) and fish meal (FM). Diets contained 15.5% CP, of which 40% was supplied by SBM or FM. Corn or barley provided 39% of dietary DM that contained equal amounts of grass hay and wheat straw. Fish meal diets produced a lower (P less than .05) ruminal NH3 concentration and resulted in less CP degradation and bacterial protein flow to the duodenum than did SBM diets. Replacing SBM with FM increased (P less than .05) ruminal digestion of all fiber fractions. In addition, cellulose and hemicellulose digestibilities in the rumen tended to increase (P greater than .05) when barley replaced corn in the FM diets. Carbohydrate x protein interactions (P less than .05) were observed for OM digestion in the rumen and AA absorption in the small intestine (percentage of AA entering); these interactions were highest for the barley-FM diet. These results suggest that feeding FM with barley, which is high in both degradable carbohydrate and protein, might benefit ruminants more than feeding FM with corn, which is high in degradable carbohydrate but relatively low in degradable protein. PMID:1648551

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

    NASA Technical Reports Server (NTRS)

    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

  3. Effect of dietary fat, carbohydrate, and protein on branched-chain amino acid catabolism during caloric restriction.

    PubMed Central

    Vazquez, J A; Morse, E L; Adibi, S A

    1985-01-01

    To assess the effect of each dietary caloric source on the catabolism of branched-chain amino acids, we investigated the rate of leucine oxidation before and after obese volunteers consumed one of the following diets for one week: (a) starvation, (b) 300 or 500 cal of fat/d, (c) 300 or 500 cal of carbohydrate/d, (d) 300 or 500 cal of protein/d, (e) a mixture of carbohydrate (300 cal/d) and fat (200 cal/d), or (f) a mixture of carbohydrate (300 cal/d) and protein (200 cal/d). Starvation significantly increased the rate of leucine oxidation (1.4 +/- 0.11 vs. 1.8 +/- 0.16 mmol/h, P less than 0.01). The same occurred with the fat and protein diets. In sharp contrast, the 500-cal carbohydrate diet significantly decreased the rate of leucine oxidation (1.3 +/- 0.13 vs. 0.6 +/- 0.09 mmol/h, P less than 0.01). The same occurred when a portion of the carbohydrate diet was isocalorically replaced with either fat or protein. The cumulative nitrogen excretion during the fat diet and starvation was not significantly different. As compared with the fat diets, the carbohydrate diets on the average reduced the urinary nitrogen excretion by 12 g/wk. Nitrogen balance was positive during the consumption of the 500-cal protein diet, but negative during the consumption of carbohydrate-protein diet. The fat diets, like the protein diets and starvation, greatly increased plasma leucine (119 +/- 13 vs. 222 +/- 15 microM, P less than 0.01) and beta-hydroxybutyrate (0.12 +/- 0.02 vs. 4.08 +/- 0.43 mM, P less than 0.01) concentrations, and significantly decreased plasma glucose (96 +/- 4 vs. 66 +/- 3 mg/dl, P less than 0.01) and insulin (18 +/- 4 vs. 9 +/- 1 microU/ml, P less than 0.05) concentrations. These changes did not occur, or were greatly attenuated, when subjects consumed carbohydrate alone or in combination with fat or protein. We conclude that during brief caloric restriction, dietary lipid and protein, unlike carbohydrate, do not diminish the catabolism of branched-chain amino

  4. Hepatic fatty acid biosynthesis is more responsive to protein than carbohydrate in rainbow trout during acute stimulations.

    PubMed

    Dai, Weiwei; Panserat, Stéphane; Kaushik, Sadasivam; Terrier, Frédéric; Plagnes-Juan, Elisabeth; Seiliez, Iban; Skiba-Cassy, Sandrine

    2016-01-01

    The link between dietary carbohydrate/protein and de novo lipogenesis (DNL) remains debatable in carnivorous fish. We aimed to evaluate and compare the response of hepatic lipogenic gene expression to dietary carbohydrate intake/glucose and dietary protein intake/amino acids (AAs) during acute stimulations using both in vivo and in vitro approaches. For the in vivo trial, three different diets and a controlled-feeding method were employed to supply fixed amount of dietary protein or carbohydrate in a single meal; for the in vitro trial, primary hepatocytes were stimulated with a low or high level of glucose (3 mM or 20 mM) and a low or high level of AAs (one-fold or four-fold concentrated AAs). In vitro data showed that a high level of AAs upregulated the expression of enzymes involved in DNL [fatty acid synthase (FAS) and ATP citrate lyase (ACLY)], lipid bioconversion [elongation of very long chain fatty acids like-5 (Elovl5), Elovl2, Δ6 fatty acyl desaturase (D6D) and stearoyl-CoA desaturase-1 (SCD1)], NADPH production [glucose-6-phosphate dehydrogenase (G6PDH) and malic enzyme (ME)], and transcriptional factor sterol regulatory element binding protein 1-like, while a high level of glucose only elevated the expression of ME. Data in trout liver also showed that high dietary protein intake induced higher lipogenic gene expression (FAS, ACLY, and Elovl2) regardless of dietary carbohydrate intake, while high carbohydrate intake markedly suppressed the expression of acetyl-CoA carboxylase (ACC) and Elovl5. Overall, we conclude that, unlike rodents or humans, hepatic fatty acid biosynthetic gene expression in rainbow trout is more responsive to dietary protein intake/AAs than dietary carbohydrate intake/glucose during acute stimulations. This discrepancy probably represents one important physiological and metabolic difference between carnivores and omnivores. PMID:26491101

  5. Extension of microwave-accelerated residue-specific acid cleavage to proteins with carbohydrate side chains and disulfide linkages

    NASA Astrophysics Data System (ADS)

    Li, Jinxi; Shefcheck, Kevin; Callahan, John; Fenselau, Catherine

    2008-12-01

    This laboratory has introduced a chemical method for residue-specific protein cleavage and has provided a preliminary assessment of the suitability of microwave-accelerated acid cleavage as a proteomic tool. This report is a continuing assessment of the fate of common protein modifications in microwave-accelerated acid cleavage. We have examined the cleavage of ribonuclease A and the related N-linked glycoprotein ribonuclease B, and the O-linked glycoprotein alpha crystallin A chain, using MALDI-TOF and LC-ESI-MS to identify the peptide products. RNase A and B each contains four disulfide bonds, and the addition of a reducing reagent, such as dithiothreitol, was found to be required to achieve efficient acidic proteolysis. The linkage of the glycosidic group to the asparagine side chain in ribonuclease B was found not to be cleaved by brief microwave treatment in 12.5% acetic acid. The distribution of the heterogeneous carbohydrate side chain in the glycopeptide products of acid cleavage was compared to that of the glycopeptide products of tryptic digestion. Hydrolysis within the carbohydrate chain itself is minimal under the conditions used. The O-linked side chain on alpha crystalline A was found to be cleaved during acid cleavage of the protein.

  6. Combined nitrogen limitation and cadmium stress stimulate total carbohydrates, lipids, protein and amino acid accumulation in Chlorella vulgaris (Trebouxiophyceae).

    PubMed

    Chia, Mathias Ahii; Lombardi, Ana Teresa; da Graça Gama Melão, Maria; Parrish, Christopher C

    2015-03-01

    Metals have interactive effects on the uptake and metabolism of nutrients in microalgae. However, the effect of trace metal toxicity on amino acid composition of Chlorella vulgaris as a function of varying nitrogen concentrations is not known. In this research, C. vulgaris was used to investigate the influence of cadmium (10(-7) and 2.0×10(-8)molL(-1) Cd) under varying nitrogen (2.9×10(-6), 1.1×10(-5) and 1.1×10(-3)molL(-1)N) concentrations on its growth rate, biomass and biochemical composition. Total carbohydrates, total proteins, total lipids, as well as individual amino acid proportions were determined. The combination of Cd stress and N limitation significantly inhibited growth rate and cell density of C. vulgaris. However, increasing N limitation and Cd stress stimulated higher dry weight and chlorophyll a production per cell. Furthermore, biomolecules like total proteins, carbohydrates and lipids increased with increasing N limitation and Cd stress. Ketogenic and glucogenic amino acids were accumulated under the stress conditions investigated in the present study. Amino acids involved in metal chelation like proline, histidine and glutamine were significantly increased after exposure to combined Cd stress and N limitation. We conclude that N limitation and Cd stress affects the physiology of C. vulgaris by not only decreasing its growth but also stimulating biomolecule production. PMID:25625522

  7. Carbohydrate/protein selection in a single meal correlated with plasma tryptophan and tyrosine ratios to neutral amino acids in fasting individuals.

    PubMed

    Møller, S E

    1986-01-01

    Plasma ratios of tryptophan (Trp) and tyrosine (Tyr) to their respective competing large neutral amino acids (LNAA) for brain uptake, serum insulin and plasma glucose concentrations were determined in 31 fasting healthy female subjects, and in two smaller groups of smokers and oral contraceptive users, who were subsequently allowed to compose individual breakfast meals from a selection of 25 dietary products. Additional blood samples were collected at 2 hr after the meal. Smokers consumed less carbohydrate (-22%) and total calories (-23%) and showed decreased basal serum insulin level, when compared to controls on the same age. Females on oral contraceptives consumed significantly more carbohydrate (+54%) and total calories (+32%) than comparable controls. In the 31 females there was no significant correlation between any of the biological variables and the intake of fat or total calories. The ratio of carbohydrate/protein eaten was significantly and directly correlated with age and with the sum of plasma ratios Trp/LNAA and Tyr/LNAA, and these independent variables associated with 37% of the variance in the ratio carbohydrate/protein consumed, as evaluated by multiple regression analysis. After the meal, the plasma ratio Tyr/LNAA was increased, whereas the ratio Trp/LNAA was decreased in subjects whose ratio carbohydrate/protein consumed was below the mean of the full sample, whereas subjects who consumed meals with a high ratio carbohydrate/protein showed an increase in plasma ratio Trp/LNAA. It is concluded that biological variables in man are significantly associated with the choice between nutrients with different carbohydrate and protein contents for breakfast. The changes in the plasma ratios Trp/LNAA and Tyr/LNAA after consumption were generally moderate. PMID:3797484

  8. Dietary fat, carbohydrate and protein: effects on plasma lipoprotein profiles fat, carbohydrate and protein and plasma lipids

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In general, under isoweight conditions, different types of dietary protein or individual amino acids have little effect on lipoprotein patterns. Dietary carbohydrate tends to increase plasma triglyceride when it displaces fat, accompanied by a decrease in HDL cholesterol concentrations. Potential ...

  9. Lower vegetable protein intake and higher dietary acid load associated with lower carbohydrate intake are risk factors for metabolic syndrome in patients with type 2 diabetes: Post-hoc analysis of a cross-sectional study

    PubMed Central

    Iwase, Hiroya; Tanaka, Muhei; Kobayashi, Yukiko; Wada, Sayori; Kuwahata, Masashi; Kido, Yasuhiro; Hamaguchi, Masahide; Asano, Mai; Yamazaki, Masahiro; Hasegawa, Goji; Nakamura, Naoto; Fukui, Michiaki

    2015-01-01

    Aims/Introduction A low-carbohydrate diet based on animal sources is associated with higher all-cause mortality, whereas a vegetable-based low-carbohydrate diet is associated with lower cardiovascular disease mortality. It has been suggested that acid/base imbalance might play an important role in some cardiometabolic abnormalities. The aims of the present study were to evaluate whether carbohydrate intake is associated with quality of dietary protein and acid load, and whether these are related to metabolic syndrome in patients with type 2 diabetes. Materials and Methods The present cross-sectional study involved 149 patients with type 2 diabetes. Dietary intake was assessed using a validated self-administered diet history questionnaire. Dietary acid load was assessed by potential renal acid load and net endogenous acid production. Results Mean daily total energy intake, carbohydrate intake, animal protein intake and vegetable protein intake were 1821.5 kcal, 248.8 g, 36.1 g and 31.1 g, respectively. Carbohydrate energy/total energy was negatively correlated with animal protein energy/total energy, potential renal acid load or net endogenous acid production score, and was positively correlated with vegetable protein energy/total energy. Logistic regression analyses showed that the subgroup of patients with a lower vegetable protein energy/total energy or higher potential renal acid load or net endogenous acid production score was significantly associated with the prevalence of metabolic syndrome. Conclusions The present study showed that carbohydrate intake was associated with the quality of dietary protein and dietary acid load. Furthermore, decreased vegetable protein intake and increased dietary acid load were associated with the prevalence of metabolic syndrome. PMID:26221526

  10. Carbohydrate Polymers for Nonviral Nucleic Acid Delivery

    PubMed Central

    Sizovs, Antons; McLendon, Patrick M.; Srinivasachari, Sathya

    2014-01-01

    Carbohydrates have been investigated and developed as delivery vehicles for shuttling nucleic acids into cells. In this review, we present the state of the art in carbohydrate-based polymeric vehicles for nucleic acid delivery, with the focus on the recent successes in preclinical models, both in vitro and in vivo. Polymeric scaffolds based on the natural polysaccharides chitosan, hyaluronan, pullulan, dextran, and schizophyllan each have unique properties and potential for modification, and these results are discussed with the focus on facile synthetic routes and favorable performance in biological systems. Many of these carbohydrates have been used to develop alternative types of biomaterials for nucleic acid delivery to typical polyplexes, and these novel materials are discussed. Also presented are polymeric vehicles that incorporate copolymerized carbohydrates into polymer backbones based on polyethylenimine and polylysine and their effect on transfection and biocompatibility. Unique scaffolds, such as clusters and polymers based on cyclodextrin (CD), are also discussed, with the focus on recent successes in vivo and in the clinic. These results are presented with the emphasis on the role of carbohydrate and charge on transfection. Use of carbohydrates as molecular recognition ligands for cell-type specific delivery is also briefly reviewed. We contend that carbohydrates have contributed significantly to progress in the field of non-viral DNA delivery, and these new discoveries are impactful for developing new vehicles and materials for treatment of human disease. PMID:21504102

  11. Carbohydrate polymers for nonviral nucleic acid delivery.

    PubMed

    Sizovs, Antons; McLendon, Patrick M; Srinivasachari, Sathya; Reineke, Theresa M

    2010-01-01

    Carbohydrates have been investigated and developed as delivery vehicles for shuttling nucleic acids into cells. In this review, we present the state of the art in carbohydrate-based polymeric vehicles for nucleic acid delivery, with the focus on the recent successes in preclinical models, both in vitro and in vivo. Polymeric scaffolds based on the natural polysaccharides chitosan, hyaluronan, pullulan, dextran, and schizophyllan each have unique properties and potential for modification, and these results are discussed with the focus on facile synthetic routes and favorable performance in biological systems. Many of these carbohydrates have been used to develop alternative types of biomaterials for nucleic acid delivery to typical polyplexes, and these novel materials are discussed. Also presented are polymeric vehicles that incorporate copolymerized carbohydrates into polymer backbones based on polyethylenimine and polylysine and their effect on transfection and biocompatibility. Unique scaffolds, such as clusters and polymers based on cyclodextrin (CD), are also discussed, with the focus on recent successes in vivo and in the clinic. These results are presented with the emphasis on the role of carbohydrate and charge on transfection. Use of carbohydrates as molecular recognition ligands for cell-type specific delivery is also briefly reviewed. We contend that carbohydrates have contributed significantly to progress in the field of non-viral DNA delivery, and these new discoveries are impactful for developing new vehicles and materials for treatment of human disease. PMID:21504102

  12. Characterizing carbohydrate-protein interactions by NMR

    PubMed Central

    Bewley, Carole A.; Shahzad-ul-Hussan, Syed

    2013-01-01

    Interactions between proteins and soluble carbohydrates and/or surface displayed glycans are central to countless recognition, attachment and signaling events in biology. The physical chemical features associated with these binding events vary considerably, depending on the biological system of interest. For example, carbohydrate-protein interactions can be stoichiometric or multivalent, the protein receptors can be monomeric or oligomeric, and the specificity of recognition can be highly stringent or rather promiscuous. Equilibrium dissociation constants for carbohydrate binding are known to vary from micromolar to millimolar, with weak interactions being far more prevalent; and individual carbohydrate binding sites can be truly symmetrical or merely homologous, and hence, the affinities of individual sites within a single protein can vary, as can the order of binding. Several factors, including the weak affinities with which glycans bind their protein receptors, the dynamic nature of the glycans themselves, and the non-equivalent interactions among oligomeric carbohydrate receptors, have made NMR an especially powerful tool for studying and defining carbohydrate-protein interactions. Here we describe those NMR approaches that have proven to be the most robust in characterizing these systems, and explain what type of information can (or cannot) be obtained from each. Our goal is to provide to the reader the information necessary for selecting the correct experiment or sets of experiments to characterize their carbohydrate-protein interaction of interest. PMID:23784792

  13. [Carbohydrate-binding proteins of marine invertebrates].

    PubMed

    Luk'ianov, P A; Chernikov, O V; Kobelev, S S; Chikalovets, I V; Molchanova, V I; Li, W

    2007-01-01

    The information on the carbohydrate specificity and molecular organization of some carbohydrate-binding proteins (lectins) of marine invertebrates is reported. Antiviral activity of some of the lectins against human immunodeficiency virus has been studied. Lectins of marine invertebrates are promising tools for studying natural glycoconjugates and cell effectors in vitro. PMID:17375673

  14. Selective fermentation of carbohydrate and protein fractions of Scenedesmus, and biohydrogenation of its lipid fraction for enhanced recovery of saturated fatty acids.

    PubMed

    Lai, YenJung Sean; Parameswaran, Prathap; Li, Ang; Aguinaga, Alyssa; Rittmann, Bruce E

    2016-02-01

    Biofuels derived from microalgae have promise as carbon-neutral replacements for petroleum. However, difficulty extracting microalgae-derived lipids and the co-extraction of non-lipid components add major costs that detract from the benefits of microalgae-based biofuel. Selective fermentation could alleviate these problems by managing microbial degradation so that carbohydrates and proteins are hydrolyzed and fermented, but lipids remain intact. We evaluated selective fermentation of Scenedesmus biomass in batch experiments buffered at pH 5.5, 7, or 9. Carbohydrates were fermented up to 45% within the first 6 days, protein fermentation followed after about 20 days, and lipids (measured as fatty acid methyl esters, FAME) were conserved. Fermentation of the non-lipid components generated volatile fatty acids, with acetate, butyrate, and propionate being the dominant products. Selective fermentation of Scenedesmus biomass increased the amount of extractable FAME and the ratio of FAME to crude lipids. It also led to biohydrogenation of unsaturated FAME to more desirable saturated FAME (especially to C16:0 and C18:0), and the degree of saturation was inversely related to the accumulation of hydrogen gas after fermentation. Moreover, the microbial communities after selective fermentation were enriched in bacteria from families known to perform biohydrogenation, i.e., Porphyromonadaceae and Ruminococcaceae. Thus, this study provides proof-of-concept that selective fermentation can improve the quantity and quality of lipids that can be extracted from Scenedesmus. PMID:26222672

  15. The Mitochondrial Sulfur Dioxygenase ETHYLMALONIC ENCEPHALOPATHY PROTEIN1 Is Required for Amino Acid Catabolism during Carbohydrate Starvation and Embryo Development in Arabidopsis1[C][W

    PubMed Central

    Krüßel, Lena; Junemann, Johannes; Wirtz, Markus; Birke, Hannah; Thornton, Jeremy D.; Browning, Luke W.; Poschet, Gernot; Hell, Rüdiger; Balk, Janneke; Braun, Hans-Peter; Hildebrandt, Tatjana M.

    2014-01-01

    The sulfur dioxygenase ETHYLMALONIC ENCEPHALOPATHY PROTEIN1 (ETHE1) catalyzes the oxidation of persulfides in the mitochondrial matrix and is essential for early embryo development in Arabidopsis (Arabidopsis thaliana). We investigated the biochemical and physiological functions of ETHE1 in plant metabolism using recombinant Arabidopsis ETHE1 and three transfer DNA insertion lines with 50% to 99% decreased sulfur dioxygenase activity. Our results identified a new mitochondrial pathway catalyzing the detoxification of reduced sulfur species derived from cysteine catabolism by oxidation to thiosulfate. Knockdown of the sulfur dioxygenase impaired embryo development and produced phenotypes of starvation-induced chlorosis during short-day growth conditions and extended darkness, indicating that ETHE1 has a key function in situations of high protein turnover, such as seed production and the use of amino acids as alternative respiratory substrates during carbohydrate starvation. The amino acid profile of mutant plants was similar to that caused by defects in the electron-transfer flavoprotein/electron-transfer flavoprotein:ubiquinone oxidoreductase complex and associated dehydrogenases. Thus, in addition to sulfur amino acid catabolism, ETHE1 also affects the oxidation of branched-chain amino acids and lysine. PMID:24692429

  16. Impact of diets with a high content of greaves-meal protein or carbohydrates on faecal characteristics, volatile fatty acids and faecal calprotectin concentrations in healthy dogs

    PubMed Central

    2013-01-01

    Background Research suggests that dietary composition influences gastrointestinal function and bacteria-derived metabolic products in the dog colon. We previously reported that dietary composition impacts upon the faecal microbiota of healthy dogs. This study aims at evaluating the dietary influences on bacteria-derived metabolic products associated with the changes in faecal microbiota that we had previously reported. We fed high-carbohydrate starch based (HCS), [crude protein: 194 g/kg, starch: 438 g/kg], high-protein greaves-meal (HPGM), [crude protein: 609 g/kg, starch: 54 g/kg] and dry commercial (DC), [crude protein: 264 g/kg, starch: 277 g/kg] diets, and studied their effects on the metabolism of the colonic microbiota and faecal calprotectin concentrations in five Beagle dogs, allocated according to the Graeco-Latin square design. Each dietary period lasted for three weeks and was crossed-over with washout periods. Food intake, body weight, and faecal consistency scores, dry matter, pH, ammonia, volatile fatty acids (VFAs), and faecal canine calprotectin concentrations were determined. Results Faecal ammonia concentrations decreased with the HCS diet. All dogs fed the HPGM diet developed diarrhoea, which led to differences in faecal consistency scores between the diets. Faecal pH was higher with the HPGM diet. Moreover, decreases in propionic and acetic acids coupled with increases in branched-chain fatty acids and valeric acid caused changes in faecal total VFAs in dogs on the HPGM diet. Faecal canine calprotectin concentration was higher with the HPGM diet and correlated positively with valeric acid concentration. Conclusions The HPGM diet led to diarrhoea in all dogs, and there were differences in faecal VFA profiles and faecal canine calprotectin concentrations. PMID:24107268

  17. Phenol-Sulfuric Acid Method for Total Carbohydrates

    NASA Astrophysics Data System (ADS)

    Nielsen, S. Suzanne

    The phenol-sulfuric acid method is a simple and rapid colorimetric method to determine total carbohydrates in a sample. The method detects virtually all classes of carbohydrates, including mono-, di-, oligo-, and polysaccharides. Although the method detects almost all carbohydrates, the absorptivity of the different carbohydrates varies. Thus, unless a sample is known to contain only one carbohydrate, the results must be expressed arbitrarily in terms of one carbohydrate.

  18. Impact of Dietary Carbohydrate and Protein Levels on Carbohydrate Metabolism

    ERIC Educational Resources Information Center

    Lasker, Denise Ann

    2009-01-01

    The goal of this dissertation was to investigate the impact of changing dietary carbohydrate (CARB) intakes within recommended dietary guidelines on metabolic outcomes specifically associated with glycemic regulations and carbohydrate metabolism. This research utilized both human and animal studies to examine changes in metabolism across a wide…

  19. Postexercise recovery period: carbohydrate and protein metabolism.

    PubMed

    Viru, A

    1996-02-01

    The essence of the postexercise recovery period is normalization of function and homeostatic equilibrium, and replenishment of energy resources and accomplishment of the reconstructive function. The repletion of energy stores is actualized in a certain sequence and followed by a transitory supercompensation. The main substrate for repletion of the muscle glycogen store is blood glucose derived from hepatic glucose output as well as from consumption of carbohydrates during the postexercise period. The repletion of liver glycogen is realized less rapidly. It depends to a certain extent on hepatic gluconeogenesis but mainly on supply with exogenous carbohydrates. The constructive function is founded on elevated protein turnover and adaptive protein synthesis. Whereas during and shortly after endurance exercise intensive protein breakdown was found in less active fast-twitch glycolytic fibers, during the later course of the recovery period the protein degradation rate increased together with intensification of protein synthesis rate in more active fast-twitch glycolytic oxidative and slow-twitch oxidative fibers. PMID:8680938

  20. Analysis of Carbohydrate and Fatty Acid Marker Abundance in Ricin Toxin Preparations for Forensic Information

    SciTech Connect

    Colburn, Heather A.; Wunschel, David S.; Kreuzer-Martin, Helen W.; Moran, James J.; Antolick, Kathryn C.; Melville, Angela M.

    2010-07-15

    One challenge in the forensic analysis of ricin samples is determining the method and extent of sample preparation. Ricin purification from the source castor seeds is essentially a protein purification through removal of the non-protein fractions of the seed. Two major, non-protein constituents in the seed are the castor oil and carbohydrates. Ricinoleic acid is a relatively unique fatty acid in nature and is the most abundant component of castor oil, which comprises roughly half the seed weight. The carbohydrate component comprises roughly half of the remaining “mash” left after oil and hull removal. We used derivatization of carbohydrate and fatty acid markers followed by identification and quantification using gas chromatography/mass spectrometry (GC/MS) to assess compositional changes in ricin samples purified by different methods. The loss of ricinoleic acid indicated steps for oil removal had occurred. Changes to the carbohydrate content of the sample were also observed following protein precipitation. The differential loss of arabinose relative to mannose indicated removal of the major carbohydrate fraction of the seed and enrichment of the protein content. Taken together, these changes in fatty acid and carbohydrate abundance are indicative of the preparation method used for each sample.

  1. Effect of the Presence of Carbohydrates during Acid Hydrolysis upon the Subsequent Recovery Free Amino Acids

    PubMed Central

    Schulze, John; Presley, Jack

    2012-01-01

    Amino acid analysis is a classic biochemical technique which has been well characterized with pure protein samples. Much less is known about the effect of the presence other substances in hydrolyzed heterogeneous samples upon the final results. At the Molecular Structure Facility at UCDavis (MSF), we examined amino acid recovery following hydrolysis to determine if the presence of carbohydrates during hydrolysis influenced the recovery of the amino acids. The MSF works with a diverse sample set for different customers and have a keen interest if any of the many substances present in the sample can influence the final results. A typical sample is subjected to 6N HCl for 24hr at 110°C then brought back up in an acidic diluent to run on our dedicated Hitachi 8800 which utilizes ion-exchange chromatography with a post-column reaction with ninhydrin for quantification of each amino acid. We used this typical/routine hydrolysis in our experiments. One technique which is often employed to promote complete hydrolysis is to presoak the sample in dilute acid was also examined. Using various model proteins as well as varying percentages of carbohydrates we demonstrated that the presence of carbohydrates has little effect on the recovery of protein across a wide range of concentrations.

  2. Acute effect of protein or carbohydrate breakfasts on human cerebrospinal fluid monoamine precursor and metabolite levels.

    PubMed

    Teff, K L; Young, S N; Marchand, L; Botez, M I

    1989-01-01

    Patients with normal pressure hydrocephalus who had three lumbar punctures during 1 week ingested either water, a protein breakfast, or a carbohydrate breakfast 2.5 h before each of the lumbar punctures. The CSF was analyzed for biogenic amine precursors and metabolites. The protein meal raised CSF tyrosine levels, a finding consistent with animal data, but did not alter those of tryptophan or any of the biogenic amine metabolites. The carbohydrate meal increased CSF 3-methoxy-4-hydroxyphenylethylene glycol, an unexplained finding. The carbohydrate meal did not affect CSF tryptophan, tyrosine, 5-hydroxyindoleacetic acid, or homovanillic acid. Our results support the idea that in humans protein or carbohydrate meals do not alter plasma amino acid levels sufficiently to cause appreciable changes in CNS tryptophan levels or 5-hydroxytryptamine synthesis. PMID:2462018

  3. Reinforcement effect of soy protein and carbohydrates in polymer composites

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The modulus of soft polymer material can be increased by filler reinforcement. A review of using soy protein and carbohydrates as alternative renewable reinforcement material is presented here. Dry soy protein and carbohydrates are rigid and can form strong filler networks through hydrogen-bonding...

  4. Degradation properties of protein and carbohydrate during sludge anaerobic digestion.

    PubMed

    Yang, Guang; Zhang, Panyue; Zhang, Guangming; Wang, Yuanyuan; Yang, Anqi

    2015-09-01

    Degradation of protein and carbohydrate is vital for sludge anaerobic digestion performance. However, few studies focused on degradation properties of protein and carbohydrate. This study investigated detailed degradation properties of sludge protein and carbohydrate in order to gain insight into organics removal during anaerobic digestion. Results showed that carbohydrate was more efficiently degraded than protein and was degraded prior to protein. The final removal efficiencies of carbohydrate and protein were 49.7% and 32.2%, respectively. The first 3 days were a lag phase for protein degradation since rapid carbohydrate degradation in this phase led to repression of protease formation. Kinetics results showed that, after initial lag phase, protein degradation followed the first-order kinetic with rate constants of 0.0197 and 0.0018 d(-1) during later rapid degradation phase and slow degradation phase, respectively. Carbohydrate degradation also followed the first-order kinetics with a rate constant of 0.007 d(-1) after initial quick degradation phase. PMID:26025350

  5. Recommended proportions of carbohydrates to fats to proteins in diets

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Concern persists among physically active people regarding practical guidelines for amounts of dietary carbohydrate, protein and fat to facilitate recovery between training sessions and to promote optimal performance. This review summarizes current knowledge of the metabolic and physiological effect...

  6. Carbohydrates

    MedlinePlus

    Carbohydrates are one of the main types of nutrients. They are the most important source of energy for your body. Your digestive system changes carbohydrates into glucose (blood sugar). Your body uses this ...

  7. ANALYSIS OF RICIN TOXIN PREPARATIONS FOR CARBOHYDRATE AND FATTY ACID ABUNDANCE AND ISOTOPE RATIO INFORMATION

    SciTech Connect

    Wunschel, David S.; Kreuzer-Martin, Helen W.; Antolick, Kathryn C.; Colburn, Heather A.; Moran, James J.; Melville, Angela M.

    2009-12-01

    This report describes method development and preliminary evaluation for analyzing castor samples for signatures of purifying ricin. Ricin purification from the source castor seeds is essentially a problem of protein purification using common biochemical methods. Indications of protein purification will likely manifest themselves as removal of the non-protein fractions of the seed. Two major, non-protein, types of biochemical constituents in the seed are the castor oil and various carbohydrates. The oil comprises roughly half the seed weight while the carbohydrate component comprises roughly half of the remaining “mash” left after oil and hull removal. Different castor oil and carbohydrate components can serve as indicators of specific toxin processing steps. Ricinoleic acid is a relatively unique fatty acid in nature and is the most abundant component of castor oil. The loss of ricinoleic acid indicates a step to remove oil from the seeds. The relative amounts of carbohydrates and carbohydrate-like compounds, including arabinose, xylose, myo-inositol fucose, rhamnose, glucosamine and mannose detected in the sample can also indicate specific processing steps. For instance, the differential loss of arabinose relative to mannose and N-acetyl glucosamine indicates enrichment for the protein fraction of the seed using protein precipitation. The methods developed in this project center on fatty acid and carbohydrate extraction from castor samples followed by derivatization to permit analysis by gas chromatography-mass spectrometry (GC-MS). Method descriptions herein include: the source and preparation of castor materials used for method evaluation, the equipment and description of procedure required for chemical derivatization, and the instrument parameters used in the analysis. Two types of derivatization methods describe analysis of carbohydrates and one procedure for analysis of fatty acids. Two types of GC-MS analysis is included in the method development, one

  8. Amino Acid Change in the Carbohydrate Response Element Binding Protein is associated with lower triglycerides and myocardial infarction incidence depending on level of adherence to the Mediterranean diet in the PREDIMED trial

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A variant (rs3812316, C771G, and Gln241His) in the MLXIPL (Max-like protein X interacting protein-like) gene encoding the carbohydrate response element binding protein has been associated with lower triglycerides. However, its association with cardiovascular diseases and gene-diet interactions modul...

  9. Endurance in high-fat-fed rats: effects of carbohydrate content and fatty acid profile.

    PubMed

    Helge, J W; Ayre, K; Chaunchaiyakul, S; Hulbert, A J; Kiens, B; Storlien, L H

    1998-10-01

    The purpose of this experiment was to study endurance performance and substrate storage and utilization in fat- or carbohydrate-fed rats. Ninety-nine rats were randomly divided into three groups and over 4 wk were fed either a carbohydrate-rich [CHO; 10% total energy content in the diet (E%) fat, 20 E% protein, 70 E% carbohydrate] diet or one of two fat-rich diets (65 E% fat, 20 E% protein, 15 E% carbohydrate) containing either saturated (Sat) or monounsaturated fatty acids (Mono). Each dietary group was randomly assigned to a trained (6 days/wk, progressive to 60 min, 28 m/min at a 10% incline) or a sedentary group. Rats were killed either before or after a treadmill endurance run to exhaustion. Training increased endurance (206%), but diet composition did not affect endurance in either trained or sedentary rats. beta-Hydroxyacyl-CoA dehydrogenase activity was increased in fat-fed but not carbohydrate-fed rats (P < 0.05). Respiratory exchange ratio during the initial phase of exercise was lower after the Mono compared with the Sat diet (P < 0. 05) and higher after the CHO than the Sat diet (P < 0.05). Thus adaptation to a high-fat diet containing a moderate amount of carbohydrates did not induce enhanced endurance in either trained or untrained rats; however, substrate utilization was modulated by both amount and type of dietary fat during the initial stage of exercise in trained and sedentary rats. PMID:9760326

  10. Characterization of carbohydrate-protein matrices for nutrient delivery.

    PubMed

    Zhou, Yankun; Roos, Yrjö H

    2011-05-01

    Amorphous carbohydrates may show glass transition and crystallization as a result of thermal or water plasticization. Proteins often affect the state transitions of carbohydrates in carbohydrate-protein systems. Water sorption behavior and effects of water on glass transition and crystallization in freeze-dried lactose, trehalose, lactose-casein (3: 1), lactose-soy protein isolate (3:1), trehalose-casein (3:1), and trehalose-soy protein isolate (3:1) systems were studied. Water sorption was determined gravimetrically as a function of time, and Brunauer-Emmett-Teller (BET) and Guggenheim-Anderson-de Boer (GAB) models were fitted to the experimental data. Glass transition temperature (T(g)) and instant crystallization temperature (T(ic)) in anhydrous and water plasticized systems were measured using differential scanning calorimetry (DSC). The Gordon-Taylor equation was used to model water content dependence of the T(g) values. The critical water content and water activity (a(w)) at 24 °C were calculated and crystallization of lactose and trehalose in the systems was followed at and above 0.54 a(w). Carbohydrate-protein systems showed higher amounts of sorbed water and less rapid sugar crystallization than pure sugars. A greater sugar crystallization delay was found in carbohydrate-casein systems than in carbohydrate-soy protein isolate systems. The T(g) and T(ic) values decreased with increasing water content and a(w). However, higher T(ic) values for lactose-protein systems were found than for lactose at the same a(w). Trehalose showed lower T(ic) value than lactose at 0.44 a(w) but no instant crystallization was measured below 0.44 a(w). State diagrams for each system are useful in selecting processing parameters and storage conditions in nutrient delivery applications. PMID:22417357

  11. The Structural and Energetic Basis of Carbohydrate Aromatic Packing Interactions in Proteins

    PubMed Central

    Chen, Wentao; Enck, Sebastian; Price, Joshua L.; Powers, David L.; Powers, Evan T.; Wong, Chi-Huey; Dyson, H. Jane; Kelly, Jeffery W.

    2013-01-01

    Carbohydrate-aromatic interactions mediate many biological processes. However, the structure–energy relationships underpinning direct carbohydrate–aromatic packing in aqueous solution have been difficult to assess experimentally and remain elusive. Here, we determine the structures and folding energetics of chemically synthesized glycoproteins to quantify the contributions of the hydrophobic effect and CH–π interactions to carbohydrate–aromatic packing interactions in proteins. We find that the hydrophobic effect contributes significantly to protein–carbohydrate interactions. Interactions between carbohydrates and aromatic amino acid side chains, however, are supplemented by CH–π interactions. The strengths of experimentally determined carbohydrate–π interactions do not correlate with the electrostatic properties of the involved aromatic residues, suggesting that the electrostatic component of CH–π interactions in aqueous solution is small. Thus, tight binding of carbohydrates and aromatic residues is driven by the hydrophobic effect and CH–π interactions featuring a dominating dispersive component. PMID:23742246

  12. Interactions of polyphenols with carbohydrates, lipids and proteins.

    PubMed

    Jakobek, Lidija

    2015-05-15

    Polyphenols are secondary metabolites in plants, investigated intensively because of their potential positive effects on human health. Their bioavailability and mechanism of positive effects have been studied, in vitro and in vivo. Lately, a high number of studies takes into account the interactions of polyphenols with compounds present in foods, like carbohydrates, proteins or lipids, because these food constituents can have significant effects on the activity of phenolic compounds. This paper reviews the interactions between phenolic compounds and lipids, carbohydrates and proteins and their impact on polyphenol activity. PMID:25577120

  13. Carbohydrates

    MedlinePlus

    ... beans Vegetables, such as broccoli, Brussels sprouts, corn, potato with skin Fruits, such as raspberries, pears, apples, ... high in carbohydrates: Starchy vegetables: 1 cup mashed potato or sweet potato, 1 small ear of corn ...

  14. The statolith compartment in Chara rhizoids contains carbohydrate and protein

    NASA Technical Reports Server (NTRS)

    Wang-Cahill, F.; Kiss, J. Z.

    1995-01-01

    In contrast to higher plants, the alga Chara has rhizoids with single membrane-bound compartments that function as statoliths in gravity perception. Previous work has demonstrated that these statoliths contain barium sulfate crystals. In this study, we show that statoliths in Chara rhizoids react with a Coomassie Brilliant Blue cytochemical stain for proteins. While statoliths did not react with silver methenamine carbohydrate cytochemistry, the monoclonal antibody CCRC-M2, which is against a carbohydrate (sycamore-maple rhamnogalacturonan I), labeled the statolith compartment. These results demonstrate that in addition to barium sulfate, statoliths in Chara rhizoids have an organic matrix that consists of protein and carbohydrate moieties. Since the statoliths were silver methenamine negative, the carbohydrate in this compartment could be a 3-linked polysaccharide. CCRC-M2 also labeled Golgi cisternae, Golgi-associated vesicles, apical vesicles, and cell walls in the rhizoids. The specificity of CCRC-M2 immunolabeling was verified by several control experiments, including the demonstration that labeling was abolished when the antibody was preabsorbed with its antigen. Since in this and a previous study (John Z. Kiss and L. Andrew Staehelin, American Journal of Botany 80: 273-282, 1993) antibodies against higher plant carbohydrates crossreacted with cell walls of Chara in a specific manner, Characean algae may be a useful model system in biochemical and molecular studies of cell walls.

  15. Analysis of amino acids and carbohydrates in green coffee.

    PubMed

    Murkovic, Michael; Derler, Karin

    2006-11-30

    The analysis of carbohydrates and amino acids in green coffee is of the utmost importance since these two classes of compounds act as precursors of the Maillard reaction during which the colour and aroma are formed. During the course of the Maillard reaction potentially harmful substances like acrylamide or 5-hydroxymethyl-furfural accrue as well. The carbohydrates were analysed by anion-exchange chromatography with pulsed amperometric detection and the amino acids by reversed phase chromatography after derivatization with 6-amino-quinolyl-N-hydroxysuccinimidyl carbamate and fluorescence detection. Both methods had to be optimized to obtain a sufficient resolution of the analytes for identification and quantification. Sucrose is the dominant carbohydrate in green coffee with a concentration of up to 90 mg/g (mean = 73 mg/g) in arabica beans and significantly lower amounts in robusta beans (mean=45 mg/g). Alanine is the amino acid with the highest concentration (mean = 1200 microg/g) followed by asparagine (mean = 680 microg/g) in robusta and 800 microg/g and 360 microg/g in arabica respectively. In general, the concentration of amino acids is higher in robusta than in arabica. PMID:16563515

  16. Effects of carbohydrate, protein and lipid content of organic waste on hydrogen production and fermentation products.

    PubMed

    Alibardi, Luca; Cossu, Raffaello

    2016-01-01

    Organic waste from municipalities, food waste and agro-industrial residues are ideal feedstocks for use in biological conversion processes in biorefinery chains, representing biodegradable materials containing a series of substances belonging to the three main groups of the organic matter: carbohydrates, proteins and lipids. Biological hydrogen production by dark fermentation may assume a central role in the biorefinery concept, representing an up-front treatment for organic waste capable of hydrolysing complex organics and producing biohydrogen. This research study was aimed at evaluating the effects of carbohydrate, protein and lipid content of organic waste on hydrogen yields, volatile fatty acid production and carbon-fate. Biogas and hydrogen productions were linearly correlated to carbohydrate content of substrates while proteins and lipids failed to produce significant contributions. Chemical composition also produced effects on the final products of dark fermentation. Acetic and butyric acids were the main fermentation products, with their ratio proving to correlate with carbohydrate and protein content. The results obtained in this research study enhance the understanding of data variability on hydrogen yields from organic waste. Detailed information on waste composition and chemical characterisation are essential to clearly identify the potential performances of the dark fermentation process. PMID:26254676

  17. A statistical comparison of protein and carbohydrate characterisation methodology applied on sewage sludge samples.

    PubMed

    Jimenez, Julie; Vedrenne, Fabien; Denis, Cécile; Mottet, Alexis; Déléris, Stephane; Steyer, Jean-Philippe; Cacho Rivero, Jesús Andrés

    2013-04-01

    Biochemical characterization of organic matter is becoming of key importance in wastewater treatment. The main objectives are to predict organic matter properties, such as granulation or flocculation, and hence treatment performance. Although standardized methods do exist for some organic molecules, such as volatile fatty acids or lipids, there are no standard methods to measure proteins and carbohydrates content, both biochemical families being the main components of sewage sludge. Consequently, the aim of the present work is to investigate the efficiency of several colorimetric methods to determine proteins and carbohydrates content as well as their compatibility with the sludge matrices. The different methods have been evaluated based on statistical criteria such as sensitivity, linearity, accuracy, rightness, and specificity using standard molecules such as Bovine Serum Albumin (BSA), glucose, cellulose and a certified reference product. The Lowry and the Dubois methods have been shown to be the best compromise for the considered criteria after having been tested on sewage sludge samples obtained from different locations in a wastewater treatment plant. In average, the measured volatile fatty acids, lipids, proteins and carbohydrates contents represented 80 ± 7% (% volatile solids) of the organic matter. Proteins and carbohydrates represented in average 69 ± 3%. This study underlined that the choice of a relevant methodology is of great importance for organic matter measurement. PMID:23357791

  18. Stacking Interactions between Carbohydrate and Protein Quantified by Combination of Theoretical and Experimental Methods

    PubMed Central

    Nečasová, Ivona; Mishra, Sushil Kumar; Komárek, Jan; Koča, Jaroslav

    2012-01-01

    Carbohydrate – receptor interactions are an integral part of biological events. They play an important role in many cellular processes, such as cell-cell adhesion, cell differentiation and in-cell signaling. Carbohydrates can interact with a receptor by using several types of intermolecular interactions. One of the most important is the interaction of a carbohydrate's apolar part with aromatic amino acid residues, known as dispersion interaction or CH/π interaction. In the study presented here, we attempted for the first time to quantify how the CH/π interaction contributes to a more general carbohydrate - protein interaction. We used a combined experimental approach, creating single and double point mutants with high level computational methods, and applied both to Ralstonia solanacearum (RSL) lectin complexes with α-l-Me-fucoside. Experimentally measured binding affinities were compared with computed carbohydrate-aromatic amino acid residue interaction energies. Experimental binding affinities for the RSL wild type, phenylalanine and alanine mutants were −8.5, −7.1 and −4.1 kcal.mol−1, respectively. These affinities agree with the computed dispersion interaction energy between carbohydrate and aromatic amino acid residues for RSL wild type and phenylalanine, with values −8.8, −7.9 kcal.mol−1, excluding the alanine mutant where the interaction energy was −0.9 kcal.mol−1. Molecular dynamics simulations show that discrepancy can be caused by creation of a new hydrogen bond between the α-l-Me-fucoside and RSL. Observed results suggest that in this and similar cases the carbohydrate-receptor interaction can be driven mainly by a dispersion interaction. PMID:23056230

  19. Recovery from cycling exercise: effects of carbohydrate and protein beverages.

    PubMed

    Goh, Qingnian; Boop, Christopher A; Luden, Nicholas D; Smith, Alexia G; Womack, Christopher J; Saunders, Michael J

    2012-07-01

    The effects of different carbohydrate-protein (CHO + Pro) beverages were compared during recovery from cycling exercise. Twelve male cyclists (VO(2peak): 65 ± 7 mL/kg/min) completed ~1 h of high-intensity intervals (EX1). Immediately and 120 min following EX1, subjects consumed one of three calorically-similar beverages (285-300 kcal) in a cross-over design: carbohydrate-only (CHO; 75 g per beverage), high-carbohydrate/low-protein (HCLP; 45 g CHO, 25 g Pro, 0.5 g fat), or low-carbohydrate/high-protein (LCHP; 8 g CHO, 55 g Pro, 4 g fat). After 4 h of recovery, subjects performed subsequent exercise (EX2; 20 min at 70% VO(2peak) + 20 km time-trial). Beverages were also consumed following EX2. Blood glucose levels (30 min after beverage ingestion) differed across all treatments (CHO > HCLP > LCHP; p < 0.05), and serum insulin was higher following CHO and HCLP ingestion versus LCHP. Peak quadriceps force, serum creatine kinase, muscle soreness, and fatigue/energy ratings measured pre- and post-exercise were not different between treatments. EX2 performance was not significantly different between CHO (48.5 ± 1.5 min), HCLP (48.8 ± 2.1 min) and LCHP (50.3 ± 2.7 min). Beverages containing similar caloric content but different proportions of carbohydrate/protein provided similar effects on muscle recovery and subsequent exercise performance in well-trained cyclists. PMID:22852050

  20. Interactive Effects of Indigestible Carbohydrates, Protein Type, and Protein Level on Biomarkers of Large Intestine Health in Rats.

    PubMed

    Taciak, Marcin; Barszcz, Marcin; Tuśnio, Anna; Pastuszewska, Barbara

    2015-01-01

    The effects of indigestible carbohydrates, protein type, and protein level on large intestine health were examined in rats. For 21 days, 12 groups of six 12-week-old male Wistar rats were fed diets with casein (CAS), or potato protein concentrate (PPC), providing 14% (lower protein level; LP), or 20% (higher protein level; HP) protein, and containing cellulose, resistant potato starch, or pectin. Fermentation end-products, pH, and β-glucuronidase levels in cecal digesta, and ammonia levels in colonic digesta were determined. Cecal digesta, tissue weights, cecal and colon morphology, and colonocyte DNA damage were also analyzed. Digesta pH was lower, whereas relative mass of cecal tissue and digesta were higher in rats fed pectin diets than in those fed cellulose. Cecal parameters were greater in rats fed PPC and HP diets than in those fed CAS and LP diets, respectively. Short-chain fatty acid (SCFA) concentrations were unaffected by protein or carbohydrate type. Total SCFA, acetic acid, and propionic acid concentrations were greater in rats fed LP diets than in those fed HP. Cecal pool of isobutyric and isovaleric acids was greater in rats fed PPC than in those fed CAS diets. PPC diets decreased phenol concentration and increased ammonia concentration in cecal and colonic digesta, respectively. Cecal crypt depth was greater in rats fed PPC and HP diets, and was unaffected by carbohydrates; whereas colonic crypt depth was greater in rats fed cellulose. Myenteron thickness in the cecum was unaffected by nutrition, but was greater in the colon of rats fed cellulose. Colonocyte DNA damage was greater in rats fed LP diets than in those fed HP diets, and was unaffected by carbohydrate or protein type. It was found that nutritional factors decreasing cecal digesta weight contribute to greater phenol production, increased DNA damage, and reduced ammonia concentration in the colon. PMID:26536028

  1. Interactive Effects of Indigestible Carbohydrates, Protein Type, and Protein Level on Biomarkers of Large Intestine Health in Rats

    PubMed Central

    Taciak, Marcin; Barszcz, Marcin; Tuśnio, Anna; Pastuszewska, Barbara

    2015-01-01

    The effects of indigestible carbohydrates, protein type, and protein level on large intestine health were examined in rats. For 21 days, 12 groups of six 12-week-old male Wistar rats were fed diets with casein (CAS), or potato protein concentrate (PPC), providing 14% (lower protein level; LP), or 20% (higher protein level; HP) protein, and containing cellulose, resistant potato starch, or pectin. Fermentation end-products, pH, and β-glucuronidase levels in cecal digesta, and ammonia levels in colonic digesta were determined. Cecal digesta, tissue weights, cecal and colon morphology, and colonocyte DNA damage were also analyzed. Digesta pH was lower, whereas relative mass of cecal tissue and digesta were higher in rats fed pectin diets than in those fed cellulose. Cecal parameters were greater in rats fed PPC and HP diets than in those fed CAS and LP diets, respectively. Short-chain fatty acid (SCFA) concentrations were unaffected by protein or carbohydrate type. Total SCFA, acetic acid, and propionic acid concentrations were greater in rats fed LP diets than in those fed HP. Cecal pool of isobutyric and isovaleric acids was greater in rats fed PPC than in those fed CAS diets. PPC diets decreased phenol concentration and increased ammonia concentration in cecal and colonic digesta, respectively. Cecal crypt depth was greater in rats fed PPC and HP diets, and was unaffected by carbohydrates; whereas colonic crypt depth was greater in rats fed cellulose. Myenteron thickness in the cecum was unaffected by nutrition, but was greater in the colon of rats fed cellulose. Colonocyte DNA damage was greater in rats fed LP diets than in those fed HP diets, and was unaffected by carbohydrate or protein type. It was found that nutritional factors decreasing cecal digesta weight contribute to greater phenol production, increased DNA damage, and reduced ammonia concentration in the colon. PMID:26536028

  2. Improved Feed Protein Fractional Schemes for Formulating Rations With the Cornell Net Carbohydrate and Protein System

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Adequate predictions of rumen-degradable protein (RDP) and rumen-undegradable protein (RUP) supplies are necessary to optimize performance while minimizing losses of excess nitrogen (N). The objectives of this study were to evaluate the original Cornell Net Carbohydrate Protein System (CNCPS) protei...

  3. Transient decrements in mood during energy deficit are independent of dietary protein-to-carbohydrate ratio.

    PubMed

    Karl, J Philip; Thompson, Lauren A; Niro, Philip J; Margolis, Lee M; McClung, James P; Cao, Jay J; Whigham, Leah D; Combs, Gerald F; Young, Andrew J; Lieberman, Harris R; Pasiakos, Stefan M

    2015-02-01

    Energy deficit and dietary macronutrient intake are thought to independently modulate cognition, mood and sleep. To what extent manipulating the dietary ratio of protein-to-carbohydrate affects mood, cognition and sleep during short-term energy deficit is undetermined. Using a randomized, block design, 39 non-obese young adults (21±1 years, BMI 25±1 kg/m(2)) consumed diets containing 0.8 g, 1.6 g or 2.4 g protein per kg body weight per day for 31 days. Carbohydrate intake was reduced to accommodate higher protein intakes while dietary fat was maintained at 30% of total energy intake. Cognitive performance, mood, self-reported sleep quality, and plasma amino acid concentrations were periodically assessed during a 10-day energy balance period and a subsequent 21-day, 40% energy deficit period. Anger, tension and total mood disturbance increased during the initial ten days of energy deficit (P<0.05), but by the end of the energy deficit returned to levels not different from those measured during energy balance. No effects of dietary protein-to-carbohydrate ratio on cognitive performance, mood or self-reported sleep quality were observed during energy balance or energy deficit. Thus, high-protein, low-carbohydrate, moderate-fat diets do not appear to benefit or impair cognition, mood or sleep in non-obese adults during energy deficit. These findings suggest that energy deficit may initially be psychologically difficult for non-obese individuals attempting to lose weight, but that these changes are transient. Employing strategies that alleviate decrements in mood during this initial period of adaptation may help sustain weight loss efforts. PMID:25479571

  4. Protein-Carbohydrate Interactions Studied by NMR: From Molecular Recognition to Drug Design

    PubMed Central

    Fernández-Alonso, María del Carmen; Díaz, Dolores; Berbis, Manuel Álvaro; Marcelo, Filipa; Cañada, Javier; Jiménez-Barbero, Jesús

    2012-01-01

    Diseases that result from infection are, in general, a consequence of specific interactions between a pathogenic organism and the cells. The study of host-pathogen interactions has provided insights for the design of drugs with therapeutic properties. One area that has proved to be promising for such studies is the constituted by carbohydrates which participate in biological processes of paramount importance. On the one hand, carbohydrates have shown to be information carriers with similar, if not higher, importance than traditionally considered carriers as amino acids and nucleic acids. On the other hand, the knowledge on molecular recognition of sugars by lectins and other carbohydrate-binding proteins has been employed for the development of new biomedical strategies. Biophysical techniques such as X-Ray crystallography and NMR spectroscopy lead currently the investigation on this field. In this review, a description of traditional and novel NMR methodologies employed in the study of sugar-protein interactions is briefly presented in combination with a palette of NMR-based studies related to biologically and/or pharmaceutically relevant applications. PMID:23305367

  5. Selection of dietary protein and carbohydrate by rats: Changes with maturation

    NASA Technical Reports Server (NTRS)

    Yokogoshi, Hidehiko; Theall, Cynthia L.; Wurtman, Richard J.

    1985-01-01

    Weaning (21-day-old; 40-50 g) male rats given simultaneous access to foods, containing 18 percent casein and 15 or 70 percent carbohydrate (dextrin), tended to consume only 29-35 percent as much protein as carbohydrate (i.e., protein/carbohydrate ratios were 0.29-0.35). With maturation, when animals weighed 100 g or more, about half continued this pattern of nutrient choice, but the others abruptly began to consume considerably larger proportions of protein, exhibiting protein/carbohydrate ratios as high as 0.80-1.00. Each adult animal's protein/carbohydrate ratio tended to vary only slightly (s.e. = 3 percent of means). Adult protein/carbohydrate ratios were not correlated with fasting brain 5-HT or 5-HIAA levels. These marked differences among rats in eating behavior would not be observed when--as is usually the case--animals are given access to only one diet.

  6. Simultaneous assay of pigments, carbohydrates, proteins and lipids in microalgae.

    PubMed

    Chen, Yimin; Vaidyanathan, Seetharaman

    2013-05-01

    Biochemical compositional analysis of microbial biomass is a useful tool that can provide insight into the behaviour of an organism and its adaptational response to changes in its environment. To some extent, it reflects the physiological and metabolic status of the organism. Conventional methods to estimate biochemical composition often employ different sample pretreatment strategies and analytical steps for analysing each major component, such as total proteins, carbohydrates, and lipids, making it labour-, time- and sample-intensive. Such analyses when carried out individually can also result in uncertainties of estimates as different pre-treatment or extraction conditions are employed for each of the component estimations and these are not necessarily standardised for the organism, resulting in observations that are not easy to compare within the experimental set-up or between laboratories. We recently reported a method to estimate total lipids in microalgae (Chen, Vaidyanathan, Anal. Chim. Acta, 724, 67-72). Here, we propose a unified method for the simultaneous estimation of the principal biological components, proteins, carbohydrates, lipids, chlorophyll and carotenoids, in a single microalgae culture sample that incorporates the earlier published lipid assay. The proposed methodology adopts an alternative strategy for pigment assay that has a high sensitivity. The unified assay is shown to conserve sample (by 79%), time (67%), chemicals (34%) and energy (58%) when compared to the corresponding assay for each component, carried out individually on different samples. The method can also be applied to other microorganisms, especially those with recalcitrant cell walls. PMID:23601278

  7. Apparent low ability of liver and muscle to adapt to variation of dietary carbohydrate:protein ratio in rainbow trout (Oncorhynchus mykiss).

    PubMed

    Skiba-Cassy, Sandrine; Panserat, Stéphane; Larquier, Mélanie; Dias, Karine; Surget, Anne; Plagnes-Juan, Elisabeth; Kaushik, Sadasivam; Seiliez, Iban

    2013-04-28

    The rainbow trout (Oncorhynchus mykiss) exhibits high dietary amino acid requirements and an apparent inefficiency to use dietary carbohydrates. Using this species, we investigated the metabolic consequences of long-term high carbohydrates/low protein feeding. Fish were fed two experimental diets containing either 20% carbohydrates/50% proteins (C20P50), or high levels of carbohydrates at the expense of proteins (35% carbohydrates/35% proteins--C35P35). The expression of genes related to hepatic and muscle glycolysis (glucokinase (GK), pyruvate kinase and hexokinase) illustrates the poor utilisation of carbohydrates irrespective of their dietary levels. The increased postprandial GK activity and the absence of inhibition of the gluconeogenic enzyme glucose-6-phosphatase activity support the hypothesis of the existence of a futile cycle around glucose phosphorylation extending postprandial hyperglycaemia. After 9 weeks of feeding, the C35P35-fed trout displayed lower body weight and feed efficiency and reduced protein and fat gains than those fed C20P50. The reduced activation of eukaryotic translation initiation factor 4-E binding protein 1 (4E-BP1) in the muscle in this C35P35 group suggests a reduction in protein synthesis, possibly contributing to the reduction in N gain. An increase in the dietary carbohydrate:protein ratio decreased the expression of genes involved in amino acid catabolism (serine dehydratase and branched-chain α-keto acid dehydrogenase E1α and E1β), and increased that of carnitine palmitoyltransferase 1, suggesting a higher reliance on lipids as energy source in fish fed high-carbohydrate and low-protein diets. This probably also contributes to the lower fat gain. Together, these results show that different metabolic pathways are affected by a high-carbohydrate/low-protein diet in rainbow trout. PMID:22951215

  8. Periexercise coingestion of branched-chain amino acids and carbohydrate in men does not preferentially augment resistance exercise-induced increases in phosphatidylinositol 3 kinase/protein kinase B-mammalian target of rapamycin pathway markers indicative of muscle protein synthesis.

    PubMed

    Ferreira, Maria Pontes; Li, Rui; Cooke, Matthew; Kreider, Richard B; Willoughby, Darryn S

    2014-03-01

    The effects of a single bout of resistance exercise (RE) in conjunction with periexercise branched-chain amino acid (BCAA) and carbohydrate (CHO) ingestion on skeletal muscle signaling markers indicative of muscle protein synthesis were determined. It was hypothesized that CHO + BCAA would elicit a more profound effect on these signaling markers compared with CHO. Twenty-seven males were randomly assigned to CHO, CHO + BCAA, or placebo (PLC) groups. Four sets of leg presses and leg extensions were performed at 80% 1 repetition maximum. Supplements were ingested 30 minutes and immediately before and after RE. Venous blood and muscle biopsy samples were obtained immediately before supplement ingestion and 0.5, 2, and 6 hours after RE. Serum insulin and glucose and phosphorylated levels of muscle insulin receptor substrate 1 (IRS-1), protein kinase B, mammalian target of rapamycin, phosphorylated 70S6 kinase, and 4E binding protein 1 were assessed. Data were analyzed by 2-way repeated-measures analysis of variance. Significant group × time interactions were observed for glucose and insulin (P < .05) showing that CHO and CHO + BCAA were significantly greater than PLC. Significant time main effects were observed for IRS-1 (P = .001), protein kinase B (P = .031), mammalian target of rapamycin (P = .003), and phosphorylated 70S6 kinase (P = .001). Carbohydrate and CHO + BCAA supplementation significantly increased IRS-1 compared with PLC (P = .002). However, periexercise coingestion of CHO and BCAA did not augment RE-induced increases in skeletal muscle signaling markers indicative of muscle protein synthesis when compared with CHO. PMID:24655485

  9. Carbohydrate metabolism during prolonged exercise and recovery: interactions between pyruvate dehydrogenase, fatty acids, and amino acids.

    PubMed

    Mourtzakis, Marina; Saltin, Bengt; Graham, Terry; Pilegaard, Henriette

    2006-06-01

    During prolonged exercise, carbohydrate oxidation may result from decreased pyruvate production and increased fatty acid supply and ultimately lead to reduced pyruvate dehydrogenase (PDH) activity. Pyruvate also interacts with the amino acids alanine, glutamine, and glutamate, whereby the decline in pyruvate production could affect tricarboxycylic acid cycle flux as well as gluconeogenesis. To enhance our understanding of these interactions, we studied the time course of changes in substrate utilization in six men who cycled at 44+/-1% peak oxygen consumption (mean+/-SE) until exhaustion (exhaustion at 3 h 23 min+/-11 min). Femoral arterial and venous blood, blood flow measurements, and muscle samples were obtained hourly during exercise and recovery (3 h). Carbohydrate oxidation peaked at 30 min of exercise and subsequently decreased for the remainder of the exercise bout (P<0.05). PDH activity peaked at 2 h of exercise, whereas pyruvate production peaked at 1 h of exercise and was reduced (approximately 30%) thereafter, suggesting that pyruvate availability primarily accounted for reduced carbohydrate oxidation. Increased free fatty acid uptake (P<0.05) was also associated with decreasing PDH activity (P<0.05) and increased PDH kinase 4 mRNA (P<0.05) during exercise and recovery. At 1 h of exercise, pyruvate production was greatest and was closely linked to glutamate, which was the predominant amino acid taken up during exercise and recovery. Alanine and glutamine were also associated with pyruvate metabolism, and they comprised approximately 68% of total amino-acid release during exercise and recovery. Thus reduced pyruvate production was primarily associated with reduced carbohydrate oxidation, whereas the greatest production of pyruvate was related to glutamate, glutamine, and alanine metabolism in early exercise. PMID:16424076

  10. Studies on the carbohydrate moiety of α1-acid glycoprotein (orosomucoid) by using alkaline hydrolysis and deamination by nitrous acid

    PubMed Central

    Isemura, M.; Schmid, K.

    1971-01-01

    Alkaline hydrolysis followed by deamination with nitrous acid was applied for the first time to a glycoprotein, human plasma α1-acid glycoprotein (orosomucoid). This procedure, which specifically cleaves the glycosaminidic bonds, yielded well-defined oligosaccharides. The trisaccharides, which were obtained from the native protein, consisted of a sialic acid derivative, galactose and 2,5-anhydromannose. The linkage between galactose and 2,5-anhydromannose is most probably a (1→4)-glycosidic bond. A hitherto unknown linkage between N-acetylneuraminic acid and galactose was also established, namely a (2→2)-linkage. The three linkages between sialic acid and galactose described in this paper appear to be about equally resistant to mild acid hydrolysis. The disaccharide that was derived from the desialized glycoprotein consisted of galactose and 2,5-anhydromannose. Evidence was obtained for the presence of a new terminal sialyl→N-acetylglucosamine disaccharide accounting for approximately 1mol/mol of protein. The presence of this disaccharide may explain the relatively severe requirements for the complete acid hydrolysis of the sialyl residues. The present study indicates that alkaline hydrolysis followed by nitrous acid deamination in conjunction with gas–liquid chromatography will afford relatively rapid determination of the partial structure of the complex carbohydrate moiety of glycoproteins. PMID:5135244

  11. Reinforcement effect of soy protein/carbohydrate ratio in styrene-butadiene polymer

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Soy protein and carbohydrate at different ratios were blended with latex to form composites. The variation of protein to carbohydrate ratio has a sifnificant effect on the composite properties and the results from dynamic mechanical method showed a substantial reinforcement effect. The composites ...

  12. Intake of Protein Plus Carbohydrate during the First Two Hours after Exhaustive Cycling Improves Performance the following Day.

    PubMed

    Rustad, Per I; Sailer, Manuela; Cumming, Kristoffer T; Jeppesen, Per B; Kolnes, Kristoffer J; Sollie, Ove; Franch, Jesper; Ivy, John L; Daniel, Hannelore; Jensen, Jørgen

    2016-01-01

    Intake of protein immediately after exercise stimulates protein synthesis but improved recovery of performance is not consistently observed. The primary aim of the present study was to compare performance 18 h after exhaustive cycling in a randomized diet-controlled study (175 kJ·kg(-1) during 18 h) when subjects were supplemented with protein plus carbohydrate or carbohydrate only in a 2-h window starting immediately after exhaustive cycling. The second aim was to investigate the effect of no nutrition during the first 2 h and low total energy intake (113 kJ·kg(-1) during 18 h) on performance when protein intake was similar. Eight endurance-trained subjects cycled at 237±6 Watt (~72% VO2max) until exhaustion (TTE) on three occasions, and supplemented with 1.2 g carbohydrate·kg(-1)·h(-1) (CHO), 0.8 g carbohydrate + 0.4 g protein·kg(-1)·h(-1) (CHO+PRO) or placebo without energy (PLA). Intake of CHO+PROT increased plasma glucose, insulin, and branch chained amino acids, whereas CHO only increased glucose and insulin. Eighteen hours later, subjects performed another TTE at 237±6 Watt. TTE was increased after intake of CHO+PROT compared to CHO (63.5±4.4 vs 49.8±5.4 min; p<0.05). PLA reduced TTE to 42.8±5.1 min (p<0.05 vs CHO). Nitrogen balance was positive in CHO+PROT, and negative in CHO and PLA. In conclusion, performance was higher 18 h after exhaustive cycling with intake of CHO+PROT compared to an isocaloric amount of carbohydrate during the first 2 h post exercise. Intake of a similar amount of protein but less carbohydrate during the 18 h recovery period reduced performance. PMID:27078151

  13. Intake of Protein Plus Carbohydrate during the First Two Hours after Exhaustive Cycling Improves Performance the following Day

    PubMed Central

    Rustad, Per I.; Kolnes, Kristoffer J.; Sollie, Ove; Franch, Jesper; Ivy, John L.; Daniel, Hannelore; Jensen, Jørgen

    2016-01-01

    Intake of protein immediately after exercise stimulates protein synthesis but improved recovery of performance is not consistently observed. The primary aim of the present study was to compare performance 18 h after exhaustive cycling in a randomized diet-controlled study (175 kJ·kg-1 during 18 h) when subjects were supplemented with protein plus carbohydrate or carbohydrate only in a 2-h window starting immediately after exhaustive cycling. The second aim was to investigate the effect of no nutrition during the first 2 h and low total energy intake (113 kJ·kg-1 during 18 h) on performance when protein intake was similar. Eight endurance-trained subjects cycled at 237±6 Watt (~72% VO2max) until exhaustion (TTE) on three occasions, and supplemented with 1.2 g carbohydrate·kg-1·h-1 (CHO), 0.8 g carbohydrate + 0.4 g protein·kg-1·h-1 (CHO+PRO) or placebo without energy (PLA). Intake of CHO+PROT increased plasma glucose, insulin, and branch chained amino acids, whereas CHO only increased glucose and insulin. Eighteen hours later, subjects performed another TTE at 237±6 Watt. TTE was increased after intake of CHO+PROT compared to CHO (63.5±4.4 vs 49.8±5.4 min; p<0.05). PLA reduced TTE to 42.8±5.1 min (p<0.05 vs CHO). Nitrogen balance was positive in CHO+PROT, and negative in CHO and PLA. In conclusion, performance was higher 18 h after exhaustive cycling with intake of CHO+PROT compared to an isocaloric amount of carbohydrate during the first 2 h post exercise. Intake of a similar amount of protein but less carbohydrate during the 18 h recovery period reduced performance. PMID:27078151

  14. Proteins and Amino Acids

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Proteins are the most abundant substances in living organisms and cells. All proteins are constructed from the same twenty amino acids that are linked together by covalent bonds. Shorter chains of two or more amino acids can be linked by covalent bonds to form polypeptides. There are twenty amino...

  15. Boronic Acid-modified DNA that Changes Fluorescent Properties upon Carbohydrate Binding†

    PubMed Central

    Yang, Xiaochuan; Dai, Chaofeng; Molina, Angie Dayan Calderon

    2010-01-01

    A long wavelength boronic acid-modified TTP (NB-TTP) has been synthesized and enzymatically incorporated into DNA. Such DNA shows intrinsic fluorescent changes upon carbohydrate addition. PMID:20126717

  16. The influence of carbohydrate-protein co-ingestion following endurance exercise on myofibrillar and mitochondrial protein synthesis.

    PubMed

    Breen, Leigh; Philp, Andrew; Witard, Oliver C; Jackman, Sarah R; Selby, Anna; Smith, Ken; Baar, Keith; Tipton, Kevin D

    2011-08-15

    The aim of the present study was to determine mitochondrial and myofibrillar muscle protein synthesis (MPS) when carbohydrate (CHO) or carbohydrate plus protein (C+P) beverages were ingested following prolonged cycling exercise. The intracellular mechanisms thought to regulate MPS were also investigated. In a single-blind, cross-over study, 10 trained cyclists (age 29 ± 6 years, VO2max 66.5 ± 5.1 ml kg(−1) min(−1)) completed two trials in a randomized order. Subjects cycled for 90 min at 77 ± 1% VO2max before ingesting a CHO (25 g of carbohydrate) or C+P (25 g carbohydrate + 10 g whey protein) beverage immediately and 30 min post-exercise. A primed constant infusion of L-[ring-(13)C6]phenylalanine began 1.5 h prior to exercise and continued until 4 h post-exercise. Muscle biopsy samples were obtained to determine myofibrillar and mitochondrial MPS and the phosphorylation of intracellular signalling proteins. Arterialized blood samples were obtained throughout the protocol. Plasma amino acid and urea concentrations increased following ingestion of C+P only. Serum insulin concentration increased more for C+P than CHO. Myofibrillar MPS was ∼35% greater for C+P compared with CHO (0.087 ± 0.007 and 0.057 ± 0.006% h(−1), respectively; P = 0.025). Mitochondrial MPS rates were similar for C+P and CHO (0.082 ± 0.011 and 0.086 ± 0.018% h(−1), respectively). mTOR(Ser2448) phosphorylation was greater for C+P compared with CHO at 4 h post-exercise (P < 0.05). p70S6K(Thr389) phosphorylation increased at 4 h post-exercise for C+P (P < 0.05), whilst eEF2(Thr56) phosphorylation increased by ∼40% at 4 h post-exercise for CHO only (P < 0.01). The present study demonstrates that the ingestion of protein in addition to carbohydrate stimulates an increase in myofibrillar, but not mitochondrial, MPS following prolonged cycling. These data indicate that the increase in myofibrillar MPS for C+P could, potentially, be mediated through p70S6K, downstream of mTOR, which in

  17. Acid-Catalyzed Algal Biomass Pretreatment for Integrated Lipid and Carbohydrate-Based Biofuels Production

    SciTech Connect

    Laurens, L. M. L.; Nagle, N.; Davis, R.; Sweeney, N.; Van Wychen, S.; Lowell, A.; Pienkos, P. T.

    2014-11-12

    One of the major challenges associated with algal biofuels production in a biorefinery-type setting is improving biomass utilization in its entirety, increasing the process energetic yields and providing economically viable and scalable co-product concepts. We demonstrate the effectiveness of a novel, integrated technology based on moderate temperatures and low pH to convert the carbohydrates in wet algal biomass to soluble sugars for fermentation, while making lipids more accessible for downstream extraction and leaving a protein-enriched fraction behind. We studied the effect of harvest timing on the conversion yields, using two algal strains; Chlorella and Scenedesmus, generating biomass with distinctive compositional ratios of protein, carbohydrate, and lipids. We found that the late harvest Scenedesmus biomass had the maximum theoretical biofuel potential at 143 gasoline gallon equivalent (GGE) combined fuel yield per dry ton biomass, followed by late harvest Chlorella at 128 GGE per ton. Our experimental data show a clear difference between the two strains, as Scenedesmus was more successfully converted in this process with a demonstrated 97 GGE per ton. Our measurements indicated a release of >90% of the available glucose in the hydrolysate liquors and an extraction and recovery of up to 97% of the fatty acids from wet biomass. Techno-economic analysis for the combined product yields indicates that this process exhibits the potential to improve per-gallon fuel costs by up to 33% compared to a lipids-only process for one strain, Scenedesmus, grown to the mid-point harvest condition.

  18. Breakfast high in whey protein or carbohydrates improves coping with workload in healthy subjects.

    PubMed

    Sihvola, Nora; Korpela, Riitta; Henelius, Andreas; Holm, Anu; Huotilainen, Minna; Müller, Kiti; Poussa, Tuija; Pettersson, Kati; Turpeinen, Anu; Peuhkuri, Katri

    2013-11-14

    Dietary components may affect brain function and influence behaviour by inducing the synthesis of neurotransmitters. The aim of the present study was to examine the influence of consumption of a whey protein-containing breakfast drink v. a carbohydrate drink v. control on subjective and physiological responses to mental workload in simulated work. In a randomised cross-over design, ten healthy subjects (seven women, median age 26 years, median BMI 23 kg/m(2)) participated in a single-blinded, placebo-controlled study. The subjects performed demanding work-like tasks after having a breakfast drink high in protein (HP) or high in carbohydrate (HC) or a control drink on separate sessions. Subjective states were assessed using the NASA Task Load Index (NASA-TLX), the Karolinska sleepiness scale (KSS) and the modified Profile of Mood States. Heart rate was recorded during task performance. The ratio of plasma tryptophan (Trp) to the sum of the other large neutral amino acids (LNAA) and salivary cortisol were also analysed. The plasma Trp:LNAA ratio was 30 % higher after the test drinks HP (median 0·13 (μmol/l)/(μmol/l)) and HC (median 0·13 (μmol/l)/(μmol/l)) than after the control drink (median 0·10 (μmol/l)/(μmol/l)). The increase in heart rate was smaller after the HP (median 2·7 beats/min) and HC (median 1·9 beats/min) drinks when compared with the control drink (median 7·2 beats/min) during task performance. Subjective sleepiness was reduced more after the HC drink (median KSS - 1·5) than after the control drink (median KSS - 0·5). There were no significant differences between the breakfast types in the NASA-TLX index, cortisol levels or task performance. We conclude that a breakfast drink high in whey protein or carbohydrates may improve coping with mental tasks in healthy subjects. PMID:23591085

  19. Carbohydrate and amino acid metabolism of Spironucleus vortens.

    PubMed

    Millet, Coralie O M; Lloyd, David; Coogan, Michael P; Rumsey, Joanna; Cable, Joanne

    2011-09-01

    The metabolism of Spironucleus vortens, a parasitic, diplomonad flagellate related to Giardia intestinalis, was investigated using a combination of membrane inlet mass spectrometry, (1)H NMR, (13)C NMR, bioscreen continuous growth monitoring, and ion exchange chromatography. The products of glucose-fuelled and endogenous metabolism were identified by (1)H NMR and (13)C NMR as ethanol, acetate, alanine and lactate. Mass spectrometric monitoring of gas metabolism in buffered cell suspensions showed that glucose and ethanol could be used by S. vortens as energy-generating substrates, but bioscreen automated monitoring of growth in culture medium, as well as NMR analyses, suggested that neither of these compounds are the substrates of choice for this organism. Ion-exchange chromatographic analyses of free amino-acid and amino-acid hydrolysate of growth medium revealed that, despite the availability of large pools of free amino-acids in the medium, S. vortens hydrolysed large amounts of proteins during growth. The organism produced alanine and aspartate, and utilised lysine, arginine, leucine, cysteine and urea. However, mass spectrometric and bioscreen investigations showed that addition of the utilised amino acids to diluted culture medium did not induce any significant increase in metabolic or growth rates. Moreover, as no significant amounts of ornithine were produced, and addition of arginine under aerobic conditions did not generate NO production, there was no evidence of the presence of an energy-generating, arginine dihydrolase pathway in S. vortens under in vitro conditions. PMID:21679707

  20. Weight Loss at a Cost: Implications of High-Protein, Low- Carbohydrate Diets.

    ERIC Educational Resources Information Center

    Gabel, Kathe A.; Lund, Robin J.

    2002-01-01

    Addresses three claims of high-protein, low-carbohydrate diets: weight loss is attributed to the composition of the diet; insulin promotes the storage of fat, thereby, by limiting carbohydrates, dieters will decrease levels of insulin and body fat; and weight loss is the result of fat loss. The paper examines relevant scientific reports and notes…

  1. Carbohydrate content of acid alpha-glucosidase (gamma-amylase) from human liver.

    PubMed

    Belen'ky, D M; Mikhajlov, V I; Rosenfeld, E L

    1979-05-01

    The presence of carbohydrates in homogeneous preparations of human liver acid alpha-glucosidase has been established and the carbohydrate content of the enzyme determined. The enzyme was purified with the specific purpose of removing all low-molecular-weight carbohydrates. It was specifically adsorbed on Concanavalin A-Sepharose, eluted with methyl-alpha-D-mannopyranoside and gave a positive reaction with the phenol-sulphuric acid reagent. These facts taken together provide evidence that the enzyme studied is a glycoprotein. The analysis of the carbohydrate content of human liver acid alpha-glucosidase showed that there were 8.3 glucosamine, 13.2 mannose and possibly 3--4 glucose residues per molecule of the enzyme with a molecular weight of 98,000. PMID:376187

  2. Orchestration of carbohydrate processing for crassulacean acid metabolism.

    PubMed

    Borland, Anne M; Guo, Hao-Bo; Yang, Xiaohan; Cushman, John C

    2016-06-01

    The production of phosphoenolpyruvate as a substrate for nocturnal CO2 uptake represents a significant sink for carbohydrate in CAM plants which has to be balanced with the provisioning of carbohydrate for growth and maintenance. In starch-storing CAM species, diversification in chloroplast metabolite transporters, and the deployment of both phosphorolytic and hydrolytic routes of starch degradation accommodate a division of labour in directing C-skeletons towards nocturnal carboxylation or production of sucrose for growth. In soluble-sugar storing CAM plants, the vacuole plays a central role in managing carbon homeostasis. The molecular identities of various types of vacuolar sugar transporters have only been identified for C3 species within the last 10 years. The recent availability of CAM genomes enables the identification of putative orthologues of vacuolar sugar transporters which represent strategic targets for orchestrating the diel provisioning of substrate for nocturnal carboxylation and growth. PMID:27101569

  3. Intestinal absorption of end products from digestion of carbohydrates and proteins in the pig.

    PubMed

    Rerat, A A

    1985-07-01

    The kinetics of appearance of various nutrients in the portal vein during the postprandial period was studied in conscious pigs by means of a technique based on measurement of the porto-arterial differences in nutrient concentrations simultaneously with that of the portal blood flow rate. The rate and level of appearance of sugars in the portal vein varied with the carbohydrate ingested. It was very rapid after intake of glucose and sucrose, slower after that of maize starch and very slow after that of lactose. The absorption of the latter became very rapid again if it was hydrolysed prior to its ingestion. During absorption, some sugars (fructose or galactose) released from the corresponding sucrose and lactose, respectively during digestion, were partly metabolized into glucose by the enterocyte. The rate of absorption of amino acids released in the digestive tract varied according to the origin of the food ingested, i.e. it was more rapid after intake of wheat or fish proteins than after that of barley. In the case of barley the absorption rate of amino acids differed from that of glucose of the starch. The profile of the amino acid mixtures appearing in the portal vein during absorption differed a little from the profiles of those present in the ingested proteins in the case of essential amino acids and differed much in the case of non essential amino acids. Some essential amino acids (histidine, aromatic amino acids) appeared more rapidly and others more slowly, (lysine, sulphur amino acids, arginine). Because of transaminations, only small amounts of glutamic acid occurred in the portal vein whereas the amounts of alanine as compared to those ingested, were very large. The hierarchy of amino acid absorption was the same whatever the protein studied (fish, wheat, barley). The appearance in the portal vein of alpha-amino nitrogen from enzyme hydrolysates perfused through the duodenum was more rapid than after perfusion of a mixture of free amino acids. During

  4. Towards complete hydrolysis of soy flour carbohydrates by enzyme mixtures for protein enrichment: A modeling approach.

    PubMed

    Loman, Abdullah Al; Ju, Lu-Kwang

    2016-05-01

    Soy protein is a well-known nutritional supplement in proteinaceous food and animal feed. However, soybeans contain complex carbohydrate. Selective carbohydrate removal by enzymes could increase the protein content and remove the indigestibility of soy products for inclusion in animal feed. Complete hydrolysis of soy flour carbohydrates is challenging due to the presence of proteins and different types of non-structural polysaccharides. This study is designed to guide complex enzyme mixture required for hydrolysis of all types of soy flour carbohydrates. Enzyme broths from Aspergillus niger, Aspergillus aculeatus and Trichoderma reesei fermentations were evaluated in this study for soy carbohydrate hydrolysis. The resultant hydrolysate was measured for solubilized carbohydrate by both total carbohydrate and reducing sugar analyses. Conversion data attained after 48h hydrolysis were first fitted with models to determine the maximum fractions of carbohydrate hydrolyzable by each enzyme group, i.e., cellulase, xylanase, pectinase and α-galactosidase. Kinetic models were then developed to describe the increasing conversions over time under different enzyme activities and process conditions. The models showed high fidelity in predicting soy carbohydrate hydrolysis over broad ranges of soy flour loading (5-25%) and enzyme activities: per g soy flour, cellulase, 0.04-30 FPU; xylanase, 3.5-618U; pectinase, 0.03-120U; and α-galactosidase, 0.01-60U. The models are valuable in guiding the development and production of optimal enzyme mixtures toward hydrolysis of all types of carbohydrates present in soy flour and in optimizing the design and operation of hydrolysis reactor and process. PMID:26992789

  5. Aliphatic, Cyclic, and Aromatic Organic Acids, Vitamins, and Carbohydrates in Soil: A Review

    PubMed Central

    Vranova, Valerie; Rejsek, Klement; Formanek, Pavel

    2013-01-01

    Organic acids, vitamins, and carbohydrates represent important organic compounds in soil. Aliphatic, cyclic, and aromatic organic acids play important roles in rhizosphere ecology, pedogenesis, food-web interactions, and decontamination of sites polluted by heavy metals and organic pollutants. Carbohydrates in soils can be used to estimate changes of soil organic matter due to management practices, whereas vitamins may play an important role in soil biological and biochemical processes. The aim of this work is to review current knowledge on aliphatic, cyclic, and aromatic organic acids, vitamins, and carbohydrates in soil and to identify directions for future research. Assessments of organic acids (aliphatic, cyclic, and aromatic) and carbohydrates, including their behaviour, have been reported in many works. However, knowledge on the occurrence and behaviour of D-enantiomers of organic acids, which may be abundant in soil, is currently lacking. Also, identification of the impact and mechanisms of environmental factors, such as soil water content, on carbohydrate status within soil organic matter remains to be determined. Finally, the occurrence of vitamins in soil and their role in biological and biochemical soil processes represent an important direction for future research. PMID:24319374

  6. Aliphatic, cyclic, and aromatic organic acids, vitamins, and carbohydrates in soil: a review.

    PubMed

    Vranova, Valerie; Rejsek, Klement; Formanek, Pavel

    2013-01-01

    Organic acids, vitamins, and carbohydrates represent important organic compounds in soil. Aliphatic, cyclic, and aromatic organic acids play important roles in rhizosphere ecology, pedogenesis, food-web interactions, and decontamination of sites polluted by heavy metals and organic pollutants. Carbohydrates in soils can be used to estimate changes of soil organic matter due to management practices, whereas vitamins may play an important role in soil biological and biochemical processes. The aim of this work is to review current knowledge on aliphatic, cyclic, and aromatic organic acids, vitamins, and carbohydrates in soil and to identify directions for future research. Assessments of organic acids (aliphatic, cyclic, and aromatic) and carbohydrates, including their behaviour, have been reported in many works. However, knowledge on the occurrence and behaviour of D-enantiomers of organic acids, which may be abundant in soil, is currently lacking. Also, identification of the impact and mechanisms of environmental factors, such as soil water content, on carbohydrate status within soil organic matter remains to be determined. Finally, the occurrence of vitamins in soil and their role in biological and biochemical soil processes represent an important direction for future research. PMID:24319374

  7. Coronavirus receptor switch explained from the stereochemistry of protein-carbohydrate interactions and a single mutation.

    PubMed

    Bakkers, Mark J G; Zeng, Qinghong; Feitsma, Louris J; Hulswit, Ruben J G; Li, Zeshi; Westerbeke, Aniek; van Kuppeveld, Frank J M; Boons, Geert-Jan; Langereis, Martijn A; Huizinga, Eric G; de Groot, Raoul J

    2016-05-31

    Hemagglutinin-esterases (HEs) are bimodular envelope proteins of orthomyxoviruses, toroviruses, and coronaviruses with a carbohydrate-binding "lectin" domain appended to a receptor-destroying sialate-O-acetylesterase ("esterase"). In concert, these domains facilitate dynamic virion attachment to cell-surface sialoglycans. Most HEs (type I) target 9-O-acetylated sialic acids (9-O-Ac-Sias), but one group of coronaviruses switched to using 4-O-Ac-Sias instead (type II). This specificity shift required quasisynchronous adaptations in the Sia-binding sites of both lectin and esterase domains. Previously, a partially disordered crystal structure of a type II HE revealed how the shift in lectin ligand specificity was achieved. How the switch in esterase substrate specificity was realized remained unresolved, however. Here, we present a complete structure of a type II HE with a receptor analog in the catalytic site and identify the mutations underlying the 9-O- to 4-O-Ac-Sia substrate switch. We show that (i) common principles pertaining to the stereochemistry of protein-carbohydrate interactions were at the core of the transition in lectin ligand and esterase substrate specificity; (ii) in consequence, the switch in O-Ac-Sia specificity could be readily accomplished via convergent intramolecular coevolution with only modest architectural changes in lectin and esterase domains; and (iii) a single, inconspicuous Ala-to-Ser substitution in the catalytic site was key to the emergence of the type II HEs. Our findings provide fundamental insights into how proteins "see" sugars and how this affects protein and virus evolution. PMID:27185912

  8. Investigation of phospholipid synthesis and the disposition of amino acid and carbohydrate

    SciTech Connect

    Boehme, D.S.

    1986-01-01

    The synthesis of pulmonary phospholipids by offspring of diabetic female rats was assessed by means of high performance liquid chromatography combined with automated phosphate analysis. No changes in the pool sizes of the major phospholipids or their precursors were observed. However, offspring of both insulin-treated and untreated diabetic mothers displayed increased pulmonary lyso-phosphatidylcholine. The concentration of glycerylphosphorylcholine, the metabolic product of lyso-phosphatidylcholine, was also increased in these offspring, providing further evidence of a reduced reacylation pathway in the offspring of diabetic mothers. The concentration of phosphatidylglycerol was reduced in the lungs from offspring of diabetic mothers. Preliminary investigation suggested that the mechanism of insulin action on lungs from offspring of diabetic rats may be the diversion of substrate from lipid synthetic pathways into protein synthesis. The utilization of (14C)-labeled amino acids and carbohydrates by normal fetal rat lung, however, revealed no direct insulin effect on protein synthesis. The ability of the fetal lung to convert amino acids into Krebs Cycle intermediates was demonstrated.

  9. CHARACTERIZATION OF THE CARBOHYDRATE COMPONENTS OF Taenia solium ONCOSPHERE PROTEINS AND THEIR ROLE IN THE ANTIGENICITY

    PubMed Central

    Arana, Yanina; Verastegui, Manuela; Tuero, Iskra; Grandjean, Louis; Garcia, Hector H.; Gilman, Robert H.

    2015-01-01

    This study examines the carbohydrate composition of Taenia solium whole oncosphere antigens (WOAs), in order to improve the understanding of the antigenicity of the T. solium. Better knowledge of oncosphere antigens is crucial to accurately diagnose previous exposure to T. solium eggs and thus predict the development of neurocysticercosis. A set of seven lectins conjugates with wide carbohydrate specificity were used on parasite fixations and somatic extracts. Lectin fluorescence revealed that D-mannose, D-glucose, D-galactose and N-acetyl-D-galactosamine residues were the most abundant constituents of carbohydrate chains on the surface of T. solium oncosphere. Lectin blotting showed that post-translational modification with N-glycosylation was abundant while little evidence of O-linked carbohydrates was observed. Chemical oxidation and enzymatic deglycosylation in situ were performed to investigate the immunoreactivity of the carbohydrate moieties. Linearizing or removing the carbohydrate moieties from the protein backbones did not diminish the immunoreactivity of these antigens, suggesting that a substantial part of the host immune response against T. solium oncosphere is directed against the peptide epitopes on the parasite antigens. Finally, using carbohydrate probes, we demonstrated for the first time that the presence of several lectins on the surface of the oncosphere was specific to carbohydrates found in intestinal mucus, suggesting a possible role in initial attachment of the parasite to host cells. PMID:23982308

  10. Acid-Catalyzed Algal Biomass Pretreatment for Integrated Lipid and Carbohydrate-Based Biofuels Production

    DOE PAGESBeta

    Laurens, L. M. L.; Nagle, N.; Davis, R.; Sweeney, N.; Van Wychen, S.; Lowell, A.; Pienkos, P. T.

    2014-11-12

    One of the major challenges associated with algal biofuels production in a biorefinery-type setting is improving biomass utilization in its entirety, increasing the process energetic yields and providing economically viable and scalable co-product concepts. We demonstrate the effectiveness of a novel, integrated technology based on moderate temperatures and low pH to convert the carbohydrates in wet algal biomass to soluble sugars for fermentation, while making lipids more accessible for downstream extraction and leaving a protein-enriched fraction behind. We studied the effect of harvest timing on the conversion yields, using two algal strains; Chlorella and Scenedesmus, generating biomass with distinctive compositionalmore » ratios of protein, carbohydrate, and lipids. We found that the late harvest Scenedesmus biomass had the maximum theoretical biofuel potential at 143 gasoline gallon equivalent (GGE) combined fuel yield per dry ton biomass, followed by late harvest Chlorella at 128 GGE per ton. Our experimental data show a clear difference between the two strains, as Scenedesmus was more successfully converted in this process with a demonstrated 97 GGE per ton. Our measurements indicated a release of >90% of the available glucose in the hydrolysate liquors and an extraction and recovery of up to 97% of the fatty acids from wet biomass. Techno-economic analysis for the combined product yields indicates that this process exhibits the potential to improve per-gallon fuel costs by up to 33% compared to a lipids-only process for one strain, Scenedesmus, grown to the mid-point harvest condition.« less

  11. In vitro studies into some parameters of protein and carbohydrate metabolism in lymphocytes infected with bovine leucosis virus.

    PubMed

    Madej, J A; Sobiech, K A; Klimentowski, S

    1989-11-01

    Several parameters of protein and carbohydrate metabolism were determined in normal and leukemic lymphocytes in vitro in cattle, including arylamidase activity toward beta-naphthylamides of L-amino acids. The homogenate of bovine leukemic lymphocytes, in comparison with the control revealed increase of gamma-glutamyltransferase, activity trypsin inhibitor and papain inhibitor concentration and aldolase activity. On the other hand, proteolytic activity toward casein and histomucoid content decreased. Out of the 7 substrates used in the study, only 2, alanyl-beta-naphthylamide and leucyl-beta-naphthylamide, demonstrated lower activity in the leukemic material. Disorders in carbohydrate and protein metabolism in the observed lymphocytes in vitro in cattle are presented in the paper. PMID:2559671

  12. Effects of Synchronicity of Carbohydrate and Protein Degradation on Rumen Fermentation Characteristics and Microbial Protein Synthesis

    PubMed Central

    Seo, J. K.; Kim, M. H.; Yang, J. Y.; Kim, H. J.; Lee, C. H.; Kim, K. H.; Ha, Jong K.

    2013-01-01

    A series of in vitro studies were carried out to determine i) the effects of enzyme and formaldehyde treatment on the degradation characteristics of carbohydrate and protein sources and on the synchronicity of these processes, and ii) the effects of synchronizing carbohydrate and protein supply on rumen fermentation and microbial protein synthesis (MPS) in in vitro experiments. Untreated corn (C) and enzyme-treated corn (EC) were combined with soy bean meal with (ES) and without (S) enzyme treatment or formaldehyde treatment (FS). Six experimental feeds (CS, CES, CFS, ECS, ECES and ECFS) with different synchrony indices were prepared. Highly synchronous diets had the greatest dry matter (DM) digestibility when untreated corn was used. However, the degree of synchronicity did not influence DM digestibility when EC was mixed with various soybean meals. At time points of 12 h and 24 h of incubation, EC-containing diets showed lower ammonia-N concentrations than those of C-containing diets, irrespective of the degree of synchronicity, indicating that more efficient utilization of ammonia-N for MPS was achieved by ruminal microorganisms when EC was offered as a carbohydrate source. Within C-containing treatments, the purine base concentration increased as the diets were more synchronized. This effect was not observed when EC was offered. There were significant effects on VFA concentration of both C and S treatments and their interactions. Similar to purine concentrations, total VFA production and individual VFA concentration in the groups containing EC as an energy source was higher than those of other groups (CS, CES and CFS). The results of the present study suggested that the availability of energy or the protein source are the most limiting factors for rumen fermentation and MPS, rather than the degree of synchronicity. PMID:25049798

  13. Disorders of Carbohydrate Metabolism

    MedlinePlus

    ... Metabolic Disorders Disorders of Carbohydrate Metabolism Disorders of Amino Acid Metabolism Disorders of Lipid Metabolism Carbohydrates are sugars. ... Metabolic Disorders Disorders of Carbohydrate Metabolism Disorders of Amino Acid Metabolism Disorders of Lipid Metabolism NOTE: This is ...

  14. Nutrient digestibility and evaluation of protein and carbohydrate fractionation of citrus by-products.

    PubMed

    Lashkari, S; Taghizadeh, A

    2013-08-01

    The protein and carbohydrate fractionation and nutrient digestibility of citrus by-products were determined. Ruminal, intestinal and total tract CP disappearance values were measured by a modified three-step (MTSP) method and in vitro CP disappearance method (IVCP). Test feeds were orange pulp (OP), lime pulp (LP), lemon pulp (LEP), grapefruit pulp (GP), sweet lemon pulp (SLP), bitter lemon pulp (BLP), bergamot orange pulp (BP) and tangerine pulp (TP). The rumen undegradable protein (RUP) fractions of the feedstuffs were obtained by ruminal incubation in three cannulated wethers and incubation in protease solution (protease type xiv, Streptomyces griseus). The data were analysed using completely randomized design. There were significant differences between the tested feeds in protein fractions and acid detergent insoluble nitrogen (ADIN; C fraction) was highest in GP (14.56%) (p<0.001). For carbohydrate fraction, the highest C fraction was also observed in GP (2.67%) and in relation to the other citrus pulps (p<0.001). Ruminal CP disappearance was highest in OP (71.89%) (p<0.001). The level of post-ruminal CP disappearance, measured by MTSP, was highest for BP (34.94%) (p<0.001). The highest in vitro dry matter digestibility (IVDMD) was found for TP (80.44%) followed by that estimated for BP (78.38%) (p<0.001). The estimated metabolizable energy (MJ/kg DM) varied from 9.77 for LP to 12.91 for BP. Tangerine pulp had the highest true rumen digestibility (TRD) (p<0.001). According to the results, it could be concluded that citrus by-products have high nutritive value and also, the in vitro techniques can be easily used to determine of the nutritive value of citrus by-products. PMID:22703299

  15. Nutritional Evaluation of Young Bulls on Tropical Pasture Receiving Supplements with Different Protein:Carbohydrate Ratios

    PubMed Central

    Valente, E. E. L.; Paulino, M. F.; Barros, L. V.; Almeida, D. M.; Martins, L. S.; Cabral, C. H. A.

    2014-01-01

    The objective of this work was to evaluate the nutritional parameters of young bulls supplemented with different ratios of protein: carbohydrate on tropical pastures from 4 until 18 months old. Fifty-five non-castrated beef calves (138.3±3.4 kg, 90 to 150 d of age) were used. The calves (young bulls) were subjected to a 430-d experimental period encompassing 4 seasons. The treatments were as follows: control, only mineral mixture; HPHC, high protein and high carbohydrate supplement; HPLC, high protein and low carbohydrate supplement; LPHC, low protein and high carbohydrate supplement; and LPLC, low protein and low carbohydrate supplement. The amount of supplement was adjusted every 28 d. Dry matter (DM) intake was higher in the dry-to-rainy transition and rainy seasons for all nutritional plans. Non-supplemented animals had lower intakes of DM and total digestible nutrients (TDN) than supplemented young bulls in all seasons. Although differences in DM intake were not observed between supplemented animals, the supplements with high carbohydrate (HPHC and LPHC) had lower forage intake during suckling (rainy-to-dry transition season) and in the rainy season. However, the HPHC treatment animals had higher intake and digestibility of neutral detergent fiber. It can be concluded that supplementation with high protein levels (supplying 50% of the crude protein requirement) provide the best nutritional parameters for grazing young bulls in most seasons, increasing intake and digestibility of diet, and these effects are more intense when associated with high carbohydrate levels level (supplying 30% TDN requirement). PMID:25178297

  16. Comparison of low fat and low carbohydrate diets on circulating fatty acid composition and markers of inflammation.

    PubMed

    Forsythe, Cassandra E; Phinney, Stephen D; Fernandez, Maria Luz; Quann, Erin E; Wood, Richard J; Bibus, Doug M; Kraemer, William J; Feinman, Richard D; Volek, Jeff S

    2008-01-01

    Abnormal distribution of plasma fatty acids and increased inflammation are prominent features of metabolic syndrome. We tested whether these components of metabolic syndrome, like dyslipidemia and glycemia, are responsive to carbohydrate restriction. Overweight men and women with atherogenic dyslipidemia consumed ad libitum diets very low in carbohydrate (VLCKD) (1504 kcal:%CHO:fat:protein = 12:59:28) or low in fat (LFD) (1478 kcal:%CHO:fat:protein = 56:24:20) for 12 weeks. In comparison to the LFD, the VLCKD resulted in an increased proportion of serum total n-6 PUFA, mainly attributed to a marked increase in arachidonate (20:4n-6), while its biosynthetic metabolic intermediates were decreased. The n-6/n-3 and arachidonic/eicosapentaenoic acid ratio also increased sharply. Total saturated fatty acids and 16:1n-7 were consistently decreased following the VLCKD. Both diets significantly decreased the concentration of several serum inflammatory markers, but there was an overall greater anti-inflammatory effect associated with the VLCKD, as evidenced by greater decreases in TNF-alpha, IL-6, IL-8, MCP-1, E-selectin, I-CAM, and PAI-1. Increased 20:4n-6 and the ratios of 20:4n-6/20:5n-3 and n-6/n-3 are commonly viewed as pro-inflammatory, but unexpectedly were consistently inversely associated with responses in inflammatory proteins. In summary, a very low carbohydrate diet resulted in profound alterations in fatty acid composition and reduced inflammation compared to a low fat diet. PMID:18046594

  17. Substrate interaction in intravenous feeding: comparative effects of carbohydrate and fat on amino acid utilization in fasting man.

    PubMed

    Wolfe, B M; Culebras, J M; Sim, A J; Ball, M R; Moore, F D

    1977-10-01

    emulsion was more effective than the available glycerol alone. THE ACCOMPANYING ENDOCRINE AND BIOCHEMICAL CHANGES SUGGEST THAT THE MILIEU FOR IDEAL UTILIZATION OF INFUSED AMINO ACIDS IS VARIABLE: ketones at low range (carbohydrate) or moderately elevated (fat emulsion); insulin elevated (carbohydrate) or unchanged (fat emulsion). The utilization of the infused amino acids was markedly improved in both endocrine settings, suggesting that it is the provision of energy as substrate as well as the endocrine setting that determines amino acid utilization. There were other changes in plasma intermediates, particularly fatty acids, glucose and urea, all consistent with the concept that when amino acids are given without other substrates, the amino acids must be maximally utilized for gluconeogenesis. When other substrates are provided (particularly glucose at high dose) then this mandate no longer exists and protein synthesis from the amino acids is favored. Several of the plasma amino acid concentrations responded to glucose when added to amino acid infusion. Amino acids alone produced increases in concentration of all the amino acids found in the infusion with the exception of alanine, arginine, and threonine. Many of these increases were abated by the addition of glucose to the amino acid infusion, suggesting an increased utilization rate. Glycerol and fat emulsion, while modulating increases in the plasma amino acid concentration, did so to a lesser extent than did glucose. This lowering of amino acid concentration was unaccompanied by an increase in urinary excretion. The assumption is therefore made that the provision of the added glucose favors the incorporation of amino acid into protein. There is no evidence from these data to suggest that a rising concentration of ketones in the blood favors amino acid utilization or protein synthesis. PMID:410376

  18. Purification and characterization of a carbohydrate: acceptor oxidoreductase from Paraconiothyrium sp. that produces lactobionic acid efficiently.

    PubMed

    Kiryu, Takaaki; Nakano, Hirofumi; Kiso, Taro; Murakami, Hiromi

    2008-03-01

    A carbohydrate:acceptor oxidoreductase from Paraconiothyrium sp. was purified and characterized. The enzyme efficiently oxidized beta-(1-->4) linked sugars, such as lactose, xylobiose, and cellooligosaccharides. The enzyme also oxidized maltooligosaccharides, D-glucose, D-xylose, D-galactose, L-arabinose, and 6-deoxy-D-glucose. It specifically oxidized the beta-anomer of lactose. Molecular oxygen and 2,6-dichlorophenol indophenol were reduced by the enzyme as electron acceptors. The Paraconiothyrium enzyme was identified as a carbohydrate:acceptor oxidoreductase according to its specificity for electron donors and acceptors, and its molecular properties, as well as the N-terminal amino acid sequence. Further comparison of the amino acid sequences of lactose oxidizing enzymes indicated that carbohydrate:acceptor oxidoreductases belong to the same group as glucooligosaccharide oxidase, while they differ from cellobiose dehydrogenases and cellobiose:quinone oxidoreductases. PMID:18323642

  19. Fate of proteins and carbohydrates in membrane bioreactor operated at high sludge age.

    PubMed

    Hocaoglu, Selda Murat; Orhon, Derin

    2010-01-01

    The paper evaluated the fate of proteins and carbohydrates in the course of substrate removal by membrane bioreactor (MBR), which was used for the biological treatment of black and grey water components of a controlled decentralized residential area. The MBRs were operated at a high sludge age of 60 days to better observe the magnitude of soluble residual products. Both groups were detected in the raw wastewater and represented 15% of the soluble chemical oxygen demand (COD) content for black water and 9% for grey water. Corresponding ratios in the process effluent were significantly increased to 70% and 24% respectively, indicating that both proteins and carbohydrates were likely to be generated as residual soluble microbial products. Residual soluble organics accumulated in the reactor at much higher levels as compared to the effluent due to cake filtration occurring on the surface of the membrane, entrapping fractions larger than 4-8 nm for proteins, and around 14 nm for carbohydrates. Mass balance showed that proteins and carbohydrates accumulated in the reactor were partially removed due to longer retention and possible acclimation of the biomass. The observed removal rate was much lower for carbohydrates compared with proteins. PMID:20560086

  20. Molecular cloning and expression of chicken carbohydrate response element binding protein and Max-like protein X gene homologues

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Carbohydrate response element binding protein (ChREBP) and sterol regulatory element binding protein-1c (SREBP-1c) are transcription factors that are known to be key regulators of glucose metabolism and lipid synthesis in mammals. Since ChREBP and its co-activator Max-like protein X (Mlx) have not ...

  1. Characterization of protein and carbohydrate mid-IR spectral features in crop residues

    NASA Astrophysics Data System (ADS)

    Xin, Hangshu; Zhang, Yonggen; Wang, Mingjun; Li, Zhongyu; Wang, Zhibo; Yu, Peiqiang

    2014-08-01

    To the best of our knowledge, a few studies have been conducted on inherent structure spectral traits related to biopolymers of crop residues. The objective of this study was to characterize protein and carbohydrate structure spectral features of three field crop residues (rice straw, wheat straw and millet straw) in comparison with two crop vines (peanut vine and pea vine) by using Fourier transform infrared spectroscopy (FTIR) technique with attenuated total reflectance (ATR). Also, multivariate analyses were performed on spectral data sets within the regions mainly related to protein and carbohydrate in this study. The results showed that spectral differences existed in mid-IR peak intensities that are mainly related to protein and carbohydrate among these crop residue samples. With regard to protein spectral profile, peanut vine showed the greatest mid-IR band intensities that are related to protein amide and protein secondary structures, followed by pea vine and the rest three field crop straws. The crop vines had 48-134% higher spectral band intensity than the grain straws in spectral features associated with protein. Similar trends were also found in the bands that are mainly related to structural carbohydrates (such as cellulosic compounds). However, the field crop residues had higher peak intensity in total carbohydrates region than the crop vines. Furthermore, spectral ratios varied among the residue samples, indicating that these five crop residues had different internal structural conformation. However, multivariate spectral analyses showed that structural similarities still exhibited among crop residues in the regions associated with protein biopolymers and carbohydrate. Further study is needed to find out whether there is any relationship between spectroscopic information and nutrition supply in various kinds of crop residue when fed to animals.

  2. Degradation of carbohydrates during dilute sulfuric acid pretreatment can interfere with lignin measurements in solid residues.

    PubMed

    Katahira, Rui; Sluiter, Justin B; Schell, Daniel J; Davis, Mark F

    2013-04-01

    The lignin content measured after dilute sulfuric acid pretreatment of corn stover indicates more lignin than could be accounted for on the basis of the untreated corn stover lignin content. This phenomenon was investigated using a combination of (13)C cross-polarization/magic-angle spinning (CP/MAS) solid-state nuclear magnetic resonance (NMR) spectroscopy and lignin removal using acid chlorite bleaching. Only minimal contamination with carbohydrates and proteins was observed in the pretreated corn stover. Incorporating degradation products from sugars was also investigated using (13)C-labeled sugars. The results indicate that sugar degradation products are present in the pretreatment residue and may be intimately associated with the lignin. Studies comparing whole corn stover (CS) to extractives-free corn stover [CS(Ext)] clearly demonstrated that extractives are a key contributor to the high-lignin mass balance closure (MBC). Sugars and other low molecular weight compounds present in plant extractives polymerize and form solids during pretreatment, resulting in apparent Klason lignin measurements that are biased high. PMID:23428141

  3. Engineered Carbohydrate-Binding Module (CBM) Protein-Suspended Single-Walled Carbon Nanotubes in Water

    SciTech Connect

    Xu,Q.; Song, Q.; Ai, X.; McDonald, T. J.; Long, H.; Ding. S. Y.; Himmel, M. E.; Rumbles, G.

    2009-01-01

    Engineered protein, CtCBM4, the first carbohydrate-binding module (CBM) protein is successfully used to debundle and suspend single-walled carbon nanotubes (SWNTs) effectively in aqueous solution, which opens up a new avenue in further functionalizing and potential selectively fractionating SWNTs for diverse biology- and/or energy-related applications.

  4. Activation of carbohydrate response element binding protein (ChREBP) by ethanol

    PubMed Central

    Liangpunsakul, Suthat; Ross, Ruth A.; Crabb, David W.

    2012-01-01

    Carbohydrate response element binding protein (ChREBP) is a transcription factor involved in hepatic lipogenesis. Its function is in part under the control of AMP-activated protein kinase (AMPK) and protein phosphatase 2A (PP2A). Given known effects of ethanol on AMPK and PP2A, it is plausible that ethanol might enhance fatty acid synthesis by increasing the activity of ChREBP. We hypothesized that another potential pathway of ethanol-induced hepatic steatosis is mediated by activation of ChREBP. Methods The effects of ethanol on ChREBP were assessed in hepatoma cells and in C57BL/6J mice fed with the Lieber-DeCarli diet. Results When the cells were exposed to ethanol (50 mM) for 24 hrs, the activity of a liver pyruvate kinase (LPK) promoter-luciferase reporter was increased by ~4-fold. Ethanol feeding of mice resulted in the translocation of ChREBP from cytosol to the nucleus. PP2A activity was increased in the liver of ethanol-fed mice by 22%. We found no difference in the levels of hepatic Xu-5-P between ethanol-fed mice and controls. Transfection of a constitutively active AMPK expression plasmid suppressed the basal activity of the LPK luciferase reporter and abolished the effect of ethanol on the reporter activity. However, transfection of rat hepatoma cells with a dominant negative AMPK expression plasmid induced basal LPK luciferase activity by only ~20%. The effect of ethanol on ChREBP was attenuated in the presence of okadaic acid, an inhibitor of PP2A. Conclusions The effects of ethanol on AMPK and PP2A may result in activation of ChREBP, providing another potential mechanism for ethanol-induced hepatic steatosis. However, additional okadaic acid-insensitive effects appear to be important as well. PMID:23266705

  5. Effects of protein and carbohydrate on an insect herbivore: the vista from a fitness landscape.

    PubMed

    Le Gall, Marion; Behmer, Spencer T

    2014-11-01

    Protein and carbohydrates are important nutrients driving the growth of herbivores; however, their content in plants is highly variable. Multiple studies have explored their effect on herbivores, but only one other study (using a caterpillar) has provided a comprehensive overview that includes a simultaneous evaluation of their ratios and concentrations. In the present work, we ran two experiments using nymphs of the generalist grasshopper Melanoplus differentialis. Grasshoppers and caterpillars differ in a number of important ways, which might affect their feeding and physiological responses to foods with variable content of protein and carbohydrates. First, in a choice experiment, we measured performance and related this to the self-selected intake of nutrients. No differences were found for duration of development across treatments, but gain in mass was lower on a diet of low macronutrient concentration. Consumption of protein was always tightly regulated, but intake of carbohydrate was significantly reduced when consuming diluted food. In the second experiment, insects were constrained to one of nine diets and we plotted performance and consumption using a fitness-landscape approach that mimics the natural variation of nutrients in plants. We found significant effects of protein and carbohydrate content on gain in mass and in duration of development. The concentration of macronutrients in the food had more pronounced effects than did the protein-to-carbohydrate ratio. The protein-carbohydrate content also significantly affected the intake of food and energy (calories), production of frass, and digestive efficiency. On foods with low macronutrient concentration consumption was high, but digestive efficiency was low. Our results suggest that insects will favor protein-biased foods when the total macronutrient content of available foods is low, and that in the short-term compensatory feeding responses can overcome nutritional deficits and/or imbalances. However

  6. Metabolic responses to dietary protein/carbohydrate ratios in zebra sea bream (Diplodus cervinus, Lowe, 1838) juveniles.

    PubMed

    Coutinho, Filipe; Peres, Helena; Castro, Carolina; Pérez-Jiménez, Amalia; Pousão-Ferreira, Pedro; Oliva-Teles, Aires; Enes, Paula

    2016-02-01

    This study aims to evaluate the effect of diets with different protein to carbohydrate ratios (P:C) on the omnivorous zebra sea bream (Diplodus cervinus) juveniles growth performance, feed efficiency, N excretion and metabolic response of intermediary metabolism enzymes. Four isoenergetic and isolipidic diets were formulated to contain increasing protein levels (25, 35, 45 and 55%) at the expense of carbohydrates (43, 32, 21 and 9%): diets P25C43, P35C32, P45C21 and P55C9. Growth performance, feed efficiency (FE), N intake [(g kg(-1) average body weight (ABW) day(-1))], N retention (g kg(-1) ABW day(-1)) and energy retention (kJ kg(-1) ABW day(-1)) increased with the increase of P:C ratio. The best growth performance and FE were achieved with diet P45C21. Ammonia excretion (mg NH4–N kg(-1) ABW day(-1)) increased as dietary protein level increased. Alanine aminotransferase and glutamate dehydrogenase activities increased with the increase of dietary P:C ratio. The opposite was observed for malic enzyme activity. Aspartate aminotransferase, hexokinase, glucokinase, fructose-1, 6-bisphosphatase and fatty acid synthetase activities were unaffected by dietary treatments. Response of key amino acid catabolic enzymes and N excretion levels to dietary P:C ratio supports the metabolic adaptability of this species to dietary protein inclusion levels. Overall, zebra sea bream seems capable of better utilize dietary protein rather than dietary carbohydrates as energy source which may be an obstacle for using more economically diets and thus for reducing environmental N loads in semi-intensive aquaculture of this species. PMID:26480835

  7. Carbohydrate, Organic Acid, and Amino Acid Composition of Bacteroids and Cytosol from Soybean Nodules 1

    PubMed Central

    Streeter, John G.

    1987-01-01

    Metabolites in Bradyrhizobium japonicum bacteroids and in Glycine max (L.) Merr. cytosol from root nodules were analyzed using an isolation technique which makes it possible to estimate and correct for changes in concentration which may occur during bacteroid isolation. Bacteroid and cytosol extracts were fractionated on ion-exchange columns and were analyzed for carbohydrate composition using gas-liquid chromatography and for organic acid and amino acid composition using high performance liquid chromatography. Analysis of organic acids in plant tissues as the phenacyl derivatives is reported for the first time and this approach revealed the presence of several unknown organic acids in nodules. The time required for separation of bacteroids and cytosol was varied, and significant change in concentration of individual compounds during the separation of the two fractions was estimated by calculating the regression of concentration on time. When a statistically significant slope was found, the true concentration was estimated by extrapolating the regression line to time zero. Of 78 concentration estimates made, there was a statistically significant (5% level) change in concentration during sample preparation for only five metabolites: glucose, sucrose, and succinate in the cytosol and d-pinitol and serine in bacteroids. On a mass basis, the major compounds in bacteroids were (descending order of concentration): myo-inositol, d-chiro-inositol, α,α-trehalose, sucrose, aspartate, glutamate, d-pinitol, arginine, malonate, and glucose. On a proportional basis (concentration in bacteroid as percent of concentration in bacteroid + cytosol fractions), the major compounds were: α-aminoadipate (94), trehalose (66), lysine (58), and arginine (46). The results indicate that metabolite concentrations in bacteroids can be reliably determined. PMID:16665774

  8. A convenient method for synthesis of glyconanoparticles for colorimetric measuring carbohydrate-protein interactions

    SciTech Connect

    Chuang, Yen-Jun; Zhou, Xichun; Pan, Zhengwei; Turchi, Craig

    2009-11-06

    Carbohydrate functionalized nanoparticles, i.e., the glyconanoparticles, have wide application ranging from studies of carbohydrate-protein interactions, in vivo cell imaging, biolabeling, etc. Currently reported methods for preparation of glyconanoparticles require multi-step modifications of carbohydrates moieties to conjugate to nanoparticle surface. However, the required synthetic manipulations are difficult and time consuming. We report herewith a simple and versatile method for preparing glyconanoparticles. This method is based on the utilization of clean and convenient microwave irradiation energy for one-step, site-specific conjugation of unmodified carbohydrates onto hydrazide-functionalized Au nanoparticles. A colorimetric assay that utilizes the ensemble of gold glyconanoparticles and Concanavalin A (ConA) was also presented. This feasible assay system was developed to analyze multivalent interactions and to determine the dissociation constant (K{sub d}) for five kind of Au glyconanoparticles with lectin. Surface plasmon changes of the Au glyconanoparticles as a function of lectin-carbohydrate interactions were measured and the dissociation constants were determined based on non-linear curve fitting. The strength of the interaction of carbohydrates with ConA was found to be as follows: maltose > mannose > glucose > lactose > MAN5.

  9. Restricted dynamics of water around a protein-carbohydrate complex: Computer simulation studies

    NASA Astrophysics Data System (ADS)

    Jana, Madhurima; Bandyopadhyay, Sanjoy

    2012-08-01

    Water-mediated protein-carbohydrate interaction is a complex phenomenon responsible for different biological processes in cellular environment. One of the unexplored but important issues in this area is the role played by water during the recognition process and also in controlling the microscopic properties of the complex. In this study, we have carried out atomistic molecular dynamics simulations of a protein-carbohydrate complex formed between the hyaluronan binding domain of the murine Cd44 protein and the octasaccharide hyaluronan in explicit water. Efforts have been made to explore the heterogeneous influence of the complex on the dynamic properties of water present in different regions around it. It is revealed from our analyses that the heterogeneous dynamics of water around the complex are coupled with differential time scales of formation and breaking of hydrogen bonds at the interface. Presence of a highly rigid thin layer of motionally restricted water molecules bridging the protein and the carbohydrate in the common region of the complex has been identified. Such water molecules are expected to play a crucial role in controlling properties of the complex. Importantly, it is demonstrated that the formation of the protein-carbohydrate complex affects the transverse and longitudinal degrees of freedom of the interfacial water molecules in a heterogeneous manner.

  10. Pretreatment of Sugar Beet Pulp with Dilute Sulfurous Acid is Effective for Multipurpose Usage of Carbohydrates.

    PubMed

    Kharina, M; Emelyanov, V; Mokshina, N; Ibragimova, N; Gorshkova, T

    2016-05-01

    Sulfurous acid was used for pretreatment of sugar beet pulp (SBP) in order to achieve high efficiency of both extraction of carbohydrates and subsequent enzymatic hydrolysis of the remaining solids. The main advantage of sulfurous acid usage as pretreatment agent is the possibility of its regeneration. Application of sulfurous acid as hydrolyzing agent in relatively low concentrations (0.6-1.0 %) during a short period of time (10-20 min) and low solid to liquid ratio (1:3, 1:6) allowed effective extraction of carbohydrates from SBP and provided positive effect on subsequent enzymatic hydrolysis. The highest obtained concentration of reducing substances (RS) in hydrolysates was 8.5 %; up to 33.6 % of all carbohydrates present in SBP could be extracted. The major obtained monosaccharides were arabinose and glucose (9.4 and 7.3 g/l, respectively). Pretreatment of SBP with sulfurous acid increased 4.6 times the yield of glucose during subsequent enzymatic hydrolysis of remaining solids with cellulase cocktail, as compared to the untreated SBP. Total yield of glucose during SBP pretreatment and subsequent enzymatic hydrolysis amounted to 89.4 % of the theoretical yield. The approach can be applied directly to the wet SBP. Hydrolysis of sugar beet pulp with sulfurous acid is recommended for obtaining of individual monosaccharides, as well as nutritional media. PMID:26821256

  11. Effects of Water Stress on the Organic Acid and Carbohydrate Compositions of Cotton Plants

    PubMed Central

    Timpa, Judy D.; Burke, John J.; Quisenberry, Jerry E.; Wendt, Charles W.

    1986-01-01

    Two photoperiodic cotton (Gossypium hirsutum L.) strains (T185 and T466) which had been empirically selected because of poor performance and two strains (T25 and T256) selected because of enhanced performance under field water stress were evaluated for stress-induced changes in their organic acids and carbohydrates. Profiles and quantitation of organic acids and carbohydrates from aqueous extractions of cotton leaf tissue were determined by high performance liquid chromatography. In all cases, the water-stressed plants showed two to five times greater amounts of organic acids and carbohydrates over the values determined for the irrigated samples. Under stress, sucrose accumulation was observed in wilting strains (poor performers) probably related to rate of translocation out of the leaf. The most dramatic response to water stress was the accumulation of citric acid in strains T25 and T256 as compared to T185 and T466. Citric/malic acid ratios for both the irrigated and water-stressed samples of T25 and T256 were twice those of T185 and T466. PMID:16665100

  12. Carbohydrate Source and Protein Degradability Alter Lactation, Ruminal, and Blood Measures.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Effects of nonfiber carbohydrate source (NFC) and protein degradability (RDP) in the diets of lactating dairy cattle on intake, production, efficiency, and ruminal measures were evaluated in a three period (21 d) partially balanced incomplete latin square design with a 3x2 factorial arrangement of t...

  13. Protein and Carbohydrate Interactions Alter Ruminal Fermentation, Digesta Characteristics, and Behavior in Lactating Dairy Cattle

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The effect of altering dietary nonfiber carbohydrate complement and ruminally degradable protein was evaluated in an incomplete partially balanced Latin square design with a 2 x 2 factorial arrangement of treatments (trt) and two 21-d periods. Eight ruminally cannulated Holstein dairy cows were rand...

  14. Systemic Glucose Level Changes with a Carbohydrate-Restricted and Higher Protein Diet Combined with Exercise

    ERIC Educational Resources Information Center

    Bowden, Rodney G.; Lanning, Beth A.; Doyle, Eva I.; Slonaker, Becky; Johnston, Holly M.; Scanes, Georgene

    2007-01-01

    Objective: The authors' purpose in this study was to compare the effects of macronutrient intake on systemic glucose levels in previously sedentary participants who followed 1 of 4 diets that were either higher protein or high carbohydrate, while initiating an exercise program. Participants and Methods: The authors randomly assigned 94 sedentary…

  15. Transient decrements in mood during energy deficit are independent of dietary protein-to-carbohydrate ratio

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Energy deficit and dietary macronutrient intake are thought to independently modulate cognition, mood and sleep. To what extent manipulating the dietary ratio of protein-to-carbohydrate affects mood, cognition and sleep during short-term energy deficit is undetermined. Using a randomized, block desi...

  16. Reaction of protein and carbohydrates with EDC for purpose of making products with unique functional properties

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Prior research from this laboratory has demonstrated the feasibility of using chemical and enzymatic treatments on protein and carbohydrate waste products for the purpose of making fillers to enhance the properties of leather. These treatments (microbial transglutaminase, genipin, and polyphenols i...

  17. Update: The Digestion and Absorption of Carbohydrate and Protein: Role of the Small Intestine.

    ERIC Educational Resources Information Center

    Leese, H. J.

    1984-01-01

    Discusses the role of the small intestine in the digestion and absorption of carbohydrates and proteins. Indicates as outdated the view that these materials must be broken down to monomeric units before absorption and that the gut secretes a mixture of digestive juices which brings about absorption. (JN)

  18. Fractionation of oats into products enriched with protein, beta-glucan, starch, or other carbohydrates

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A modified wet method was developed to fractionate ground oat groats into 4 fractions enriched with beta-glucan (BG), protein, starch, and other carbohydrates (CHO), respectively. Effects of defatting oats and centrifuge force for separation were also investigated. Results show that, depending on ...

  19. Analysis and quality control of carbohydrates in therapeutic proteins with fluorescence HPLC.

    PubMed

    Liu, Kun; Huang, Jian; Luo, Delun; Xu, Kai; Wu, Zhigang; Xu, Xun

    2016-09-16

    Conbercept is an Fc fusion protein with very complicated carbohydrate profiles which must be carefully monitored through manufacturing process. Here, we introduce an optimized fluorescence derivatization high-performance liquid chromatographic method for glycan mapping in conbercept. Compared with conventional glycan analysis method, this method has much better resolution and higher reproducibility making it excellent for product quality control. PMID:27514451

  20. Reaction of protein and carbohydrates with EDC for making unique biomaterials

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Prior research from this laboratory has demonstrated the feasibility of using chemical and enzymatic treatments on protein and carbohydrate waste products for the purpose of making fillers to enhance the properties of leather. These treatments (microbial transglutaminase, genipin, and polyphenols i...

  1. Protein and Carbohydrate Contents of Plant Seeds: An Introduction to Biochemical Analysis

    ERIC Educational Resources Information Center

    Deutch, Charles E.; Egan, Todd P.; Meekins, J. Forrest; Siegel, Carol

    2004-01-01

    The first of two projects developed for an introductory biology course of science majors titled Biological Concepts I is described. Students were divided into groups and were asked to determine the total amount of protein and carbohydrate in different types of seeds that were provided to them.

  2. Zinc status specifically changes preferences for carbohydrate and protein in rats selecting from separate carbohydrate-, protein-, and fat-containing diets.

    PubMed

    Rains, T M; Shay, N F

    1995-11-01

    This study examined how macronutrient intake preferences were specifically altered in the loss of appetite caused by experimentally produced zinc deficiency. Outbred female rats were allowed to freely select from simultaneously provided carbohydrate-, protein-, and fat-rich diets to provide themselves with an acceptable total diet. Rats were divided into two groups and provided the three diets containing either adequate (30 mg/kg; Zn+) or deficient (1 mg/kg; Zn-) levels of zinc (Zn). After 28 d, rats offered the Zn- diet were returned to a Zn+ diet (Zn repletion). Intakes from each of the three macronutrient diets were measured to determine macronutrient preferences of Zn-adequate, Zn-deficient, and Zn-repleted rats. In two 28-d studies involving a total of 66 rats, total metabolizable energy intake in Zn deficient rats was between 20 and 35% lower than in Zn+ rats, and carbohydrate intake accounted for essentially 100% of the lower energy intake. Fat and protein intakes were not affected by Zn deficiency. When Zn-deficient rats were repleted with Zn by providing diets containing adequate Zn, carbohydrate intake was restored to normal levels after 1 d of feeding. A transient difference in protein intake was noted during the repletion period, peaking during d 2-4 of repletion. Protein intake increased by more than 50% during this period. We hypothesize that specific changes in macronutrient intake patterns during development and recovery from Zn deficiency may be reflections, at least in part, of Zn-mediated changes in the central control of appetite. PMID:7472669

  3. Efficacy of reducing sugar and phenol-sulfuric acid assays for analysis of soluble carbohydrates in feedstuffs

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Reducing sugar (RSA) and phenol–sulfuric acid (PSA) assays are commonly used to analyze water-soluble carbohydrates. However, questions have arisen as to their accuracy for measurement of feedstuffs with diverse carbohydrate profiles. This study evaluated the efficacy of RSA and PSA as they would co...

  4. Alveolar cells: incorporation of carbohydrate into protein and evidence for intracellular protein transport

    PubMed Central

    Massaro, Donald

    1968-01-01

    Alveolar cells incubated with radioactive glucosamine, galactose, and mannose incorporate radioactivity into protein, that is, into material insoluble in cold and hot trichloroacetic acid and not extracted by lipid solvents. This incorporation is incompletely inhibited by puromycin hydrochloride. The kinetics of the subcellular distribution of radioactivity are consistent with a precursor-product relationship between microsomal protein and the protein of particles sedimenting at 15,000 g. It is thus suggested that alveolar cells incorporate these substrates intact into protein at the microsomal level with subsequent transfer of this newly formed material to particles sedimenting at 15,000 g. PMID:12066780

  5. Use of glass transitions in carbohydrate excipient design for lyophilized protein formulations.

    PubMed

    Roughton, Brock C; Topp, E M; Camarda, Kyle V

    2012-01-10

    This work describes an effort to apply methods from process systems engineering to a pharmaceutical product design problem, with a novel application of statistical approaches to comparing solutions. A computational molecular design framework was employed to design carbohydrate molecules with high glass transition temperatures and low water content in the maximally freeze-concentrated matrix, with the objective of stabilizing lyophilized protein formulations. Quantitative structure-property relationships were developed for glass transition temperature of the anhydrous solute, glass transition temperature of the maximally concentrated solute, melting point of ice and Gordon-Taylor constant for carbohydrates. An optimization problem was formulated to design an excipient with optimal property values. Use of a stochastic optimization algorithm, Tabu search, provided several carbohydrate excipient candidates with statistically similar property values, as indicated by prediction intervals calculated for each property. PMID:24385675

  6. Carbohydrate Loading.

    ERIC Educational Resources Information Center

    Csernus, Marilyn

    Carbohydrate loading is a frequently used technique to improve performance by altering an athlete's diet. The objective is to increase glycogen stored in muscles for use in prolonged strenuous exercise. For two to three days, the athlete consumes a diet that is low in carbohydrates and high in fat and protein while continuing to exercise and…

  7. The role of Monosaccharide Transport Proteins in carbohydrate assimilation, distribution, metabolism and homeostasis

    PubMed Central

    Cura, Anthony J.; Carruthers, Anthony

    2012-01-01

    The facilitated diffusion of glucose, galactose, fructose, urate, myoinositol and dehydroascorbic acid in mammals is catalyzed by a family of 14 monosaccharide transport proteins called GLUTs. These transporters may be divided into 3 classes according to sequence similarity and function/substrate specificity. GLUT1 appears to be highly expressed in glycolytically active cells and has been co-opted in vitamin C auxotrophs to maintain the redox state of the blood through transport of dehydroascorbate. Several GLUTs are definitive glucose/galactose transporters, GLUT2 and GLUT5 are physiologically important fructose transporters, GLUT9 appears to be a urate transporter while GLUT13 (HMIT1) is a proton/myoinositol co-transporter. The physiologic substrates of some GLUTs remain to be established. The GLUTs are expressed in a tissue specific manner where affinity, specificity and capacity for substrate transport are paramount for tissue function. Although great strides have been made in characterizing GLUT-catalyzed monosaccharide transport and mapping GLUT membrane topography and determinants of substrate specificity, a unifying model for GLUT structure and function remains elusive. The GLUTs play a major role in carbohydrate homeostasis and the redistribution of sugar-derived carbons among the various organ systems. This is accomplished through a multiplicity of GLUT-dependent glucose sensing and effector mechanisms that regulate monosaccharide ingestion, absorption, distribution, cellular transport and metabolism and recovery/retention. Glucose transport and metabolism have co-evolved in mammals to support cerebral glucose utilization. PMID:22943001

  8. Impact of 1 wk of diabetes on the regulation of myocardial carbohydrate and fatty acid oxidation.

    PubMed

    Chatham, J C; Gao, Z P; Forder, J R

    1999-08-01

    The aim of this study was to investigate the effect of increasing exogenous palmitate concentration on carbohydrate and palmitate oxidation in hearts from control and 1-wk diabetic rats. Hearts were perfused with glucose, [3-(13)C]lactate, and [U-(13)C]palmitate. Substrate oxidation rates were determined by combining (13)C-NMR glutamate isotopomer analysis of tissue extracts with measurements of oxygen consumption. Carbohydrate oxidation was markedly depressed after diabetes in the presence of low (0.1 mM) but not high (1.0 mM) palmitate concentration. Increasing exogenous palmitate concentration 10-fold resulted in a 7-fold increase in the contribution of palmitate to energy production in controls but only a 30% increase in the diabetic group. Consequently, at 0.1 mM palmitate, the rate of fatty acid oxidation was higher in the diabetic group than in controls; however, at 1.0 mM fatty acid oxidation, it was significantly depressed. Therefore, after 1 wk of diabetes, the major differences in carbohydrate and fatty acid metabolism occur primarily at low rather than high exogenous palmitate concentration. PMID:10444431

  9. The effect of paper industry effluent on growth, pigments, carbohydrates and proteins of rice seedlings.

    PubMed

    Misra, R N; Behera, P K

    1991-01-01

    The effect of paper industry effluent on the growth and content of certain macromolecules of seedlings of rice (Oryza sativa L. cv. Kesari-82K) has been examined. The effects were investigated in relation to both concentration of effluent and time of exposure to the effluent. Percentage of germination, water imbibing capacity, growth, pigment, carbohydrate and protein content showed a decreasing trend with increase in effluent concentration and time. Protein content was the most sensitive macromolecule affected by effluent. Measurement of protein and protein enzymes might therefore provide a useful criterion for the evaluation of the phytotoxicity of effluent released from the pulp and paper industries. PMID:15092110

  10. Diet structure, butyric acid, and fermentable carbohydrates influence growth performance, gut morphology, and cecal fermentation characteristics in broilers

    PubMed Central

    Qaisrani, S. N.; van Krimpen, M. M.; Kwakkel, R. P.; Verstegen, M. W. A.; Hendriks, W. H.

    2015-01-01

    An experiment with 288 male (Ross 308) 1-d-old broilers was conducted to test the hypothesis that a coarse diet supplemented with butyric acid (BA) and fermentable carbohydrates (FC) improves performance of broilers with a poorly digestible protein source. The interaction effects of diet structure (fine or coarse), FC supplementation (with or without), and BA supplementation (with or without) in a poorly digestible diet based on rapeseed meal (RSM) were tested in a factorial arrangement of 8 (2 × 2 × 2) dietary treatments. The coarseness of the diet affected feed intake (FI) (P < 0.001), BW gain (P = 0.001), and the feed conversion ratio (FCR) (P = 0.001) positively. Broilers fed the coarse diets had, on average, 14% heavier gizzards and 11, 7, 5, and 6% lower relative empty weights of the crop, duodenum, jejunum, and ileum, respectively, compared with those fed the fine diets. Dietary coarseness resulted in, on average, 6% greater ileal protein digestibility, 20% lower gizzard pH, 19% greater villus height, 18% lower crypt depth, and 23% reduced cecal branched chain fatty acids (BCFA) compared with chickens fed the fine diets. Broilers fed BA-supplemented diets had an improved FCR (P = 0.004) and decreased crypt depth (P < 0.001) compared with those fed diets without BA. Fermentable carbohydrate supplementation did not influence growth performance, gut development, or contents of total BCFA and total biogenic amines in the cecal digesta (P > 0.05). Supplementation with FC, however, decreased the cecal concentration of spermine by approximately 31% compared with broilers fed diets without FC (P = 0.002). In conclusion, feeding a coarse diet supplemented with BA improved performance of broilers fed a diet containing a poorly digestible protein source. The negative effects of a poorly digestible protein source can thus be partly counterbalanced by coarse grinding and BA supplementation in the diet. PMID:26175052

  11. Crystal Structure of Trimeric Carbohydrate Recognition and Neck Domains of Surfactant Protein A

    SciTech Connect

    Head,J.; Mealy, T.; McCormack, F.; Seaton, B.

    2003-01-01

    Surfactant protein A (SP-A), one of four proteins associated with pulmonary surfactant, binds with high affinity to alveolar phospholipid membranes, positioning the protein at the first line of defense against inhaled pathogens. SP-A exhibits both calcium-dependent carbohydrate binding, a characteristic of the collectin family, and specific interactions with lipid membrane components. The crystal structure of the trimeric carbohydrate recognition domain and neck domain of SP-A was solved to 2.1-{angstrom} resolution with multiwavelength anomalous dispersion phasing from samarium. Two metalbinding sites were identified, one in the highly conserved lectin site and the other 8.5 {angstrom} away. The interdomain carbohydrate recognition domain-neck angle is significantly less in SP-A than in the homologous collectins, surfactant protein D, and mannose-binding protein. This conformational difference may endow the SP-A trimer with a more extensive hydrophobic surface capable of binding lipophilic membrane components. The appearance of this surface suggests a putative binding region for membrane-derived SP-A ligands such as phosphatidylcholine and lipid A, the endotoxic lipid component of bacterial lipopolysaccharide that mediates the potentially lethal effects of Gram-negative bacterial infection.

  12. Evolutionary bases of carbohydrate recognition and substrate discrimination in the ROK protein family.

    PubMed

    Conejo, Maria S; Thompson, Steven M; Miller, Brian G

    2010-06-01

    The ROK (repressor, open reading frame, kinase) protein family (Pfam 00480) is a large collection of bacterial polypeptides that includes sugar kinases, carbohydrate responsive transcriptional repressors, and many functionally uncharacterized gene products. ROK family sugar kinases phosphorylate a range of structurally distinct hexoses including the key carbon source D: -glucose, various glucose epimers, and several acetylated hexosamines. The primary sequence elements responsible for carbohydrate recognition within different functional categories of ROK polypeptides are largely unknown due to a limited structural characterization of this protein family. In order to identify the structural bases for substrate discrimination in individual ROK proteins, and to better understand the evolutionary processes that led to the divergent evolution of function in this family, we constructed an inclusive alignment of 227 representative ROK polypeptides. Phylogenetic analyses and ancestral sequence reconstructions of the resulting tree reveal a discrete collection of active site residues that dictate substrate specificity. The results also suggest a series of mutational events within the carbohydrate-binding sites of ROK proteins that facilitated the expansion of substrate specificity within this family. This study provides new insight into the evolutionary relationship of ROK glucokinases and non-ROK glucokinases (Pfam 02685), revealing the primary sequence elements shared between these two protein families, which diverged from a common ancestor in ancient times. PMID:20512568

  13. Simultaneous determination of amino acids and carbohydrates in culture media of Clostridium thermocellum by valve-switching ion chromatography.

    PubMed

    Fa, Yun; Yang, Haiyan; Ji, Chengshuai; Cui, He; Zhu, Xinshu; Du, Juan; Gao, Jun

    2013-10-10

    An improved method for the simultaneous determination of 20 amino acids and 7 carbohydrates using one-valve switching after injection, ion chromatography, and integrated pulsed amperometric detection is proposed. The resolution of the amino acids and carbohydrates in the cation trap column was investigated. In addition, parameters including flow liquid type, flow rate, concentration, and valve-switch timing were optimized. The method is time-saving, effective, and accurate for the simultaneous separation of amino acids and carbohydrates, with a mean correlation coefficient of >0.99 and repeatability of 0.5-4.6% for eight replicates. The method was successfully applied in the analysis of amino acids and carbohydrates in aseptic media and in extracellular culture media of three phenotypes of Clostridium thermocellum. PMID:24070489

  14. Balancing of lipid, protein, and carbohydrate intake in a predatory beetle following hibernation, and consequences for lipid restoration.

    PubMed

    Noreika, Norbertas; Madsen, Natalia E L; Jensen, Kim; Toft, Søren

    2016-05-01

    Carnivorous animals are known to balance their consumption of lipid and protein, and recent studies indicate that some mammalian carnivores also regulate their intake of carbohydrate. We investigated macronutrient balancing and lipid restoration following hibernation in the ground beetle Anchomenus dorsalis, hypothesizing that carbohydrates might be important energy sources upon hibernation when predator lipid stores are exhausted and prey are equally lean. We recorded the consumption of lipid, protein, and carbohydrate over nine days following hibernation, as the beetles foraged to refill their lipid stores. Each beetle was given the opportunity to regulate consumption from two semi-artificial foods differing in the proportion of two of the three macronutrients, while the third macronutrient was kept constant. When analyzing consumption of the three macronutrients on an energetic basis, it became apparent that the beetles regulated lipid and carbohydrate energy interchangeably and balanced the combined energy intake from the two macronutrients against protein intake. Restoration of lipid stores was independent of the availability of any specific macronutrient. However, the energetic consumption required to refill lipid stores was higher when a low proportion of lipids was ingested, suggesting that lipids were readily converted into lipid stores while there were energetic costs associated with converting carbohydrate and protein into stored lipids. Our experiment demonstrates that carbohydrates are consumed and regulated as a non-protein energy source by A. dorsalis despite an expectedly low occurrence of carbohydrates in their natural diet. Perhaps carbohydrates are in fact an overlooked supplementary energy source in the diet of carnivorous arthropods. PMID:26868725

  15. Effect of nutrient deprivation on lipid, carbohydrate, DNA, RNA, and protein levels in Vibrio cholerae.

    PubMed Central

    Hood, M A; Guckert, J B; White, D C; Deck, F

    1986-01-01

    The response of Vibrio cholerae to low nutrient levels was determined by measuring the concentrations of lipids, carbohydrates, DNA, RNA, and proteins over a 30-day starvation period. Ultrastructural integrity was observed by transmission electron microscopy. Total lipids and carbohydrates declined rapidly within the first 7 days, while DNA and protein exhibited a more constant decline over the 30 days of starvation. In contrast, RNA showed little decrease upon starvation. Although neutral lipids were lost, the percentage of neutral lipids did not decline as rapidly as the phospholipids. Detectable levels of poly-beta-hydroxybutyrate disappeared completely by 7 days. Carbohydrate profiles revealed the relative loss of the five-carbon sugar ribose and N-acetylglucosamine and a relative increase in the total six-carbon sugars, especially glucose. Morphologically, ribosomes appeared to exhibit no structural change, while inclusion bodies and mesosomelike structures disappeared completely, and cell wall and membrane integrity was lost. The data suggest that V. cholerae differs somewhat from other marine vibrios in its response to low nutrients but shares some characteristics in common with them. The data also suggest that certain lipids and carbohydrates may provide the endogenous energy sources needed for dormancy preparation and cell maintenance under nutrient starvation. Images PMID:2430523

  16. Localizing Carbohydrate Binding Sites in Proteins Using Hydrogen/Deuterium Exchange Mass Spectrometry

    NASA Astrophysics Data System (ADS)

    Zhang, Jingjing; Kitova, Elena N.; Li, Jun; Eugenio, Luiz; Ng, Kenneth; Klassen, John S.

    2016-01-01

    The application of hydrogen/deuterium exchange mass spectrometry (HDX-MS) to localize ligand binding sites in carbohydrate-binding proteins is described. Proteins from three bacterial toxins, the B subunit homopentamers of Cholera toxin and Shiga toxin type 1 and a fragment of Clostridium difficile toxin A, and their interactions with native carbohydrate receptors, GM1 pentasaccharides (β-Gal-(1→3)-β-GalNAc-(1→4)[α-Neu5Ac-(2→3)]-β-Gal-(1→4)-Glc), Pk trisaccharide (α-Gal-(1→4)-β-Gal-(1→4)-Glc) and CD-grease (α-Gal-(1→3)-β-Gal-(1→4)-β-GlcNAcO(CH2)8CO2CH3), respectively, served as model systems for this study. Comparison of the differences in deuterium uptake for peptic peptides produced in the absence and presence of ligand revealed regions of the proteins that are protected against deuterium exchange upon ligand binding. Notably, protected regions generally coincide with the carbohydrate binding sites identified by X-ray crystallography. However, ligand binding can also result in increased deuterium exchange in other parts of the protein, presumably through allosteric effects. Overall, the results of this study suggest that HDX-MS can serve as a useful tool for localizing the ligand binding sites in carbohydrate-binding proteins. However, a detailed interpretation of the changes in deuterium exchange upon ligand binding can be challenging because of the presence of ligand-induced changes in protein structure and dynamics.

  17. The bacterial phosphoenolpyruvate:carbohydrate phosphotransferase system: regulation by protein phosphorylation and phosphorylation-dependent protein-protein interactions.

    PubMed

    Deutscher, Josef; Aké, Francine Moussan Désirée; Derkaoui, Meriem; Zébré, Arthur Constant; Cao, Thanh Nguyen; Bouraoui, Houda; Kentache, Takfarinas; Mokhtari, Abdelhamid; Milohanic, Eliane; Joyet, Philippe

    2014-06-01

    The bacterial phosphoenolpyruvate (PEP):carbohydrate phosphotransferase system (PTS) carries out both catalytic and regulatory functions. It catalyzes the transport and phosphorylation of a variety of sugars and sugar derivatives but also carries out numerous regulatory functions related to carbon, nitrogen, and phosphate metabolism, to chemotaxis, to potassium transport, and to the virulence of certain pathogens. For these different regulatory processes, the signal is provided by the phosphorylation state of the PTS components, which varies according to the availability of PTS substrates and the metabolic state of the cell. PEP acts as phosphoryl donor for enzyme I (EI), which, together with HPr and one of several EIIA and EIIB pairs, forms a phosphorylation cascade which allows phosphorylation of the cognate carbohydrate bound to the membrane-spanning EIIC. HPr of firmicutes and numerous proteobacteria is also phosphorylated in an ATP-dependent reaction catalyzed by the bifunctional HPr kinase/phosphorylase. PTS-mediated regulatory mechanisms are based either on direct phosphorylation of the target protein or on phosphorylation-dependent interactions. For regulation by PTS-mediated phosphorylation, the target proteins either acquired a PTS domain by fusing it to their N or C termini or integrated a specific, conserved PTS regulation domain (PRD) or, alternatively, developed their own specific sites for PTS-mediated phosphorylation. Protein-protein interactions can occur with either phosphorylated or unphosphorylated PTS components and can either stimulate or inhibit the function of the target proteins. This large variety of signal transduction mechanisms allows the PTS to regulate numerous proteins and to form a vast regulatory network responding to the phosphorylation state of various PTS components. PMID:24847021

  18. The Bacterial Phosphoenolpyruvate:Carbohydrate Phosphotransferase System: Regulation by Protein Phosphorylation and Phosphorylation-Dependent Protein-Protein Interactions

    PubMed Central

    Aké, Francine Moussan Désirée; Derkaoui, Meriem; Zébré, Arthur Constant; Cao, Thanh Nguyen; Bouraoui, Houda; Kentache, Takfarinas; Mokhtari, Abdelhamid; Milohanic, Eliane; Joyet, Philippe

    2014-01-01

    SUMMARY The bacterial phosphoenolpyruvate (PEP):carbohydrate phosphotransferase system (PTS) carries out both catalytic and regulatory functions. It catalyzes the transport and phosphorylation of a variety of sugars and sugar derivatives but also carries out numerous regulatory functions related to carbon, nitrogen, and phosphate metabolism, to chemotaxis, to potassium transport, and to the virulence of certain pathogens. For these different regulatory processes, the signal is provided by the phosphorylation state of the PTS components, which varies according to the availability of PTS substrates and the metabolic state of the cell. PEP acts as phosphoryl donor for enzyme I (EI), which, together with HPr and one of several EIIA and EIIB pairs, forms a phosphorylation cascade which allows phosphorylation of the cognate carbohydrate bound to the membrane-spanning EIIC. HPr of firmicutes and numerous proteobacteria is also phosphorylated in an ATP-dependent reaction catalyzed by the bifunctional HPr kinase/phosphorylase. PTS-mediated regulatory mechanisms are based either on direct phosphorylation of the target protein or on phosphorylation-dependent interactions. For regulation by PTS-mediated phosphorylation, the target proteins either acquired a PTS domain by fusing it to their N or C termini or integrated a specific, conserved PTS regulation domain (PRD) or, alternatively, developed their own specific sites for PTS-mediated phosphorylation. Protein-protein interactions can occur with either phosphorylated or unphosphorylated PTS components and can either stimulate or inhibit the function of the target proteins. This large variety of signal transduction mechanisms allows the PTS to regulate numerous proteins and to form a vast regulatory network responding to the phosphorylation state of various PTS components. PMID:24847021

  19. Gluconeogenesis from dihydroxyacetone in rat hepatocytes during the shift from a low protein, high carbohydrate to a high protein, carbohydrate-free diet.

    PubMed

    Azzout, B; Chanez, M; Bois-Joyeux, B; Peret, J

    1984-11-01

    Pyruvate kinase activity and rates of gluconeogenesis and glycolysis in rat hepatocytes were evaluated by production of glucose and lactate + pyruvate from dihydroxyacetone during the first 48 hours after the shift from a low protein, high carbohydrate diet to a high protein, carbohydrate-free diet. The effect of glucagon was also studied. In the absence of glucagon, 11-17 hours after the dietary shift when glycogen was lowest, gluconeogenesis was maximal and glycolysis minimal. The concentration of fructose 1,6-biphosphate was high and did not change during the experiment. The activity ratio of pyruvate kinase measured with phosphoenolpyruvate (PEP) (V0.5 mM PEP/V4 mM PEP) was high in crude extracts and low in (NH4)2SO4-treated extracts, but remained unchanged during the whole experiment. There was no correlation of the rates of gluconeogenesis or glycolysis from dihydroxyacetone with the activity ratio of pyruvate kinase. With glucagon, gluconeogenesis from dihydroxyacetone was increased and a concurrent decrease in glycolysis was paralleled with a decrease in the fructose 1,6-bisphosphate concentration and in the activity ratio of pyruvate kinase. The activity ratio of pyruvate kinase in (NH4)2SO4-treated cells represented about 50% of that in the absence of the hormone. This difference may be related to glucagon-induced phosphorylation of pyruvate kinase. PMID:6491768

  20. Patterns of organic acids exuded by pioneering fungi from a glacier forefield are affected by carbohydrate sources

    NASA Astrophysics Data System (ADS)

    Brunner, Ivano; Goren, Asena; Schlumpf, Alessandro

    2014-01-01

    Bare soils in the area of retreating glaciers are ideal environments to study the role of microorganisms in the early soil formation and in processes of mineral weathering. The aim of our study was to investigate whether the source of carbohydrate would influence the patterns of organic acids exuded by fungal species. Three pioneering fungus species, isolated from fine granitic sediments in front of the Damma glacier from the central Swiss Alps, have previously been found to have the capability to exude organic acids and dissolve granite powder. In batch experiments, various carbohydrates, including glucose, cellulose, pectin, pollen, and cell remnants of cyanobacteria, fungi, and algae, were applied as carbohydrate sources and the patterns of exuded organic acids recorded. The results showed that two fungi, the zygomycete fungus Mucor hiemalis and the ascomycete fungus Penicillium chrysogenum, released a significantly higher amount of organic acids in dependence on specific carbohydrate sources. Pollen and algae as carbohydrate sources triggered significantly the exudation of malate in M. hiemalis, and pollen and cellulose that of oxalate in P. chrysogenum. We conclude that the occurrence of complex carbohydrate sources in nutrient-deficient deglaciated soils may positively influence the exudation of organic acids of fungi. In particular, pollen and remnants of other microorganisms can trigger the exudation of organic acids of fungi in order to promote the weathering of minerals and to make nutrients available that would otherwise be trapped in that cryospheric environment.

  1. Dietary Protein to Carbohydrate Ratio and Caloric Restriction: Comparing Metabolic Outcomes in Mice.

    PubMed

    Solon-Biet, Samantha M; Mitchell, Sarah J; Coogan, Sean C P; Cogger, Victoria C; Gokarn, Rahul; McMahon, Aisling C; Raubenheimer, David; de Cabo, Rafael; Simpson, Stephen J; Le Couteur, David G

    2015-06-16

    Both caloric restriction (CR) and low-protein, high-carbohydrate (LPHC) ad-libitum-fed diets increase lifespan and improve metabolic parameters such as insulin, glucose, and blood lipids. Severe CR, however, is unsustainable for most people; therefore, it is important to determine whether manipulating macronutrient ratios in ad-libitum-fed conditions can generate similar health outcomes. We present the results of a short-term (8 week) dietary manipulation on metabolic outcomes in mice. We compared three diets varying in protein to carbohydrate ratio under both CR and ad libitum conditions. Ad libitum LPHC diets delivered similar benefits to CR in terms of levels of insulin, glucose, lipids, and HOMA, despite increased energy intake. CR on LPHC diets did not provide additional benefits relative to ad libitum LPHC. We show that LPHC diets under ad-libitum-fed conditions generate the metabolic benefits of CR without a 40% reduction in total caloric intake. PMID:26027933

  2. The nutrient composition of European ready meals: protein, fat, total carbohydrates and energy.

    PubMed

    Kanzler, Sonja; Manschein, Martin; Lammer, Guido; Wagner, Karl-Heinz

    2015-04-01

    Despite the increasing social importance of ready meals, only few studies have been conducted on their nutrient composition. Therefore, 32 chilled, frozen and heat-treated ready meals (only main dishes) from the continental European market were analysed for protein, fat, total carbohydrate and energy. Half of the meals were nutritionally imbalanced by providing elevated fat (>30% of energy) and low carbohydrate levels (<50% of energy). Protein was generally above recommendations and ranged from 8.0 to 47.2g per serving. The inter-package variation was high, reaching 19.04 ± 2.90 g/package for fat. After proposing understandable guidelines to improve nutritional quality for the food industry, seven "nutritionally optimised" ready meals were created at the European level and analysed, however success was limited. If product labelling is to be useful for consumers, our results also indicate a need for better quality control to reduce the differences between content and labelling. PMID:25442542

  3. Carbohydrate microarray for the detection of glycan-protein interactions using metal-enhanced fluorescence.

    PubMed

    Yang, Jie; Moraillon, Anne; Siriwardena, Aloysius; Boukherroub, Rabah; Ozanam, François; Gouget-Laemmel, Anne Chantal; Szunerits, Sabine

    2015-04-01

    Carbohydrate arrays are potentially one of the most attractive tools to study carbohydrate-based interactions. This paper describes a new analytical platform that exploits metal-enhanced fluorescence for the sensitive and selective screening of carbohydrate-lectin interactions. The chip consists of a glass slide covered with gold nanostructures, postcoated with a thin layer of amorphous silicon-carbon alloy (a-Si0.8C0.2:H). An immobilization strategy based on the formation of a covalent bond between propargyl-terminated glycans and surface-linked azide groups was used to attach various glycans at varying surface densities onto the interface and to fabricate a carbohydrate array via efficient local "click" chemistry strategy. The specific association of the new interface with fluorescently labeled lectins was assessed by fluorescence imaging and an excellent selectivity to specific proteins was achieved. Optimization of the surface architecture and the plasmonic transducer resulted in an enhancement of the fluorescence intensity by 1 order of magnitude, when compared to the corresponding substrate devoid of gold nanostructures. The limit of detection (LOD) of such microarrays is in the picomolar range, making it a promising system for development in pharmaceutical or biomedical applications. PMID:25729928

  4. L: (+)-Lactic acid production from non-food carbohydrates by thermotolerant Bacillus coagulans.

    PubMed

    Ou, Mark S; Ingram, Lonnie O; Shanmugam, K T

    2011-05-01

    Lactic acid is used as an additive in foods, pharmaceuticals, and cosmetics, and is also an industrial chemical. Optically pure lactic acid is increasingly used as a renewable bio-based product to replace petroleum-based plastics. However, current production of lactic acid depends on carbohydrate feedstocks that have alternate uses as foods. The use of non-food feedstocks by current commercial biocatalysts is limited by inefficient pathways for pentose utilization. B. coagulans strain 36D1 is a thermotolerant bacterium that can grow and efficiently ferment pentoses using the pentose-phosphate pathway and all other sugar constituents of lignocellulosic biomass at 50°C and pH 5.0, conditions that also favor simultaneous enzymatic saccharification and fermentation (SSF) of cellulose. Using this bacterial biocatalyst, high levels (150-180 g l(-1)) of lactic acid were produced from xylose and glucose with minimal by-products in mineral salts medium. In a fed-batch SSF of crystalline cellulose with fungal enzymes and B. coagulans, lactic acid titer was 80 g l(-1) and the yield was close to 80%. These results demonstrate that B. coagulans can effectively ferment non-food carbohydrates from lignocellulose to L: (+)-lactic acid at sufficient concentrations for commercial application. The high temperature fermentation of pentoses and hexoses to lactic acid by B. coagulans has these additional advantages: reduction in cellulase loading in SSF of cellulose with a decrease in enzyme cost in the process and a reduction in contamination of large-scale fermentations. PMID:20694852

  5. Multidomain Carbohydrate-binding Proteins Involved in Bacteroides thetaiotaomicron Starch Metabolism*

    PubMed Central

    Cameron, Elizabeth A.; Maynard, Mallory A.; Smith, Christopher J.; Smith, Thomas J.; Koropatkin, Nicole M.; Martens, Eric C.

    2012-01-01

    Human colonic bacteria are necessary for the digestion of many dietary polysaccharides. The intestinal symbiont Bacteroides thetaiotaomicron uses five outer membrane proteins to bind and degrade starch. Here, we report the x-ray crystallographic structures of SusE and SusF, two outer membrane proteins composed of tandem starch specific carbohydrate-binding modules (CBMs) with no enzymatic activity. Examination of the two CBMs in SusE and three CBMs in SusF reveals subtle differences in the way each binds starch and is reflected in their Kd values for both high molecular weight starch and small maltooligosaccharides. Thus, each site seems to have a unique starch preference that may enable these proteins to interact with different regions of starch or its breakdown products. Proteins similar to SusE and SusF are encoded in many other polysaccharide utilization loci that are possessed by human gut bacteria in the phylum Bacteroidetes. Thus, these proteins are likely to play an important role in carbohydrate metabolism in these abundant symbiotic species. Understanding structural changes that diversify and adapt related proteins in the human gut microbial community will be critical to understanding the detailed mechanistic roles that they perform in the complex digestive ecosystem. PMID:22910908

  6. Verification of protein sparing by feeding carbohydrate to common carp Cyprinus carpio

    NASA Astrophysics Data System (ADS)

    Cheng, Zhenyan; Li, Jinghui; Zhang, Baolong; Fang, Zhenzhen; Sun, Jinhui; Bai, Dongqing; Sun, Jinsheng; Qiao, Xiuting

    2016-06-01

    A 9-week feeding trial in floating freshwater cages (1.0 m×1.0 m×2.0 m) was conducted to study the effects of diff erent dietary levels of protein and starch on growth, body composition, and gene expression of enzymes in common carp, Cyprinus carpio (mean body weight, 36.12±1.18 g) to evaluate the protein-sparing effect of dietary carbohydrate. Four diets were formulated with corn starch as the carbohydrate source to obtain corn starch levels of 6.5%, 13%, 19.5%, or 26% and protein levels of 30.5%, 28.2%, 26.4%, and 24.2%. The results showed no diff erences in growth performance of fish fed the diets with diff erent protein and corn starch levels, but body composition and glucose metabolic enzyme activity of carp were significantly aff ected by the diff erent diets (P<0.05). Weight gain, specific growth rate, and the feed conversion ratio were not diff erent in fish fed the diff erent dietary treatments. Protein efficiency ratio increased significantly as corn starch level increased (P<0.05). Whole-body crude lipid composition increased with increasing dietary corn starch level (P<0.05). Glucokinase (GK), hexokinase, and pyruvate kinase (PK) activities increased significantly with increasing dietary corn starch level (P<0.05), whereas glucose-6-phosphate (G6Pase) activity decreased with increasing dietary corn starch level (P<0.05). GK gene expression was significantly higher in fish fed the high-corn starch diet than those fed the low-corn starch diet (P<0.05). G6pase gene expression tended to decrease with increasing starch level (P>0.05). In summary, the results indicate a protein-sparing effect by substituting carbohydrate in the diet of common carp.

  7. Sulfenic acids in the carbohydrate field. An example of straightforward access to novel multivalent thiosaccharides.

    PubMed

    Aversa, Maria C; Barattucci, Anna; Bilardo, Maria Cristina; Bonaccorsi, Paola; Giannetto, Placido; Rollin, Patrick; Tatibouët, Arnaud

    2005-09-01

    [reaction: see text] Both anomers of O-protected 1-thio-D-gluco- and -D-mannopyranoses were selected to provide the substrates for developing a smooth and general methodology that gives access to anomeric glycosulfoxides. The behavior of the corresponding beta-D-galactopyran derivatives was also investigated. 2-[1-[(2,3,4,6-Tetra-O-acetyl-beta-D-glucopyranosyl)sulfinyl](1-methyl)ethyl]malonic acid diethyl esters 4 were thermolyzed in refluxing dichloromethane for generating 2,3,4,6-tetra-O-acetyl-beta-D-glucopyranose-1-sulfenic acid (8), in the presence of 2-propynyl beta-d-glucopyranoside tetraacetate (32). The syn-addition of transient 8 onto the triple bond of 32 furnished 2-[(2,3,4,6-tetra-O-acetyl-beta-D-glucopyranosyl)sulfonyl]-2-propenyl beta-d-glucopyranoside tetraacetate (34), after m-CPBA oxidation of the corresponding sulfinyl epimeric mixture 33. This synthetic pathway appears particularly attractive since it represents an example of a mild and versatile approach to thiodisaccharides of foreseeably significant biological behavior. Various carbohydrate-derived sulfenic acids, different in glycosyl moiety and sulfenic function positioning, and various alkynylated carbohydrates can be adopted as combining units in the synthesis of alkene-linked multivalent thiosaccharides. PMID:16122264

  8. Monomeric carbohydrates production from olive tree pruning biomass: modeling of dilute acid hydrolysis.

    PubMed

    Puentes, Juan G; Mateo, Soledad; Fonseca, Bruno G; Roberto, Inês C; Sánchez, Sebastián; Moya, Alberto J

    2013-12-01

    Statistical modeling and optimization of dilute sulfuric acid hydrolysis of olive tree pruning biomass has been performed using response surface methodology. Central composite rotatable design was applied to assess the effect of acid concentration, reaction time and temperature on efficiency and selectivity of hemicellulosic monomeric carbohydrates to d-xylose. Second-order polynomial model was fitted to experimental data to find the optimum reaction conditions by multiple regression analysis. The monomeric d-xylose recovery 85% (as predicted by the model) was achieved under optimized hydrolysis conditions (1.27% acid concentration, 96.5°C and 138 min), confirming the high validity of the developed model. The content of d-glucose (8.3%) and monosaccharide degradation products (0.1% furfural and 0.04% 5-hydroxymethylfurfural) provided a high quality subtract, ready for subsequent biochemical conversion to value-added products. PMID:24096282

  9. Changes in Atherogenic Dyslipidemia Induced by Carbohydrate Restriction in Men Are Dependent on Dietary Protein Source1234

    PubMed Central

    Mangravite, Lara M.; Chiu, Sally; Wojnoonski, Kathleen; Rawlings, Robin S.; Bergeron, Nathalie; Krauss, Ronald M.

    2011-01-01

    Previous studies have shown that multiple features of atherogenic dyslipidemia are improved by replacement of dietary carbohydrate with mixed sources of protein and that these lipid and lipoprotein changes are independent of dietary saturated fat content. Because epidemiological evidence suggests that red meat intake may adversely affect cardiovascular disease risk, we tested the effects of replacing dietary carbohydrate with beef protein in the context of high- vs. low-saturated fat intake in 40 healthy men. After a 3-wk baseline diet [50% daily energy (E) as carbohydrate, 13% E as protein, 15% E as saturated fat], participants consumed for 3 wk each in a randomized crossover design two high-beef diets in which protein replaced carbohydrate (31% E as carbohydrate, 31% E as protein, with 10% E as beef protein). The high-beef diets differed in saturated fat content (8% E vs. 15% E with exchange of saturated for monounsaturated fat). Two-week washout periods were included following the baseline diet period and between the randomized diets periods. Plasma TG concentrations were reduced after the 2 lower carbohydrate dietary periods relative to after the baseline diet period and these reductions were independent of saturated fat intake. Plasma total, LDL, and non-HDL cholesterol as well as apoB concentrations were lower after the low-carbohydrate, low-saturated fat diet period than after the low-carbohydrate, high-saturated fat diet period. Given our previous observations with mixed protein diets, the present findings raise the possibility that dietary protein source may modify the effects of saturated fat on atherogenic lipoproteins. PMID:22031660

  10. Dietary Proportions of Carbohydrates, Fat, and Protein and Risk of Oesophageal Cancer by Histological Type

    PubMed Central

    Lagergren, Katarina; Lindam, Anna; Lagergren, Jesper

    2013-01-01

    Background Dietary habits influence the risk of cancer of the oesophagus and oesophago-gastric junction, but the role of proportions of the main dietary macronutrients carbohydrates, fats and proteins is uncertain. Methods Data was derived from a nationwide Swedish population-based case-control study conducted in 1995–1997, in which case ascertainment was rapid, and all cases were uniformly classified. Information on the subjects' history of dietary intake was collected in personal interviews. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated using logistic regression, with adjustment for potentially confounding factors. Results Included were 189 oesophageal adenocarcinomas, 262 oesophago-gastric adenocarcinomas, 167 oesophageal squamous cell carcinomas, and 820 control subjects. Regarding oesophageal or oesophago-gastric junctional adenocarcinoma, a high dietary proportion of carbohydrates decreased the risk (OR 0.50, CI 0.34–0.73), and a high portion of fat increased the risk (OR 1.96, CI 1.34–2.87), while a high proportion of protein did not influence the risk (OR 1. 08, 95% CI 0.75–1.56). Regarding oesophageal squamous cell carcinoma, the single macronutrients did not influence the risk statistically significantly. Conclusions A diet with a low proportion of carbohydrates and a high proportion of fat might increase the risk of oesophageal adenocarcinoma. PMID:23349988

  11. Aerobic Exercise Training Adaptations Are Increased by Postexercise Carbohydrate-Protein Supplementation

    PubMed Central

    Ferguson-Stegall, Lisa; McCleave, Erin; Ding, Zhenping; Doerner III, Phillip G.; Liu, Yang; Wang, Bei; Healy, Marin; Kleinert, Maximilian; Dessard, Benjamin; Lassiter, David G.; Kammer, Lynne; Ivy, John L.

    2011-01-01

    Carbohydrate-protein supplementation has been found to increase the rate of training adaptation when provided postresistance exercise. The present study compared the effects of a carbohydrate and protein supplement in the form of chocolate milk (CM), isocaloric carbohydrate (CHO), and placebo on training adaptations occurring over 4.5 weeks of aerobic exercise training. Thirty-two untrained subjects cycled 60 min/d, 5 d/wk for 4.5 wks at 75–80% of maximal oxygen consumption (VO2 max). Supplements were ingested immediately and 1 h after each exercise session. VO2 max and body composition were assessed before the start and end of training. VO2 max improvements were significantly greater in CM than CHO and placebo. Greater improvements in body composition, represented by a calculated lean and fat mass differential for whole body and trunk, were found in the CM group compared to CHO. We conclude supplementing with CM postexercise improves aerobic power and body composition more effectively than CHO alone. PMID:21773022

  12. Carbohydrate-to-carbohydrate interactions between α2,3-linked sialic acids on α2 integrin subunits and asialo-GM1 underlie the bone metastatic behaviour of LNCAP-derivative C4-2B prostate cancer cells

    PubMed Central

    Van Slambrouck, Séverine; Groux-Degroote, Sophie; Krzewinski-Recchi, Marie-Ange; Cazet, Aurélie; Delannoy, Philippe; Steelant, Wim F. A.

    2014-01-01

    Complex interplays among proteins, lipids and carbohydrates can alter the phenotype and are suggested to have a crucial role in tumour metastasis. Our previous studies indicated that a complex of the GSLs (glycosphingolipids), AsGM1 (asialo-GM1), which lacks α2,3-linked sialic acid, and α2β1 integrin receptors is responsible for the metastatic behaviour of C4-2B prostate cancer cells. Herein, we identified and addressed the functional significance of changes in sialylation during prostate cancer progression. We observed an increase in α2,3-linked sialic acid residues on α2 subunits of α2β1 integrin receptors, correlating with increased gene expression of α2,3-STs (sialyltransferases), particularly ST3GAL3. Cell surface α2,3-sialylation of α2 subunits was required for the integrin α2β1-dependent cell adhesion to collagen type I and the same α2,3-linked sialic acid residues on the integrin receptor were responsible for the interaction with the carbohydrate moiety of AsGM1, explaining the complex formation between AsGM1 and α2β1 integrin receptors. These results provide novel insights into the role of sialic acids in the organization and function of important membrane components in invasion and metastatic processes. PMID:25137483

  13. Carbohydrate and dietary fiber

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Carbohydrate provides 50 to 60% of the calories consumed by the average American. Although relatively little carbohydrate is needed in the diet, carbohydrate spares protein and fat being metabolized for calories. The principal dietary carbohydrates are sugars and starches. Sugars (simple carbohydrat...

  14. Catalytic conversion of carbohydrates to 5-hydroxymethylfurfural from the waste liquid of acid hydrolysis NCC.

    PubMed

    Sun, Yonghui; Liu, Pengtao; Liu, Zhong

    2016-05-20

    The principal goal of this work was to reuse the carbohydrates and recycle sulfuric acid in the waste liquid of acid hydrolysis nanocrystalline cellulose (NCC). Therefore, in this work, the optimizations of further hydrolysis of waste liquid of acid hydrolysis NCC and catalytic conversion of L4 to 5-hydroxymethylfurfural (5-HMF) were studied. Sulfuric acid was separated by spiral wound diffusion dialysis (SWDD). The results revealed that cellulose can be hydrolyze to glucose absolutely under the condition of temperature 35 °C, 3 h, and sulfuric acid's concentration 62 wt%. And 78.3% sulfuric acid was recovered by SWDD. The yield of 5-HMF was highest in aqueous solution under the optimal condition was as follows, temperature 160 °C, 3 h, and sulfuric acid's concentration 12 wt%. Then the effect of biphasic solvent systems catalytic conversion and inorganic salt as additives were still examined. The results showed that both of them contributed to prepare 5-HMF. The yield and selectivity of 5-HMF was up to 21.0% and 31.4%, respectively. PMID:26917388

  15. Transformation of cellulose and its derived carbohydrates into formic and lactic acids catalyzed by vanadyl cations.

    PubMed

    Tang, Zhenchen; Deng, Weiping; Wang, Yanliang; Zhu, Enze; Wan, Xiaoyue; Zhang, Qinghong; Wang, Ye

    2014-06-01

    The transformation of cellulose or cellulose-derived carbohydrates into platform chemicals is the key to establish biomass-based sustainable chemical processes. The systems able to catalyze the conversion of cellulose into key chemicals in water without the consumption of hydrogen are limited. We report that simple vanadyl (VO(2+)) cations catalyze the conversions of cellulose and its monomer, glucose, into lactic acid and formic acid in water. We have discovered an interesting shift of the major product from formic acid to lactic acid on switching the reaction atmosphere from oxygen to nitrogen. Our studies suggest that VO(2+) catalyzes the isomerization of glucose to fructose, the retro-aldol fragmentation of fructose to two trioses, and the isomerization of trioses, which leads to the formation of lactic acid under anaerobic conditions. The oxidative cleavage of C-C bonds in the intermediates caused by the redox conversion of VO2(+)/VO(2+) under aerobic conditions results in formic acid and CO2. We demonstrate that the addition of an alcohol suppresses the formation of CO2 and enhances the formic acid yield significantly to 70-75 %. PMID:24798653

  16. Association of protein structure, protein and carbohydrate subfractions with bioenergy profiles and biodegradation functions in modeled forage.

    PubMed

    Ji, Cuiying; Zhang, Xuewei; Yu, Peiqiang

    2016-03-15

    The objectives of this study were to detect unique aspects and association of forage protein inherent structure, biological compounds, protein and carbohydrate subfractions, bioenergy profiles, and biodegradation features. In this study, common available alfalfa hay from two different sourced-origins (FSO vs. CSO) was used as a modeled forage for inherent structure profile, bioenergy, biodegradation and their association between their structure and bio-functions. The molecular spectral profiles were determined using non-invasive molecular spectroscopy. The parameters included: protein structure amide I group, amide II group and their ratios; protein subfractions (PA1, PA2, PB1, PB2, PC); carbohydrate fractions (CA1, CA2, CA3, CA4, CB1, CB2, CC); biodegradable and undegradable fractions of protein (RDPA2, RDPB1, RDPB2, RDP; RUPA2 RUPB1, RUPB2, RUPC, RUP); biodegradable and undegradable fractions of carbohydrate (RDCA4, RDCB1, RDCB2, RDCB3, RDCHO; RUCA4, RUCB1; RUCB2; RUCB3 RUCC, RUCHO) and bioenergy profiles (tdNDF, tdFA, tdCP, tdNFC, TDN1×, DE3×, ME3×, NEL3×; NEm, NEg). The results show differences in protein and carbohydrate (CHO) subfractions in the moderately degradable true protein fraction (PB1: 502 vs. 420 g/kg CP, P=0.09), slowly degraded true protein fraction (PB2: 45 vs. 96 g/kg CP, P=0.02), moderately degradable CHO fraction (CB2: 283 vs. 223 g/kg CHO, P=0.06) and slowly degraded CHO fraction (CB3: 369 vs. 408 g/kg CHO) between the two sourced origins. As to biodegradable (RD) fractions of protein and CHO in rumen, there were differences in RD of PB1 (417 vs. 349 g/kg CP, P=0.09), RD of PB2 (29 vs. 62 g/kg CP, P=0.02), RD of CB2 (251 vs. 198 g/kg DM, P=0.06), RD of CB3 (236 vs. 261 g/kg CHO, P=0.08). As to bioenergy profile, there were differences in total digestible nutrient (TDN: 551 vs. 537 g/kg DM, P=0.06), and metabolic bioenergy (P=0.095). As to protein molecular structure, there were differences in protein structure 1st and 2nd amide groups (P

  17. Association of protein structure, protein and carbohydrate subfractions with bioenergy profiles and biodegradation functions in modeled forage

    NASA Astrophysics Data System (ADS)

    Ji, Cuiying; Zhang, Xuewei; Yu, Peiqiang

    2016-03-01

    The objectives of this study were to detect unique aspects and association of forage protein inherent structure, biological compounds, protein and carbohydrate subfractions, bioenergy profiles, and biodegradation features. In this study, common available alfalfa hay from two different sourced-origins (FSO vs. CSO) was used as a modeled forage for inherent structure profile, bioenergy, biodegradation and their association between their structure and bio-functions. The molecular spectral profiles were determined using non-invasive molecular spectroscopy. The parameters included: protein structure amide I group, amide II group and their ratios; protein subfractions (PA1, PA2, PB1, PB2, PC); carbohydrate fractions (CA1, CA2, CA3, CA4, CB1, CB2, CC); biodegradable and undegradable fractions of protein (RDPA2, RDPB1, RDPB2, RDP; RUPA2 RUPB1, RUPB2, RUPC, RUP); biodegradable and undegradable fractions of carbohydrate (RDCA4, RDCB1, RDCB2, RDCB3, RDCHO; RUCA4, RUCB1; RUCB2; RUCB3 RUCC, RUCHO) and bioenergy profiles (tdNDF, tdFA, tdCP, tdNFC, TDN1 ×, DE3 ×, ME3 ×, NEL3 ×; NEm, NEg). The results show differences in protein and carbohydrate (CHO) subfractions in the moderately degradable true protein fraction (PB1: 502 vs. 420 g/kg CP, P = 0.09), slowly degraded true protein fraction (PB2: 45 vs. 96 g/kg CP, P = 0.02), moderately degradable CHO fraction (CB2: 283 vs. 223 g/kg CHO, P = 0.06) and slowly degraded CHO fraction (CB3: 369 vs. 408 g/kg CHO) between the two sourced origins. As to biodegradable (RD) fractions of protein and CHO in rumen, there were differences in RD of PB1 (417 vs. 349 g/kg CP, P = 0.09), RD of PB2 (29 vs. 62 g/kg CP, P = 0.02), RD of CB2 (251 vs. 198 g/kg DM, P = 0.06), RD of CB3 (236 vs. 261 g/kg CHO, P = 0.08). As to bioenergy profile, there were differences in total digestible nutrient (TDN: 551 vs. 537 g/kg DM, P = 0.06), and metabolic bioenergy (P = 0.095). As to protein molecular structure, there were differences in protein structure 1st

  18. Changes of Mouse Gut Microbiota Diversity and Composition by Modulating Dietary Protein and Carbohydrate Contents: A Pilot Study

    PubMed Central

    Kim, Eunjung; Kim, Dan-Bi; Park, Jae-Yong

    2016-01-01

    Dietary proteins influence colorectal cancer (CRC) risk, depending on their quantity and quality. Here, using pyrosequencing, we compared the fecal microbiota composition in Balb/c mice fed either a normal protein/carbohydrate diet (ND, 20% casein and 68% carbohydrate) or a high-protein/low-carbohydrate diet (HPLCD, 30% casein and 57% carbohydrate). The results showed that HPLCD feeding for 2 weeks reduced the diversity and altered the composition of the microbiota compared with the ND mice, which included a decrease in the proportion of the family Lachnospiraceae and Ruminococcaceae and increases in the proportions of the genus Bacteroides and Parabacteroides, especially the species EF09600_s and EF604598_s. Similar changes were reported in patients with inflammatory bowel disease, and in mouse models of CRC and colitis, respectively. This suggests that HPLCD may lead to a deleterious luminal environment and may have adverse effects on the intestinal health of individuals consuming such a diet. PMID:27069907

  19. Changes of Mouse Gut Microbiota Diversity and Composition by Modulating Dietary Protein and Carbohydrate Contents: A Pilot Study.

    PubMed

    Kim, Eunjung; Kim, Dan-Bi; Park, Jae-Yong

    2016-03-01

    Dietary proteins influence colorectal cancer (CRC) risk, depending on their quantity and quality. Here, using pyrosequencing, we compared the fecal microbiota composition in Balb/c mice fed either a normal protein/carbohydrate diet (ND, 20% casein and 68% carbohydrate) or a high-protein/low-carbohydrate diet (HPLCD, 30% casein and 57% carbohydrate). The results showed that HPLCD feeding for 2 weeks reduced the diversity and altered the composition of the microbiota compared with the ND mice, which included a decrease in the proportion of the family Lachnospiraceae and Ruminococcaceae and increases in the proportions of the genus Bacteroides and Parabacteroides, especially the species EF09600_s and EF604598_s. Similar changes were reported in patients with inflammatory bowel disease, and in mouse models of CRC and colitis, respectively. This suggests that HPLCD may lead to a deleterious luminal environment and may have adverse effects on the intestinal health of individuals consuming such a diet. PMID:27069907

  20. Continuous-flow reactor-based synthesis of carbohydrate and dihydrolipoic acid-capped quantum dots.

    PubMed

    Laurino, Paola; Kikkeri, Raghavendra; Seeberger, Peter H

    2011-08-01

    A detailed protocol for the large-scale synthesis of carbohydrate and dihydrolipoic acid (DHLA)-coated CdSe/ZnS and CdTe/ZnS nanoparticles using continuous flow reactors is described here. Three continuous flow microreaction systems, operating at three different temperatures, are used for the synthesis of mannose-, galactose- or DHLA-functionalized quantum dots (QDs). In the first step of synthesis, the CdSe and CdTe nanoparticles are prepared. The size and spectral properties of the CdSe core of the nanoparticles are controlled by adjustment of the residence time and the temperature. As a second step, the zinc sulfide capping under homogenous conditions is carried out at a substantially lower temperature than is required for nanoparticle growth in batch processes. Finally, the trioctylphosphine/oleic acid ligand is effectively replaced with either carbohydrate PEG-thiol moieties or DHLA at 60 °C. This new protocol allows the synthesis of biologically active fluorescent QDs in 4 d. PMID:21799489

  1. Chemotactic behavior of deep subsurface bacteria toward carbohydrates, amino acids and a chlorinated alkene

    SciTech Connect

    Lopez de Victoria, G. . Dept. of Biology)

    1989-02-01

    The chemotactic behavior of deep terrestrial subsurface bacteria toward amino acids, carbohydrates and trichloroethylene was assayed using a modification of the capillary method and bacterial enumeration by acridine orange direct counts. Eleven isolates of bacteria isolated from six different geological formations were investigated. A bimodal response rather than an absolute positive or negative response was observed in most assays. Most of the isolates were positively chemotactic to low concentrations of substrates and were repelled by high concentrations of the same substrate. However, this was not the case for trichloroethylene (TCE) which was mostly an attractant and elicited the highest responses in all the isolates when compared with amino acids and carbohydrates. The movement rates of these isolates in aseptic subsurface sediments in the absence and presence of TCE were also determined using a laboratory model. All of the isolates showed distinct response range, peak, and threshold concentrations when exposed to the same substrates suggesting that they are possibly different species as has been inferred from DNA homology studies. 101 refs., 4 figs., 57 tabs.

  2. Distribution of dissolved carbohydrates and uronic acids in a tropical estuary, India

    NASA Astrophysics Data System (ADS)

    Khodse, Vishwas B.; Bhosle, Narayan B.; Matondkar, S. G. Prabhu

    2010-08-01

    Carbohydrates including uronic acids are among the active components of dissolved organic carbon, and play an important role in biogeochemical cycling of organic carbon in marine environments. In order to understand their distribution, concentrations of total dissolved carbohydrate (TCHO), dissolved polysaccharide (PCHO), dissolved monosaccharide (MCHO), and dissolved uronic acid (URA) were measured in the Mandovi estuary, west coast of India during the monsoon and premonsoon seasons. The estuary experienced nearly fresh water condition during the monsoon season and marine condition during the pre-monsoon season. Concentrations of TCHO, MCHO and URA ranged from 17.7 to 67.3 µM C, 4.1 to 15.5 µM C and 2.3 to 10.8 µM C, and their contribution to dissolved organic carbon (DOC) varied from ˜11 to 60%, 2.5 to 9.7%, and 1.8 to 5.3%, respectively. PCHO accounted for ˜52 to 92% of the TCHO. Generally, concentrations and yields of TCHO species were greater during the monsoon season. Phytoplankton abundance and bacterial cell numbers influenced the distribution of TCHO in the pre-monsoon season but not during the monsoon season. Transport of TCHO rich (11 to 60%) dissolved organic matter from the Mandovi estuary to the coastal waters during the monsoon season may affect ecosystem function by fueling biological activity of heterotrophic micro-organisms.

  3. The impact of low-protein high-carbohydrate diets on aging and lifespan.

    PubMed

    Le Couteur, David G; Solon-Biet, Samantha; Cogger, Victoria C; Mitchell, Sarah J; Senior, Alistair; de Cabo, Rafael; Raubenheimer, David; Simpson, Stephen J

    2016-03-01

    Most research on nutritional effects on aging has focussed on the impact of manipulating single dietary factors such as total calorie intake or each of the macronutrients individually. More recent studies using a nutritional geometric approach called the Geometric Framework have facilitated an understanding of how aging is influenced across a landscape of diets that vary orthogonally in macronutrient and total energy content. Such studies have been performed using ad libitum feeding regimes, thus taking into account compensatory feeding responses that are inevitable in a non-constrained environment. Geometric Framework studies on insects and mice have revealed that diets low in protein and high in carbohydrates generate longest lifespans in ad libitum-fed animals while low total energy intake (caloric restriction by dietary dilution) has minimal effect. These conclusions are supported indirectly by observational studies in humans and a heterogeneous group of other types of interventional studies in insects and rodents. Due to compensatory feeding for protein dilution, low-protein, high-carbohydrate diets are often associated with increased food intake and body fat, a phenomenon called protein leverage. This could potentially be mitigated by supplementing these diets with interventions that influence body weight through physical activity and ambient temperature. PMID:26718486

  4. Synthesis and Evaluation of Aryl Boronic Acids as Fluorescent Artificial Receptors for Biological Carbohydrates

    PubMed Central

    Craig, Sandra

    2011-01-01

    Carbohydrates in various forms play a vital role in numerous critical biological processes. The detection of such saccharides can give insight into the progression of such diseases such as cancer. Boronic acids react with 1,2 and 1,3 diols of saccharides in non-aqueous or basic aqueous media. Herein, we describe the design, synthesis and evaluation of three bisboronic acid fluorescent probes, each having about ten linear steps in its synthesis. Among these compounds that were evaluated, 9b was shown to selectively label HepG2, liver carcinoma cell line within a concentration range of 0.5–10 μM in comparison to COS-7, a normal fibroblast cell line. PMID:22177855

  5. Exopolysaccharide assay in Escherichia coli microcolonies using a cleavable fusion protein of GFP-labeled carbohydrate-binding module.

    PubMed

    Ojima, Yoshihiro; Suparman, Asep; Nguyen, Minh Hong; Sakka, Makiko; Sakka, Kazuo; Taya, Masahito

    2015-07-01

    A fused protein composed of a carbohydrate-binding module and green fluorescence protein (GFP) was developed to measure the exopolysaccharides (EPShs) present in Escherichia coli microcolonies. The cleavage of the GFP part of this protein using a site-specific protease allowed for the non-invasive and quantitative evaluation of the EPShs. PMID:25978970

  6. Mcy protein, a potential antidiabetic agent: evaluation of carbohydrate metabolic enzymes and antioxidant status.

    PubMed

    Marella, Saritha; Maddirela, Dilip Rajasekhar; Kumar, E G T V; Tilak, Thandaiah Krishna; Badri, Kameswara Rao; Chippada, Apparao

    2016-05-01

    The objective of the present study is to elucidate the long-term effects of anti-hyperglycemic active principle, Mcy protein (MCP), isolated from the fruits of Momordica cymbalaria on carbohydrate metabolism and oxidative stress in experimental diabetic rats. We used streptozotocin induced diabetic rats for the current studies. Our studies showed that MCP (2.5mg/kg.b.w) treatment significantly normalized the deranged activities of critical carbohydrate metabolizing enzymes, hexokinase, glucose-6-phosphate dehydrogenase, glucose-6-phosphatase and fructose-1,6-bis phosphatase. In addition MCP showed inhibitory activity on α-glucosidase and aldose reductase enzymes in in vitro assays. Further MCP treatment improved the antioxidant defensive mechanism by preventing deleterious oxidative products of cellular metabolism, which initiates the lipid peroxidation and by normalizing the antioxidant enzyme (catalase, superoxide dismutase, glutathione peroxidase) activities. Additional structural studies using circular dichroism spectroscopy indicate that MCP contains majorly α-helix. Our findings suggest MCP regulates blood glucose and better manage diabetes mellitus associated complications by regulating carbohydrate metabolism and by protecting from the deleterious effects of oxidative stress. PMID:26826289

  7. Low-fat, high-carbohydrate diets improve wound healing and increase protein levels in surgically stressed rats.

    PubMed

    Nirgiotis, J G; Hennessey, P J; Black, C T; Andrassy, R J

    1991-08-01

    The specific effects of omega 3 and omega 6 polyunsaturated fatty acids on wound healing, nutrition status, or immune function are controversial. Therefore, we investigated the effects of fatty acid supplementation on wound healing and nitrogen retention in a surgically stressed rat model. Male Sprague-Dawley rats (weighing 250 g) were placed into three isocaloric, isonitrogenous feeding groups (controls [standard Vivonex]; 30% safflower oil [omega 6]; or 30% fish oil [omega 3]) for 8 days prior to receiving subcutaneous vascular graft wound cylinders in their dorsal midline. Nitrogen balance was monitored daily. Wounds healed for 10 days, animals were then euthanized, serum was drawn, and wound cylinders were harvested for analyses. The low-fat, high-carbohydrate control group had higher serum albumin levels at 10 days than either fatty acid-supplemented group (3.5 +/- 0.4 g/dL v 2.9 +/- 0.3 g/dL and 2.7 +/- 0.2 g/dL, omega 3 and omega 6, respectively; both P less than .05) and had better nitrogen balance (8.6 +/- 0.8 mg N/d v -2.6 +/- 0.9 mg N/d and 0.8 +/- 1.2 mg N/d, omega 3 and omega 6, respectively; both P less than .05). They also had better healed wounds at 10 days (450 +/- 290 micrograms 5-hydroxyproline [OHP]/cm of wound cylinder v 150 +/- 40 micrograms OHP/cm and 145 +/- 90 micrograms OHP/cm, omega 3 and omega 6, respectively). Surgically stressed rats had higher protein levels, better nitrogen balance, and improved wound healing when fed a diet high in carbohydrates and low in fat. PMID:1919985

  8. Amino acid sequence and carbohydrate-binding analysis of the N-acetyl-D-galactosamine-specific C-type lectin, CEL-I, from the Holothuroidea, Cucumaria echinata.

    PubMed

    Hatakeyama, Tomomitsu; Matsuo, Noriaki; Shiba, Kouhei; Nishinohara, Shoichi; Yamasaki, Nobuyuki; Sugawara, Hajime; Aoyagi, Haruhiko

    2002-01-01

    CEL-I is one of the Ca2+-dependent lectins that has been isolated from the sea cucumber, Cucumaria echinata. This protein is composed of two identical subunits held by a single disulfide bond. The complete amino acid sequence of CEL-I was determined by sequencing the peptides produced by proteolytic fragmentation of S-pyridylethylated CEL-I. A subunit of CEL-I is composed of 140 amino acid residues. Two intrachain (Cys3-Cys14 and Cys31-Cys135) and one interchain (Cys36) disulfide bonds were also identified from an analysis of the cystine-containing peptides obtained from the intact protein. The similarity between the sequence of CEL-I and that of other C-type lectins was low, while the C-terminal region, including the putative Ca2+ and carbohydrate-binding sites, was relatively well conserved. When the carbohydrate-binding activity was examined by a solid-phase microplate assay, CEL-I showed much higher affinity for N-acetyl-D-galactosamine than for other galactose-related carbohydrates. The association constant of CEL-I for p-nitrophenyl N-acetyl-beta-D-galactosaminide (NP-GalNAc) was determined to be 2.3 x 10(4) M(-1), and the maximum number of bound NP-GalNAc was estimated to be 1.6 by an equilibrium dialysis experiment. PMID:11866098

  9. Addition of glutamine to essential amino acids and carbohydrate does not enhance anabolism in young human males following exercise.

    PubMed

    Wilkinson, Sarah B; Kim, Paul L; Armstrong, David; Phillips, Stuart M

    2006-10-01

    We examined the effect of a post-exercise oral carbohydrate (CHO, 1 g.kg(-1).h(-1)) and essential amino acid (EAA, 9.25 g) solution containing glutamine (0.3 g/kg BW; GLN trial) versus an isoenergetic CHO-EAA solution without glutamine (control, CON trial) on muscle glycogen resynthesis and whole-body protein turnover following 90 min of cycling at 65% VO2 peak. Over the course of 3 h of recovery, muscle biopsies were taken to measure glycogen resynthesis and mixed muscle protein synthesis (MPS), by incorporation of [ring-2H5] phenylalanine. Infusion of [1-13C] leucine was used to measure whole-body protein turnover. Exercise resulted in a significant decrease in muscle glycogen (p < 0.05) with similar declines in each trial. Glycogen resynthesis following 3 h of recovery indicated no difference in total accumulation or rate of repletion. Leucine oxidation increased 2.5 fold (p < 0.05) during exercise, returned to resting levels immediately post-exercise,and was again elevated at 3 h post-exercise (p < 0.05). Leucine flux, an index of whole-body protein breakdown rate, was reduced during exercise, but increased to resting levels immediately post-exercise, and was further increased at 3 h post-exercise (p < 0.05), but only during the CON trial. Exercise resulted in a marked suppression of whole-body protein synthesis (50% of rest; p < 0.05), which was restored post-exercise; however, the addition of glutamine did not affect whole-body protein synthesis post-exercise. The rate of MPS was not different between trials. The addition of glutamine to a CHO + EAA beverage had no effect on post-exercise muscle glycogen resynthesis or muscle protein synthesis, but may suppress a rise in whole-body proteolysis during the later stages of recovery. PMID:17111006

  10. Carbohydrate vs protein supplementation for recovery of neuromuscular function following prolonged load carriage

    PubMed Central

    2010-01-01

    Background This study examined the effect of carbohydrate and whey protein supplements on recovery of neuromuscular function after prolonged load carriage. Methods Ten male participants (body mass: 81.5 ± 10.5 kg, age: 28 ± 9 years, O2max: 55.0 ± 5.5 ml·kg-1·min-1) completed three treadmill walking tests (2 hr, 6.5 km·h-1), carrying a 25 kg backpack consuming 500 ml of either: (1) Placebo (flavoured water) [PLA], (2) 6.4% Carbohydrate Solution [CHO] or (3) 7.0% Whey Protein Solution [PRO]. For three days after load carriage, participants consumed two 500 ml supplement boluses. Muscle performance was measured before and at 0, 24, 48 and 72 h after load carriage, during voluntary and electrically stimulated contractions. Results Isometric knee extension force decreased immediately after load carriage with no difference between conditions. During recovery, isometric force returned to pre-exercise values at 48 h for CHO and PRO but at 72 h for PLA. Voluntary activation decreased immediately after load carriage and returned to pre-exercise values at 24 h in all conditions (P = 0.086). During recovery, there were no differences between conditions for the change in isokinetic peak torque. Following reductions immediately after load carriage, knee extensor and flexor peak torque (60°·s-1) recovered to pre-exercise values at 72 h. Trunk extensor and flexor peak torque (15°·s-1) recovered to pre-exercise values at 24 h (P = 0.091) and 48 h (P = 0.177), respectively. Conclusion Recovery of neuromuscular function after prolonged load carriage is improved with either carbohydrate or whey protein supplementation for isometric contractions but not for isokinetic contractions. PMID:20157419

  11. Evaluation of Selected Classical Force Fields for Alchemical Binding Free Energy Calculations of Protein-Carbohydrate Complexes.

    PubMed

    Mishra, Sushil K; Calabró, Gaetano; Loeffler, Hannes H; Michel, Julien; Koča, Jaroslav

    2015-07-14

    Protein-carbohydrate recognition is crucial in many vital biological processes including host-pathogen recognition, cell-signaling, and catalysis. Accordingly, computational prediction of protein-carbohydrate binding free energies is of enormous interest for drug design. However, the accuracy of current force fields (FFs) for predicting binding free energies of protein-carbohydrate complexes is not well understood owing to technical challenges such as the highly polar nature of the complexes, anomerization, and conformational flexibility of carbohydrates. The present study evaluated the performance of alchemical predictions of binding free energies with the GAFF1.7/AM1-BCC and GLYCAM06j force fields for modeling protein-carbohydrate complexes. Mean unsigned errors of 1.1 ± 0.06 (GLYCAM06j) and 2.6 ± 0.08 (GAFF1.7/AM1-BCC) kcal·mol(-1) are achieved for a large data set of monosaccharide ligands for Ralstonia solanacearum lectin (RSL). The level of accuracy provided by GLYCAM06j is sufficient to discriminate potent, moderate, and weak binders, a goal that has been difficult to achieve through other scoring approaches. Accordingly, the protocols presented here could find useful applications in carbohydrate-based drug and vaccine developments. PMID:26575767

  12. Effects of protein, lipid, or carbohydrate supplementation on hepatic lipid accumulation during rapid weight loss in obese cats.

    PubMed

    Biourge, V C; Massat, B; Groff, J M; Morris, J G; Rogers, Q R

    1994-10-01

    Effects of restricted tube-feeding (25% of energy requirements) of protein, lipid, or carbohydrates on body weight loss; hematologic and clinical chemical variables; plasma lipid and amino acid concentrations; nitrogen balance; and hepatic histologic features and lipid concentrations were compared with values in voluntary-fasting cats (control, CON). Twelve obese cats (6.1 +/- 0.1 kg, > 40% above optimal body weight) were randomly assigned to 4 matched treatment groups (n = 3)--protein (PRO), lipid (LIP), carbohydrate (CHO), and CON--and were offered a low-palatability diet for 4 weeks. Cats of the PRO, LIP, and CHO groups were also tube-fed isocaloric amounts (88 kcal of metabolizable energy) of a casein-soybean protein mixture, corn oil, or a dextrin-dextrose mixture, respectively, during the 4 weeks. All cats fasted, rather than eat the low-palatability purified diet. Cats of the PRO group lost weight at a lower rate (P < 0.05) than did cats of other groups. After 4 weeks of fasting, serum alkaline phosphatase activities were higher than reference values in all cats of the CON and LIP groups and in 2 cats of the CHO group. At that time, 1 cat of the LIP group had lethargy, hepatomegaly, and hyperbilirubinemia. Total hepatic lipid and triglyceride concentrations increased in all groups during the study, but the increase was significantly (P < 0.05) less in cats of the PRO group, compared with those of the CON and LIP groups, and those of the CHO group, compared with those of the LIP group.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7998698

  13. Genetically Encoded Fragment-Based Discovery of Glycopeptide Ligands for Carbohydrate-Binding Proteins

    DOE PAGESBeta

    Ng, Simon; Lin, Edith; Kitov, Pavel I.; Tjhung, Katrina F.; Gerlits, Oksana O.; Deng, Lu; Kasper, Brian; Sood, Amika; Paschal, Beth M.; Zhang, Ping; et al

    2015-04-10

    Here we describe an approach to accelerate the search for competitive inhibitors for carbohydrate-recognition domains (CRDs). Genetically encoded fragment-based-discovery (GE-FBD) uses selection of phagedisplayed glycopeptides to dock a glycan fragment at the CRD and guide selection of Synergistic peptide motifs adjacent to the CRD. Starting from concanavalin A (ConA), a mannose (Man)-binding protein, as a bait, we narrowed a library of 108 glycopeptides to 86 leads that share a consensus motif, Man-WYD. Validation of synthetic leads yielded Man-WYDLF that exhibited 40 50-fold enhancement in affinity over methyl α-D-mannopyranoside (MeMan). Lectin array Suggested specificity: Man-WYD derivative bound only to 3 outmore » of 17 proteins-ConA, LcH, and PSA-that bind to Man. An X-ray structure of ConA.:Man-WYD proved that the trimannoside core and Man-WYD exhibit identical CRD docking; but their extra-CRD binding modes are significantly. different. Still, they have comparable affinity and selectivity for various Man-binding proteins. The intriguing observation provides new insight into functional mimicry :of carbohydrates by peptide ligands. GE-FBD may provide an alternative to rapidly search for competitive inhibitors for lectins.« less

  14. Genetically Encoded Fragment-Based Discovery of Glycopeptide Ligands for Carbohydrate-Binding Proteins

    SciTech Connect

    Ng, Simon; Lin, Edith; Kitov, Pavel I.; Tjhung, Katrina F.; Gerlits, Oksana O.; Deng, Lu; Kasper, Brian; Sood, Amika; Paschal, Beth M.; Zhang, Ping; Ling, Chang-Chun; Klassen, John S.; Noren, Christopher J.; Mahal, Lara K.; Woods, Robert J.; Coates, Leighton; Derda, Ratmir

    2015-04-10

    Here we describe an approach to accelerate the search for competitive inhibitors for carbohydrate-recognition domains (CRDs). Genetically encoded fragment-based-discovery (GE-FBD) uses selection of phagedisplayed glycopeptides to dock a glycan fragment at the CRD and guide selection of Synergistic peptide motifs adjacent to the CRD. Starting from concanavalin A (ConA), a mannose (Man)-binding protein, as a bait, we narrowed a library of 108 glycopeptides to 86 leads that share a consensus motif, Man-WYD. Validation of synthetic leads yielded Man-WYDLF that exhibited 40 50-fold enhancement in affinity over methyl α-D-mannopyranoside (MeMan). Lectin array Suggested specificity: Man-WYD derivative bound only to 3 out of 17 proteins-ConA, LcH, and PSA-that bind to Man. An X-ray structure of ConA.:Man-WYD proved that the trimannoside core and Man-WYD exhibit identical CRD docking; but their extra-CRD binding modes are significantly. different. Still, they have comparable affinity and selectivity for various Man-binding proteins. The intriguing observation provides new insight into functional mimicry :of carbohydrates by peptide ligands. GE-FBD may provide an alternative to rapidly search for competitive inhibitors for lectins.

  15. Carbohydrate affinity for the glucose-galactose binding protein is regulated by allosteric domain motions.

    PubMed

    Ortega, Gabriel; Castaño, David; Diercks, Tammo; Millet, Oscar

    2012-12-01

    Protein function, structure, and dynamics are intricately correlated, but studies on structure-activity relationships are still only rarely complemented by a detailed analysis of dynamics related to function (functional dynamics). Here, we have applied NMR to investigate the functional dynamics in two homologous periplasmic sugar binding proteins with bidomain composition: Escherichia coli glucose/galactose (GGBP) and ribose (RBP) binding proteins. In contrast to their structural and functional similarity, we observe a remarkable difference in functional dynamics: For RBP, the absence of segmental motions allows only for isolated structural adaptations upon carbohydrate binding in line with an induced fit mechanism; on the other hand, GGBP shows extensive segmental mobility in both apo and holo states, enabling selection of the most favorable conformation upon carbohydrate binding in line with a population shift mechanism. Collective segmental motions are controlled by the hinge composition: by swapping two identified key residues between RBP and GGBP we also interchange their segmental hinge mobility, and the doubly mutated GGBP* no longer experiences changes in conformational entropy upon ligand binding while the complementary RBP* shows the segmental dynamics observed in wild-type GGBP. Most importantly, the segmental interdomain dynamics always increase the apparent substrate affinity and thus, are functional, underscoring the allosteric control that the hinge region exerts on ligand binding. PMID:23148479

  16. Structure and Stability of Carbohydrate-Lipid Interactions. Methylmannose Polysaccharide-Fatty Acid Complexes.

    PubMed

    Liu, Lan; Siuda, Iwona; Richards, Michele R; Renaud, Justin; Kitova, Elena N; Mayer, Paul M; Tieleman, D Peter; Lowary, Todd L; Klassen, John S

    2016-08-17

    We report a detailed study of the structure and stability of carbohydrate-lipid interactions. Complexes of a methylmannose polysaccharide (MMP) derivative and fatty acids (FAs) served as model systems. The dependence of solution affinities and gas-phase dissociation activation energies (Ea ) on FA length indicates a dominant role of carbohydrate-lipid interactions in stabilizing (MMP+FA) complexes. Solution (1) H NMR results reveal weak interactions between MMP methyl groups and FA acyl chain; MD simulations suggest the complexes are disordered. The contribution of FA methylene groups to the Ea is similar to that of heats of transfer of n-alkanes from the gas phase to polar solvents, thus suggesting that MMP binds lipids through dipole-induced dipole interactions. The MD results point to hydrophobic interactions and H-bonds with the FA carboxyl group. Comparison of collision cross sections of deprotonated (MMP+FA) ions with MD structures suggests that the gaseous complexes are disordered. PMID:27253157

  17. Production of hydrogen, ethanol and volatile fatty acids from the seaweed carbohydrate mannitol.

    PubMed

    Xia, Ao; Jacob, Amita; Herrmann, Christiane; Tabassum, Muhammad Rizwan; Murphy, Jerry D

    2015-10-01

    Fermentative hydrogen from seaweed is a potential biofuel of the future. Mannitol, which is a typical carbohydrate component of seaweed, was used as a substrate for hydrogen fermentation. The theoretical specific hydrogen yield (SHY) of mannitol was calculated as 5 mol H2/mol mannitol (615.4 mL H2/g mannitol) for acetic acid pathway, 3 mol H2/mol mannitol (369.2 mL H2/g mannitol) for butyric acid pathway and 1 mol H2/mol mannitol (123.1 mL H2/g mannitol) for lactic acid and ethanol pathways. An optimal SHY of 1.82 mol H2/mol mannitol (224.2 mL H2/g mannitol) was obtained by heat pre-treated anaerobic digestion sludge under an initial pH of 8.0, NH4Cl concentration of 25 mM, NaCl concentration of 50mM and mannitol concentration of 10 g/L. The overall energy conversion efficiency achieved was 96.1%. The energy was contained in the end products, hydrogen (17.2%), butyric acid (38.3%) and ethanol (34.2%). PMID:26163759

  18. How Phosphotransferase System-Related Protein Phosphorylation Regulates Carbohydrate Metabolism in Bacteria†

    PubMed Central

    Deutscher, Josef; Francke, Christof; Postma, Pieter W.

    2006-01-01

    The phosphoenolpyruvate(PEP):carbohydrate phosphotransferase system (PTS) is found only in bacteria, where it catalyzes the transport and phosphorylation of numerous monosaccharides, disaccharides, amino sugars, polyols, and other sugar derivatives. To carry out its catalytic function in sugar transport and phosphorylation, the PTS uses PEP as an energy source and phosphoryl donor. The phosphoryl group of PEP is usually transferred via four distinct proteins (domains) to the transported sugar bound to the respective membrane component(s) (EIIC and EIID) of the PTS. The organization of the PTS as a four-step phosphoryl transfer system, in which all P derivatives exhibit similar energy (phosphorylation occurs at histidyl or cysteyl residues), is surprising, as a single protein (or domain) coupling energy transfer and sugar phosphorylation would be sufficient for PTS function. A possible explanation for the complexity of the PTS was provided by the discovery that the PTS also carries out numerous regulatory functions. Depending on their phosphorylation state, the four proteins (domains) forming the PTS phosphorylation cascade (EI, HPr, EIIA, and EIIB) can phosphorylate or interact with numerous non-PTS proteins and thereby regulate their activity. In addition, in certain bacteria, one of the PTS components (HPr) is phosphorylated by ATP at a seryl residue, which increases the complexity of PTS-mediated regulation. In this review, we try to summarize the known protein phosphorylation-related regulatory functions of the PTS. As we shall see, the PTS regulation network not only controls carbohydrate uptake and metabolism but also interferes with the utilization of nitrogen and phosphorus and the virulence of certain pathogens. PMID:17158705

  19. Vascular effects of a low-carbohydrate high-protein diet

    PubMed Central

    Foo, Shi Yin; Heller, Eric R.; Wykrzykowska, Joanna; Sullivan, Christopher J.; Manning-Tobin, Jennifer J.; Moore, Kathryn J.; Gerszten, Robert E.; Rosenzweig, Anthony

    2009-01-01

    The cardiovascular complications of obesity have prompted interest in dietary interventions to reduce weight, including low-carbohydrate diets that are generally high in protein and fat. However, little is known about the long-term effects of these diets on vascular health. We examined the cardiovascular effects of a low-carbohydrate, high-protein diet (LCHP) in the ApoE−/− mouse model of atherosclerosis and in a model of ischemia-induced neovascularization. Mice on a LCHP were compared with mice maintained on either the standard chow diet (SC) or the Western diet (WD) which contains comparable fat and cholesterol to the LCHP. LCHP-fed mice developed more aortic atherosclerosis and had an impaired ability to generate new vessels in response to tissue ischemia. These changes were not explained by alterations in serum cholesterol, inflammatory mediators or infiltrates, or oxidative stress. The LCHP diet substantially reduced the number of bone marrow and peripheral blood endothelial progenitor cells (EPCs), a marker of vascular regenerative capacity. EPCs from mice on a LCHP diet also manifest lower levels of activated (phosphorylated) Akt, a serine-threonine kinase important in EPC mobilization, proliferation, and survival. Taken together, these data demonstrate that in animal models LCHP diets have adverse vascular effects not reflected in serum markers and that nonlipid macronutrients can modulate vascular progenitor cells and pathophysiology. PMID:19706393

  20. Effects of Step-Wise Increases in Dietary Carbohydrate on Circulating Saturated Fatty Acids and Palmitoleic Acid in Adults with Metabolic Syndrome

    PubMed Central

    Volk, Brittanie M.; Kunces, Laura J.; Freidenreich, Daniel J.; Kupchak, Brian R.; Saenz, Catherine; Artistizabal, Juan C.; Fernandez, Maria Luz; Bruno, Richard S.; Maresh, Carl M.; Kraemer, William J.; Phinney, Stephen D.; Volek, Jeff S.

    2014-01-01

    Recent meta-analyses have found no association between heart disease and dietary saturated fat; however, higher proportions of plasma saturated fatty acids (SFA) predict greater risk for developing type-2 diabetes and heart disease. These observations suggest a disconnect between dietary saturated fat and plasma SFA, but few controlled feeding studies have specifically examined how varying saturated fat intake across a broad range affects circulating SFA levels. Sixteen adults with metabolic syndrome (age 44.9±9.9 yr, BMI 37.9±6.3 kg/m2) were fed six 3-wk diets that progressively increased carbohydrate (from 47 to 346 g/day) with concomitant decreases in total and saturated fat. Despite a distinct increase in saturated fat intake from baseline to the low-carbohydrate diet (46 to 84 g/day), and then a gradual decrease in saturated fat to 32 g/day at the highest carbohydrate phase, there were no significant changes in the proportion of total SFA in any plasma lipid fractions. Whereas plasma saturated fat remained relatively stable, the proportion of palmitoleic acid in plasma triglyceride and cholesteryl ester was significantly and uniformly reduced as carbohydrate intake decreased, and then gradually increased as dietary carbohydrate was re-introduced. The results show that dietary and plasma saturated fat are not related, and that increasing dietary carbohydrate across a range of intakes promotes incremental increases in plasma palmitoleic acid, a biomarker consistently associated with adverse health outcomes. PMID:25415333

  1. EFFECT OF DIETARY PROTEIN AND CARBOHYDRATE LEVELS ON WEIGHT GAIN AND GONAD PRODUCTION IN THE SEA URCHIN LYTECHINUS VARIEGATUS

    PubMed Central

    Heflin, Laura E.; Gibbs, Victoria K.; Powell, Mickie L; Makowsky, Robert; Lawrence, John M.; Lawrence, Addison L.; Watts, Stephen A.

    2014-01-01

    Adult Lytechinus variegatus were fed eight formulated diets with different protein (ranging from 12 to 36%) and carbohydrate (ranging from 21 to 39 %) levels. Each sea urchin (n = 8 per treatment) was fed a daily sub-satiation ration of 1.5% of average body weight for 9 weeks. Akaike information criterion analysis was used to compare six different hypothesized dietary composition models across eight growth measurements. Dietary protein level and protein: energy ratio were the best models for prediction of total weight gain. Diets with the highest (> 68.6 mg P kcal−-1) protein: energy ratios produced the most wet weight gain after 9 weeks. Dietary carbohydrate level was a poor predictor for most growth parameters examined in this study. However, the model containing a protein × carbohydrate interaction effect was the best model for protein efficiency ratio (PER). PER decreased with increasing dietary protein level, more so at higher carbohydrate levels. Food conversion ratio (FCR) was best modeled by total dietary energy levels: Higher energy diets produced lower FCRs. Dietary protein level was the best model of gonad wet weight gain. These data suggest that variations in dietary nutrients and energy differentially affect organismal growth and growth of body components. PMID:24994942

  2. Effects of dietary amino acids, carbohydrates, and choline on neurotransmitter synthesis

    NASA Technical Reports Server (NTRS)

    Wurtman, Richard J.

    1988-01-01

    The ability of a meal to increase or decrease brain neurotransmitter synthesis has been studied. It is concluded that brain serotonin synthesis is directly controlled by the proportions of carbohydrate to protein in meals and snacks that increase or decrease brain tryptophan levels, thereby changing the substrate saturation of tryptophan hydroxylase and the rate of serotonin synthesis. The ability of serotoninergic neurons to have their output coupled to dietary macronutrients enables them to function as sensors of peripheral metabolism, and to subserve an important role in the control of appetite. The robust and selective responses of catecholaminergic and cholinergic neurons to supplemental tyrosine and choline suggest that these compounds may become useful as a new type of drug for treating deseases or conditions in which adequate quantities of the transmitter would otherwise be unavailable.

  3. Effects of CO₂ on Acer negundo pollen fertility, protein content, allergenic properties, and carbohydrates.

    PubMed

    Silva, M; Ribeiro, H; Abreu, I; Cruz, A; Esteves da Silva, J C G

    2015-05-01

    Atmospheric gaseous pollutants can induce qualitative and quantitative changes in airborne pollen characteristics. In this work, it was investigated the effects of carbon dioxide (CO2) on Acer negundo pollen fertility, protein content, allergenic properties, and carbohydrates. Pollen was collected directly from the anthers and in vitro exposed to three CO2 levels (500, 1000, and 3000 ppm) for 6 and 24 h in an environmental chamber. Pollen fertility was determined using viability and germination assays, total soluble protein was determined with Coomassie Protein Assay Reagent, and the antigenic and allergenic properties were investigated by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and immunological techniques using patients' sera. Also, pollen fructose, sucrose, and glucose values were determined. Carbon dioxide exposure affected negatively pollen fertility, total soluble protein content, and fructose content. The patient sera revealed increased IgE reactivity to proteins of A. negundo pollen exposed to increasing levels of the pollutant. No changes were detected in the SDS-PAGE protein profiles and in sucrose and glucose levels. Our results indicate that increase in atmospheric CO2 concentrations can have a negative influence of some features of A. negundo airborne pollen that can influence the reproductive processes as well as respiratory pollen allergies in the future. PMID:25471717

  4. A net carbohydrate and protein system for evaluating cattle diets: III. Cattle requirements and diet adequacy.

    PubMed

    Fox, D G; Sniffen, C J; O'Connor, J D; Russell, J B; Van Soest, P J

    1992-11-01

    The Cornell Net Carbohydrate and Protein System (CNCPS) has equations for predicting nutrient requirements, feed intake, and feed utilization over wide variations in cattle (frame size, body condition, and stage of growth), feed carbohydrate and protein fractions and their digestion and passage rates, and environmental conditions. Independent data were used to validate the ability of the CNCPS to predict responses compared to National Research Council (NRC) systems. With DMI in steers, the CNCPS had a 12% lower standard error of the Y estimate (Sy.x) and three percentage units less bias than the NRC system. For DMI in heifers, both systems had a similar Sy.x but the NRC had four percentage units less bias. With lactating dairy cows' DMI, the CNCPS had a 12% lower Sy.x. Observed NEm requirement averaged 5% under NRC and 6% under CNCPS predicted values at temperatures above 9 degrees C but were 18% over NRC and 9% under CNCPS at temperatures under 9 degrees C. Energy retained was predicted with an R2 of .80 and .95 and a bias of 8 and 4% for the NRC and CNCPS, respectively. Protein retained was predicted with an R2 of .75 and .85 with a bias of 0 and -1% for NRC and CNCPS, respectively. Biases due to frame size, implant, or NEg were small. Body condition scores predicted body fat percentage in dairy cows with an R2 of .93 and a Sy.x of 2.35% body fat. The CNCPS predicted metabolizable protein allowable ADG with a bias of 1.6% with a Sy.x of .07 kg compared to values of -30% and .10 kg, respectively for the NRC system. PMID:1334063

  5. Species Differences in the Carbohydrate Binding Preferences of Surfactant Protein D

    PubMed Central

    Crouch, Erika C.; Smith, Kelly; McDonald, Barbara; Briner, David; Linders, Bruce; McDonald, Joseph; Holmskov, Uffe; Head, James; Hartshorn, Kevan

    2006-01-01

    Interactions of surfactant protein D (SP-D) with micro-organisms and organic antigens involve binding to the trimeric neck plus carbohydrate recognition domain (neck+CRD). In these studies, we compared the ligand binding of homologous human, rat, and mouse trimeric neck+CRD fusion proteins, each with identical N-terminal tags remote from the ligand-binding surface. Although rat and mouse showed similar affinities for saccharide competitors, both differed markedly from the human protein. The human neck+CRD preferentially recognized N-acetyl-mannosamine, whereas the rat and mouse proteins showed greater affinity for myoinositol, maltose, and glucose. Although human neck+CRDs bound to maltosyl-agarose and fungal mannan, only rat and mouse neck+CRDs showed significant binding to maltosyl-Toyopearl beads, solid-phase maltosyl-albumin neo-glycoprotein, or the Phil82 strain of influenza A virus. Likewise, human SP-D dodecamers and trimeric subunits of full-length rat, but not full-length human SP-D trimers, bound to maltosyl-Toyopearl. Site-directed mutagenesis of the human neck+CRD demonstrated an important role of Asp324-Asp325 in the recognition of N-acetyl-mannosamine, and substitution of the corresponding murine sequence (Asn324-Asn325) conferred a capacity to interact with immobilized maltose. Thus, ligand recognition by human SP-D involves a complex interplay between saccharide presentation, the valency of trimeric subunits, and species-specific residues that flank the primary carbohydrate binding site. PMID:16514117

  6. Effect of Carbohydrate Sources and Levels of Cotton Seed Meal in Concentrate on Feed Intake, Nutrient Digestibility, Rumen Fermentation and Microbial Protein Synthesis in Young Dairy Bulls

    PubMed Central

    Wanapat, M.; Anantasook, N.; Rowlinson, P.; Pilajun, R.; Gunun, P.

    2013-01-01

    The objective of this study was to investigate the effect of levels of cottonseed meal with various carbohydrate sources in concentrate on feed intake, nutrient digestibility, rumen fermentation and microbial protein synthesis in dairy bulls. Four, 6 months old dairy bulls were randomly assigned to receive four dietary treatments according to a 2×2 factorial arrangement in a 4×4 Latin square design. Factor A was carbohydrate source; cassava chip (CC) and cassava chip+rice bran in the ratio of 3:1 (CR3:1), and factor B was cotton seed meal levels in the concentrate; 109 g CP/kg (LCM) and 328 g CP/kg (HCM) at similar overall CP levels (490 g CP/kg). Bulls received urea-lime treated rice straw ad libitum and were supplemented with 10 g of concentrate/kg BW. It was found that carbohydrate source and level of cotton seed meal did not have significant effects on ruminal pH, ammonia nitrogen concentration, microbial protein synthesis or feed intake. Animals which received CC showed significantly higher BUN concentration, ruminal propionic acid and butyric acid proportions, while dry matter, organic matter digestibility, populations of total viable bacteria and proteolytic bacteria were lower than those in the CR3:1 treatment. The concentration of total volatile fatty acids was higher in HCM than LCM treatments, while the concentration of butyric acid was higher in LCM than HCM treatments. The population of proteolytic bacteria with the LCM treatments was higher than the HCM treatments; however other bacteria groups were similar among the different levels of cotton seed meal. Bulls which received LCM had higher protein digestibility than those receiving HCM. Therefore, using high levels of cassava chip and cotton seed meal might positively impact on energy and nitrogen balance for the microbial population in the rumen of the young dairy bull. PMID:25049819

  7. Synthesis and emulsifying properties of carbohydrate fatty acid esters produced from Agave tequilana fructans by enzymatic acylation.

    PubMed

    Casas-Godoy, Leticia; Arrizon, Javier; Arrieta-Baez, Daniel; Plou, Francisco J; Sandoval, Georgina

    2016-08-01

    Carbohydrate fatty acid esters are non-ionic surfactants with a broad spectrum of applications. These molecules are generally synthesized using short carbohydrates or linear fructans; however in this research carbohydrate fatty acid esters were produced for the first time with branched fructans from Agave tequilana. Using immobilized lipases we successfully acylated A. tequilana fructans with vinyl laurate, obtaining products with different degrees of polymerization (DP). Lipozyme 435 was the most efficient lipase to catalyze the transesterification reaction. HPLC and ESI-MS analysis proved the presence of a mixture of acylated products as a result of the chemical complexity of fructans in the A. tequilana. The ESI-MS spectra showed a molecular mass shift between 183 and 366g/mol for fructooligosaccharides with a DP lower than 6, which indicated the presence of Agave fructans that had been mono- and diacylated with lauric acid. The carbohydrate fatty acid esters (CFAE) obtained showed good emulsifying properties in W/O emulsions. PMID:26988522

  8. AMP-activated protein kinase and carbohydrate response element binding protein: A study of two potential regulatory factors in the hepatic lipogenic program of broiler chickens

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This study investigated the effects of fasting and refeeding on AMP-activated protein kinase (AMPK) and carbohydrate response element binding protein (ChREBP) mRNA, protein and activity levels; as well as the expression of lipogenic genes involved in regulating lipid synthesis in broiler chicken liv...

  9. Improved purification of brine-shrimp (Artemia saline) (Na+ + K+)-activated adenosine triphosphatase and amino-acid and carbohydrate analyses of the isolated subunits.

    PubMed

    Peterson, G L; Hokin, L E

    1980-10-15

    Purification of the (Na+ + K+)-activated ATPase has been improved 2-fold the respect to both purity and yield over the previous method [Peterson, Ewing, Hootman & Conte (1978) J. Biol. Chem. 253, 4762-4770] by using Lubrol WX and non-denaturing concentrations of sodium dodecyl sulphate (SDS). The enzyme was purified 200-fold over the homogenate. The preparation had a specific activity of about 600 mumol of Pi/h per mg of protein, and was about 60% pure according to quantification of Coomassie Blue-stained SDS/polyacrylamide gels. The yield of purified enzyme was about 10 mg of protein per 100g of dry brine-shrimp (Artemia salina) cysts. The method is highly suitable for purification either on a small scale (10-25g of dry cysts) or on a large scale (900g of dry cysts) and methods are described for both. The large (Na+ + K+)-activated ATPase subunit (alpha-subunit) was isolated in pure form by SDS-gel filtration on Bio-Gel A 1.5m. The small subunit (beta-subunit) was eluted with other contaminating proteins on the Bio-Gel column, but was isolated in pure form by extraction from SDS/polyacrylamide gels. The amino acid and carbohydrate compositions of both subunits are reported. The alpha-subunit contained 5.2% carbohydrate by weight, and the beta-subunit 9.2%. Sialic acid was absent from both subunits. PMID:6272692

  10. Methylmalonic acid blood test

    MedlinePlus

    ... acid is a substance produced when proteins, called amino acids, in the body break down. The health care ... Cederbaum S, Berry GT. Inborn errors of carbohydrate, ammonia, amino acid, and organic acid metabolism. In: Gleason CA, Devaskar ...

  11. Oxidation of lactose to lactobionic acid by a Microdochium nivale carbohydrate oxidase: kinetics and operational stability.

    PubMed

    Nordkvist, Mikkel; Nielsen, Per Munk; Villadsen, John

    2007-07-01

    Oxidation of lactose to lactobionic acid by a Microdochium nivale carbohydrate oxidase was studied. The K(m)-value for lactose, obtained by a traditional enzymatic assay, was 0.066 mM at pH 6.4 and 38 degrees C. The effect of oxygen on the enzymatic rate of reaction as well as the operational stability of the enzyme was studied by performing reactions at constant pH and temperature in a stirred tank reactor. Catalase was included in all reactions to avoid inhibition and deactivation of the oxidase by hydrogen peroxide. At pH 6.4 and 38 degrees C, K(m) for oxygen was 0.97 mM, while the catalytical rate constant, k(cat), was 94 s(-1). Furthermore, we found that the operational stability of the oxidase was dependent on the type of base used for neutralization of the acid produced. Thus, when 2 M NaOH was used for neutralization of a reaction medium containing 50 mM phosphate buffer, significant deactivation of the oxidase was observed. Also, we found that the oxidase was protected against deactivation by base at high lactose concentrations. A simple model is proposed to explain the obtained results. PMID:17154316

  12. Updating the Cornell Net Carbohydrate and Protein System feed library and analyzing model sensitivity to feed inputs.

    PubMed

    Higgs, R J; Chase, L E; Ross, D A; Van Amburgh, M E

    2015-09-01

    The Cornell Net Carbohydrate and Protein System (CNCPS) is a nutritional model that evaluates the environmental and nutritional resources available in an animal production system and enables the formulation of diets that closely match the predicted animal requirements. The model includes a library of approximately 800 different ingredients that provide the platform for describing the chemical composition of the diet to be formulated. Each feed in the feed library was evaluated against data from 2 commercial laboratories and updated when required to enable more precise predictions of dietary energy and protein supply. A multistep approach was developed to predict uncertain values using linear regression, matrix regression, and optimization. The approach provided an efficient and repeatable way of evaluating and refining the composition of a large number of different feeds against commercially generated data similar to that used by CNCPS users on a daily basis. The protein A fraction in the CNCPS, formerly classified as nonprotein nitrogen, was reclassified to ammonia for ease and availability of analysis and to provide a better prediction of the contribution of metabolizable protein from free AA and small peptides. Amino acid profiles were updated using contemporary data sets and now represent the profile of AA in the whole feed rather than the insoluble residue. Model sensitivity to variation in feed library inputs was investigated using Monte Carlo simulation. Results showed the prediction of metabolizable energy was most sensitive to variation in feed chemistry and fractionation, whereas predictions of metabolizable protein were most sensitive to variation in digestion rates. Regular laboratory analysis of samples taken on-farm remains the recommended approach to characterizing the chemical components of feeds in a ration. However, updates to the CNCPS feed library provide a database of ingredients that are consistent with current feed chemistry information and

  13. Effects of inadequate maternal dietary protein:carbohydrate ratios during pregnancy on offspring immunity in pigs

    PubMed Central

    2012-01-01

    Background Inadequate nutrition in utero may retard foetal growth and alter physiological development of offspring. This study investigated the effects of low and high protein diets fed to primiparous German Landrace sows throughout pregnancy on the immune function of their offspring at different ages. Sows were fed diets with adequate (AP, 12.1%; n = 13), low (LP, 6.5%; n = 15), or high (HP, 30%; n = 14) protein content, made isoenergetic by varying carbohydrate levels. Cortisol, total protein and immunoglobulin (IgG, IgM, IgA) concentrations were measured in the blood of sows over the course of pregnancy. Cortisol, total protein, immunoglobulins, lymphocyte proliferation, immune cell counts, and cytokines were assessed in the blood of offspring at baseline and under challenging conditions (weaning; lipopolysaccharide (LPS) administration). Results In sows, the LP diet increased cortisol (P < 0.05) and decreased protein levels (P < 0.01) at the end of pregnancy. Immunoglobulin concentrations were decreased in LP (IgA) and HP piglets (IgG, IgM and IgA) on the first day of life (P < 0.05), whereas the number of lymphocytes and mitogen-induced lymphocyte proliferation of the piglets were unaffected by the maternal diet. Mortality during the suckling period was higher in LP piglets compared with AP and HP offspring (P < 0.01). Furthermore, LP piglets showed an elevated cortisol response to weaning, and in HP piglets, the CD4+ cell percentage and the CD4+/CD8+ ratio increased after weaning (P < 0.05). The lipopolysaccharide-induced rise of IL-6 was higher in LP (P = 0.09) and HP (P < 0.01) compared with AP piglets, and LP piglets displayed higher IL-10 levels than AP piglets (P < 0.05). Conclusions Our results indicate that both low and high protein:carbohydrate ratios in the diet of pregnant sows can induce short-term as well as long-lasting effects on immune competence in piglets that may have serious consequences for host

  14. Quantitative determination of carboxylic acids, amino acids, carbohydrates, ethanol and hydroxymethylfurfural in honey by (1)H NMR.

    PubMed

    del Campo, Gloria; Zuriarrain, Juan; Zuriarrain, Andoni; Berregi, Iñaki

    2016-04-01

    A method using (1)H NMR spectroscopy has been developed to quantify simultaneously thirteen analytes in honeys without previous separation or pre-concentration steps. The method has been successfully applied to determine carboxylic acids (acetic, formic, lactic, malic and succinic acids), amino acids (alanine, phenylalanine, proline and tyrosine), carbohydrates (α- and β-glucose and fructose), ethanol and hydroxymethylfurfural in eucalyptus, heather, lavender, orange blossom, thyme and rosemary honeys. Quantification was performed by using the area of the signal of each analyte in the honey spectra, together with external standards. The regression analysis of the signal area against concentration plots, used for the calibration of each analyte, indicates a good linearity over the concentration ranges found in honeys, with correlation coefficients higher than 0.985 for the thirteen quantified analytes. The recovery studies give values over the 93.7-105.4% range with relative standard deviations lower than 7.4%. Good precision, with relative standard deviations over the range of 0.78-5.21% is obtained. PMID:26593586

  15. Elucidating glycosaminoglycan–protein–protein interactions using carbohydrate microarray and computational approaches

    PubMed Central

    Rogers, Claude J.; Clark, Peter M.; Tully, Sarah E.; Abrol, Ravinder; Garcia, K. Christopher; Goddard, William A.; Hsieh-Wilson, Linda C.

    2011-01-01

    Glycosaminoglycan polysaccharides play critical roles in many cellular processes, ranging from viral invasion and angiogenesis to spinal cord injury. Their diverse biological activities are derived from an ability to regulate a remarkable number of proteins. However, few methods exist for the rapid identification of glycosaminoglycan–protein interactions and for studying the potential of glycosaminoglycans to assemble multimeric protein complexes. Here, we report a multidisciplinary approach that combines new carbohydrate microarray and computational modeling methodologies to elucidate glycosaminoglycan–protein interactions. The approach was validated through the study of known protein partners for heparan and chondroitin sulfate, including fibroblast growth factor 2 (FGF2) and its receptor FGFR1, the malarial protein VAR2CSA, and tumor necrosis factor-α (TNF-α). We also applied the approach to identify previously undescribed interactions between a specific sulfated epitope on chondroitin sulfate, CS-E, and the neurotrophins, a critical family of growth factors involved in the development, maintenance, and survival of the vertebrate nervous system. Our studies show for the first time that CS is capable of assembling multimeric signaling complexes and modulating neurotrophin signaling pathways. In addition, we identify a contiguous CS-E-binding site by computational modeling that suggests a potential mechanism to explain how CS may promote neurotrophin-tyrosine receptor kinase (Trk) complex formation and neurotrophin signaling. Together, our combined microarray and computational modeling methodologies provide a general, facile means to identify new glycosaminoglycan–protein–protein interactions, as well as a molecular-level understanding of those complexes. PMID:21628576

  16. An olive pollen protein with allergenic activity, Ole e 10, defines a novel family of carbohydrate-binding modules and is potentially implicated in pollen germination

    PubMed Central

    2005-01-01

    CBMs (carbohydrate-binding modules) are the most common non-catalytic modules associated with enzymes active in plant cell-wall hydrolysis. They have been frequently identified by amino acid sequence alignments, but only a few have been experimentally established to have a carbohydrate-binding activity. A small olive pollen protein, Ole e 10 (10 kDa), has been described as a major inducer of type I allergy in humans. In the present study, the ability of Ole e 10 to bind several polysaccharides has been analysed by affinity gel electrophoresis, which demonstrated that the protein bound 1,3-β-glucans preferentially. Analytical ultracentrifugation studies confirmed binding to laminarin, at a protein/ligand ratio of 1:1. The interaction of Ole e 10 with laminarin induced a conformational change in the protein, as detected by CD and fluorescence analyses, and an increase of 3.6 °C in the thermal denaturation temperature of Ole e 10 in the presence of the glycan. These results, and the absence of alignment of the sequence of Ole e 10 with that of any classified CBM, indicate that this pollen protein defines a novel family of CBMs, which we propose to name CBM43. Immunolocalization of Ole e 10 in mature and germinating pollen by transmission electron microscopy and confocal laser scanning microscopy demonstrated the co-localization of Ole e 10 and callose (1,3-β-glucan) in the growing pollen tube, suggesting a role for this protein in the metabolism of carbohydrates and in pollen tube wall re-formation during germination. PMID:15882149

  17. Apoptosis induced by a low-carbohydrate and high-protein diet in rat livers

    PubMed Central

    Monteiro, Maria Emília L; Xavier, Analucia R; Oliveira, Felipe L; Filho, Porphirio JS; Azeredo, Vilma B

    2016-01-01

    AIM: To determine whether high-protein, high-fat, and low-carbohydrate diets can cause lesions in rat livers. METHODS: We randomly divided 20 female Wistar rats into a control diet group and an experimental diet group. Animals in the control group received an AIN-93M diet, and animals in the experimental group received an Atkins-based diet (59.46% protein, 31.77% fat, and 8.77% carbohydrate). After 8 wk, the rats were anesthetized and exsanguinated for transaminases analysis, and their livers were removed for flow cytometry, immunohistochemistry, and light microscopy studies. We expressed the data as mean ± standard deviation (SD) assuming unpaired and parametric data; we analyzed differences using the Student’s t-test. Statistical significance was set at P < 0.05. RESULTS: We found that plasma alanine aminotransferase and aspartate aminotransferase levels were significantly higher in the experimental group than in the control group. According to flow cytometry, the percentages of nonviable cells were 11.67% ± 1.12% for early apoptosis, 12.07% ± 1.11% for late apoptosis, and 7.11% ± 0.44% for non-apoptotic death in the experimental diet group and 3.73% ± 0.50% for early apoptosis, 5.67% ± 0.72% for late apoptosis, and 3.82% ± 0.28% for non-apoptotic death in the control diet group. The mean percentage of early apoptosis was higher in the experimental diet group than in the control diet group. Immunohistochemistry for autophagy was negative in both groups. Sinusoidal dilation around the central vein and small hepatocytes was only observed in the experimental diet group, and fibrosis was not identified by hematoxylin-eosin or Trichrome Masson staining in either group. CONCLUSION: Eight weeks of an experimental diet resulted in cellular and histopathological lesions in rat livers. Apoptosis was our principal finding; elevated plasma transaminases demonstrate hepatic lesions. PMID:27298559

  18. Effect of quarantine treatments on the carbohydrate and organic acid content of mangoes (cv. Tommy Atkins)

    NASA Astrophysics Data System (ADS)

    Cruz, J. N.; Soares, C. A.; Fabbri, A. D. T.; Cordenunsi, B. R.; Sabato, S. F.

    2012-08-01

    Brazil is one of the largest mango producers and the third largest mango exporter worldwide. Irradiation treatment and its commercial feasibility have been studied in our country to make it possible to develop new markets and, consequently, to compete with the major exporters of mangoes, Mexico and India. This work was designed to compare irradiation treatment with the hot water dip treatment in mangoes cv. Tommy Atkins for export and to verify that the main attributes for acceptance, color and texture, as well as carbohydrate and organic acid contents, were maintained. In this study, the fruit was divided into groups: control, hot water dip-treated (46 °C for 90 min), and irradiation-treated at doses of 0.4 kGy and 1.0 kGy. The fruit was stored at low temperature (11 °C±2) for 14 days and then at room temperature (23 °C±2) until the end of the study. The results indicated that the fruit given a dose of 1.0 kGy remained in a less advanced stage of ripening (stage 3) throughout the storage period, but experienced a greater loss of texture in the beginning of the experiment. It was noted that only the control group had higher levels of citric acid and succinic acid on the last day of the experiment. There were no significant differences in the total sugar content between any treatment groups. Gamma radiation can be used as a quarantine treatment and does not interfere negatively with the quality attributes of mangoes.

  19. Spatiotemporal variation of dissolved carbohydrates and amino acids in Jiaozhou Bay, China

    NASA Astrophysics Data System (ADS)

    Shi, Di; Yang, Guipeng; Sun, Yan; Wu, Guanwei

    2016-06-01

    Surface seawater samples were collected from Jiaozhou Bay, China, during six cruises (March-May 2010, September-November 2010) to study the distribution of dissolved organic matter including dissolved organic carbon (DOC), total dissolved carbohydrates, namely monosaccharides (MCHO) and polysaccharides (PCHO) and total hydrolysable amino acids. These included dissolved free amino acids (DFAA) and combined amino acids (DCAA). The goal was to investigate possible relationships between these dissolved organic compounds and environmental parameters. During spring, the concentrations of MCHO and PCHO were 9.6 (2.8-22.6) and 11.0 (2.9-42.5) μmol C/L, respectively. In autumn, MCHO and PCHO were 9.1 (2.6-27.0) and 10.8 (2.4-25.6) μmol C/L, respectively. The spring concentrations of DFAA and DCAA were 1.7 (1.1-4.1) and 7.6 (1.1-31.0) μmol C/L, respectively, while in autumn, DFAA and DCAA were 2.3 (1.1-8.0) and 3.3 (0.6-7.2) μmol C/L, respectively. Among these compounds, the concentrations of PCHO were the highest, accounting for nearly a quarter of the DOC, followed by MCHO, DCAA and DFAA. The concentrations of the organic compounds exhibited a decreasing trend from the coastal to the central regions of the bay. A negative correlation between concentrations of DOC and salinity in each cruise suggested that riverine inputs around the bay have an important impact on the distribution of DOC in the surface water. A significant positive correlation was found between DOC and total bacteria count in spring and autumn, suggesting bacteria play an important role in the marine carbon cycle.

  20. Protein-sparing effect of carbohydrate in diets for juvenile turbot Scophthalmus maximus reared at different salinities

    NASA Astrophysics Data System (ADS)

    Zeng, Lin; Lei, Jilin; Ai, Chunxiang; Hong, Wanshu; Liu, Bin

    2015-01-01

    The aim of the present study was to investigate the protein-sparing effect of carbohydrate in diets for juvenile turbot ( Scophthalmus maximus) reared at five salinities (12, 18, 24, 30, and 36). The fish were fed three isocaloric and isolipidic diets for 60 days. The results show that specific growth rate (SGR) and feed conversion efficiency (FCE) were higher in fish reared at salinities of 18 and 36, but lower at 12. Fish fed with diet C25P40 (25% carbohydrate and 40% protein) had lower SGR and FCE values compared with those fed with the C5P52 (5% carbohydrate and 52% protein) and C15P46 (15% carbohydrate and 46% protein) diets; however, there was no statistical difference between diet C5P52 and C15P46. SGR and FCE values were unaffected by diet composition in fish reared at salinity 36. Hepatic lipogenic enzyme activities were higher in fish reared at 18 and 36, but lower at 12, while glucokinase (GK) activity was higher in fish reared at 12, and lower at 18 and 36. Dietary starch enhanced GK activity while depressing lipogenic enzyme activity. However, lipogenic enzyme activity increased with increasing dietary starch in fish reared at 36. It is recommended that salinity should be maintained >12 in the farming of juvenile turbot. In addition, an increase in gelatinized starch from 5% to 15% could spare 6% dietary protein in fish reared at salinities of 18-30, while higher salinity (36) could improve dietary carbohydrate use and enhance the protein-sparing effect, which is linked with the induction of lipogenic capacities.

  1. Rhinacanthus nasutus Improves the Levels of Liver Carbohydrate, Protein, Glycogen, and Liver Markers in Streptozotocin-Induced Diabetic Rats

    PubMed Central

    Visweswara Rao, Pasupuleti; Madhavi, K.; Dhananjaya Naidu, M.; Gan, Siew Hua

    2013-01-01

    The present study was designed to investigate the total carbohydrate, total protein, and glycogen levels in the liver and to measure functional liver markers such as aspartate aminotransferase (AST) and alanine aminotransferase (ALT) in streptozotocin-(STZ-) induced diabetic rats after treatment with methanolic extract of Rhinacanthus nasutus (R. nasutus). The methanolic extract of R. nasutus was orally administered at 200 mg/kg/day while glibenclamide was administered at 50 mg/kg/day. All animals were treated for 30 days before being sacrificed. The amounts of carbohydrate, glycogen, proteins, and liver markers (AST and ALT) were measured in the liver tissue of the experimental animals. The levels of carbohydrate, glycogen, and proteins were significantly reduced in the diabetic rats but were augmented considerably after 30 days of R. nasutus treatment. The elevated AST and ALT levels in diabetic rats showed a significant decline after treatment with R. nasutus for 30 days. These results show that the administration of R. nasutus ameliorates the altered levels of carbohydrate, glycogen, proteins, and AST and ALT observed in diabetic rats and indicate that R. nasutus restores overall metabolism and liver function in experimental diabetic rats. In conclusion, the outcomes of the present study support the traditional belief that R. nasutus could ameliorate the diabetic state. PMID:24204387

  2. Effect of Host Plant on the Chemical Composition of Tetranychus urticae (Prostigmata: Tetranychidae): Variability in Soluble Protein, Anions, and Carbohydrates.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Chemical analyses of two-spotted spider mite, Tetranychus urticae (Koch), and 3 of their host plants, Phaseolus vulgaris L., Phaseolus lunatus L., and Vigna unguiculata L. show that the content of total soluble protein, carbohydrates, and anions in the mites varies independently from the concentrat...

  3. Influence of thermally processed carbohydrate/amino acid mixtures on the fermentation by Saccharomyces cerevisiae.

    PubMed

    Tauer, Andreas; Elss, Sandra; Frischmann, Matthias; Tellez, Patricia; Pischetsrieder, Monika

    2004-04-01

    The production of alcoholic beverages such as Tequila, Mezcal, whiskey, or beer includes the fermentation of a mash containing Maillard reaction products. Because excessive heating of the mash can lead to complications during the following fermentation step, the impact of Maillard products on the metabolism of Saccharomyces cerevisiae was investigated. For this purpose, fermentation was carried out in a model system in the presence and absence of Maillard reaction products and formation of ethanol served as a marker for the progression of fermentation. We found that increasing amounts of Maillard products reduced the formation of ethanol up to 80%. This effect was dependent on the pH value during the Maillard reaction, reaction time, as well as the carbohydrate and amino acid component used for the generation of Maillard reaction products. Another important factor is the pH value during fermentation: The inhibitory effect of Maillard products was not detectable at a pH of 4 and increased with higher pH-values. These findings might be of relevance for the production of above-mentioned beverages. PMID:15053549

  4. Characterization of carbohydrate-binding protein p33/41: relation with annexin IV, molecular basis of the doublet forms (p33 and p41), and modulation of the carbohydrate binding activity by phospholipids.

    PubMed

    Kojima, K; Yamamoto, K; Irimura, T; Osawa, T; Ogawa, H; Matsumoto, I

    1996-03-29

    A protein, p33/41, expressed in bovine kidney and many other tissues was identified as a lectin which binds to sialoglycoproteins and glycosaminoglycans in a calcium-dependent manner. Partial amino acid sequences of p33/41 are highly homologous to those of calcium/phospholipid-binding annexin protein, annexin IV (endonexin), p33/41 exhibited similar calcium/phospholipid-binding activity (Kojima, K., Ogawa, H., Seno, N., Yamamoto, K., Irimura, T., Osawa, T., and Matsumoto, I. (1993) J. Biol. Chem. 267, 20536-20539). To further characterize p33/41, we cloned the p33/41 cDNA and characterized the recombinant protein encoded by this cDNA. Oligonucleotide probes were synthesized based on partial amino acid sequences of p33/41 and used for screening. A p33/41 cDNA clone was isolated encoding a protein of 319 amino acids with a calculated molecular mass of 35,769 Da. The deduced amino acid sequence was identical to that of bovine annexin IV except for one amino acid substitution. The recombinant protein gave two 33-kDa (p33) and 41-kDa (p41) bands on SDS-polyacrylamide gel electrophoresis under non-reducing conditions, and only one 33-kDa band under reducing conditions, as did the native protein. Mass spectrometric analysis combined with site-directed mutagenesis of each of the four cysteine residues of the recombinant protein revealed that p41 is a dimer of p33 cross-linked at Cys-198 via a disulfide bond. The recombinant protein bound to columns of heparin and fetuin glycopeptides in a calcium dependent manner and to phospholipid vesicles composed of phosphatidylserine (PS)/phosphatidylcholine (PC), phosphatidylethanolamine (PE)/PC or phosphatidylinositol (PI)/PC. Furthermore, concurrent binding assays showed that the binding of the recombinant protein to phospholipid vesicles was not affected by heparin, whereas that to heparin was influenced by the phospholipid composition of the vesicles; the highest binding was observed with vesicles composed of PE/PC. These results

  5. Effect of hyperbaric oxygenation on carbohydrate metabolism protein synthesis in the myocardium during sustained hypodynamia

    NASA Technical Reports Server (NTRS)

    Makarov, G. A.

    1980-01-01

    Glycolysis and the intensity of protein synthesis were studied in 140 white male rats in subcellular fractions of the myocardium during 45 day hypodynamia and hyperbaric oxygenation. Hypodynamia increased: (1) the amount of lactic acids; (2) the amount of pyruvic acid; (3) the lactate/pyruvate coefficient; and (4) the activities of aldolase and lactate dehydrogenase. Hyperbaric oxygenation was found to have a favorable metabolic effect on the animals with hypodynamia.

  6. Altering fatty acid availability does not impair prolonged, continuous running to fatigue: evidence for carbohydrate dependence.

    PubMed

    Leckey, Jill J; Burke, Louise M; Morton, James P; Hawley, John A

    2016-01-15

    We determined the effect of suppressing lipolysis via administration of nicotinic acid (NA) on fuel substrate selection and half-marathon running capacity. In a single-blinded, Latin square design, 12 competitive runners completed four trials involving treadmill running until volitional fatigue at a pace based on 95% of personal best half-marathon time. Trials were completed in a fed or overnight fasted state: 1) carbohydrate (CHO) ingestion before (2 g CHO·kg(-1)·body mass(-1)) and during (44 g/h) [CFED]; 2) CFED plus NA ingestion [CFED-NA]; 3) fasted with placebo ingestion during [FAST]; and 4) FAST plus NA ingestion [FAST-NA]. There was no difference in running distance (CFED, 21.53 ± 1.07; CFED-NA, 21.29 ± 1.69; FAST, 20.60 ± 2.09; FAST-NA, 20.11 ± 1.71 km) or time to fatigue between the four trials. Concentrations of plasma free fatty acids (FFA) and glycerol were suppressed following NA ingestion irrespective of preexercise nutritional intake but were higher throughout exercise in FAST compared with all other trials (P < 0.05). Rates of whole-body CHO oxidation were unaffected by NA ingestion in the CFED and FAST trials, but were lower in the FAST trial compared with the CFED-NA trial (P < 0.05). CHO was the primary substrate for exercise in all conditions, contributing 83-91% to total energy expenditure with only a small contribution from fat-based fuels. Blunting the exercise-induced increase in FFA via NA ingestion did not impair intense running capacity lasting ∼85 min, nor did it alter patterns of substrate oxidation in competitive athletes. Although there was a small but obligatory use of fat-based fuels, the oxidation of CHO-based fuels predominates during half-marathon running. PMID:26586912

  7. High Sensitive Detection of Carbohydrate Binding Proteins in an ELISA-Solid Phase Assay Based on Multivalent Glyconanoparticles

    PubMed Central

    Chiodo, Fabrizio; Marradi, Marco; Tefsen, Boris; Snippe, Harm; van Die, Irma; Penadés, Soledad

    2013-01-01

    Improved detection of anti-carbohydrate antibodies is a need in clinical identification of biomarkers for cancer cells or pathogens. Here, we report a new ELISA approach for the detection of specific immunoglobulins (IgGs) against carbohydrates. Two nanometer gold glyconanoparticles bearing oligosaccharide epitopes of HIV or Streptococcus pneumoniae were used as antigens to coat ELISA-plates. A ~3,000-fold improved detection of specific IgGs in mice immunized against S. pneumoniae respect to the well known BSA-glycoconjugate ELISA was achieved. Moreover, these multivalent glyconanoparticles have been employed in solid phase assays to detect the carbohydrate-dependent binding of human dendritic cells and the lectin DC-SIGN. Multivalent glyconanoparticles in ELISA provide a versatile, easy and highly sensitive method to detect and quantify the binding of glycan to proteins and to facilitate the identification of biomarkers. PMID:24014084

  8. Glucose-6-phosphate mediates activation of the carbohydrate responsive binding protein (ChREBP)

    SciTech Connect

    Li, Ming V.; Chen, Weiqin; Harmancey, Romain N.; Nuotio-Antar, Alli M.; Imamura, Minako; Saha, Pradip; Taegtmeyer, Heinrich; Chan, Lawrence

    2010-05-07

    Carbohydrate response element binding protein (ChREBP) is a Mondo family transcription factor that activates a number of glycolytic and lipogenic genes in response to glucose stimulation. We have previously reported that high glucose can activate the transcriptional activity of ChREBP independent of the protein phosphatase 2A (PP2A)-mediated increase in nuclear entry and DNA binding. Here, we found that formation of glucose-6-phosphate (G-6-P) is essential for glucose activation of ChREBP. The glucose response of GAL4-ChREBP is attenuated by D-mannoheptulose, a potent hexokinase inhibitor, as well as over-expression of glucose-6-phosphatase (G6Pase); kinetics of activation of GAL4-ChREBP can be modified by exogenously expressed GCK. Further metabolism of G-6-P through the two major glucose metabolic pathways, glycolysis and pentose-phosphate pathway, is not required for activation of ChREBP; over-expression of glucose-6-phosphate dehydrogenase (G6PD) diminishes, whereas RNAi knockdown of the enzyme enhances, the glucose response of GAL4-ChREBP, respectively. Moreover, the glucose analogue 2-deoxyglucose (2-DG), which is phosphorylated by hexokinase, but not further metabolized, effectively upregulates the transcription activity of ChREBP. In addition, over-expression of phosphofructokinase (PFK) 1 and 2, synergistically diminishes the glucose response of GAL4-ChREBP. These multiple lines of evidence support the conclusion that G-6-P mediates the activation of ChREBP.

  9. Metabolism and fatty acid profile in fat and lean rainbow trout lines fed with vegetable oil: effect of carbohydrates.

    PubMed

    Kamalam, Biju Sam; Médale, Françoise; Larroquet, Laurence; Corraze, Geneviève; Panserat, Stephane

    2013-01-01

    The present study investigated the effect of dietary carbohydrates on metabolism, with special focus on fatty acid bioconversion and flesh lipid composition in two rainbow trout lines divergently selected for muscle lipid content and fed with vegetable oils. These lines were chosen based on previously demonstrated potential differences in LC-PUFA synthesis and carbohydrate utilization. Applying a factorial study design, juvenile trout from the lean (L) and the fat (F) line were fed vegetable oil based diets with or without gelatinised starch (17.1%) for 12 weeks. Blood, liver, muscle, intestine and adipose tissue were sampled after the last meal. Feed intake and growth was higher in the L line than the F line, irrespective of the diet. Moderate postprandial hyperglycemia, strong induction of hepatic glucokinase and repressed glucose-6-phosphatase transcripts confirmed the metabolic response of both lines to carbohydrate intake. Further at the transcriptional level, dietary carbohydrate in the presence of n-3 LC-PUFA deficient vegetable oils enhanced intestinal chylomicron assembly, disturbed hepatic lipid metabolism and importantly elicited a higher response of key desaturase and elongase enzymes in the liver and intestine that endorsed our hypothesis. PPARγ was identified as the factor mediating this dietary regulation of fatty acid bioconversion enzymes in the liver. However, these molecular changes were not sufficient to modify the fatty acid composition of muscle or liver. Concerning the genotype effect, there was no evidence of substantial genotypic difference in lipid metabolism, LC-PUFA synthesis and flesh fatty acid profile when fed with vegetable oils. The minor reduction in plasma glucose and triglyceride levels in the F line was linked to potentially higher glucose and lipid uptake in the muscle. Overall, these data emphasize the importance of dietary macro-nutrient interface in evolving fish nutrition strategies. PMID:24124573

  10. Metabolism and Fatty Acid Profile in Fat and Lean Rainbow Trout Lines Fed with Vegetable Oil: Effect of Carbohydrates

    PubMed Central

    Kamalam, Biju Sam; Médale, Françoise; Larroquet, Laurence; Corraze, Geneviève; Panserat, Stephane

    2013-01-01

    The present study investigated the effect of dietary carbohydrates on metabolism, with special focus on fatty acid bioconversion and flesh lipid composition in two rainbow trout lines divergently selected for muscle lipid content and fed with vegetable oils. These lines were chosen based on previously demonstrated potential differences in LC-PUFA synthesis and carbohydrate utilization. Applying a factorial study design, juvenile trout from the lean (L) and the fat (F) line were fed vegetable oil based diets with or without gelatinised starch (17.1%) for 12 weeks. Blood, liver, muscle, intestine and adipose tissue were sampled after the last meal. Feed intake and growth was higher in the L line than the F line, irrespective of the diet. Moderate postprandial hyperglycemia, strong induction of hepatic glucokinase and repressed glucose-6-phosphatase transcripts confirmed the metabolic response of both lines to carbohydrate intake. Further at the transcriptional level, dietary carbohydrate in the presence of n-3 LC-PUFA deficient vegetable oils enhanced intestinal chylomicron assembly, disturbed hepatic lipid metabolism and importantly elicited a higher response of key desaturase and elongase enzymes in the liver and intestine that endorsed our hypothesis. PPARγ was identified as the factor mediating this dietary regulation of fatty acid bioconversion enzymes in the liver. However, these molecular changes were not sufficient to modify the fatty acid composition of muscle or liver. Concerning the genotype effect, there was no evidence of substantial genotypic difference in lipid metabolism, LC-PUFA synthesis and flesh fatty acid profile when fed with vegetable oils. The minor reduction in plasma glucose and triglyceride levels in the F line was linked to potentially higher glucose and lipid uptake in the muscle. Overall, these data emphasize the importance of dietary macro-nutrient interface in evolving fish nutrition strategies. PMID:24124573

  11. The N-Terminal Domain of the Flo1 Flocculation Protein from Saccharomyces cerevisiae Binds Specifically to Mannose Carbohydrates

    PubMed Central

    Goossens, Katty V. Y.; Stassen, Catherine; Stals, Ingeborg; Donohue, Dagmara S.; Devreese, Bart; De Greve, Henri; Willaert, Ronnie G.

    2011-01-01

    Saccharomyces cerevisiae cells possess a remarkable capacity to adhere to other yeast cells, which is called flocculation. Flocculation is defined as the phenomenon wherein yeast cells adhere in clumps and sediment rapidly from the medium in which they are suspended. These cell-cell interactions are mediated by a class of specific cell wall proteins, called flocculins, that stick out of the cell walls of flocculent cells. The N-terminal part of the three-domain protein is responsible for carbohydrate binding. We studied the N-terminal domain of the Flo1 protein (N-Flo1p), which is the most important flocculin responsible for flocculation of yeast cells. It was shown that this domain is both O and N glycosylated and is structurally composed mainly of β-sheets. The binding of N-Flo1p to d-mannose, α-methyl-d-mannoside, various dimannoses, and mannan confirmed that the N-terminal domain of Flo1p is indeed responsible for the sugar-binding activity of the protein. Moreover, fluorescence spectroscopy data suggest that N-Flo1p contains two mannose carbohydrate binding sites with different affinities. The carbohydrate dissociation constants show that the affinity of N-Flo1p for mono- and dimannoses is in the millimolar range for the binding site with low affinity and in the micromolar range for the binding site with high affinity. The high-affinity binding site has a higher affinity for low-molecular-weight (low-MW) mannose carbohydrates and no affinity for mannan. However, mannan as well as low-MW mannose carbohydrates can bind to the low-affinity binding site. These results extend the cellular flocculation model on the molecular level. PMID:21076009

  12. Impact of the core components of the phosphoenolpyruvate-carbohydrate phosphotransferase system, HPr and EI, on differential protein expression in Ralstonia eutropha H16.

    PubMed

    Kaddor, Chlud; Voigt, Birgit; Hecker, Michael; Steinbüchel, Alexander

    2012-07-01

    In Ralstonia eutropha H16, seven genes encoding proteins being involved in the phosphoenolpyruvate-carbohydrate phosphotransferase system (PEP-PTS) were identified. In order to provide more insights into the poly(3-hydroxybutyrate) (PHB)-leaky phenotype of the HPr/EI deletion mutants H16ΔptsH, H16ΔptsI, and H16ΔptsHI when grown on the non-PTS substrate gluconate, parallel fermentations for comparison of their growth behavior were performed. Samples from the exponential, the early stationary, and late stationary growth phases were investigated by microscopy, gas chromatography and (phospho-) proteome analysis. A total of 71 differentially expressed proteins were identified using 2D-PAGE, Pro-Q Diamond and Coomassie staining, and MALDI-TOF analysis. Detected proteins were classified into five major functional groups: carbon metabolism, energy metabolism, amino acid metabolism, translation, and membrane transport/outer membrane proteins. Proteome analyses revealed enhanced expression of proteins involved in the Entner-Doudoroff pathway and in subsequent reactions in cells of strain H16 compared to the mutant H16ΔptsHI. Furthermore, proteins involved in PHB accumulation showed increased abundance in the wild-type. This expression pattern allowed us to identify proteins affecting carbon metabolism/PHB biosynthesis in strain H16 and translation/amino acid metabolism in strain H16ΔptsHI, and to gain insight into the molecular response of R. eutropha to the deletion of HPr/EI. PMID:22630130

  13. Metabolite Regulation of Nuclear Localization of Carbohydrate-response Element-binding Protein (ChREBP): ROLE OF AMP AS AN ALLOSTERIC INHIBITOR.

    PubMed

    Sato, Shogo; Jung, Hunmin; Nakagawa, Tsutomu; Pawlosky, Robert; Takeshima, Tomomi; Lee, Wan-Ru; Sakiyama, Haruhiko; Laxman, Sunil; Wynn, R Max; Tu, Benjamin P; MacMillan, John B; De Brabander, Jef K; Veech, Richard L; Uyeda, Kosaku

    2016-05-13

    The carbohydrate-response element-binding protein (ChREBP) is a glucose-responsive transcription factor that plays an essential role in converting excess carbohydrate to fat storage in the liver. In response to glucose levels, ChREBP is regulated by nuclear/cytosol trafficking via interaction with 14-3-3 proteins, CRM-1 (exportin-1 or XPO-1), or importins. Nuclear localization of ChREBP was rapidly inhibited when incubated in branched-chain α-ketoacids, saturated and unsaturated fatty acids, or 5-aminoimidazole-4-carboxamide ribonucleotide. Here, we discovered that protein-free extracts of high fat-fed livers contained, in addition to ketone bodies, a new metabolite, identified as AMP, which specifically activates the interaction between ChREBP and 14-3-3. The crystal structure showed that AMP binds directly to the N terminus of ChREBP-α2 helix. Our results suggest that AMP inhibits the nuclear localization of ChREBP through an allosteric activation of ChREBP/14-3-3 interactions and not by activation of AMPK. AMP and ketone bodies together can therefore inhibit lipogenesis by restricting localization of ChREBP to the cytoplasm during periods of ketosis. PMID:26984404

  14. Cloning, expression, purification, crystallization and preliminary X-ray diffraction analysis of the VP8* carbohydrate-binding protein of the human rotavirus strain Wa

    SciTech Connect

    Kraschnefski, Mark J.; Scott, Stacy A.; Holloway, Gavan; Coulson, Barbara S.; Itzstein, Mark von; Blanchard, Helen

    2005-11-01

    The carbohydrate-binding component (VP8*{sub 64–223}) of the human Wa rotavirus spike protein has been overexpressed in E. coli, purified and crystallized in two different crystal forms. X-ray diffraction data have been collected that have enabled determination of the Wa VP8*{sub 64–223} structure by molecular replacement. Rotaviruses exhibit host-specificity and the first crystallographic information on a rotavirus strain that infects humans is reported here. Recognition and attachment to host cells, leading to invasion and infection, is critically linked to the function of the outer capsid spike protein of the rotavirus particle. In some strains the VP8* component of the spike protein is implicated in recognition and binding of sialic-acid-containing cell-surface carbohydrates, thereby enabling infection by the virus. The cloning, expression, purification, crystallization and initial X-ray diffraction analysis of the VP8* core from human Wa rotavirus is reported. Two crystal forms (trigonal P3{sub 2}21 and monoclinic P2{sub 1}) have been obtained and X-ray diffraction data have been collected, enabling determination of the VP8*{sub 64–223} structure by molecular replacement.

  15. Protein and carbohydrate intake influence sperm number and fertility in male cockroaches, but not sperm viability.

    PubMed

    Bunning, Harriet; Rapkin, James; Belcher, Laurence; Archer, C Ruth; Jensen, Kim; Hunt, John

    2015-03-01

    It is commonly assumed that because males produce many, tiny sperm, they are cheap to produce. Recent work, however, suggests that sperm production is not cost-free. If sperm are costly to produce, sperm number and/or viability should be influenced by diet, and this has been documented in numerous species. Yet few studies have examined the exact nutrients responsible for mediating these effects. Here, we quantify the effects of protein (P) and carbohydrate (C) intake on sperm number and viability in the cockroach Nauphoeta cinerea, as well as the consequences for male fertility. We found the intake of P and C influenced sperm number, being maximized at a high intake of diets with a P : C ratio of 1 : 2, but not sperm viability. The nutritional landscapes for male fertility and sperm number were closely aligned, suggesting that sperm number is the major determinant of male fertility in N. cinerea. Under dietary choice, males regulate nutrient intake at a P : C ratio of 1 : 4.95, which is midway between the ratios needed to maximize sperm production and pre-copulatory attractiveness in this species. This raises the possibility that males regulate nutrient intake to balance the trade-off between pre- and post-copulatory traits in this species. PMID:25608881

  16. Effects of immediate postexercise carbohydrate ingestion with and without protein on neutrophil degranulation.

    PubMed

    Costa R, J S; Walters, Robert; Bilzon J, L J; Walsh, Neil P

    2011-06-01

    The purpose of the study was to determine the effects of carbohydrate (CHO) intake, with and without protein (PRO), immediately after prolonged strenuous exercise on circulating bacterially stimulated neutrophil degranulation. Twelve male runners completed 3 feeding interventions, 1 week apart, in randomized order after 2 hr of running at 75% VO2max. The feeding interventions included a placebo solution, a CHO solution equal to 1.2 g CHO/kg body mass (BM), and a CHO-PRO solution equal to 1.2 g CHO/kg BM and 0.4 g PRO/kg BM (CHO+PRO) immediately postexercise. All solutions were flavor and water-volume equivalent (12 ml/kg BM). Circulating leukocyte counts, bacterially stimulated neutrophil degranulation, plasma insulin, and cortisol were determined from blood samples collected preexercise, immediately postexercise, and every 30 min until 180 min postexercise. The immediate postexercise circulating leukocytosis, neutrophilia, and lymphocytosis (p < .01 vs. preexercise) and the delayed lymphopenia (90 min postexercise, p < .05 vs. preexercise) were similar on all trials. Bacterially stimulated neutrophil degranulation decreased during recovery in control (23% at 180 min, p < .01 vs. preexercise) but remained above preexercise levels with CHO and CHO+PRO. In conclusion, CHO ingestion, with or without PRO, immediately after prolonged strenuous exercise prevented the decrease in bacterially stimulated neutrophil degranulation during recovery. PMID:21719901

  17. Quantitative assessment of the multivalent protein-carbohydrate interactions on silicon.

    PubMed

    Yang, Jie; Chazalviel, Jean-Noël; Siriwardena, Aloysius; Boukherroub, Rabah; Ozanam, François; Szunerits, Sabine; Gouget-Laemmel, Anne Chantal

    2014-10-21

    A key challenge in the development of glycan arrays is that the sensing interface be fabricated reliably so as to ensure the sensitive and accurate analysis of the protein-carbohydrate interaction of interest, reproducibly. These goals are complicated in the case of glycan arrays as surface sugar density can influence dramatically the strength and mode of interaction of the sugar ligand at any interface with lectin partners. In this Article, we describe the preparation of carboxydecyl-terminated crystalline silicon (111) surfaces onto which are grafted either mannosyl moieties or a mixture of mannose and spacer alcohol molecules to provide "diluted" surfaces. The fabrication of the silicon surfaces was achieved efficiently through a strategy implicating a "click" coupling step. The interactions of these newly fabricated glycan interfaces with the lectin, Lens culinaris, have been characterized using quantitative infrared (IR) spectroscopy in the attenuated total geometry (ATR). The density of mannose probes and lectin targets was precisely determined for the first time by the aid of special IR calibration experiments, thus allowing for the interpretation of the distribution of mannose and its multivalent binding with lectins. These experimental findings were accounted for by numerical simulations of lectin adsorption. PMID:25216376

  18. Protein and carbohydrate intake influence sperm number and fertility in male cockroaches, but not sperm viability

    PubMed Central

    Bunning, Harriet; Rapkin, James; Belcher, Laurence; Archer, C. Ruth; Jensen, Kim; Hunt, John

    2015-01-01

    It is commonly assumed that because males produce many, tiny sperm, they are cheap to produce. Recent work, however, suggests that sperm production is not cost-free. If sperm are costly to produce, sperm number and/or viability should be influenced by diet, and this has been documented in numerous species. Yet few studies have examined the exact nutrients responsible for mediating these effects. Here, we quantify the effects of protein (P) and carbohydrate (C) intake on sperm number and viability in the cockroach Nauphoeta cinerea, as well as the consequences for male fertility. We found the intake of P and C influenced sperm number, being maximized at a high intake of diets with a P : C ratio of 1 : 2, but not sperm viability. The nutritional landscapes for male fertility and sperm number were closely aligned, suggesting that sperm number is the major determinant of male fertility in N. cinerea. Under dietary choice, males regulate nutrient intake at a P : C ratio of 1 : 4.95, which is midway between the ratios needed to maximize sperm production and pre-copulatory attractiveness in this species. This raises the possibility that males regulate nutrient intake to balance the trade-off between pre- and post-copulatory traits in this species. PMID:25608881

  19. Biosynthesis of the carbohydrate moieties of arabinogalactan proteins by membrane-bound β-glucuronosyltransferases from radish primary roots.

    PubMed

    Endo, Maya; Kotake, Toshihisa; Watanabe, Yoko; Kimura, Kazumasa; Tsumuraya, Yoichi

    2013-12-01

    A membrane fraction from etiolated 6-day-old primary radish roots (Raphanus sativus L. var hortensis) contained β-glucuronosyltransferases (GlcATs) involved in the synthesis of the carbohydrate moieties of arabinogalactan proteins (AGPs). The GlcATs transferred [(14)C]GlcA from UDP-[(14)C]GlcA on to β-(1 → 3)-galactan as an exogenous acceptor substrate, giving a specific activity of 50-150 pmol min(-1) (mg protein)(-1). The enzyme specimen also catalyzed the transfer of [(14)C]GlcA on to an enzymatically modified AGP from mature radish root. Analysis of the transfer products revealed that the transfer of [(14)C]GlcA occurred preferentially on to consecutive (1 → 3)-linked β-Gal chains as well as single branched β-(1 → 6)-Gal residues through β-(1 → 6) linkages, producing branched acidic side chains. The enzymes also transferred [(14)C]GlcA residues on to several oligosaccharides, such as β-(1 → 6)- and β-(1 → 3)-galactotrioses. A trisaccharide, α-L-Araf-(1 → 3)-β-Gal-(1 → 6)-Gal, was a good acceptor, yielding a branched tetrasaccharide, α-L-Araf-(1 → 3)[β-GlcA-(1 → 6)]-β-Gal-(1 → 6)-Gal. We report the first in vitro assay system for β-GlcATs involved in the AG synthesis as a step toward full characterization and cloning. PMID:24057431

  20. Human Protein and Amino Acid Requirements.

    PubMed

    Hoffer, L John

    2016-05-01

    Human protein and amino acid nutrition encompasses a wide, complex, frequently misunderstood, and often contentious area of clinical research and practice. This tutorial explains the basic biochemical and physiologic principles that underlie our current understanding of protein and amino acid nutrition. The following topics are discussed: (1) the identity, measurement, and essentiality of nutritional proteins; (2) the definition and determination of minimum requirements; (3) nutrition adaptation; (4) obligatory nitrogen excretion and the minimum protein requirement; (5) minimum versus optimum protein intakes; (6) metabolic responses to surfeit and deficient protein intakes; (7) body composition and protein requirements; (8) labile protein; (9) N balance; (10) the principles of protein and amino acid turnover, including an analysis of the controversial indicator amino acid oxidation technique; (11) general guidelines for evaluating protein turnover articles; (12) amino acid turnover versus clearance; (13) the protein content of hydrated amino acid solutions; (14) protein requirements in special situations, including protein-catabolic critical illness; (15) amino acid supplements and additives, including monosodium glutamate and glutamine; and (16) a perspective on the future of protein and amino acid nutrition research. In addition to providing practical information, this tutorial aims to demonstrate the importance of rigorous physiologic reasoning, stimulate intellectual curiosity, and encourage fresh ideas in this dynamic area of human nutrition. In general, references are provided only for topics that are not well covered in modern textbooks. PMID:26796095

  1. Metabolic determinants of body weight after cats were fed a low-carbohydrate high-protein diet or a high-carbohydrate low-protein diet ad libitum for 8 wk.

    PubMed

    Coradini, M; Rand, J S; Morton, J M; Rawlings, J M

    2014-10-01

    Overweight and obese conditions are common in cats and are associated with the development of a number of diseases. Knowledge of metabolic determinants and predictors of weight gain may enable better preventative strategies for obesity in cats. Lean, healthy cats were fed either a low-carbohydrate high-protein diet (n 16) or a high-carbohydrate low-protein (n 16) diet ad libitum for 8 wk. Potential determinants and predictors of final body weight assessed were body fat and lean masses, energy required for maintenance, energy requirements above maintenance for each kilogram of weight gain, insulin sensitivity index, fasting, mean 24-h and peak plasma glucose, insulin, and leptin concentrations, and fasting and mean 24-h serum adiponectin concentrations. In cats fed the low-carbohydrate high-protein diet, after adjusting for initial body weight, those with higher energy requirements for weight gain and higher fasting glucose concentration had higher final body weights (P ≤ 0.01). Predicted final body weights using initial body weight, fasting glucose and mean 24-h insulin concentrations (partial R(2) 37.3%) were imprecise. An equation using just initial body weight and fasting glucose concentration would be of more practical value, but was marginally less precise. In cats fed the high-carbohydrate low-protein diet, those with lower fasting leptin concentration initially had higher final body weights (P = 0.01). Predicted final body weights using initial body weight, energy requirements for maintenance, total body fat percentage and fasting leptin concentration (partial R(2) 39.2%) were reasonably precise. Further studies are warranted to confirm these findings and to improve the precision of predicted final body weights. PMID:25084314

  2. Impact of glucose polymer chain length on heat and physical stability of milk protein-carbohydrate nutritional beverages.

    PubMed

    Chen, Biye; O'Mahony, James A

    2016-11-15

    This study investigated the impact of glucose polymer chain length on heat and physical stability of milk protein isolate (MPI)-carbohydrate nutritional beverages containing 8.5% w/w total protein and 5% w/w carbohydrate. The maltodextrin and corn syrup solids glucose polymers used had dextrose equivalent (DE) values of 17 or 38, respectively. Increasing DE value of the glucose polymers resulted in a greater increase in brown colour development, ionic calcium, protein particle size, apparent viscosity and pseudoplastic rheological behaviour, and greater reduction in pH, hydration and heat stability on sterilisation at 120°C. Incorporation of glucose polymers with MPI retarded sedimentation of protein during accelerated physical stability testing, with maltodextrin DE17 causing a greater reduction in sedimentation velocity and compressibility of sediment formed than corn syrup solids DE38. The results demonstrate that chain length of the glucose polymer used strongly impacts heat and physical stability of MPI-carbohydrate nutritional beverages. PMID:27283657

  3. Glucose-6-phosphate mediates activation of the carbohydrate responsive binding protein (ChREBP)

    PubMed Central

    Li, Ming V.; Chen, Weiqin; Harmancey, Romain N; Nuotio-Antar, Alli M.; Imamura, Minako; Saha, Pradip; Taegtmeyer, Heinrich; Chan, Lawrence

    2010-01-01

    Carbohydrate Response Element Binding Protein (ChREBP) is a Mondo family transcription factor that activates a number of glycolytic and lipogenic genes in response to glucose stimulation. We have previously reported that high glucose can activate the transcriptional activity of ChREBP independent of the protein phosphatase 2A (PP2A)-mediated increase in nuclear entry and DNA binding. Here we found that formation of glucose-6-phosphate (G-6-P) is essential for glucose activation of ChREBP. The glucose response of GAL4-ChREBP is attenuated by D-mannoheptulose, a potent hexokinase inhibitor, as well as over-expression of glucose-6-phosphatase (G6Pase); kinetics of activation of GAL4-ChREBP can be modified by exogenously expressed GCK. Further metabolism of G-6-P through the two major glucose metabolic pathways, glycolysis and pentose phosphate pathway, is not required for activation of ChREBP; over-expression of glucose-6-phosphate dehydrogenase (G6PD) diminishes, whereas RNAi knockdown of the enzyme enhances, the glucose response of GAL4-ChREBP, respectively. Moreover, the glucose analogue 2-deoxyglucose (2-DG), which is phosphorylated by hexokinase, but not further metabolized, effectively upregulates the transcription activity of ChREBP. In addition, over-expression of phosphofructokinase (PFK) 1 and 2, synergistically diminishes the glucose response of GAL4-ChREBP. These multiple lines of evidence support the conclusion that G-6-P mediates the activation of ChREBP. PMID:20382127

  4. Magnetic nanoparticles--templated assembly of protein subunits: a new platform for carbohydrate-based MRI nanoprobes.

    PubMed

    Valero, Elsa; Tambalo, Stefano; Marzola, Pasquina; Ortega-Muñoz, Mariano; López-Jaramillo, F Javier; Santoyo-González, Francisco; de Dios López, Juan; Delgado, Juan J; Calvino, José J; Cuesta, Rafael; Domínguez-Vera, José M; Gálvez, Natividad

    2011-04-01

    A new approach for the preparation of carbohydrate-coated magnetic nanoparticles is reported. In a first step, we show that the pH-driven assembly-disassembly natural process that occurs in apoferritin protein is effective for the encapsulation of maghemite nanoparticles of different sizes: 4 and 6 nm. In a second step, we demonstrate that the presence of functional amine groups in the outer shell of apoferritin allows functionalization with two carbohydrates, N-acetyl-D-glucosamine and d-mannose. High-resolution electron microscopy (HREM), high angle annular dark field scanning electron microscopy (HAADF-STEM), electron energy loss spectroscopy (EELS), X-ray diffraction (XRD), and SQUID technique have been used to characterize the magnetic samples, termed herein Apomaghemites. The in vivo magnetic resonance imaging (MRI) studies showed the efficiency in contrasting images for these samples; that is, the r(2) NMR relaxivities are comparable with Endorem (a commercial superparamagnetic MRI contrast agent). The r(2) relaxivity values as well as the pre-contrast and post-contrast T(2)*-weighted images suggested that our systems could be used as perspective superparamagnetic contrast agents for magnetic resonance imaging (MRI). The carbohydrate-functionalized Apomaghemite nanoparticles retained their recognition abilities, as demonstrated by the strong affinity with their corresponding carbohydrate-binding lectins. PMID:21384882

  5. Two integral membrane proteins located in the cis-middle and trans-part of the Golgi system acquire sialylated N-linked carbohydrates and display different turnovers and sensitivity to cAMP-dependent phosphorylation.

    PubMed

    Yuan, L; Barriocanal, J G; Bonifacino, J S; Sandoval, I V

    1987-07-01

    The localization and chemical characteristics of two Golgi integral membrane proteins (GIMPs) have been studied using monoclonal antibodies. The two proteins are segregated in different parts of the Golgi system and whereas GIMPc(130 kD) is located in the cis and medial cisternae, GIMPt (100 kD) is confined in the trans-most cisterna and trans-tubular network. Both GIMPs are glycoproteins that contain N- and O-linked carbohydrates. The N-linked carbohydrates were exclusively of the complex type. Although excluded from the trans-side of the Golgi system, where sialylation is believed to occur, GIMPc acquires sialic acid in both its N- and O-linked carbohydrates. Sialic acid was also detected in the N-linked carbohydrates of GIMPt. GIMPc is apparently phosphorylated in the luminal domain in vivo. Phosphorylation occurred exclusively on serine and was stimulated by dibutyryl cyclic AMP. GIMPc and GIMPt displayed half-lives of 20 and 9 h, respectively. PMID:3301866

  6. Low and high dietary protein:carbohydrate ratios during pregnancy affect materno-fetal glucose metabolism in pigs.

    PubMed

    Metges, Cornelia C; Görs, Solvig; Lang, Iris S; Hammon, Harald M; Brüssow, Klaus-Peter; Weitzel, Joachim M; Nürnberg, Gerd; Rehfeldt, Charlotte; Otten, Winfried

    2014-02-01

    Inadequate dietary protein during pregnancy causes intrauterine growth retardation. Whether this is related to altered maternal and fetal glucose metabolism was examined in pregnant sows comparing a high-protein:low-carbohydrate diet (HP-LC; 30% protein, 39% carbohydrates) with a moderately low-protein:high-carbohydrate diet (LP-HC; 6.5% protein, 68% carbohydrates) and the isoenergetic standard diet (ST; 12.1% protein, 60% carbohydrates). During late pregnancy, maternal and umbilical glucose metabolism and fetal hepatic mRNA expression of gluconeogenic enzymes were examined. During an i.v. glucose tolerance test (IVGTT), the LP-HC-fed sows had lower insulin concentrations and area under the curve (AUC), and higher glucose:insulin ratios than the ST- and the HP-LC-fed sows (P < 0.05). Insulin sensitivity and glucose clearance were higher in the LP-HC sows compared with ST sows (P < 0.05). Glucagon concentrations during postabsorptive conditions and IVGTT, and glucose AUC during IVGTT, were higher in the HP-LC group compared with the other groups (P < 0.001). (13)C glucose oxidation was lower in the HP-LC sows than in the ST and LP-HC sows (P < 0.05). The HP-LC fetuses were lighter and had a higher brain:liver ratio than the ST group (P < 0.05). The umbilical arterial inositol concentration was greater in the HP-LC group (P < 0.05) and overall small fetuses (230-572 g) had higher values than medium and heavy fetuses (≥573 g) (P < 0.05). Placental lactate release was lower in the LP-HC group than in the ST group (P < 0.05). Fetal glucose extraction tended to be lower in the LP-HC group than in the ST group (P = 0.07). In the HP-LC and LP-HC fetuses, hepatic mRNA expression of cytosolic phosphoenolpyruvate carboxykinase (PCK1) and glucose-6-phosphatase (G6PC) was higher than in the ST fetuses (P < 0.05). In conclusion, the HP-LC and LP-HC sows adapted by reducing glucose turnover and oxidation and having higher glucose utilization, respectively. The HP-LC and LP

  7. Probing the Functions of Carbohydrate Binding Modules in the CBEL Protein from the Oomycete Phytophthora parasitica

    PubMed Central

    Martinez, Thomas; Texier, Hélène; Nahoum, Virginie; Lafitte, Claude; Cioci, Gianluca; Heux, Laurent; Dumas, Bernard; O’Donohue, Michael

    2015-01-01

    Oomycetes are microorganisms that are distantly related to true fungi and many members of this phylum are major plant pathogens. Oomycetes express proteins that are able to interact with plant cell wall polysaccharides, such as cellulose. This interaction is thought to be mediated by carbohydrate-binding modules that are classified into CBM family 1 in the CAZy database. In this study, the two CBMs (1–1 and 1–2) that form part of the cell wall glycoprotein, CBEL, from Phytophthora parasitica have been submitted to detailed characterization, first to better quantify their interaction with cellulose and second to determine whether these CBMs can be useful for biotechnological applications, such as biomass hydrolysis. A variety of biophysical techniques were used to study the interaction of the CBMs with various substrates and the data obtained indicate that CBEL’s CBM1-1 exhibits much greater cellulose binding ability than CBM1-2. Engineering of the family 11 xylanase from Talaromyces versatilis (TvXynB), an enzyme that naturally bears a fungal family 1 CBM, has produced two variants. The first one lacks its native CBM, whereas the second contains the CBEL CBM1-1. The study of these enzymes has revealed that wild type TvXynB binds to cellulose, via its CBM1, and that the substitution of its CBM by oomycetal CBM1-1 does not affect its activity on wheat straw. However, intriguingly the addition of CBEL during the hydrolysis of wheat straw actually potentiates the action of TvXynB variant lacking a CBM1. This suggests that the potentiating effect of CBM1-1 might not require the formation of a covalent linkage to TvXynB. PMID:26390127

  8. Probing the Functions of Carbohydrate Binding Modules in the CBEL Protein from the Oomycete Phytophthora parasitica.

    PubMed

    Martinez, Thomas; Texier, Hélène; Nahoum, Virginie; Lafitte, Claude; Cioci, Gianluca; Heux, Laurent; Dumas, Bernard; O'Donohue, Michael; Gaulin, Elodie; Dumon, Claire

    2015-01-01

    Oomycetes are microorganisms that are distantly related to true fungi and many members of this phylum are major plant pathogens. Oomycetes express proteins that are able to interact with plant cell wall polysaccharides, such as cellulose. This interaction is thought to be mediated by carbohydrate-binding modules that are classified into CBM family 1 in the CAZy database. In this study, the two CBMs (1-1 and 1-2) that form part of the cell wall glycoprotein, CBEL, from Phytophthora parasitica have been submitted to detailed characterization, first to better quantify their interaction with cellulose and second to determine whether these CBMs can be useful for biotechnological applications, such as biomass hydrolysis. A variety of biophysical techniques were used to study the interaction of the CBMs with various substrates and the data obtained indicate that CBEL's CBM1-1 exhibits much greater cellulose binding ability than CBM1-2. Engineering of the family 11 xylanase from Talaromyces versatilis (TvXynB), an enzyme that naturally bears a fungal family 1 CBM, has produced two variants. The first one lacks its native CBM, whereas the second contains the CBEL CBM1-1. The study of these enzymes has revealed that wild type TvXynB binds to cellulose, via its CBM1, and that the substitution of its CBM by oomycetal CBM1-1 does not affect its activity on wheat straw. However, intriguingly the addition of CBEL during the hydrolysis of wheat straw actually potentiates the action of TvXynB variant lacking a CBM1. This suggests that the potentiating effect of CBM1-1 might not require the formation of a covalent linkage to TvXynB. PMID:26390127

  9. Regional blood flow in rats after a single low-protein, high-carbohydrate test meal.

    PubMed

    Glick, Z; Wickler, S J; Stern, J S; Horwitz, B A

    1984-07-01

    It was previously observed that a single low-protein, high-carbohydrate test meal results in increased in vitro thermic activity of brown adipose tissue. In the present study, we have examined whether such a meal increases the in vivo thermic activity, estimated from measurement of the rate of blood flow. With radioactively labeled microspheres, blood flows into brown fat and several other tissues were determined in meal-deprived (n = 11) and meal-fed (n = 11) rats. The microspheres were injected into the heart of anesthetized animals about 2-2.5 h after the test meal, one injection in the resting state and one during maximal norepinephrine stimulation. In the resting state, blood flow per gram tissue more than doubled in the brown fat (P less than 0.05) and was increased more than 50% in the heart (P less than 0.01) of the fed group. Blood flows into liver and retroperitoneal white fat were reduced by 40 (P less than 0.01) and 30%, respectively, in the fed group. During norepinephrine infusion, significant meal-associated increases in blood flow were evident only in brown fat (P less than 0.05) and the soleus muscle (P less than 0.05), whereas a significant decrease was observed in the liver (P less than 0.05). No statistically significant meal-associated changes in norepinephrine-stimulated blood flow were found in the other tissues examined (i.e., heart, gastrocnemius, and diaphragm muscles, kidneys, white fat, spleen, and adrenals). Our in vivo data thus support the view that brown fat plays a role in the thermic effect of a meal. PMID:6742226

  10. Combined carbohydrate-protein supplementation improves competitive endurance exercise performance in the heat.

    PubMed

    Cathcart, Andrew J; Murgatroyd, Scott R; McNab, Alison; Whyte, Laura J; Easton, Chris

    2011-09-01

    Laboratory-based studies have demonstrated that adding protein (PRO) to a carbohydrate (CHO) supplement can improve thermoregulatory capacity, exercise performance and recovery. However, no study has investigated these effects in a competitive sporting context. This study assessed the effects of combined CHO-PRO supplementation on physiological responses and exercise performance during 8 days of strenuous competition in a hot environment. Twenty-eight cyclists participating in the TransAlp mountain bike race were randomly assigned to fitness-matched placebo (PLA 76 g L(-1) CHO) or CHO-PRO (18 g L(-1) PRO, 72 g L(-1) CHO) groups. Participants were given enough supplements to allow ad libitum consumption. Physiological and anthropometric variables were recorded pre- and post-exercise. Body mass decreased significantly from race stage 1 to 8 in the PLA group (-0.75 ± 0.22 kg, P = 0.01) but did not change in the CHO-PRO group (0.42 ± 0.42 kg, P = 0.35). Creatine kinase concentration and muscle soreness were substantially elevated during the race, but were not different between groups (P = 0.82, P = 0.44, respectively). Urine osmolality was significantly higher in the CHO-PRO versus the PLA group (P = 0.04) and the rise in tympanic temperature from pre- to post-exercise was significantly less in CHO-PRO versus PLA (P = 0.01). The CHO-PRO group also completed the 8 stages significantly quicker than the PLA group (2,277 ± 127 vs. 2,592 ± 68 min, respectively, P = 0.02). CHO-PRO supplementation therefore appears to prevent body mass loss, enhance thermoregulatory capacity and improve competitive exercise performance despite no effect on muscle damage. PMID:21259024

  11. Effect of high contents of dietary animal-derived protein or carbohydrates on canine faecal microbiota

    PubMed Central

    2012-01-01

    Background Considerable evidence suggests that food impacts both the gastro-intestinal (GI) function and the microbial ecology of the canine GI tract. The aim of this study was to evaluate the influence of high-carbohydrate (HC), high-protein (HP) and dry commercial (DC) diets on the canine colonic microbiota in Beagle dogs. Diets were allocated according to the Graeco-Latin square design. For this purpose, microbial DNA was isolated from faecal samples and separated by density gradient centrifugation, resulting in specific profiling based on the guanine-cytosine content (%G + C). In addition, 16 S rRNA gene amplicons were obtained from the most abundant %G + C peaks and analysed by sequence analysis, producing a total of 720 non-redundant sequences (240 sequences per diet). Results The DC diet sample showed high abundance of representatives of the orders Clostridiales, Lactobacillales, Coriobacteriales and Bacteroidales. Sequence diversity was highest for DC diet samples and included representatives of the orders Lactobacillales and Bacteroidales, which were not detected in samples from the HP and HC diets. These latter two diets also had reduced levels of representatives of the family Lachnospiraceae, specifically Clostridial cluster XIVa. The HC diet favoured representatives of the order Erysipelotrichales, more specifically the Clostridial cluster XVIII, while the HP diet favoured representatives of the order Fusobacteriales. Conclusions This study detected Coriobacteriales in dog faeces, possibly due to the non-selective nature of the %G + C profiling method used in combination with sequencing. Moreover, our work demonstrates that the effect of diet on faecal microbiota can be explained based on the metabolic properties of the detected microbial taxa. PMID:22735212

  12. Protein, carbohydrate, lipid concentrations and HSP 70-HSP 90 (stress protein) expression over an annual cycle: useful tools to detect feeding constraints in a benthic suspension feeder

    NASA Astrophysics Data System (ADS)

    Rossi, Sergio; Snyder, Mark J.; Gili, Josep-Marìa

    2006-03-01

    In the present paper we suggest an effect of seasonal variations in food availability on two ecophysiological parameters in a warm temperate benthic suspension feeder: the tissue concentrations of proteins, carbohydrates and lipids on the one hand, and the expression of stress proteins (HSP 70 and 90, inducible and/or constitutive) on the other hand. The concentrations of biomacromolecules have already been used to describe bentho-pelagic and reproductive processes, but this is the first time that stress protein expression is suggested to be directly related with food constraints in marine organisms. Paramuricea clavata (Cnidaria: Gorgonacea) express HSP 70 and 90 (constitutive and/or inducible) throughout the seasonal cycle, and HSP 70 levels are twice as high as the levels of HSP 90. In summer and autumn, when seston availability to suspension feeders was low, P. clavata showed low levels of carbohydrates and lipids, but high levels of HSPs expression. The levels of HSP 70 and 90 expression fit with negative exponential functions of carbohydrate and lipid concentrations. We suggest a direct effect of food availability on the studied ecophysiological parameters while the effect of temperature may be rather indirect. HSP expression as well as the tissue concentrations of carbohydrate and lipids may be used as biomarkers of environmental changes and seston availability to benthic suspension feeders.

  13. Effect of pH and temperature on comparative antioxidant activity of nonenzymatically browned proteins produced by reaction with oxidized lipids and carbohydrates.

    PubMed

    Alaiz, M; Hidalgo, F J; Zamora, R

    1999-02-01

    The antioxidative activity of nonenzymatically browned bovine serum albumin (BSA) produced by reaction with ribose (RI), hydroperoxides of methyl linoleate oxidation (HP), and secondary products of methyl linoleate oxidation (SP), at different pHs (4, 7, and 10) and temperatures (25, 37, 50, 80, and 120 degrees C), was studied to compare the antioxidative effects of carbohydrate- and oxidized lipids-modified proteins. The modified proteins (RIBSA, HPBSA, and SPBSA) were tested for antioxidative activity (at 100 ppm) in soybean oil using the thiobarbituric acid-reactive substances (TBARS) assay. All of them decreased significantly (p < 0.05) the TBARS formation in the oil and exhibited different effectiveness as a function of the temperature and the pH of the medium. In addition, there was a good correlation between the antioxidative activity of the protein and the amino acid losses produced during the nonenzymatic browning. These results are in agreement with an analogous and complimentary contribution of both Maillard and oxidized lipid/protein reactions to the antioxidative activity produced in foods during processing and storage. PMID:10563964

  14. Effects of sulfhydryl compounds, carbohydrates, organic acids, and sodium sulfite on the formation of lysinoalanine in preserved egg.

    PubMed

    Luo, Xu-Ying; Tu, Yong-Gang; Zhao, Yan; Li, Jian-Ke; Wang, Jun-Jie

    2014-08-01

    To identify inhibitors for lysinoalanine formation in preserved egg, sulfhydryl compounds (glutathione, L-cysteine), carbohydrates (sucrose, D-glucose, maltose), organic acids (L-ascorbic acid, citric acid, DL-malic acid, lactic acid), and sodium sulfite were individually added at different concentrations to a pickling solution to prepare preserved eggs. Lysinoalanine formation as an index of these 10 substances was determined. Results indicate that glutathione, D-glucose, maltose, L-ascorbic acid, citric acid, lactic acid, and sodium sulfite all effectively diminished lysinoalanine formation in preserved egg albumen and yolk. When 40 and 80 mmol/L of sodium sulfite, citric acid, L-ascorbic acid, and D-glucose were individually added into the pickling solution, the inhibition rates of lysinoalanine in the produced preserved egg albumen and yolk were higher. However, the attempt of minimizing lysinoalanine formation was combined with the premise of ensuring preserved eggs quality. Moreover, the addition of 40 and 80 mmol/L of sodium sulfite, 40 and 80 mmol/L of D-glucose, 40 mmol/L of citric acid, and 40 mmol/L of L-ascorbic acid was optimal to produce preserved eggs. The corresponding inhibition rates of lysinoalanine in the albumen were approximately 76.3% to 76.5%, 67.6% to 67.8%, 74.6%, and 74.6%, and the corresponding inhibition rates of lysinoalanine in the yolk were about 68.7% to 69.7%, 50.6% to 51.8%, 70.4%, and 57.8%. It was concluded that sodium sulfite, D-glucose, L-ascorbic, and citric acid at suitable concentrations can be used to control the formation of lysinoalanine during preserved egg processing. PMID:25047093

  15. Nutritional physiology of life-history trade-offs: how food protein-carbohydrate content influences life-history traits in the wing-polymorphic cricket Gryllus firmus.

    PubMed

    Clark, Rebecca M; Zera, Anthony J; Behmer, Spencer T

    2015-01-15

    Although life-history trade-offs result from the differential acquisition and allocation of nutritional resources to competing physiological functions, many aspects of this topic remain poorly understood. Wing-polymorphic insects, which possess alternative morphs that trade off allocation to flight capability versus early reproduction, provide a good model system for exploring this topic. In this study, we used the wing-polymorphic cricket Gryllus firmus to test how expression of the flight capability versus reproduction trade-off was modified across a heterogeneous protein-carbohydrate nutritional landscape. Newly molted adult female long- and short-winged crickets were given one of 13 diets with different concentrations and ratios of protein and digestible carbohydrate; for each cricket, we measured consumption patterns, growth and allocation to reproduction (ovary mass) versus flight muscle maintenance (flight muscle mass and somatic lipid stores). Feeding responses in both morphs were influenced more by total macronutrient concentration than by protein-carbohydrate ratio, except at high-macronutrient concentration, where protein-carbohydrate balance was important. Mass gain tended to be greatest on protein-biased diets for both morphs, but was consistently lower across all diets for long-winged females. When long-winged females were fed high-carbohydrate foods, they accumulated greater somatic lipid stores; on high-protein foods, they accumulated greater somatic protein stores. Food protein-carbohydrate content also affected short-winged females (selected for early reproductive onset), which showed dramatic increases in ovary size, including ovarian stores of lipid and protein, on protein-biased foods. This is the first study to show how the concentration and ratio of dietary protein and carbohydrate affects consumption and allocation to key physiological features associated with the reproduction-dispersal life-history trade-off. PMID:25524979

  16. Effect of a carbohydrate-protein multi-ingredient supplement on intermittent sprint performance and muscle damage in recreational athletes.

    PubMed

    Naclerio, Fernando; Larumbe-Zabala, Eneko; Cooper, Robert; Jimenez, Alfonso; Goss-Sampson, Mark

    2014-10-01

    Carbohydrate-protein-based multi-ingredient supplements have been proposed as an effective strategy for limiting the deleterious effects of exercise-induced muscle damage. This study compares the effects of a commercially available carbohydrate-protein supplement enriched with l-glutamine and l-carnitine-l-tartrate to carbohydrate alone or placebo on sprint performance, muscle damage markers, and recovery from intermittent exercise. On 3 occasions, 10 recreationally trained males ingested a multi-ingredient, a carbohydrate supplement, or a placebo before, during, and immediately after a 90-min intermittent repeated sprint test. Fifteen-metre sprint times, creatine kinase, myoglobin, and interleukin-6 were assessed before (pre), immediately after (post), 1 h after (1h), and 24 h after (24h) exercise. Total sprint time measured during the intermittent protocol was not different between conditions. Fifteen-metre sprint time was slower (p < 0.05) at post, 1h and 24h compared with pre without differences between conditions (p > 0.05). Creatine kinase at 24h was lower (p < 0.05) in the multi-ingredient (461.8 ± 271.8 U·L) compared with both carbohydrate and placebo (606 ± 314.5 U·L and 636 ± 344.6 U·L, respectively). Myoglobin increased (p < 0.05) in all 3 conditions at post and 1h compared with pre, showing lower values at 1h (p < 0.05) for the carbohydrate and a trend (p = 0.060) for multi-ingredient compared with the placebo condition (211.4 ± 127.2 ng·mL(-1) and 239.4 ± 103.8 ng·mL(-1) vs. 484.6 ± 200.0 ng·mL(-1), respectively). Interleukin-6 increased at both post and 1h compared with pre (p < 0.05) with no differences between conditions. In conclusion, ingesting a multi-ingredient supplement before, during, and immediately after a 90-min intermittent sprint test resulted in no effects on performance and fatigue while the accumulation of some biomarkers of muscle damage could be attenuated. PMID:25029675

  17. Complete amino acid sequence and structure characterization of the taste-modifying protein, miraculin.

    PubMed

    Theerasilp, S; Hitotsuya, H; Nakajo, S; Nakaya, K; Nakamura, Y; Kurihara, Y

    1989-04-25

    The taste-modifying protein, miraculin, has the unusual property of modifying sour taste into sweet taste. The complete amino acid sequence of miraculin purified from miracle fruits by a newly developed method (Theerasilp, S., and Kurihara, Y. (1988) J. Biol. Chem. 263, 11536-11539) was determined by an automatic Edman degradation method. Miraculin was a single polypeptide with 191 amino acid residues. The calculated molecular weight based on the amino acid sequence and the carbohydrate content (13.9%) was 24,600. Asn-42 and Asn-186 were linked N-glycosidically to carbohydrate chains. High homology was found between the amino acid sequences of miraculin and soybean trypsin inhibitor. PMID:2708331

  18. Protein biosynthesis with conformationally restricted amino acids

    SciTech Connect

    Mendel, D. Lawrence Berkeley Lab., CA ); Ellman, J.; Schultz, P.G. )

    1993-05-19

    The incorporation of conformationally constrained amino acids into peptides is a powerful approach for generating structurally defined peptides as conformational probes and bioactive agents. The ability to site-specifically introduce constrained amino acids into large polypeptide chains would provide a similar opportunity to probe the flexibility, conformation, folding and stability of proteins. To this end, we have examined the competence of the Escherichia coli protein biosynthetic machinery to incorporate a number of these unnatural amino acids into the 164 residue protein T4 lysozyme (T4L). Results clearly demonstrate that the protein biosynthetic machinery can accommodate a wide variety of conformationally constrained amino acids. The expansion of structural motifs that can be biosynthetically incorporated into proteins to include a large number of conformationally constrained amino acids significantly increases the power of mutagenesis methods as probes of protein structure and function and provides additional insights into the steric requirements of the translational machinery. 13 refs., 2 figs.

  19. Effect of timing of protein and carbohydrate intake after resistance exercise on nitrogen balance in trained and untrained young men

    PubMed Central

    2014-01-01

    Background Resistance exercise alters the post-exercise response of anabolic and catabolic hormones. A previous study indicated that the turnover of muscle protein in trained individuals is reduced due to alterations in endocrine factors caused by resistance training, and that muscle protein accumulation varies between trained and untrained individuals due to differences in the timing of protein and carbohydrate intake. We investigated the effect of the timing of protein and carbohydrate intake after resistance exercise on nitrogen balance in trained and untrained young men. Methods Subjects were 10 trained healthy men (mean age, 23 ± 4 years; height, 173.8 ± 3.1 cm; weight, 72.3 ± 4.3 kg) and 10 untrained healthy men (mean age, 23 ± 1 years; height, 171.8 ± 5.0 cm; weight, 64.5 ± 5.0 kg). All subjects performed four sets of 8 to 10 repetitions of a resistance exercise (comprising bench press, shoulder press, triceps pushdown, leg extension, leg press, leg curl, lat pulldown, rowing, and biceps curl) at 80% one-repetition maximum. After each resistance exercise session, subjects were randomly divided into two groups with respect to intake of protein (0.3 g/kg body weight) and carbohydrate (0.8 g/kg body weight) immediately after (P0) or 6 h (P6) after the session. All subjects were on an experimental diet that met their individual total energy requirement. We assessed whole-body protein metabolism by measuring nitrogen balance at P0 and P6 on the last 3 days of exercise training. Results The nitrogen balance was significantly lower in the trained men than in the untrained men at both P0 (P <0.05) and P6 (P <0.01). The nitrogen balance in trained men was significantly higher at P0 than at P6 (P <0.01), whereas that in the untrained men was not significantly different between the two periods. Conclusion The timing of protein and carbohydrate intake after resistance exercise influences nitrogen balance differently in trained and

  20. Distinguishing Proteins From Arbitrary Amino Acid Sequences

    PubMed Central

    Yau, Stephen S.-T.; Mao, Wei-Guang; Benson, Max; He, Rong Lucy

    2015-01-01

    What kinds of amino acid sequences could possibly be protein sequences? From all existing databases that we can find, known proteins are only a small fraction of all possible combinations of amino acids. Beginning with Sanger's first detailed determination of a protein sequence in 1952, previous studies have focused on describing the structure of existing protein sequences in order to construct the protein universe. No one, however, has developed a criteria for determining whether an arbitrary amino acid sequence can be a protein. Here we show that when the collection of arbitrary amino acid sequences is viewed in an appropriate geometric context, the protein sequences cluster together. This leads to a new computational test, described here, that has proved to be remarkably accurate at determining whether an arbitrary amino acid sequence can be a protein. Even more, if the results of this test indicate that the sequence can be a protein, and it is indeed a protein sequence, then its identity as a protein sequence is uniquely defined. We anticipate our computational test will be useful for those who are attempting to complete the job of discovering all proteins, or constructing the protein universe. PMID:25609314

  1. Detection of AGEs as markers for carbohydrate metabolism and protein denaturation

    PubMed Central

    Nagai, Ryoji; Shirakawa, Jun-ichi; Fujiwara, Yukio; Ohno, Rei-ichi; Moroishi, Narumi; Sakata, Noriyuki; Nagai, Mime

    2014-01-01

    Approximately 100 years have passed since the Maillard reaction was first reported in the field of food chemistry as a condensation reaction between reducing sugars and amino acids. This reaction is thought to progress slowly primarily from glucose with proteins in vivo. An early-stage product, called the ”Amadori product”, is converted into advanced glycation end products. Those accumulate in the body in accordance with age, with such accumulation being enhanced by lifestyle-related diseases that result in the denaturation of proteins. Recent studies have demonstrated that intermediate carbonyls are generated by several pathways, and rapidly generate many glycation products. However, accurate quantification of glycation products in vivo is difficult due to instability and differences in physicochemical properties. In this connection, little is known about the relationship between the structure of glycation products and pathology. Furthermore, the interaction between proteins modified by glycation and receptors for advanced glycation end products is also known to induce the production of several inflammatory cytokines. Therefore, those inhibitors have been developed over the world to prevent lifestyle-related diseases. In this review, we describe the process of protein denaturation induced by glycation and discuss the possibility of using the process as a marker of age-related diseases. PMID:25120273

  2. Fabrication of hydrophobic polymer foams with double acid sites on surface of macropore for conversion of carbohydrate.

    PubMed

    Pan, Jianming; Mao, Yanli; Gao, Heping; Xiong, Qingang; Qiu, Fengxian; Zhang, Tao; Niu, Xiangheng

    2016-06-01

    Herein we reported a simple and novel synthetic strategy for the fabrication of two kinds of hydrophobic polymer foam catalysts (i.e. Cr(3+)-HPFs-1-H(+) and HPFs-1-H(+)) with hierarchical porous structure, inhomogeneous acidic composition and Lewis-Brønsted double acid sites distributed on the surface, which was used to one-pot conversion of carbohydrate (such as cellulose, glucose and fructose) to a key chemical platform (i.e. 5-hydroxymethylfurfural, HMF). The water-in-oil (W/O) high internal phase emulsions (HIPEs), stabilized by both Span 80 and acidic prepolymers as analogous particles offered the acidic actives, were used as the template for simultaneous polymerization of oil phase in the presence of divinylbenzene (DVB) and styrene (St). After subsequent ion-exchange process, Lewis and Brønsted acid sites derived from exchanged Cr(3+) and H(+) ion were both fixed on the surface of cell of the catalysts. The HPFs-1-H(+) and Cr(3+)-HPFs-1-H(+) had similar hierarchical porous, hydrophobic surface and acid sites (HPFs-1-H(+) with macropores ranging from 0.1 μm to 20 μm, uniform mesopores in 14.4 nm, water contact angle of 122° and 0.614 mmolg(-1) of Brønsted acid sites, as well as Cr(3+)-HPFs-1-H(+) with macropores ranging from 0.1 μm to 20 μm, uniform mesopores in 13.3 nm, water contact angle of 136° and 0.638 mmolg(-1) of Lewis-Brønsted acid sites). It was confirmed that Lewis acid sites of catalyst had a slight influence on the HMF yield of fructose came from the function of Brønsted acid sites, and Lewis acid sites were in favor of improving the HMF yield from cellulose and glucose. This work opens up a simple and novel route to synthesize multifunctional polymeric catalysts for efficient one-pot conversion of carbohydrate to HMF. PMID:27083362

  3. Balanced intake of protein and carbohydrate maximizes lifetime reproductive success in the mealworm beetle, Tenebrio molitor (Coleoptera: Tenebrionidae).

    PubMed

    Rho, Myung Suk; Lee, Kwang Pum

    2016-01-01

    Recent developments in insect gerontological and nutritional research have suggested that the dietary protein:carbohydrate (P:C) balance is a critical determinant of lifespan and reproduction in many insects. However, most studies investigating this important role of dietary P:C balance have been conducted using dipteran and orthopteran species. In this study, we used the mealworm beetles, Tenebrio molitor L. (Coleoptera: Tenebrionidae), to test the effects of dietary P:C balance on lifespan and reproduction. Regardless of their reproductive status, both male and female beetles had the shortest lifespan at the protein-biased ratio of P:C 5:1. Mean lifespan was the longest at P:C 1:1 for males and at both P:C 1:1 and 1:5 for females. Mating significantly curtailed the lifespan of both males and females, indicating the survival cost of mating. Age-specific egg laying was significantly higher at P:C 1:1 than at the two imbalanced P:C ratios (1:5 or 5:1) at any given age throughout their lives, resulting in the highest lifetime reproductive success at P:C 1:1. When given a choice, beetles actively regulated their intake of protein and carbohydrate to a slightly carbohydrate-biased ratio (P:C 1:1.54-1:1.64 for males and P:C 1:1.3-1:1.36 for females). The self-selected P:C ratio was significantly higher for females than males, reflecting a higher protein requirement for egg production. Collectively, our results add to a growing body of evidence suggesting the key role played by dietary macronutrient balance in shaping lifespan and reproduction in insects. PMID:27405009

  4. Effects of Synchronization of Carbohydrate and Protein Supply in Total Mixed Ration with Korean Rice Wine Residue on Ruminal Fermentation, Nitrogen Metabolism and Microbial Protein Synthesis in Holstein Steers

    PubMed Central

    Piao, Min Yu; Kim, Hyun J.; Seo, J. K.; Park, T. S.; Yoon, J. S.; Kim, K. H.; Ha, Jong K.

    2012-01-01

    Three Holstein steers in the growing phase, each with a ruminal cannula, were used to test the hypothesis that the synchronization of the hourly rate of carbohydrate and nitrogen (N) released in the rumen would increase the amount of retained nitrogen for growth and thus improve the efficiency of microbial protein synthesis (EMPS). In Experiment 1, in situ degradability coefficients of carbohydrate and N in feeds including Korean rice wine residue (RWR) were determined. In Experiment 2, three total mixed ration (TMR) diets having different rates of carbohydrate and N release in the rumen were formulated using the in situ degradability of the feeds. All diets were made to contain similar contents of crude protein (CP) and neutral detergent fiber (NDF) but varied in their hourly pattern of nutrient release. The synchrony index of the three TMRs was 0.51 (LS), 0.77 (MS) and 0.95 (HS), respectively. The diets were fed at a restricted level (2% of the animal’s body weight) in a 3×3 Latin-square design. Synchronizing the hourly supply of energy and N in the rumen did not significantly alter the digestibility of dry matter, organic matter, crude protein, NDF or acid detergent fiber (ADF) (p>0.05). The ruminal NH3-N content of the LS group at three hours after feeding was significantly higher (p<0.05) than that of the other groups; however, the mean values of ruminal NH3-N, pH and VFA concentration among the three groups were not significantly different (p>0.05). In addition, the purine derivative (PD) excretion in urine and microbial-N production (MN) among the three groups were not significantly different (p>0.05). In conclusion, synchronizing dietary energy and N supply to the rumen did not have a major effect on nutrient digestion or microbial protein synthesis (MPS) in Holstein steers. PMID:25049518

  5. Screening Carbohydrate Libraries for Protein Interactions Using the Direct ESI-MS Assay. Applications to Libraries of Unknown Concentration

    NASA Astrophysics Data System (ADS)

    Kitova, Elena N.; El-Hawiet, Amr; Klassen, John S.

    2014-08-01

    A semiquantitative electrospray ionization mass spectrometry (ESI-MS) binding assay suitable for analyzing mixtures of oligosaccharides, at unknown concentrations, for interactions with target proteins is described. The assay relies on the differences in the ratio of the relative abundances of the ligand-bound and free protein ions measured by ESI-MS at two or more initial protein concentrations to distinguish low affinity (≤103 M-1) ligands from moderate and high affinity (>105 M-1) ligands present in the library and to rank their affinities. Control experiments were performed on solutions of a single chain antibody and a mixture of synthetic oligosaccharides, with known affinities, in the absence and presence of a 40-component carbohydrate library to demonstrate the implementation and reliability of the assay. The application of the assay for screening natural libraries of carbohydrates against proteins is also demonstrated using mixtures of human milk oligosaccharides, isolated from breast milk, and fragments of a bacterial toxin and human galectin 3.

  6. The role of the glucose-sensing transcription factor carbohydrate-responsive element-binding protein pathway in termite queen fertility

    PubMed Central

    Sillam-Dussès, David; Hanus, Robert; Poulsen, Michael; Roy, Virginie; Favier, Maryline

    2016-01-01

    Termites are among the few animals that themselves can digest the most abundant organic polymer, cellulose, into glucose. In mice and Drosophila, glucose can activate genes via the transcription factor carbohydrate-responsive element-binding protein (ChREBP) to induce glucose utilization and de novo lipogenesis. Here, we identify a termite orthologue of ChREBP and its downstream lipogenic targets, including acetyl-CoA carboxylase and fatty acid synthase. We show that all of these genes, including ChREBP, are upregulated in mature queens compared with kings, sterile workers and soldiers in eight different termite species. ChREBP is expressed in several tissues, including ovaries and fat bodies, and increases in expression in totipotent workers during their differentiation into neotenic mature queens. We further show that ChREBP is regulated by a carbohydrate diet in termite queens. Suppression of the lipogenic pathway by a pharmacological agent in queens elicits the same behavioural alterations in sterile workers as observed in queenless colonies, supporting that the ChREBP pathway partakes in the biosynthesis of semiochemicals that convey the signal of the presence of a fertile queen. Our results highlight ChREBP as a likely key factor for the regulation and signalling of queen fertility. PMID:27249798

  7. The role of the glucose-sensing transcription factor carbohydrate-responsive element-binding protein pathway in termite queen fertility.

    PubMed

    Sillam-Dussès, David; Hanus, Robert; Poulsen, Michael; Roy, Virginie; Favier, Maryline; Vasseur-Cognet, Mireille

    2016-05-01

    Termites are among the few animals that themselves can digest the most abundant organic polymer, cellulose, into glucose. In mice and Drosophila, glucose can activate genes via the transcription factor carbohydrate-responsive element-binding protein (ChREBP) to induce glucose utilization and de novo lipogenesis. Here, we identify a termite orthologue of ChREBP and its downstream lipogenic targets, including acetyl-CoA carboxylase and fatty acid synthase. We show that all of these genes, including ChREBP, are upregulated in mature queens compared with kings, sterile workers and soldiers in eight different termite species. ChREBP is expressed in several tissues, including ovaries and fat bodies, and increases in expression in totipotent workers during their differentiation into neotenic mature queens. We further show that ChREBP is regulated by a carbohydrate diet in termite queens. Suppression of the lipogenic pathway by a pharmacological agent in queens elicits the same behavioural alterations in sterile workers as observed in queenless colonies, supporting that the ChREBP pathway partakes in the biosynthesis of semiochemicals that convey the signal of the presence of a fertile queen. Our results highlight ChREBP as a likely key factor for the regulation and signalling of queen fertility. PMID:27249798

  8. Treatment with Ginger Ameliorates Fructose-Induced Fatty Liver and Hypertriglyceridemia in Rats: Modulation of the Hepatic Carbohydrate Response Element-Binding Protein-Mediated Pathway

    PubMed Central

    Gao, Huanqing; Guan, Tao; Li, Chunli; Zuo, Guowei; Yamahara, Johji; Wang, Jianwei; Li, Yuhao

    2012-01-01

    Ginger has been demonstrated to improve lipid derangements. However, its underlying triglyceride-lowering mechanisms remain unclear. Fructose overconsumption is associated with increase in hepatic de novo lipogenesis, thereby resulting in lipid derangements. Here we found that coadministration of the alcoholic extract of ginger (50 mg/kg/day, oral gavage, once daily) over 5 weeks reversed liquid fructose-induced increase in plasma triglyceride and glucose concentrations and hepatic triglyceride content in rats. Plasma nonesterified fatty acid concentration was also decreased. Attenuation of the increased vacuolization and Oil Red O staining area was evident on histological examination of liver in ginger-treated rats. However, ginger treatment did not affect chow intake and body weight. Further, ginger treatment suppressed fructose-stimulated overexpression of carbohydrate response element-binding protein (ChREBP) at the mRNA and protein levels in the liver. Consequently, hepatic expression of the ChREBP-targeted lipogenic genes responsible for fatty acid biosynthesis was also downregulated. In contrast, expression of neither peroxisome proliferator-activated receptor- (PPAR-) alpha and its downstream genes, nor PPAR-gamma and sterol regulatory element-binding protein 1c was altered. Thus the present findings suggest that in rats, amelioration of fructose-induced fatty liver and hypertriglyceridemia by ginger treatment involves modulation of the hepatic ChREBP-mediated pathway. PMID:23193424

  9. Proteins and Carbohydrates from Red Seaweeds: Evidence for Beneficial Effects on Gut Function and Microbiota.

    PubMed

    Cian, Raúl E; Drago, Silvina R; de Medina, Fermín Sánchez; Martínez-Augustin, Olga

    2015-08-01

    Based on their composition, marine algae, and namely red seaweeds, are good potential functional foods. Intestinal mucosal barrier function refers to the capacity of the intestine to provide adequate containment of luminal microorganisms and molecules. Here, we will first outline the component of seaweeds and will summarize the effects of these on the regulation of mucosal barrier function. Special attention will be paid to unique components of red seaweeds: proteins and derived peptides (e.g., phycobiliproteins, glycoproteins that contain "cellulose binding domains", phycolectins and the related mycosporine-like amino acids) together with polysaccharides (e.g., floridean starch and sulfated galactans, such as carrageenans, agarans and "dl-hybrid") and minerals. These compounds have been shown to exert prebiotic effects, to regulate intestinal epithelial cell, macrophage and lymphocyte proliferation and differentiation and to modulate the immune response. Molecular mechanisms of action of peptides and polysaccharides are starting to be elucidated, and evidence indicating the involvement of epidermal growth factor receptor (EGFR), insulin-like growth factor receptor (IGFR), Toll-like receptors (TLR) and signal transduction pathways mediated by protein kinase B (PKB or AKT), nuclear factor-κB (NF-κB) and mitogen activated protein kinases (MAPK) will also be summarized. The need for further research is clear, but in vivo experiments point to an overall antiinflammatory effect of these algae, indicating that they can reinforce membrane barrier function. PMID:26308006

  10. Proteins and Carbohydrates from Red Seaweeds: Evidence for Beneficial Effects on Gut Function and Microbiota

    PubMed Central

    Cian, Raúl E.; Drago, Silvina R.; Sánchez de Medina, Fermín; Martínez-Augustin, Olga

    2015-01-01

    Based on their composition, marine algae, and namely red seaweeds, are good potential functional foods. Intestinal mucosal barrier function refers to the capacity of the intestine to provide adequate containment of luminal microorganisms and molecules. Here, we will first outline the component of seaweeds and will summarize the effects of these on the regulation of mucosal barrier function. Special attention will be paid to unique components of red seaweeds: proteins and derived peptides (e.g., phycobiliproteins, glycoproteins that contain “cellulose binding domains”, phycolectins and the related mycosporine-like amino acids) together with polysaccharides (e.g., floridean starch and sulfated galactans, such as carrageenans, agarans and “dl-hybrid”) and minerals. These compounds have been shown to exert prebiotic effects, to regulate intestinal epithelial cell, macrophage and lymphocyte proliferation and differentiation and to modulate the immune response. Molecular mechanisms of action of peptides and polysaccharides are starting to be elucidated, and evidence indicating the involvement of epidermal growth factor receptor (EGFR), insulin-like growth factor receptor (IGFR), Toll-like receptors (TLR) and signal transduction pathways mediated by protein kinase B (PKB or AKT), nuclear factor-κB (NF-κB) and mitogen activated protein kinases (MAPK) will also be summarized. The need for further research is clear, but in vivo experiments point to an overall antiinflammatory effect of these algae, indicating that they can reinforce membrane barrier function. PMID:26308006

  11. Effects of protein level, methionine supplementation and carbohydrate type of the diet on liver lipid and plasma free threonine contents in the lactating rat.

    PubMed

    Leclerc, J; Chanussot, B; Miller, M L; Poisson, J P; Belleville, J

    1989-01-01

    Eight groups of 13-15 female rats were fed purified diets after littering. Four groups received a low protein (8% casein) diet (groups 8) and the others, a normal protein (20% casein) diet (groups 20). Carbohydrates were supplied either as starch (groups S) or as starch plus 40% fructose (groups F). Half the animals received a 0.4% methionine supplementation (groups M). Four or five dams per group were sacrificed on days 2, 7 and 14 after littering. The diet intake was increased by methionine supplementation, substitution of starch for fructose and increased protein content, mainly during the second week of lactation. This influenced weight variation of the dams and litter growth. On all days, the plasma levels of cholesterol esters, triglycerides and phospholipids were positively correlated with the dietary protein level. On days 7 and 14, the liver neutral lipid content was increased in rats fed the low protein diets supplemented with methionine (groups 8SM and 8FM) and the normal protein diets containing 40% fructose (groups 20F and 20FM). The plasma free threonine content was positively correlated with the protein level in the diet. On day 14, rats fed a low protein diet had a threonine deficiency, except those in groups 8S and 8F. The plasma free threonine content of these rats was not reduced, possibly due to an impaired utilization of this amino acid. The liver lipidosis observed during lactation, in contrast to that observed during growth with a low protein diet, was not due to a threonine deficiency. PMID:2511852

  12. AMP-activated protein kinase and ATP-citrate lyase are two distinct molecular targets for ETC-1002, a novel small molecule regulator of lipid and carbohydrate metabolism.

    PubMed

    Pinkosky, Stephen L; Filippov, Sergey; Srivastava, Rai Ajit K; Hanselman, Jeffrey C; Bradshaw, Cheryl D; Hurley, Timothy R; Cramer, Clay T; Spahr, Mark A; Brant, Ashley F; Houghton, Jacob L; Baker, Chris; Naples, Mark; Adeli, Khosrow; Newton, Roger S

    2013-01-01

    ETC-1002 (8-hydroxy-2,2,14,14-tetramethylpentadecanedioic acid) is a novel investigational drug being developed for the treatment of dyslipidemia and other cardio-metabolic risk factors. The hypolipidemic, anti-atherosclerotic, anti-obesity, and glucose-lowering properties of ETC-1002, characterized in preclinical disease models, are believed to be due to dual inhibition of sterol and fatty acid synthesis and enhanced mitochondrial long-chain fatty acid β-oxidation. However, the molecular mechanism(s) mediating these activities remained undefined. Studies described here show that ETC-1002 free acid activates AMP-activated protein kinase in a Ca(2+)/calmodulin-dependent kinase β-independent and liver kinase β 1-dependent manner, without detectable changes in adenylate energy charge. Furthermore, ETC-1002 is shown to rapidly form a CoA thioester in liver, which directly inhibits ATP-citrate lyase. These distinct molecular mechanisms are complementary in their beneficial effects on lipid and carbohydrate metabolism in vitro and in vivo. Consistent with these mechanisms, ETC-1002 treatment reduced circulating proatherogenic lipoproteins, hepatic lipids, and body weight in a hamster model of hyperlipidemia, and it reduced body weight and improved glycemic control in a mouse model of diet-induced obesity. ETC-1002 offers promise as a novel therapeutic approach to improve multiple risk factors associated with metabolic syndrome and benefit patients with cardiovascular disease. PMID:23118444

  13. Carbohydrate Dehydration Demonstrations.

    ERIC Educational Resources Information Center

    Dolson, David A.; And Others

    1995-01-01

    Discusses the impact of various factors on the "charring reaction" of a carbohydrate with concentrated sulfuric acid including the type of sugar, the degree of fineness of the sugar crystals, and the amount of water added. (JRH)

  14. A functional glycoprotein competitive recognition and signal amplification strategy for carbohydrate-protein interaction profiling and cell surface carbohydrate expression evaluation

    NASA Astrophysics Data System (ADS)

    Wang, Yangzhong; Chen, Zhuhai; Liu, Yang; Li, Jinghong

    2013-07-01

    A simple and sensitive carbohydrate biosensor has been suggested as a potential tool for accurate analysis of cell surface carbohydrate expression as well as carbohydrate-based therapeutics for a variety of diseases and infections. In this work, a sensitive biosensor for carbohydrate-lectin profiling and in situ cell surface carbohydrate expression was designed by taking advantage of a functional glycoprotein of glucose oxidase acting as both a multivalent recognition unit and a signal amplification probe. Combining the gold nanoparticle catalyzed luminol electrogenerated chemiluminescence and nanocarrier for active biomolecules, the number of cell surface carbohydrate groups could be conveniently read out. The apparent dissociation constant between GOx@Au probes and Con A was detected to be 1.64 nM and was approximately 5 orders of magnitude smaller than that of mannose and Con A, which would arise from the multivalent effect between the probe and Con A. Both glycoproteins and gold nanoparticles contribute to the high affinity between carbohydrates and lectin. The as-proposed biosensor exhibits excellent analytical performance towards the cytosensing of K562 cells with a detection limit of 18 cells, and the mannose moieties on a single K562 cell were determined to be 1.8 × 1010. The biosensor can also act as a useful tool for antibacterial drug screening and mechanism investigation. This strategy integrates the excellent biocompatibility and multivalent recognition of glycoproteins as well as the significant enzymatic catalysis and gold nanoparticle signal amplification, and avoids the cell pretreatment and labelling process. This would contribute to the glycomic analysis and the understanding of complex native glycan-related biological processes.A simple and sensitive carbohydrate biosensor has been suggested as a potential tool for accurate analysis of cell surface carbohydrate expression as well as carbohydrate-based therapeutics for a variety of diseases and

  15. A functional glycoprotein competitive recognition and signal amplification strategy for carbohydrate-protein interaction profiling and cell surface carbohydrate expression evaluation.

    PubMed

    Wang, Yangzhong; Chen, Zhuhai; Liu, Yang; Li, Jinghong

    2013-08-21

    A simple and sensitive carbohydrate biosensor has been suggested as a potential tool for accurate analysis of cell surface carbohydrate expression as well as carbohydrate-based therapeutics for a variety of diseases and infections. In this work, a sensitive biosensor for carbohydrate-lectin profiling and in situ cell surface carbohydrate expression was designed by taking advantage of a functional glycoprotein of glucose oxidase acting as both a multivalent recognition unit and a signal amplification probe. Combining the gold nanoparticle catalyzed luminol electrogenerated chemiluminescence and nanocarrier for active biomolecules, the number of cell surface carbohydrate groups could be conveniently read out. The apparent dissociation constant between GOx@Au probes and Con A was detected to be 1.64 nM and was approximately 5 orders of magnitude smaller than that of mannose and Con A, which would arise from the multivalent effect between the probe and Con A. Both glycoproteins and gold nanoparticles contribute to the high affinity between carbohydrates and lectin. The as-proposed biosensor exhibits excellent analytical performance towards the cytosensing of K562 cells with a detection limit of 18 cells, and the mannose moieties on a single K562 cell were determined to be 1.8 × 10(10). The biosensor can also act as a useful tool for antibacterial drug screening and mechanism investigation. This strategy integrates the excellent biocompatibility and multivalent recognition of glycoproteins as well as the significant enzymatic catalysis and gold nanoparticle signal amplification, and avoids the cell pretreatment and labelling process. This would contribute to the glycomic analysis and the understanding of complex native glycan-related biological processes. PMID:23824149

  16. Production of hybrid diesel fuel precursors from carbohydrates and petrochemicals using formic acid as a reactive solvent.

    PubMed

    Zhou, Xiaoyuan; Rauchfuss, Thomas B

    2013-02-01

    We report the one-pot alkylation of mesitylene with carbohydrate-derived 5-(hydroxymethyl)furfural (HMF) as a step toward diesel-range liquids. Using FeCl(3) as a catalyst, HMF is shown to alkylate toluene, xylene, and mesitylene in high yields in CH(2)Cl(2) and MeNO(2) solvents. Efforts to extend this reaction to greener or safer solvents showed that most ether-based solvents are unsatisfactory. Acid catalysts (e.g, p-TsOH) also proved to be ineffective. Using formic acid as a reactive solvent, mesitylene could be alkylated to give mesitylmethylfurfural (MMF) starting from fructose with yields up to approximately 70 %. The reaction of fructose with formic acid in the absence of mesitylene gave rise to low yields of the formate ester of HMF, which indicates the stabilizing effect of replacing the hydroxyl substituent with mesityl. The arene also serves as a second phase into which the product is extracted. Even by using formic acid, the mesitylation of less expensive precursors such as glucose and cellulose proceeded only in modest yields (ca. 20 %). These simpler substrates were found to undergo mesitylation by using hydrogen chloride/formic acid via the intermediate chloromethylfurfural. PMID:23281330

  17. Production and applications of carbohydrate-derived sugar acids as generic biobased chemicals.

    PubMed

    Mehtiö, Tuomas; Toivari, Mervi; Wiebe, Marilyn G; Harlin, Ali; Penttilä, Merja; Koivula, Anu

    2016-10-01

    This review considers the chemical and biotechnological synthesis of acids that are obtained by direct oxidation of mono- or oligosaccharide, referred to as sugar acids. It focuses on sugar acids which can be readily derived from plant biomass sources and their current and future applications. The three main classes of sugar acids are aldonic, aldaric and uronic acids. Interest in organic acids derived from sugars has recently increased, as part of the interest to develop biorefineries which produce not only biofuels, but also chemicals to replace those currently derived from petroleum. More than half of the most desirable biologically produced platform chemicals are organic acids. Currently, the only sugar acid with high commercial production is d-gluconic acid. However, other sugar acids such as d-glucaric and meso-galactaric acids are being produced at a lower scale. The sugar acids have application as sequestering agents and binders, corrosion inhibitors, biodegradable chelators for pharmaceuticals and pH regulators. There is also considerable interest in the use of these molecules in the production of synthetic polymers, including polyamides, polyesters and hydrogels. Further development of these sugar acids will lead to higher volume production of the appropriate sugar acids and will help support the next generation of biorefineries. PMID:26177333

  18. Ferulic Acid Alleviates Changes in a Rat Model of Metabolic Syndrome Induced by High-Carbohydrate, High-Fat Diet.

    PubMed

    Senaphan, Ketmanee; Kukongviriyapan, Upa; Sangartit, Weerapon; Pakdeechote, Poungrat; Pannangpetch, Patchareewan; Prachaney, Parichat; Greenwald, Stephen E; Kukongviriyapan, Veerapol

    2015-08-01

    Metabolic syndrome is a cluster of metabolic abnormalities characterized by obesity, insulin resistance, hypertension and dyslipidemia. Ferulic acid (FA) is the major phenolic compound found in rice oil and various fruits and vegetables. In this study, we examined the beneficial effects of FA in minimizing insulin resistance, vascular dysfunction and remodeling in a rat model of high-carbohydrate, high-fat diet-induced metabolic changes, which is regarded as an analogue of metabolic syndrome (MS) in man. Male Sprague-Dawley rats were fed a high carbohydrate, high fat (HCHF) diet and 15% fructose in drinking water for 16 weeks, where control rats were fed with standard chow diet and tap water. FA (30 or 60 mg/kg) was orally administered to the HCHF and control rats during the last six weeks of the study. We observed that FA significantly improved insulin sensitivity and lipid profiles, and reduced elevated blood pressure, compared to untreated controls (p < 0.05). Moreover, FA also improved vascular function and prevented vascular remodeling of mesenteric arteries. The effects of FA in HCHF-induced MS may be realized through suppression of oxidative stress by down-regulation of p47phox, increased nitric oxide (NO) bioavailability with up-regulation of endothelial nitric oxide synthase (eNOS) and suppression of tumor necrosis factor-α (TNF-α). Our results suggest that supplementation of FA may have health benefits by minimizing the cardiovascular complications of MS and alleviating its symptoms. PMID:26247970

  19. Ferulic Acid Alleviates Changes in a Rat Model of Metabolic Syndrome Induced by High-Carbohydrate, High-Fat Diet

    PubMed Central

    Senaphan, Ketmanee; Kukongviriyapan, Upa; Sangartit, Weerapon; Pakdeechote, Poungrat; Pannangpetch, Patchareewan; Prachaney, Parichat; Greenwald, Stephen E.; Kukongviriyapan, Veerapol

    2015-01-01

    Metabolic syndrome is a cluster of metabolic abnormalities characterized by obesity, insulin resistance, hypertension and dyslipidemia. Ferulic acid (FA) is the major phenolic compound found in rice oil and various fruits and vegetables. In this study, we examined the beneficial effects of FA in minimizing insulin resistance, vascular dysfunction and remodeling in a rat model of high-carbohydrate, high-fat diet-induced metabolic changes, which is regarded as an analogue of metabolic syndrome (MS) in man. Male Sprague-Dawley rats were fed a high carbohydrate, high fat (HCHF) diet and 15% fructose in drinking water for 16 weeks, where control rats were fed with standard chow diet and tap water. FA (30 or 60 mg/kg) was orally administered to the HCHF and control rats during the last six weeks of the study. We observed that FA significantly improved insulin sensitivity and lipid profiles, and reduced elevated blood pressure, compared to untreated controls (p < 0.05). Moreover, FA also improved vascular function and prevented vascular remodeling of mesenteric arteries. The effects of FA in HCHF-induced MS may be realized through suppression of oxidative stress by down-regulation of p47phox, increased nitric oxide (NO) bioavailability with up-regulation of endothelial nitric oxide synthase (eNOS) and suppression of tumor necrosis factor-α (TNF-α). Our results suggest that supplementation of FA may have health benefits by minimizing the cardiovascular complications of MS and alleviating its symptoms. PMID:26247970

  20. Proteomics Profiling Reveals Carbohydrate Metabolic Enzymes and 14-3-3 Proteins Play Important Roles for Starch Accumulation during Cassava Root Tuberization.

    PubMed

    Wang, Xuchu; Chang, Lili; Tong, Zheng; Wang, Dongyang; Yin, Qi; Wang, Dan; Jin, Xiang; Yang, Qian; Wang, Liming; Sun, Yong; Huang, Qixing; Guo, Anping; Peng, Ming

    2016-01-01

    Cassava is one of the most important root crops as a reliable source of food and carbohydrates. Carbohydrate metabolism and starch accumulation in cassava storage root is a cascade process that includes large amounts of proteins and cofactors. Here, comparative proteomics were conducted in cassava root at nine developmental stages. A total of 154 identified proteins were found to be differentially expressed during starch accumulation and root tuberization. Many enzymes involved in starch and sucrose metabolism were significantly up-regulated, and functional classification of the differentially expressed proteins demonstrated that the majority were binding-related enzymes. Many proteins were took part in carbohydrate metabolism to produce energy. Among them, three 14-3-3 isoforms were induced to be clearly phosphorylated during storage root enlargement. Overexpression of a cassava 14-3-3 gene in Arabidopsis thaliana confirmed that the older leaves of these transgenic plants contained higher sugar and starch contents than the wild-type leaves. The 14-3-3 proteins and their binding enzymes may play important roles in carbohydrate metabolism and starch accumulation during cassava root tuberization. These results not only deepened our understanding of the tuberous root proteome, but also uncovered new insights into carbohydrate metabolism and starch accumulation during cassava root enlargement. PMID:26791570

  1. Proteomics Profiling Reveals Carbohydrate Metabolic Enzymes and 14-3-3 Proteins Play Important Roles for Starch Accumulation during Cassava Root Tuberization

    PubMed Central

    Wang, Xuchu; Chang, Lili; Tong, Zheng; Wang, Dongyang; Yin, Qi; Wang, Dan; Jin, Xiang; Yang, Qian; Wang, Liming; Sun, Yong; Huang, Qixing; Guo, Anping; Peng, Ming

    2016-01-01

    Cassava is one of the most important root crops as a reliable source of food and carbohydrates. Carbohydrate metabolism and starch accumulation in cassava storage root is a cascade process that includes large amounts of proteins and cofactors. Here, comparative proteomics were conducted in cassava root at nine developmental stages. A total of 154 identified proteins were found to be differentially expressed during starch accumulation and root tuberization. Many enzymes involved in starch and sucrose metabolism were significantly up-regulated, and functional classification of the differentially expressed proteins demonstrated that the majority were binding-related enzymes. Many proteins were took part in carbohydrate metabolism to produce energy. Among them, three 14-3-3 isoforms were induced to be clearly phosphorylated during storage root enlargement. Overexpression of a cassava 14-3-3 gene in Arabidopsis thaliana confirmed that the older leaves of these transgenic plants contained higher sugar and starch contents than the wild-type leaves. The 14-3-3 proteins and their binding enzymes may play important roles in carbohydrate metabolism and starch accumulation during cassava root tuberization. These results not only deepened our understanding of the tuberous root proteome, but also uncovered new insights into carbohydrate metabolism and starch accumulation during cassava root enlargement. PMID:26791570

  2. Towards a synthesis of frameworks in nutritional ecology: interacting effects of protein, carbohydrate and phosphorus on field cricket fitness

    PubMed Central

    Harrison, Sarah J.; Raubenheimer, David; Simpson, Stephen J.; Godin, Jean-Guy J.; Bertram, Susan M.

    2014-01-01

    Phosphorus has been identified as an important determinant of nutrition-related biological variation. The macronutrients protein (P) and carbohydrates (C), both alone and interactively, are known to affect animal performance. No study, however, has investigated the importance of phosphorus relative to dietary protein or carbohydrates, or the interactive effects of phosphorus with these macronutrients, on fitness-related traits in animals. We used a nutritional geometry framework to address this question in adult field crickets (Gryllus veletis). Our results showed that lifespan, weight gain, acoustic mate signalling and egg production were maximized on diets with different P : C ratios, that phosphorus did not positively affect any of these fitness traits, and that males and females had different optimal macronutrient intake ratios for reproductive performance. When given a choice, crickets selected diets that maximized both lifespan and reproductive performance by preferentially eating diets with low P : C ratios, and females selected diets with a higher P : C ratio than males. Conversely, phosphorus intake was not regulated. Overall, our findings highlight the importance of disentangling the influences of different nutrients, and of quantifying both their individual and interactive effects, on animal fitness traits, so as to gain a more integrative understanding of their nutritional ecology. PMID:25143029

  3. Towards a synthesis of frameworks in nutritional ecology: interacting effects of protein, carbohydrate and phosphorus on field cricket fitness.

    PubMed

    Harrison, Sarah J; Raubenheimer, David; Simpson, Stephen J; Godin, Jean-Guy J; Bertram, Susan M

    2014-10-01

    Phosphorus has been identified as an important determinant of nutrition-related biological variation. The macronutrients protein (P) and carbohydrates (C), both alone and interactively, are known to affect animal performance. No study, however, has investigated the importance of phosphorus relative to dietary protein or carbohydrates, or the interactive effects of phosphorus with these macronutrients, on fitness-related traits in animals. We used a nutritional geometry framework to address this question in adult field crickets (Gryllus veletis). Our results showed that lifespan, weight gain, acoustic mate signalling and egg production were maximized on diets with different P : C ratios, that phosphorus did not positively affect any of these fitness traits, and that males and females had different optimal macronutrient intake ratios for reproductive performance. When given a choice, crickets selected diets that maximized both lifespan and reproductive performance by preferentially eating diets with low P : C ratios, and females selected diets with a higher P : C ratio than males. Conversely, phosphorus intake was not regulated. Overall, our findings highlight the importance of disentangling the influences of different nutrients, and of quantifying both their individual and interactive effects, on animal fitness traits, so as to gain a more integrative understanding of their nutritional ecology. PMID:25143029

  4. Human Acid β-Glucosidase Inhibition by Carbohydrate Derived Iminosugars: Towards New Pharmacological Chaperones for Gaucher Disease.

    PubMed

    Parmeggiani, Camilla; Catarzi, Serena; Matassini, Camilla; D'Adamio, Giampiero; Morrone, Amelia; Goti, Andrea; Paoli, Paolo; Cardona, Francesca

    2015-09-21

    A collection of carbohydrate-derived iminosugars belonging to three structurally diversified sub-classes (polyhydroxylated pyrrolidines, piperidines, and pyrrolizidines) was evaluated for inhibition of human acid β-glucosidase (glucocerebrosidase, GCase), the deficient enzyme in Gaucher disease. The synthesis of several new pyrrolidine analogues substituted at the nitrogen or α-carbon atom with alkyl chains of different lengths suggested an interpretation of the inhibition data and led to the discovery of two new GCase inhibitors at sub-micromolar concentration. In the piperidine iminosugar series, two N-alkylated derivatives were found to rescue the residual GCase activity in N370S/RecNcil mutated human fibroblasts (among which one up to 1.5-fold). This study provides the starting point for the identification of new compounds in the treatment of Gaucher disease. PMID:26376302

  5. Investigation of carbohydrate and protein metabolism in the digestive organs of the rabbit under the combined influence of vibration, acceleration and irradiation

    NASA Technical Reports Server (NTRS)

    Yuy, R. I.

    1975-01-01

    During spaceflight, the organism is subjected to the influence of various extremal factors such as acceleration, vibration, irradiation, etc. The study of the influence of these factors on metabolism, especially carbohydrate and protein metabolism, in young rabbits is of great significance in simulation experiments. Dynamic factors and irradiation, depending on dose and duration, lead to reduced RNA and protein metabolism.

  6. Expression of the carbohydrate response element binding protein gene and related genes involved in hepatic lipogenesis during post-hatch development of broiler chickens

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Carbohydrate response element binding protein (ChREBP) and sterol regulatory element binding protein-1c (SREBP-1c) are important regulators of glucose metabolism and lipid synthesis in mammals. In response to glucose (ChREBP) and insulin (SREBP-1c), these two transcription factors regulate the expre...

  7. Molecular cloning and expression of the carbohydrate response element binding protein gene and related genes involved in hepatic lipogenesis during post-hatch development of broiler chickens

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Carbohydrate response element binding protein (ChREBP) and sterol regulatory element binding protein-1c (SREBP-1c) are known to be key regulators of glucose metabolism and lipid synthesis in mammals. Responding to changes in the level of glucose (ChREBP) and insulin (SREBP-1c), these two transcripti...

  8. Effects of carbohydrate, branched-chain amino acids, and arginine in recovery period on the subsequent performance in wrestlers

    PubMed Central

    2011-01-01

    Many athletes need to participate in multiple events in a single day. The efficient post-exercise glycogen recovery may be critical for the performance in subsequent exercise. This study examined whether post-exercise carbohydrate supplementation could restore the performance in the subsequent simulated wrestling match. The effect of branched-chain amino acids and arginine on glucose disposal and performance was also investigated. Nine well-trained male wrestlers participated in 3 trials in a random order. Each trial contained 3 matches with a 1-hr rest between match 1 and 2, and a 2-hr rest between match 2 and 3. Each match contained 3 exercise periods interspersed with 1-min rests. The subjects alternated 10-s all-out sprints and 20-s rests in each exercise period. At the end of match 2, 3 different supplementations were consumed: 1.2 g/kg glucose (CHO trial), 1 g/kg glucose + 0.1 g/kg Arg + 0.1 g/kg BCAA (CHO+AA trial), or water (placebo trial). The peak and average power in the 3 matches was similar in the 3 trials. After the supplementation, CHO and CHO+AA trial showed significantly higher glucose and insulin, and lower glycerol and non-esterified fatty acid concentrations than the placebo trial. There was no significant difference in these biochemical parameters between the CHO and CHO+AA trials. Supplementation of carbohydrate with or without BCAA and arginine during the post-match period had no effect on the performance in the following simulated match in wrestlers. In addition, BCAA and arginine did not provide additional insulinemic effect. PMID:22107883

  9. Catalytic air oxidation of biomass-derived carbohydrates to formic acid.

    PubMed

    Li, Jiang; Ding, Dao-Jun; Deng, Li; Guo, Qing-Xiang; Fu, Yao

    2012-07-01

    An efficient catalytic system for biomass oxidation to form formic acid was developed. The conversion of glucose to formic acid can reach up to 52% yield within 3 h when catalyzed by 5 mol% of H(5)PV(2)Mo(10)O(40) at only 373 K using air as the oxidant. Furthermore, the heteropolyacid can be used as a bifunctional catalyst in the conversion of cellulose to formic acid (yield=35%) with air as the oxidant. PMID:22499553

  10. Simultaneous analysis of carbohydrates and organic acids by HPLC-DAD-RI for monitoring goat's milk yogurts fermentation.

    PubMed

    da Costa, Marion Pereira; Frasao, Beatriz da Silva; Lima, Bruno Reis Carneiro da Costa; Rodrigues, Bruna Leal; Conte Junior, Carlos Adam

    2016-05-15

    During yogurt manufacture, the lactose fermentation and organic acid production can be used to monitor the fermentation process by starter cultures and probiotic bacteria. In the present work, a simple, sensitive and reproducible high-performance liquid chromatography with dual detectors, diode array detector and refractive index was validated by simultaneous analysis of carbohydrates and organic acids in goat milk yogurts. In addition, pH and bacterial analysis were performed. Separation of all the compounds was performed on an Aminex HPX-87H column (300×7.8 mm, 9 µm) utilizing a 3 mmol L(-1) sulfuric acid aqueous mobile phase under isocratic conditions. Lactose, glucose, galactose, citric, lactic and formic acids were used to evaluate the following performance parameters: selectivity, linearity, precision, limit of detection (LOD), limit of quantification (LOQ), decision limits (CCα), detection capabilities (CCβ), recovery and robustness. For the method application a six goat milk yogurts were elaborated: natural, probiotic, prebiotic, symbiotic, cupuassu fruit pulp, and probiotic with cupuassu fruit pulp. The validated method presented an excellent selectivity with no significant matrix effect, and a broad linear study range with coefficients of determination higher than 0.995. The relative standard deviation was lower than 10% under repeatability and within-laboratory reproducibility conditions for the studied analytes. The LOD of the method was defined from 0.001 to 0.003 µg g(-1), and the LOQ from 0.003 to 0.013 µg g(-1). The CCα was ranged from 0.032 to 0.943 µg g(-1), and the CCβ from 0.053 to 1.604 µg g(-1). The obtained recovery values were from 78% to 119%. In addition, the method exhibited an appropriate robustness for all parameter evaluated. Base in our data, it was concluded that the performance parameters demonstrated total method adequacy for the detection and quantification of carbohydrates and organic acids in goat milk yogurts. The

  11. Mutational Insights into the Roles of Amino Acid Residues in Ligand Binding for Two Closely Related Family 16 Carbohydrate Binding Modules

    SciTech Connect

    Su, Xiaoyun; Agarwal, Vinayak; Dodd, Dylan; Bae, Brian; Mackie, Roderick I.; Nair, Satish K.; Cann, Isaac K.O.

    2010-11-22

    Carbohydrate binding modules (CBMs) are specialized proteins that bind to polysaccharides and oligosaccharides. Caldanaerobius polysaccharolyticus Man5ACBM16-1/CBM16-2 bind to glucose-, mannose-, and glucose/mannose-configured substrates. The crystal structures of the two proteins represent the only examples in CBM family 16, and studies that evaluate the roles of amino acid residues in ligand binding in this family are lacking. In this study, we probed the roles of amino acids (selected based on CBM16-1/ligand co-crystal structures) on substrate binding. Two tryptophan (Trp-20 and Trp-125) and two glutamine (Gln-81 and Gln-93) residues are shown to be critical in ligand binding. Additionally, several polar residues that flank the critical residues also contribute to ligand binding. The CBM16-1 Q121E mutation increased affinity for all substrates tested, whereas the Q21G and N97R mutants exhibited decreased substrate affinity. We solved CBM/substrate co-crystal structures to elucidate the molecular basis of the increased substrate binding by CBM16-1 Q121E. The Gln-121, Gln-21, and Asn-97 residues can be manipulated to fine-tune ligand binding by the Man5A CBMs. Surprisingly, none of the eight residues investigated was absolutely conserved in CBM family 16. Thus, the critical residues in the Man5A CBMs are either not essential for substrate binding in the other members of this family or the two CBMs are evolutionarily distinct from the members available in the current protein database. Man5A is dependent on its CBMs for robust activity, and insights from this study should serve to enhance our understanding of the interdependence of its catalytic and substrate binding modules.

  12. Adaptive changes in amino acid metabolism permit normal longevity in mice consuming a low-carbohydrate ketogenic diet.

    PubMed

    Douris, Nicholas; Melman, Tamar; Pecherer, Jordan M; Pissios, Pavlos; Flier, Jeffrey S; Cantley, Lewis C; Locasale, Jason W; Maratos-Flier, Eleftheria

    2015-10-01

    Ingestion of very low-carbohydrate ketogenic diets (KD) is associated with weight loss, lowering of glucose and insulin levels and improved systemic insulin sensitivity. However, the beneficial effects of long-term feeding have been the subject of debate. We therefore studied the effects of lifelong consumption of this diet in mice. Complete metabolic analyses were performed after 8 and 80weeks on the diet. In addition we performed a serum metabolomic analysis and examined hepatic gene expression. Lifelong consumption of KD had no effect on morbidity or mortality (KD vs. Chow, 676 vs. 630days) despite hepatic steatosis and inflammation in KD mice. The KD fed mice lost weight initially as previously reported (Kennnedy et al., 2007) and remained lighter and had less fat mass; KD consuming mice had higher levels of energy expenditure, improved glucose homeostasis and higher circulating levels of β-hydroxybutyrate and triglycerides than chow-fed controls. Hepatic expression of the critical metabolic regulators including fibroblast growth factor 21 were also higher in KD-fed mice while expression levels of lipogenic enzymes such as stearoyl-CoA desaturase-1 was reduced. Metabolomic analysis revealed compensatory changes in amino acid metabolism, primarily involving down-regulation of catabolic processes, demonstrating that mice eating KD can shift amino acid metabolism to conserve amino acid levels. Long-term KD feeding caused profound and persistent metabolic changes, the majority of which are seen as health promoting, and had no adverse effects on survival in mice. PMID:26170063

  13. Glucose intolerance induced by a high-fat/low-carbohydrate diet in rats effects of nonesterified fatty acids.

    PubMed

    Wang, Yuan; Miura, Yoshikazu; Kaneko, Takashi; Li, Jue; Qin, Li-Qiang; Wang, Pei-Yu; Matsui, Hisao; Sato, Akio

    2002-04-01

    We examined the time course of effects of a high-fat/low-carbohydrate (HF/LC) diet on the impairment of glucose tolerance in rats, clarified whether insulin secretion and sensitivity were impaired by the HF/LC diet, and investigated the relationship between the increased nonesterified fatty acids (NEFA) after HF/LC diet feeding and insulin secretion and sensitivity. We found that glucose tolerance and the postglucose-loading insulin secretion were impaired after 3 and 7 d on the HF/LC diet. The glucose intolerance was accompanied by a rise in the fasting plasma NEFA level. When stimulated with 15 mmol/L of glucose, the insulin secretion was impaired in pancreatic islets from rats fed the HF/LC diet. Rats fed the HF/LC diet showed insulin resistance in vivo. The glucose-stimulated insulin secretion was inhibited in the islets following 24-h culture with palmitic acid. The 24-h infusion of palmitic acid decreased whole-body insulin sensitivity. In summary, at least 3 d on a HF/LC diet is needed to induce glucose intolerance in rats, and the impairment may be induced by decreased insulin secretion and sensitivity, which is related to the increase in the plasma NEFA level. PMID:12108518

  14. Solving the phase problem for carbohydrate-binding proteins using selenium derivatives of their ligands: a case study involving the bacterial F17-G adhesin.

    PubMed

    Buts, Lieven; Loris, Remy; De Genst, Erwin; Oscarson, Stefan; Lahmann, Martina; Messens, Joris; Brosens, Elke; Wyns, Lode; De Greve, Henri; Bouckaert, Julie

    2003-06-01

    The Escherichia coli adhesin F17-G is a carbohydrate-binding protein that allows the bacterium to attach to the intestinal epithelium of young ruminants. The structure of the 17 kDa lectin domain of F17-G was determined using the anomalous dispersion signal of a selenium-containing analogue of the monosaccharide ligand N-acetyl-d-glucosamine in which the anomeric oxygen was replaced by an Se atom. A three-wavelength MAD data set yielded good experimental phases to 2.6 A resolution. The structure was refined to 1.75 A resolution and was used to solve the structures of the ligand-free protein and the F17-G-N-acetyl-d-glucosamine complex. This selenium-carbohydrate phasing method could be of general use for determining the structures of carbohydrate-binding proteins. PMID:12777763

  15. In Situ Expression of Acidic and Thermophilic Carbohydrate Active Enzymes by Filamentous Fungi (JGI Seventh Annual User Meeting 2012: Genomics of Energy and Environment)

    ScienceCinema

    Mosier, Annika [Stanford University

    2013-01-22

    Annika Mosier, graduate student from Stanford University presents a talk titled "In Situ Expression of Acidic and Thermophilic Carbohydrate Active Enzymes by Filamentous Fungi" at the JGI User 7th Annual Genomics of Energy & Environment Meeting on March 22, 2012 in Walnut Creek, Calif

  16. In Situ Expression of Acidic and Thermophilic Carbohydrate Active Enzymes by Filamentous Fungi (JGI Seventh Annual User Meeting 2012: Genomics of Energy and Environment)

    SciTech Connect

    Mosier, Annika

    2012-03-22

    Annika Mosier, graduate student from Stanford University presents a talk titled "In Situ Expression of Acidic and Thermophilic Carbohydrate Active Enzymes by Filamentous Fungi" at the JGI User 7th Annual Genomics of Energy & Environment Meeting on March 22, 2012 in Walnut Creek, Calif

  17. Biochemical effects of the hypoglycaemic compound pent-4-enoic acid and related non-hypoglycaemic fatty acids. Carbohydrate metabolism

    PubMed Central

    Senior, A. E.; Sherratt, H. S. A.

    1968-01-01

    1. The effects of the hypoglycaemic compound, pent-4-enoic acid, and of four structurally related non-hypoglycaemic compounds (pent-2-enoic acid, pentanoic acid, cyclopropanecarboxylic acid and cyclobutanecarboxylic acid), on glycolysis, glucose oxidation and gluconeogenesis in some rat tissues were determined. 2. None of the compounds at low concentrations inhibited glycolysis by particle-free supernatant fractions from rat liver, skeletal muscle and intestinal mucosa, though there was inhibition by cyclopropanecarboxylic acid and cyclobutanecarboxylic acid at 3mm concentration. 3. Pent-4-enoic inhibited the oxidation of [1-14C]palmitate by rat liver slices, but did not increase the oxidation of [U-14C]glucose. 4. Pent-4-enoic acid (0·01mm) strongly inhibited gluconeogenesis by rat kidney slices from pyruvate or succinate, but none of the other compounds inhibited significantly at low concentrations. 5. There was also some inhibition of gluconeogenesis in kidney slices from rats injected with pent-4-enoic acid. 6. The mechanism of the hypoglycaemic effect of pent-4-enoic acid is discussed; it is suggested that there is an inhibition of fatty acid and ketone-body oxidation and of gluconeogenesis so that glucose reserves become exhausted, leading to hypoglycaemia. 7. The mechanism of the hypoglycaemic action of pent-4-enoic acid appears to be similar to that of hypoglycin. PMID:5701682

  18. Probing protein stability with unnatural amino acids

    SciTech Connect

    Mendel, D.; Ellman, J.A.; Zhiyuh Chang; Veenstra, D.L.; Kollman, P.A.; Schultz, P.G. )

    1992-06-26

    Unnatural amino acid mutagenesis, in combination with molecular modeling and simulation techniques, was used to probe the effect of side chain structure on protein stability. Specific replacements at position 133 in T4 lysozyme included (1) leucine (wt), norvaline, ethylglycine, and alanine to measure the cost of stepwise removal of methyl groups from the hydrophobic core, (2) norvaline and O-methyl serine to evaluate the effects of side chain solvation, and (3) leucine, S,S-2-amino-4-methylhexanoic acid, and S-2-amino-3-cyclopentylpropanoic acid to measure the influence of packing density and side chain conformational entropy on protein stability. All of these factors (hydrophobicity, packing, conformational entropy, and cavity formation) significantly influence protein stability and must be considered when analyzing any structural change to proteins.

  19. Developmentally regulated changes in glucosidase II association with, and carbohydrate content of, the protein tyrosine phosphatase CD45.

    PubMed

    Baldwin, T A; Ostergaard, H L

    2001-10-01

    Glucosidase II (GII) stably interacts with the external domain of CD45 in a carbohydrate-dependent manner. We have found that the association occurs in immature cells, but is significantly reduced in mature T cells. Using mannose-binding protein (MBP), in both FACS analysis and pull-down assays, we find that MBP can specifically recognize cell surface CD45 from immature, but not mature T cells. Analysis of thymocytes reveals increased MBP binding and GII association with CD45 in double-positive thymocytes compared with either double-negative or single-positive thymocytes. As well, the same pool of CD45 recognized by MBP can also associate with GII. Initial analysis of the basis of the interaction between CD45 and MBP suggests MBP binds two different glycoforms of CD45 based on the differential competition with glucose. Finally, inhibition of GII activity in cells that do not normally express MBP ligands results in significant increases in cell surface MBP ligands, including CD45. Taken together, these data suggest that the glucose content of the cell surface CD45 changes as thymocytes undergo maturation to mature T cells, and may be regulated by GII interactions. Such changes in the cell surface carbohydrate on CD45 may affect the development of thymocytes, perhaps via binding of CD45 on thymocytes to lectins on stromal cells. PMID:11564800

  20. Cyclic Sulfamidate Enabled Syntheses of Amino Acids, Peptides, Carbohydrates, and Natural Products

    EPA Science Inventory

    This article reviews the emergence of cyclic sulfamidates as versatile intermediatesfor the synthesis of unnatural amino acids, chalcogen peptides, modified sugars, drugs and drug candidates, and important natural products.

  1. The Cornell Net Carbohydrate and Protein System: Updates to the model and evaluation of version 6.5.

    PubMed

    Van Amburgh, M E; Collao-Saenz, E A; Higgs, R J; Ross, D A; Recktenwald, E B; Raffrenato, E; Chase, L E; Overton, T R; Mills, J K; Foskolos, A

    2015-09-01

    New laboratory and animal sampling methods and data have been generated over the last 10 yr that had the potential to improve the predictions for energy, protein, and AA supply and requirements in the Cornell Net Carbohydrate and Protein System (CNCPS). The objectives of this study were to describe updates to the CNCPS and evaluate model performance against both literature and on-farm data. The changes to the feed library were significant and are reported in a separate manuscript. Degradation rates of protein and carbohydrate fractions were adjusted according to new fractionation schemes, and corresponding changes to equations used to calculate rumen outflows and postrumen digestion were presented. In response to the feed-library changes and an increased supply of essential AA because of updated contents of AA, a combined efficiency of use was adopted in place of separate calculations for maintenance and lactation to better represent the biology of the cow. Four different data sets were developed to evaluate Lys and Met requirements, rumen N balance, and milk yield predictions. In total 99 peer-reviewed studies with 389 treatments and 15 regional farms with 50 different diets were included. The broken-line model with plateau was used to identify the concentration of Lys and Met that maximizes milk protein yield and content. Results suggested concentrations of 7.00 and 2.60% of metabolizable protein (MP) for Lys and Met, respectively, for maximal protein yield and 6.77 and 2.85% of MP for Lys and Met, respectively, for maximal protein content. Updated AA concentrations were numerically higher for Lys and 11 to 18% higher for Met compared with CNCPS v6.0, and this is attributed to the increased content of Met and Lys in feeds that were previously incorrectly analyzed and described. The prediction of postruminal flows of N and milk yield were evaluated using the correlation coefficient from the BLUP (R(2)BLUP) procedure or model predictions (R(2)MDP) and the

  2. Evaluation of endogenous acidic metabolic products associated with carbohydrate metabolism in tumor cells.

    PubMed

    Mazzio, Elizabeth A; Smith, Bruce; Soliman, Karam F A

    2010-06-01

    Tumor cells have a high tolerance for acidic and hypoxic microenvironments, also producing abundant lactic acid through accelerated glycolysis in the presence or absence of O(2). While the accumulation of lactate is thought to be a major contributor to the reduction of pH-circumscribing aggressive tumors, it is not known if other endogenous metabolic products contribute this acidity. Furthermore, anaerobic metabolism in cancer cells bears similarity to homo-fermentative lactic acid bacteria, however very little is known about an alternative pathway that may drive adenosine triphosphate (ATP) production independent of glycolysis. In this study, we quantify over 40 end-products (amines, acids, alcohols, aldehydes, or ketones) produced by malignant neuroblastoma under accelerated glycolysis (+glucose (GLU) supply 1-10 mM) +/- mitochondrial toxin; 1-methyl-4-phenylpyridinium (MPP(+)) to abate aerobic respiration to delineate differences between anaerobic vs. aerobic cell required metabolic pathways. The data show that an acceleration of anaerobic glycolysis prompts an expected reduction in extracellular pH (pH(ex)) from neutral to 6.7 +/- 0.006. Diverse metabolic acids associated with this drop in acidity were quantified by ionic exchange liquid chromatography (LC), showing concomitant rise in lactate (Ctrls 7.5 +/- 0.5 mM; +GLU 12.35 +/- 1.3 mM; +GLU + MPP 18.1 +/- 1.8 mM), acetate (Ctrl 0.84 +/- 0.13 mM: +GLU 1.3 +/- 0.15 mM; +GLU + MPP 2.7 +/- 0.4 mM), fumarate, and a-ketoglutarate (<10 microM) while a range of other metabolic organic acids remained undetected. Amino acids quantified by o-phthalaldehyde precolumn derivatization/electrochemical detection-LC show accumulation of L: -alanine (1.6 +/- .052 mM), L: -glutamate (285 +/- 9.7 microM), L: -asparagine (202 +/- 2.1 microM), and L: -aspartate (84.2 +/- 4.9 microM) produced during routine metabolism, while other amino acids remain undetected. In contrast, the data show no evidence for accumulation of acetaldehyde

  3. Glyco-gold nanoparticle shapes enhance carbohydrate-protein interactions in mammalian cells.

    PubMed

    Sangabathuni, Sivakoti; Vasudeva Murthy, Raghavendra; Chaudhary, Preeti Madhukar; Surve, Manalee; Banerjee, Anirban; Kikkeri, Raghavendra

    2016-07-01

    Advances in shape-dependent nanoparticle (NP) research have prompted a close scrutiny of the behaviour of nanostructures in vitro and in vivo. Data pertaining to cellular uptake and site specific sequestration of different shapes of NPs will undoubtedly assist researchers to design better nano-probes for therapeutic and imaging purposes. Herein, we investigated the shape dependent uptake of glyco-gold nanoparticles (G-AuNPs) in different cancer cell lines. Specifically, we have compared the behaviour of spherical, rod and star AuNPs with mannose and galactose conjugations. In vitro experiments showed that the rod-AuNPs exhibited the highest uptake over that of the star and spherical counterparts. Further, an investigation of the mechanism of the uptake clearly demonstrated clathrin mediated endocytosis of the specific G-AuNPs. These results reveal the benefits of different G-AuNP shapes in carbohydrate-mediated interactions. PMID:27279022

  4. Glyco-gold nanoparticle shapes enhance carbohydrate-protein interactions in mammalian cells

    NASA Astrophysics Data System (ADS)

    Sangabathuni, Sivakoti; Vasudeva Murthy, Raghavendra; Chaudhary, Preeti Madhukar; Surve, Manalee; Banerjee, Anirban; Kikkeri, Raghavendra

    2016-06-01

    Advances in shape-dependent nanoparticle (NP) research have prompted a close scrutiny of the behaviour of nanostructures in vitro and in vivo. Data pertaining to cellular uptake and site specific sequestration of different shapes of NPs will undoubtedly assist researchers to design better nano-probes for therapeutic and imaging purposes. Herein, we investigated the shape dependent uptake of glyco-gold nanoparticles (G-AuNPs) in different cancer cell lines. Specifically, we have compared the behaviour of spherical, rod and star AuNPs with mannose and galactose conjugations. In vitro experiments showed that the rod-AuNPs exhibited the highest uptake over that of the star and spherical counterparts. Further, an investigation of the mechanism of the uptake clearly demonstrated clathrin mediated endocytosis of the specific G-AuNPs. These results reveal the benefits of different G-AuNP shapes in carbohydrate-mediated interactions.Advances in shape-dependent nanoparticle (NP) research have prompted a close scrutiny of the behaviour of nanostructures in vitro and in vivo. Data pertaining to cellular uptake and site specific sequestration of different shapes of NPs will undoubtedly assist researchers to design better nano-probes for therapeutic and imaging purposes. Herein, we investigated the shape dependent uptake of glyco-gold nanoparticles (G-AuNPs) in different cancer cell lines. Specifically, we have compared the behaviour of spherical, rod and star AuNPs with mannose and galactose conjugations. In vitro experiments showed that the rod-AuNPs exhibited the highest uptake over that of the star and spherical counterparts. Further, an investigation of the mechanism of the uptake clearly demonstrated clathrin mediated endocytosis of the specific G-AuNPs. These results reveal the benefits of different G-AuNP shapes in carbohydrate-mediated interactions. Electronic supplementary information (ESI) available. See DOI: 10.1039/c6nr03008d

  5. Arabidopsis G-protein interactome reveals connections to cell wall carbohydrates and morphogenesis

    SciTech Connect

    Klopffleisch, Karsten; Phan, Nguyen; Chen, Jay; Panstruga, Ralph; Uhrig, Joachim; Jones, Alan M

    2011-01-01

    The heterotrimeric G-protein complex is minimally composed of G{alpha}, G{beta}, and G{gamma} subunits. In the classic scenario, the G-protein complex is the nexus in signaling from the plasma membrane, where the heterotrimeric G-protein associates with heptahelical G-protein-coupled receptors (GPCRs), to cytoplasmic target proteins called effectors. Although a number of effectors are known in metazoans and fungi, none of these are predicted to exist in their canonical forms in plants. To identify ab initio plant G-protein effectors and scaffold proteins, we screened a set of proteins from the G-protein complex using two-hybrid complementation in yeast. After deep and exhaustive interrogation, we detected 544 interactions between 434 proteins, of which 68 highly interconnected proteins form the core G-protein interactome. Within this core, over half of the interactions comprising two-thirds of the nodes were retested and validated as genuine in planta. Co-expression analysis in combination with phenotyping of loss-of-function mutations in a set of core interactome genes revealed a novel role for G-proteins in regulating cell wall modification.

  6. Production of levulinic acid, furfural, and gamma valerolactone from C.sub.5 and C.sub.6 carbohydrates in mono- and biphasic systems using gamma-valerolactone as a solvent

    DOEpatents

    Dumesic, James A.; Alonso, David Martin; Gurbuz, Elif I.; Wettstein, Stephanie G.

    2013-03-19

    A method to make levulinic acid (LA), furfural, or gamma-valerolactone (GVL). React cellulose (and/or other C.sub.6 carbohydrates) or xylose (and/or other C.sub.5 carbohydrates) or combinations thereof in a monophasic reaction medium comprising GVL and an acid; or (ii) a biphasic reaction system comprising an organic layer comprising GVL, and a substantially immiscible aqueous layer. At least a portion of the cellulose (and/or other C.sub.6 carbohydrates), if present, is converted to LA and at least a portion of the xylose (and/or other C.sub.5 carbohydrates), if present, is converted into furfural.

  7. Carbohydrate Analysis

    NASA Astrophysics Data System (ADS)

    Bemiller, James N.

    Carbohydrates are important in foods as a major source of energy, to impart crucial textural properties, and as dietary fiber which influences physiological processes. Digestible carbohydrates, which are converted into monosaccharides, which are absorbed, provide metabolic energy. Worldwide, carbohydrates account for more than 70% of the caloric value of the human diet. It is recommended that all persons should limit calories from fat (the other significant source) to not more than 30% and that most of the carbohydrate calories should come from starch. Nondigestible polysaccharides (all those other than starch) comprise the major portion of dietary fiber (Sect. 10.5). Carbohydrates also contribute other attributes, including bulk, body, viscosity, stability to emulsions and foams, water-holding capacity, freeze-thaw stability, browning, flavors, aromas, and a range of desirable textures (from crispness to smooth, soft gels). They also provide satiety. Basic carbohydrate structures, chemistry, and terminology can be found in references (1, 2).

  8. Effect of dietary conjugated linoleic acid isomers on lipid metabolism in hamsters fed high-carbohydrate and high- fat diets

    PubMed Central

    Tarling, Elizabeth J.; Ryan, Kevin J.P.; Bennett, Andrew J.; Salter, Andrew M.

    2008-01-01

    Dietary conjugated linoleic acids (CLA), have been reported to have a number of isomer-dependent effects on lipid metabolism including reduction in adipose tissue deposition, changes in plasma lipoprotein concentrations and hepatic lipid accumulation. The aim of this study was to compare the effect of individual CLA isomers against lipogenic and high “Western” fat background diets. Golden Syrian hamsters were fed a high-carbohydrate rodent chow or chow supplemented with 17.25% fat formulated to represent the type and amount of fatty acids found in a typical “Western” diet (including 0.2% cholesterol). Diets were further supplemented with 0.25% (w/w) rapeseed oil, cis9, trans11 (c9,t11)-CLA or trans10, cis12 (t10,c12)-CLA. Neither isomer had a significant impact on plasma lipid or lipoprotein concentrations. The t10,c12-CLA isomer significantly reduced perirenal adipose tissue depot mass. While adipose tissue acetyl coenzyme A carboxylase and fatty acid synthase mRNA concentrations (as measured by quantitative PCR) were unaffected by CLA, lipoprotein lipase mRNA was specifically reduced by t10,c12-CLA, on both background diets (p<0.001). This was associated with a specific reduction of SREBP1c expression in perirenal adipose tissue (p=0.018). The isomers appear to have divergent effects on liver triacylglycerol content with c9,t11-CLA producing lower concentrations than t10,c12-CLA. We conclude that t10,c12-CLA modestly reduces adipose tissue deposition in the Golden Syrian hamster independently of background diet and this may possibly result from reduced uptake of lipoprotein fatty acids, as a consequence of reduced LPL gene expression. PMID:18983716

  9. Effect of the Ratio of Non-fibrous Carbohydrates to Neutral Detergent Fiber and Protein Structure on Intake, Digestibility, Rumen Fermentation, and Nitrogen Metabolism in Lambs

    PubMed Central

    Ma, T.; Tu, Y.; Zhang, N. F.; Deng, K. D.; Diao, Q. Y.

    2015-01-01

    This study aimed to investigate the effect of the ratio of non-fibrous carbohydrates to neutral detergent fibre (NFC/NDF) and undegraded dietary protein (UDP) on rumen fermentation and nitrogen metabolism in lambs. Four Dorper×thin-tailed Han crossbred lambs, averaging 62.3±1.9 kg of body weight and 10 mo of age, were randomly assigned to four dietary treatments of combinations of two levels of NFC/NDF (1.0 and 1.7) and two levels of UDP (35% and 50% of crude protein [CP]). Duodenal nutrient flows were measured with dual markers of Yb and Co, and microbial N (MN) synthesis was estimated using 15N. High UDP decreased organic matter (OM) intake (p = 0.002) and CP intake (p = 0.005). Ruminal pH (p<0.001), ammonia nitrogen (NH3-N; p = 0.008), and total volatile fatty acids (p<0.001) were affected by dietary NFC/NDF. The ruminal concentration of NH3-N was also affected by UDP (p<0.001). The duodenal flow of total MN (p = 0.007) was greater for lambs fed the high NFC/NDF diet. The amount of metabolisable N increased with increasing dietary NFC:NDF (p = 0.02) or UDP (p = 0.04). In conclusion, the diets with high NFC/NDF (1.7) and UDP (50% of CP) improved metabolisable N supply to lambs. PMID:26323398

  10. A glycoconjugate of Haemophilus influenzae Type b capsular polysaccharide with tetanus toxoid protein: hydrodynamic properties mainly influenced by the carbohydrate

    PubMed Central

    Abdelhameed, Ali Saber; Adams, Gary G.; Morris, Gordon A.; Almutairi, Fahad M.; Duvivier, Pierre; Conrath, Karel; Harding, Stephen E.

    2016-01-01

    Three important physical properties which may affect the performance of glycoconjugate vaccines against serious disease are molar mass (molecular weight), heterogeneity (polydispersity), and conformational flexibility in solution. The dilute solution behaviour of native and activated capsular polyribosylribitol (PRP) polysaccharides extracted from Haemophilus influenzae type b (Hib), and the corresponding glycoconjugate made by conjugating this with the tetanus toxoid (TT) protein have been characterized and compared using a combination of sedimentation equilibrium and sedimentation velocity in the analytical ultracentrifuge with viscometry. The weight average molar mass of the activated material was considerably reduced (Mw ~ 0.24 × 106 g.mol−1) compared to the native (Mw ~ 1.2 × 106 g.mol−1). Conjugation with the TT protein yielded large polydisperse structures (of Mw ~ 7.4 × 106 g.mol−1), but which retained the high degree of flexibility of the native and activated polysaccharide, with frictional ratio, intrinsic viscosity, sedimentation conformation zoning behaviour and persistence length all commensurate with highly flexible coil behaviour and unlike the previously characterised tetanus toxoid protein (slightly extended and hydrodynamically compact structure with an aspect ratio of ~3). This non-protein like behaviour clearly indicates that it is the carbohydrate component which mainly influences the physical behaviour of the glycoconjugate in solution. PMID:26915577

  11. A glycoconjugate of Haemophilus influenzae Type b capsular polysaccharide with tetanus toxoid protein: hydrodynamic properties mainly influenced by the carbohydrate.

    PubMed

    Abdelhameed, Ali Saber; Adams, Gary G; Morris, Gordon A; Almutairi, Fahad M; Duvivier, Pierre; Conrath, Karel; Harding, Stephen E

    2016-01-01

    Three important physical properties which may affect the performance of glycoconjugate vaccines against serious disease are molar mass (molecular weight), heterogeneity (polydispersity), and conformational flexibility in solution. The dilute solution behaviour of native and activated capsular polyribosylribitol (PRP) polysaccharides extracted from Haemophilus influenzae type b (Hib), and the corresponding glycoconjugate made by conjugating this with the tetanus toxoid (TT) protein have been characterized and compared using a combination of sedimentation equilibrium and sedimentation velocity in the analytical ultracentrifuge with viscometry. The weight average molar mass of the activated material was considerably reduced (Mw ~ 0.24 × 10(6) g.mol(-1)) compared to the native (Mw ~ 1.2 × 10(6) g.mol(-1)). Conjugation with the TT protein yielded large polydisperse structures (of Mw ~ 7.4 × 10(6) g.mol(-1)), but which retained the high degree of flexibility of the native and activated polysaccharide, with frictional ratio, intrinsic viscosity, sedimentation conformation zoning behaviour and persistence length all commensurate with highly flexible coil behaviour and unlike the previously characterised tetanus toxoid protein (slightly extended and hydrodynamically compact structure with an aspect ratio of ~3). This non-protein like behaviour clearly indicates that it is the carbohydrate component which mainly influences the physical behaviour of the glycoconjugate in solution. PMID:26915577

  12. The lipopolysaccharide-binding protein participating in hemocyte nodule formation in the silkworm Bombyx mori is a novel member of the C-type lectin superfamily with two different tandem carbohydrate-recognition domains.

    PubMed

    Koizumi, N; Imamura, M; Kadotani, T; Yaoi, K; Iwahana, H; Sato, R

    1999-01-25

    We recently isolated and characterized the lipopolysaccharide (LPS)-binding protein, BmLBP, from the larval hemolymph of the silkworm Bombyx mori. BmLBP is a pattern recognition molecule that recognizes the lipid A portion of LPS and participates in a cellular defense reaction. This paper describes the cDNA cloning of BmLBP. The deduced amino acid sequence of BmLBP revealed that BmLBP is a novel member of the C-type lectin superfamily with a unique structural feature that consists of two different carbohydrate-recognition domains in tandem, a short and a long form. PMID:9989592

  13. Acid Functionalized Mesoporous Ordered Materials for the Production of 5-Hydroxymethyfurfural from Carbohydrates

    NASA Astrophysics Data System (ADS)

    Crisci, Anthony J.

    Solid acid catalysts were designed for the conversion of fructose to 5-hydroxymethylfurfural (HMF). Some of the catalysts incorporate thioether groups to promote the tautomerization of fructose to its furanose form, as well as sulfonic acid groups to catalyze its dehydration. A bifunctional silane, 3-((3-(trimethoxysilyl)propyl)thio)propane-1-sulfonic acid (TESAS), was designed for incorporation into SBA-15-type silica by co-condensation. To achieve mesopore ordering in the functionalized silica, the standard SBA-15 synthetic protocol was modified, resulting in well-formed hexagonal particles. Functional groups incorporated into mesoporous silica by co-condensation are more robust under the reaction conditions than those grafted onto a non-porous silica. In a variation, the thioether group of TESAS was oxidized by H2O 2 to the sulfone during the synthesis of the modified SBA-15. The materials were tested in batch reactors and compared in the selective dehydration of fructose to 5-hydroxymethylfurfural (HMF). Compared to benchmark catalysts, the thioether-containing TESAS-SBA-15 showed the highest activity in the dehydration of aqueous fructose, as well as the highest selectivity towards HMF (71 % at 84 % conversion). In addition, the stability of several supported acid catalysts was evaluated in tubular reactors designed to produce 5-hydroxymethylfurfural (HMF) continuously. The reactors, packed with the solid catalysts, were operated at 403 K for extended periods, up to 180 h. The behaviors of three propylsulfonic acid-functionalized, ordered porous silicas (one inorganic SBA-15-type silica, and two ethane-bridged SBA-15-type organosilicas) were compared with that of a propylsulfonic acid-modified, non-ordered porous silica. The HMF selectivity of the catalysts with ordered pore structures ranged from 60 to 75 %, while the selectivity of the non-ordered catalyst peaked at 20 %. The latter was also the least stable, deactivating with a first-order rate constant of

  14. Detection of non-protein amino acids in the presence of protein amino acids. II.

    NASA Technical Reports Server (NTRS)

    Shapshak, P.; Okaji, M.

    1972-01-01

    Studies conducted with the JEOL 5AH amino acid analyzer are described. This instrument makes possible the programming of the chromatographic process. Data are presented showing the separations of seventeen non-protein amino acids in the presence of eighteen protein amino acids. It is pointed out that distinct separations could be obtained in the case of a number of chemically similar compounds, such as ornithine and lysine, N-amidino alanine and arginine, and iminodiacetic acid and S-carboxymethyl cysteine and aspartic acid.

  15. Adipose tissue transcriptional response of lipid metabolism genes in growing Iberian pigs fed oleic acid v. carbohydrate enriched diets.

    PubMed

    Benítez, R; Núñez, Y; Fernández, A; Isabel, B; Rodríguez, C; Daza, A; López-Bote, C; Silió, L; Óvilo, C

    2016-06-01

    Diet influences animal body and tissue composition due to direct deposition and to the nutrients effects on metabolism. The influence of specific nutrients on the molecular regulation of lipogenesis is not well characterized and is known to be influenced by many factors including timing and physiological status. A trial was performed to study the effects of different dietary energy sources on lipogenic genes transcription in ham adipose tissue of Iberian pigs, at different growth periods and on feeding/fasting situations. A total of 27 Iberian male pigs of 28 kg BW were allocated to two separate groups and fed with different isocaloric feeding regimens: standard diet with carbohydrates as energy source (CH) or diet enriched with high oleic sunflower oil (HO). Ham subcutaneous adipose tissue was sampled by biopsy at growing (44 kg mean BW) and finishing (100 kg mean BW) periods. The first sampling was performed on fasted animals, while the last sampling was performed twice, with animals fasted overnight and 3 h after refeeding. Effects of diet, growth period and feeding/fasting status on gene expression were explored quantifying the expression of a panel of key genes implicated in lipogenesis and lipid metabolism processes. Quantitative PCR revealed several differentially expressed genes according to diet, with similar results at both timings: RXRG, LEP and FABP5 genes were upregulated in HO group while ME1, FASN, ACACA and ELOVL6 were upregulated in CH. The diet effect on ME1 gene expression was conditional on feeding/fasting status, with the higher ME1 gene expression in CH than HO groups, observed only in fasting samples. Results are compatible with a higher de novo endogenous synthesis of fatty acids (FA) in the carbohydrate-supplemented group and a higher FA transport in the oleic acid-supplemented group. Growth period significantly affected the expression of most of the studied genes, with all but PPARG showing higher expression in finishing pigs according to

  16. An amino acid-electrolyte beverage may increase cellular rehydration relative to carbohydrate-electrolyte and flavored water beverages

    PubMed Central

    2014-01-01

    Background In cases of dehydration exceeding a 2% loss of body weight, athletic performance can be significantly compromised. Carbohydrate and/or electrolyte containing beverages have been effective for rehydration and recovery of performance, yet amino acid containing beverages remain unexamined. Therefore, the purpose of this study is to compare the rehydration capabilities of an electrolyte-carbohydrate (EC), electrolyte-branched chain amino acid (EA), and flavored water (FW) beverages. Methods Twenty men (n = 10; 26.7 ± 4.8 years; 174.3 ± 6.4 cm; 74.2 ± 10.9 kg) and women (n = 10; 27.1 ± 4.7 years; 175.3 ± 7.9 cm; 71.0 ± 6.5 kg) participated in this crossover study. For each trial, subjects were dehydrated, provided one of three random beverages, and monitored for the following three hours. Measurements were collected prior to and immediately after dehydration and 4 hours after dehydration (3 hours after rehydration) (AE = −2.5 ± 0.55%; CE = −2.2 ± 0.43%; FW = −2.5 ± 0.62%). Measurements collected at each time point were urine volume, urine specific gravity, drink volume, and fluid retention. Results No significant differences (p > 0.05) existed between beverages for urine volume, drink volume, or fluid retention for any time-point. Treatment x time interactions existed for urine specific gravity (USG) (p < 0.05). Post hoc analysis revealed differences occurred between the FW and EA beverages (p = 0.003) and between the EC and EA beverages (p = 0.007) at 4 hours after rehydration. Wherein, EA USG returned to baseline at 4 hours post-dehydration (mean difference from pre to 4 hours post-dehydration = -0.0002; p > 0.05) while both EC (-0.0067) and FW (-0.0051) continued to produce dilute urine and failed to return to baseline at the same time-point (p < 0.05). Conclusion Because no differences existed for fluid retention, urine or drink volume at any time point, yet USG returned to

  17. Protein and amino Acid supplementation in athletes.

    PubMed

    Armsey, Thomas D; Grime, Todd E

    2002-08-01

    Amino acid supplementation is practiced by numerous individuals with the hope of increasing muscle mass and function by increasing available proteins. Theoretically, this makes a great deal of sense; the scientific facts, however, fail to conclusively prove that ingesting more than the recommended dietary allowance of protein has any effect on otherwise healthy adults. Athletes may be the exception to this rule. This review examines the most current literature pertaining to amino acid supplementation, and reports on the potential benefits and risks of this common practice. PMID:12831703

  18. EFFECT OF SOY PROTEIN AND CARBOHYDRATE RATIO ON THE VISCOELASTIC PROPERTIES OF STYRENE-BUTADIENE COMPOSITES

    Technology Transfer Automated Retrieval System (TEKTRAN)

    When soy products including soy protein isolate, defatted soy flour, soy protein concentrate, and soy spent flakes were incorporated into rubber latex to form composites, they showed substantial reinforcement effects as measured by rheological and mechanical methods. It was observed that different ...

  19. Effect of soy protein and carbohydrate ratio on the viscoelastic properties of styrene-butadiene composites

    Technology Transfer Automated Retrieval System (TEKTRAN)

    When soy products including soy protein isolate (SPI), defatted soy flour, soy protein concentrate, and soy spent flakes (SSF) were incorporated into rubber latex to form composites, they showed substantial reinforcement effects as measured by rheological and mechanical methods. It was observed tha...

  20. Nucleic acids, proteins, and chirality

    NASA Technical Reports Server (NTRS)

    Usher, D. A.; Profy, A. T.; Walstrum, S. A.; Needels, M. C.; Bulack, S. C.; Lo, K. M.

    1984-01-01

    The present investigation is concerned with experimental results related, in one case, to the chirality of nucleotides, and, in another case, to the possibility of a link between the chirality of nucleic acids, and that of peptides. It has been found that aminoacylation of the 'internal' hydroxyl group of a dinucleoside monophosphate can occur stereoselectively. However, this reaction has not yet been made a part of a working peptide synthesis scheme. The formation and cleavage of oligonucleotides is considered. In the event of the formation of a helical complex between the oligonucleotide and the polymer, 1-prime,5-prime-bonds in the oligomer are found to become more resistant towards cleavage. The conditions required for peptide bond formation are examined, taking into account the known structures of RNA and possible mechanisms for prebiotic peptide bond formation. The possibility is considered that the 2-prime,5-prime-internucleotide linkage could have played an important part in the early days of biological peptide synthesis.

  1. Evolutionary analysis of the global landscape of protein domain types and domain architectures associated with family 14 carbohydrate-binding modules.

    PubMed

    Chang, Ti-Cheng; Stergiopoulos, Ioannis

    2015-07-01

    Domain promiscuity is a powerful evolutionary force that promotes functional innovation in proteins, thus increasing proteome and organismal complexity. Carbohydrate-binding modules, in particular, are known to partake in complex modular architectures that play crucial roles in numerous biochemical and molecular processes. However, the extent, functional, and evolutionary significance of promiscuity is shrouded in mystery for most CBM families. Here, we analyzed the global promiscuity of family 14 carbohydrate-binding modules (CBM14s) and show that fusion, fission, and reorganization events with numerous other domain types interplayed incessantly in a lineage-dependent manner to likely facilitate species adaptation and functional innovation in the family. PMID:26067847

  2. Exploring the interactions between bacteriophage-encoded glycan binding proteins and carbohydrates.

    PubMed

    Simpson, David J; Sacher, Jessica C; Szymanski, Christine M

    2015-10-01

    There is an unprecedented interest in glycobiology due to the increasing appreciation of its impact on all aspects of life. Likewise, bacteriophage biology is enjoying a new renaissance as the post-antibiotic era fuels the search for novel ways to control harmful bacteria. Phages have spent the last 3 billion years developing ways of recognizing and manipulating bacterial surface glycans. Therefore, phages comprise a massive reservoir of glycan-binding and -hydrolyzing proteins with the potential to be exploited for glycan analysis, bacterial diagnostics and therapeutics. We discuss phage tail proteins that recognize bacterial surface polysaccharides, endolysins that bind and cleave peptidoglycan, Ig-like proteins that attach to mucin glycans, and phage effector proteins that recognize both bacterial and eukaryotic oligosaccharides. PMID:26275959

  3. Dihydrolipoic acid reduces cytochrome b561 proteins.

    PubMed

    Bérczi, Alajos; Zimányi, László; Asard, Han

    2013-03-01

    Cytochrome b561 (Cyt-b561) proteins constitute a family of trans-membrane proteins that are present in a wide variety of organisms. Two of their characteristic properties are the reducibility by ascorbate (ASC) and the presence of two distinct b-type hemes localized on two opposite sides of the membrane. Here we show that the tonoplast-localized and the putative tumor suppressor Cyt-b561 proteins can be reduced by other reductants than ASC and dithionite. A detailed spectral analysis of the ASC-dependent and dihydrolipoic acid (DHLA)-dependent reduction of these two Cyt-b561 proteins is also presented. Our results are discussed in relation to the known antioxidant capability of DHLA as well as its role in the regeneration of other antioxidant compounds of cells. These results allow us to speculate on new biological functions for the trans-membrane Cyt-b561 proteins. PMID:22526465

  4. Inhibition of carbohydrate-mediated glucagon-like peptide-1 (7-36)amide secretion by circulating non-esterified fatty acids.

    PubMed

    Ranganath, L; Norris, F; Morgan, L; Wright, J; Marks, V

    1999-04-01

    Two studies were performed to assess the entero-insular axis in simple obesity and the possible effect of variations in the level of circulating non-esterified fatty acids (NEFA) on one of the components of the entero-insular axis, glucagon-like peptide-1 [(7-36) amide]. In the first study, we compared the entero-pancreatic hormone response to oral carbohydrate in obese and lean women. Obese subjects demonstrated hyperinsulinaemia and impaired glucose tolerance but this was not associated with an increased secretion of either glucose-dependent insulinotropic polypeptide or glucagon-like peptide-1 (GLP-1). These findings therefore provide no support for the hypothesis that overactivity of the entero-insular axis contributes to the hyperinsulinaemia seen in obesity. Indeed, the plasma GLP-1 response to carbohydrate was markedly attenuated in obese subjects, confirming previous observations. In the second study, in which carbohydrate-stimulated GLP-1 responses were again evaluated in obese and lean women, circulating NEFA levels were modulated using either heparin (to increase serum NEFA) or acipimox (to reduce serum NEFA). Treatment with acipimox resulted in complete suppression of NEFA levels and in a markedly higher GLP-1 response than the response to carbohydrate alone or to carbohydrate plus heparin. We suggest that higher fasting and postprandial NEFA levels in obesity may tonically inhibit nutrient-mediated GLP-1 secretion, and that this results in attenuation of the GLP-1 response to carbohydrate. However, although serum NEFA levels post-acipimox were similarly suppressed in both lean and obese subjects, the GLP-1 response was again significantly lower in obese subjects, suggesting the possibility of an intrinsic defect of GLP-1 secretion in obesity. The reduction of GLP-1 levels in obesity may be important both in relation to its insulinotropic effect and to its postulated role as a satiety factor. PMID:10087239

  5. Effects of dietary levels of carbohydrate, lipid, phosphorus and zinc on the growth, feed conversion and protein efficiency ratio of Nile tilapia ( Oreochromis niloticus)

    NASA Astrophysics Data System (ADS)

    Li, Zhongjie; Lei, Wu; Yang, Yunxia; Ye, Jun

    1993-09-01

    A 54-day feeding experiment was conducted on juvenile Nile tilapia using isonitrogenous, isocaloric semipurified diets. The carbohydrate content in the diet was 9%, 32% and 50%; the corresponding lipid content was 22.2%, 12%, and 4%. The diets were supplemented with 0.85% or 1.5% phosphorus and 40 mg/kg or 100 mg/kg zinc. The experiment was carried out in flow-through aquaria using dechlorinated tap water at 23 26°C. The experiment showed that the increase of the carbohydrate content in the diets resulted in a 43 249% increase in weight gain, a 27 59% decrease in feed conversion ratio, and a 65 121% increase in protein efficiency ratio. In fish fed diets containing 36 50% carbohydrate, an increase in supplemented phosphorus to 1.5% greatly increased the weight gain. On the contrary, a high content of supplemented zinc (100 mg/kg) inhibited growth and increased feed conversion ratio.

  6. Endogenous lectins from cultured cells: nuclear localization of carbohydrate-binding protein 35 in proliferating 3T3 fibroblasts.

    PubMed Central

    Moutsatsos, I K; Wade, M; Schindler, M; Wang, J L

    1987-01-01

    Proliferating 3T3 mouse fibroblasts contain higher levels of the lectin carbohydrate-binding protein 35 (CBP35) than do quiescent cultures of the same cells. An immunofluorescence study was carried out with a rabbit antiserum directed against CBP35 to map the cellular fluorescence distribution in a large population of cells under different growth conditions. This cytometric analysis showed that the lectin is predominantly localized in the nucleus of the proliferating cells. In quiescent 3T3 cultures, the majority of the cells lost their nuclear staining and underwent a general decrease in the overall fluorescence intensity. Stimulation of serum-starved quiescent 3T3 cells by the addition of serum resulted in an increase in the level of CBP35. The percentage of cells showing distinct punctate intranuclear staining reached a maximum at about the same time as the onset of the first S-phase of the cell cycle. All of these results suggest that CBP35 may be a protein whose presence in the nucleus, in discrete punctate distribution, is coordinated with the proliferation state of the cell. Images PMID:3306680

  7. Dietary carbohydrate composition modifies the milk N efficiency in late lactation cows fed low crude protein diets.

    PubMed

    Cantalapiedra-Hijar, G; Peyraud, J L; Lemosquet, S; Molina-Alcaide, E; Boudra, H; Nozière, P; Ortigues-Marty, I

    2014-02-01

    Nitrogen emissions from dairy cows can be readily decreased by lowering the dietary CP concentration. The main objective of this work was to test whether the milk protein yield reduction associated with low N intakes could be partially compensated for by modifying the dietary carbohydrate composition (CHO). The effects of CHO on digestion, milk N efficiency (milk N/N intake; MNE) and animal performance were studied in four Jersey cows fed 100% or 80% of the recommended protein requirements using a 4×4 Latin square design. Four iso-energetic diets were formulated to two different CHO sources (starch diets with starch content of 34.3% and NDF at 32.5%, and fiber diets with starch content of 5.5% and NDF at 49.1%) and two CP levels (Low=12.0% and Normal=16.5%). The apparent digestible organic matter intake (DOMI) and the protein supply (protein digestible in the small intestine; PDIE) were similar between starch and fiber diets. As planned, microbial N flow (MNF) to the duodenum, estimated from the urinary purine derivatives (PD) excretion, was similar between Low and Normal CP diets. However, the MNF and the efficiency of microbial synthesis (g of microbial N/kg apparently DOMI) were higher for starch v. fiber diets. Milk and milk N fractions (CP, true protein, non-protein N (NPN)) yield were higher for starch compared with fiber diets and for Normal v. Low CP diets. Fecal N excretion was similar across dietary treatments. Despite a higher milk N ouput with starch v. fiber diets, the CHO modified neither the urinary N excretion nor the milk urea-N (MUN) concentration. The milk protein yield relative to both N and PDIE intakes was improved with starch compared with fiber diets. Concentrations of β-hydroxybutyrate, urea and Glu increased and those of glucose and Ala decreased in plasma of cows fed starch v. fiber diets. On the other hand, plasma concentration of albumin, urea, insulin and His increased in cows fed Normal compared with Low CP diets. This study showed

  8. Chemical Reporter for Visualizing Metabolic Cross-Talk between Carbohydrate Metabolism and Protein Modification

    PubMed Central

    2015-01-01

    Metabolic chemical reporters have been largely used to study posttranslational modifications. Generally, it was assumed that these reporters entered one biosynthetic pathway, resulting in labeling of one type of modification. However, because they are metabolized by cells before their addition onto proteins, metabolic chemical reporters potentially provide a unique opportunity to read-out on both modifications of interest and cellular metabolism. We report here the development of a metabolic chemical reporter 1-deoxy-N-pentynyl glucosamine (1-deoxy-GlcNAlk). This small-molecule cannot be incorporated into glycans; however, treatment of mammalian cells results in labeling of a variety proteins and enables their visualization and identification. Competition of this labeling with sodium acetate and an acetyltransferase inhibitor suggests that 1-deoxy-GlcNAlk can enter the protein acetylation pathway. These results demonstrate that metabolic chemical reporters have the potential to isolate and potentially discover cross-talk between metabolic pathways in living cells. PMID:25062036

  9. Carbohydrate PEGylation, an approach to improve pharmacological potency

    PubMed Central

    Giorgi, M Eugenia; Agusti, Rosalía

    2014-01-01

    Summary Conjugation with polyethylene glycol (PEG), known as PEGylation, has been widely used to improve the bioavailability of proteins and low molecular weight drugs. The covalent conjugation of PEG to the carbohydrate moiety of a protein has been mainly used to enhance the pharmacokinetic properties of the attached protein while yielding a more defined product. Thus, glycoPEGylation was successfully applied to the introduction of a PEGylated sialic acid to a preexisting or enzymatically linked glycan in a protein. Carbohydrates are now recognized as playing an important role in host–pathogen interactions in protozoal, bacterial and viral infections and are consequently candidates for chemotherapy. The short in vivo half-life of low molecular weight glycans hampered their use but methods for the covalent attachment of PEG have been less exploited. In this review, information on the preparation and application of PEG-carbohydrates, in particular multiarm PEGylation, is presented. PMID:24991298

  10. Conversion of carbohydrate biomass to γ-valerolactone by using water-soluble and reusable iridium complexes in acidic aqueous media.

    PubMed

    Deng, Jin; Wang, Yan; Pan, Tao; Xu, Qing; Guo, Qing-Xiang; Fu, Yao

    2013-07-01

    Mild-mannered manipulation: A catalytic method for the conversion of carbohydrate biomass to γ-valerolactone in acidic aqueous media has been developed. The water-soluble iridium complexes were observed to be extremely catalytically active for providing γ-valerolactone in high yields with high TONs. The homogeneous catalysts can also be recycled and reused by applying a simple phase separation process. PMID:23757330

  11. Pasting and extrusion properties of mixed carbohydrates and whey protein isolate matrices

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Mixed systems of whey protein isolate (WPI) or texturized WPI (tWPI) and different starches may form weak or strong gel pastes or rigid matrices depending on interactions. The paste viscoelasticity of starches from amioca, barley, corn starch, Hylon VII, plantain, and pea starch, mixed with whey pro...

  12. Organizing multivalency in carbohydrate recognition.

    PubMed

    Müller, Christian; Despras, Guillaume; Lindhorst, Thisbe K

    2016-06-01

    The interactions of cell surface carbohydrates as well as of soluble glycoconjugates with their receptor proteins rule fundamental processes in cell biology. One of the supramolecular principles underlying and regulating carbohydrate recognition is multivalency. Many multivalent glycoconjugates have therefore been synthesized to study multivalency effects operative in glycobiology. This review is focused on smaller multivalent structures such as glycoclusters emphasizing carbohydrate-centered and heteromultivalent glycoconjugates. We are discussing primary, secondary and tertiary structural aspects including approaches to organize multivalency. PMID:27146554

  13. The Exchangeability of Amino Acids in Proteins

    PubMed Central

    Yampolsky, Lev Y.; Stoltzfus, Arlin

    2005-01-01

    The comparative analysis of protein sequences depends crucially on measures of amino acid similarity or distance. Many such measures exist, yet it is not known how well these measures reflect the operational exchangeability of amino acids in proteins, since most are derived by methods that confound a variety of effects, including effects of mutation. In pursuit of a pure measure of exchangeability, we present (1) a compilation of data on the effects of 9671 amino acid exchanges engineered and assayed in a set of 12 proteins; (2) a statistical procedure to combine results from diverse assays of exchange effects; (3) a matrix of “experimental exchangeability” values EXij derived from applying this procedure to the compiled data; and (4) a set of three tests designed to evaluate the power of an exchangeability measure to (i) predict the effects of amino acid exchanges in the laboratory, (ii) account for the disease-causing potential of missense mutations in the human population, and (iii) model the probability of fixation of missense mutations in evolution. EX not only captures useful information on exchangeability while remaining free of other effects, but also outperforms all measures tested except for the best-performing alignment scoring matrix, which is comparable in performance. PMID:15944362

  14. Counting carbohydrates

    MedlinePlus

    ... There are 3 major types of carbohydrates: Sugars Starches Fiber Sugars are found naturally in some foods ... syrups, such as those added to canned fruit Starches are found naturally in foods. Your body breaks ...

  15. Carbohydrates on Proteins: Site-Specific Glycosylation Analysis by Mass Spectrometry

    NASA Astrophysics Data System (ADS)

    Zhu, Zhikai; Desaire, Heather

    2015-07-01

    Glycosylation on proteins adds complexity and versatility to these biologically vital macromolecules. To unveil the structure-function relationship of glycoproteins, glycopeptide-centric analysis using mass spectrometry (MS) has become a method of choice because the glycan is preserved on the glycosylation site and site-specific glycosylation profiles of proteins can be readily determined. However, glycopeptide analysis is still challenging given that glycopeptides are usually low in abundance and relatively difficult to detect and the resulting data require expertise to analyze. Viewing the urgent need to address these challenges, emerging methods and techniques are being developed with the goal of analyzing glycopeptides in a sensitive, comprehensive, and high-throughput manner. In this review, we discuss recent advances in glycoprotein and glycopeptide analysis, with topics covering sample preparation, analytical separation, MS and tandem MS techniques, as well as data interpretation and automation.

  16. Surface functionalization of liposomes with proteins and carbohydrates for use in anti-cancer applications

    NASA Astrophysics Data System (ADS)

    Platt, Virginia M.

    Liposomes can be used to exploit the altered biology of cancer thereby increasing delivery of liposome-associated anti-cancer drugs. In this dissertation, I explore methods that utilize the unique cancer expression of the polymeric glycosaminoglycan hyaluronan (HA) and the HA receptor CD44 to target liposomes to tumors, using liposomes functionalized with proteins or oligosaccharides on their surface. To make it easier to prepare protein-functionalized liposomes, a non-covalent protein/liposome association method based upon metal chelation/his 6 interaction was devised and characterized. I evaluated non-covalent attachment of the prodrug converting enzyme yeast cytosine deaminase, the far-red fluorescent protein mKate, two antigens ovalbumin and the membrane proximal region of an HIV GAG and hyaluronidase, a HA-degrading enzyme. In Chapter 2, I describe the synthesis of hyaluronan-oligosaccharide (HA-O) lipid conjugates and their incorporation into liposomes to target CD44-overexpressing cancer cells. HA-O ligands of defined-length, up to 10 monosaccharides, were attached to lipids via various linkers by reductive amination. The HA-lipids were easily incorporated into liposomes but did not mediate binding of liposomes to CD44 overexpressing cells. In Chapter 3, I evaluate the capacity of tris-NTA-Ni-lipids incorporated within a liposome bilayer to associate with his6-tagged proteins. Tris-NTA-lipids of differing structures and avidities were used to associate yeast cytosine deaminase and mKate to the surface of liposomes. Two tris-NTA-lipids and a mono-NTA lipid associated his-tagged proteins to a 1:1 molar ratio in solution. The proteins remained active while associated with the liposome surface. When challenged in vitro with fetal calf serum, tris-NTA-containing liposomes retained his-tagged proteins longer than mono-NTA. However, the tris-NTA/his6 interaction was found to be in a dynamic state; free yeast cytosine deaminase rapidly competed with pre-bound m

  17. Protein and Amino Acid Requirements during Pregnancy.

    PubMed

    Elango, Rajavel; Ball, Ronald O

    2016-07-01

    Protein forms an essential component of a healthy diet in humans to support both growth and maintenance. During pregnancy, an exceptional stage of life defined by rapid growth and development, adequate dietary protein is crucial to ensure a healthy outcome. Protein deposition in maternal and fetal tissues increases throughout pregnancy, with most occurring during the third trimester. Dietary protein intake recommendations are based on factorial estimates because the traditional method of determining protein requirements, nitrogen balance, is invasive and undesirable during pregnancy. The current Estimated Average Requirement and RDA recommendations of 0.88 and 1.1 g · kg(-1) · d(-1), respectively, are for all stages of pregnancy. The single recommendation does not take into account the changing needs during different stages of pregnancy. Recently, with the use of the minimally invasive indicator amino acid oxidation method, we defined the requirements to be, on average, 1.2 and 1.52 g · kg(-1) · d(-1) during early (∼16 wk) and late (∼36 wk) stages of pregnancy, respectively. Although the requirements are substantially higher than current recommendations, our values are ∼14-18% of total energy and fit within the Acceptable Macronutrient Distribution Range. Using swine as an animal model we showed that the requirements for several indispensable amino acids increase dramatically during late gestation compared with early gestation. Additional studies should be conducted during pregnancy to confirm the newly determined protein requirements and to determine the indispensable amino acid requirements during pregnancy in humans. PMID:27422521

  18. Impact of protein and carbohydrate supplementation on plasma volume expansion and thermoregulatory adaptation by aerobic training in older men.

    PubMed

    Okazaki, Kazunobu; Ichinose, Takashi; Mitono, Hiroyuki; Chen, Mian; Masuki, Shizue; Endoh, Hiroshi; Hayase, Hideki; Doi, Tatsuya; Nose, Hiroshi

    2009-09-01

    We examined whether protein-carbohydrate (CHO) supplementation immediately after exercise each day during aerobic training facilitated plasma volume (PV) expansion and thermoregulatory and cardiovascular adaptations in older men. Fourteen moderately active older men [68 +/- 5 (SD) yr] were divided into two groups so as to have no significant differences in anthropometric measures, PV, and peak oxygen consumption rate (Vo(2peak)). Each group was provided with a mixture of protein and CHO (3.2 kcal, 0.18 g protein/kg body wt, Pro-CHO, n = 7) or a non-protein and low-calorie placebo (0.5 kcal, 0 g protein/kg body wt, CNT, n = 7) immediately after cycling exercise (60-75% Vo(2peak), 60 min/day, 3 days/wk) each day for 8 wk at approximately 19 degrees C ambient temperature (T(a)) and approximately 43% relative humidity (RH). Before and after training, we measured PV, cardiac stroke volume (SV), and esophageal temperature (T(es)) during 20-min exercise at 60% of pretraining Vo(2peak) at 30 degrees C T(a) and 50% RH. Moreover, we determined the sensitivity of the chest sweat rate (DeltaSR/DeltaT(es)) and forearm vascular conductance (DeltaFVC/DeltaT(es)) in response to increased T(es) during exercise. After training, PV increased by approximately 6% in Pro-CHO (P < 0.001), with an approximately 10% increase in SV during exercise (P < 0.001), but not in CNT (P > 0.07). DeltaFVC/DeltaT(es) increased by 80% and DeltaSR/DeltaT(es) by 18% in Pro-CHO (both P < 0.01) but not in CNT (P > 0.07). Moreover, we found a significant interactive effect of group x training on PV, SV, and DeltaFVC/DeltaT(es) (all P < 0.02) but with no significant effect of group (P > 0.4), suggesting that the supplement enhanced these responses to aerobic training. Thus postexercise protein-CHO supplementation during training caused PV expansion and facilitated thermoregulatory and cardiovascular adaptations, possibly providing a new training regimen for older men. PMID:19608927

  19. Microbial Degradation of Whole-Grain Complex Carbohydrates and Impact on Short-Chain Fatty Acids and Health1234

    PubMed Central

    Bach Knudsen, Knud Erik

    2015-01-01

    Whole-grain cereals have a complex dietary fiber (DF) composition consisting of oligosaccharides (mostly fructans), resistant starch, and nonstarch polysaccharides (NSPs); the most important are arabinoxylans, mixed-linkage β(1,3; 1,4)-d-glucan (β-glucan), and cellulose and the noncarbohydrate polyphenolic ether lignin. The highest concentration of NSPs and lignin is found in the outer cell layers of the grain, and refined flour will consequently be depleted of a large proportion of insoluble DF components. The flow and composition of carbohydrates to the large intestine are directly related to the intake of DF. The type and composition of cereal DF can consequently be used to modulate the microbial composition and activity as well as the production and molar ratios of short-chain fatty acids (SCFAs). Arabinoxylans and β-glucan in whole-grain cereals and cereal ingredients have been shown to augment SCFA production, with the strongest relative effect on butyrate. When arabinoxylans were provided as a concentrate, the effect was only on total SCFA production. Increased SCFA production in the large intestine was shown by the concentration in the portal vein, whereas the impact on the concentration in peripheral blood was less because the majority of propionate and butyrate is cleared in the liver. Active microbial fermentation with increased SCFA production reduced the exposure of potentially toxic compounds to the epithelium, potentially stimulating anorectic hormones and acting as signaling molecules between the gut and the peripheral tissues. The latter can have implications for insulin sensitivity and glucose homeostasis. PMID:25770259

  20. Microbial degradation of whole-grain complex carbohydrates and impact on short-chain fatty acids and health.

    PubMed

    Bach Knudsen, Knud Erik

    2015-03-01

    Whole-grain cereals have a complex dietary fiber (DF) composition consisting of oligosaccharides (mostly fructans), resistant starch, and nonstarch polysaccharides (NSPs); the most important are arabinoxylans, mixed-linkage β(1,3; 1,4)-d-glucan (β-glucan), and cellulose and the noncarbohydrate polyphenolic ether lignin. The highest concentration of NSPs and lignin is found in the outer cell layers of the grain, and refined flour will consequently be depleted of a large proportion of insoluble DF components. The flow and composition of carbohydrates to the large intestine are directly related to the intake of DF. The type and composition of cereal DF can consequently be used to modulate the microbial composition and activity as well as the production and molar ratios of short-chain fatty acids (SCFAs). Arabinoxylans and β-glucan in whole-grain cereals and cereal ingredients have been shown to augment SCFA production, with the strongest relative effect on butyrate. When arabinoxylans were provided as a concentrate, the effect was only on total SCFA production. Increased SCFA production in the large intestine was shown by the concentration in the portal vein, whereas the impact on the concentration in peripheral blood was less because the majority of propionate and butyrate is cleared in the liver. Active microbial fermentation with increased SCFA production reduced the exposure of potentially toxic compounds to the epithelium, potentially stimulating anorectic hormones and acting as signaling molecules between the gut and the peripheral tissues. The latter can have implications for insulin sensitivity and glucose homeostasis. PMID:25770259

  1. Body composition, dietary carbohydrates and fatty acids determine post-fertilisation development of bovine oocytes in vitro.

    PubMed

    Adamiak, S J; Powell, K; Rooke, J A; Webb, R; Sinclair, K D

    2006-02-01

    This study assessed the interactive effects of carbohydrate type (fibre vs starch) and fatty acid (FA) supplementation (0% vs 6% calcium soaps of palm oil FA) on the post-fertilisation development of oocytes recovered from low and moderate body condition score (BCS) heifers. A secondary objective was to compare the FA composition of plasma to that of granulosa cells (GCs) and cumulus-oocyte complexes (COCs) from these animals, and to relate these findings to the developmental potential of oocytes. Plasma, GCs and COCs were recovered from 32 heifers on day 5 of a synchronised oestrous cycle for FA analyses. Oocytes were also recovered on days 10 and 15 of the same cycle after short-term ovarian stimulation (FSH + GnRH), and matured, fertilised and cultured to the blastocyst stage in vitro. High levels of dietary starch increased (P < 0.01) plasma insulin but, together with dietary FA, reduced (P < 0.05) blastocyst yields in low, but not in moderate, BCS heifers. Diet-induced alterations to the FA content of plasma were less apparent in GCs and COCs. In summary, although dietary lipids increased the FA content of COCs, the selective uptake of saturated FAs at the expense of mainly polyunsaturated FAs within the follicular compartment ensured that the FA composition of COCs was largely unaffected by diet. However, the concentration of saturated FAs within COCs was inherently high, and so further increases in FA content may have impaired post-fertilisation development. The data establish a robust nutritional framework for more detailed studies into the mechanistic effects of dietary composition on the post-fertilisation developmental potential of oocytes. PMID:16452718

  2. Production of high optical purity l-lactic acid from waste activated sludge by supplementing carbohydrate: effect of temperature and pretreatment time.

    PubMed

    Jian, Qiwei; Li, Xiang; Chen, Yinguang; Liu, Yanan; Pan, Yin

    2016-10-01

    It has been widely accepted that the most environmentally beneficial way to treat waste activated sludge (WAS), the byproduct of municipal wastewater treatment plant, is to recover the valuable organic acid. However, the bio-conversion of lactic acid, one of the high added-value chemical, is seldom reported from WAS fermentation. In this paper, l-lactic acid was observed dominant in the WAS fermentation liquid with carbohydrate addition at ambient temperature. Furthermore, the effect of temperature on l-lactic acid and d-lactic acid production was fully discussed: two isomers were rapidly produced and consumed up in one day at mesophilic condition; and almost optically pure l-lactic acid was generated at thermophilic condition, yet time-consuming with yield of l-lactic acid enhancing by 52.9% compared to that at ambient temperature. The study mechanism showed that mesophilic condition was optimal for both production and consumption of l-lactic acid and d-lactic acid, while consumption of l-lactic acid and production of d-lactic acid were severely inhibited at thermophilic condition. Therefore, by maintaining thermophilic for 4 h in advance and subsequently fermenting mesophilic for 34 h, the concentration of l-lactic acid with optical activity of 98.3% was improved to 16.6 ± 0.5 g COD/L at a high specific efficiency of 0.6097/d. PMID:26878176

  3. Hypothalamic norepinephrine turnover response to a single low protein, high carbohydrate meal in the male Wistar rat

    SciTech Connect

    Raum, W.; Glick, Z.

    1986-03-01

    A single meal stimulates norepinephrine turnover (NET) by approximately 4-fold in the brown adipose tissue (BAT). In this experiment the role of the hypothalamus in regulating this response was examined. NET was measured in the cortex (C), ventro-medial (VMH), and the lateral hypothalamus (LH). A total of 48 male Wistar rats (200 g body weight) were trained to eat during two feeding sessions per day. On the experimental day, one group (N = 24) was meal deprived and the other (N = 24) was given a low protein, high carbohydrate test meal for 2 hours. NET was determined by the synthesis inhibition method using alpha-methyltyrosine (AMT) injected within one hour after the meal. Norepinephrine (NE) content in each brain section was measured by radioimmunoassay at 4 time points (0, 1, 2, 3 hours) after AMT. The turnover rate (TR) was calculated as the slope of the decline in NE content over time (ng/mg protein/hr) following AMT. The fraction of the total pool of NE released/hr (k) was calculated by dividing the slope (TR) by the Y intercept (NE content at zero time). NET (TR) increased significantly (p < .05) in the VMH following a meal (9.36 +/- .67 vs 8.04 +/- .98 ng/hr; fed vs deprived). There was no change in TR in the C or LH, or in k in any brain section. The marked (4-fold) increase in BAT NET and minimal increase in VMH NET suggests that the meal has a direct effect on BAT with the VMH playing a secondary or modulatory role.

  4. Protein-carbohydrate interactions defining substrate specificity in Bacillus 1,3-1,4-beta-D-glucan 4-glucanohydrolases as dissected by mutational analysis.

    PubMed

    Piotukh, K; Serra, V; Borriss, R; Planas, A

    1999-12-01

    The carbohydrate-binding site of Bacillus macerans 1,3-1, 4-beta-D-glucan 4-glucanohydrolase has been analyzed through a mutational analysis to probe the role of protein-carbohydrate interactions defining substrate specificity. Amino acid residues involved in substrate binding were proposed on the basis of a modeled enzyme-substrate complex [Hahn, M., Keitel, T., and Heinemann, U. (1995) Eur. J. Biochem. 232, 849-859]. The effects of the mutations at 15 selected residues on catalysis and binding were determined by steady-state kinetics using a series of chromogenic substrates of different degree of polymerization to assign the individual H-bond and hydrophobic contributions to individual subsites in the binding site cleft. The glucopyranose rings at subsites -III and -II are tightly bound by a number of H-bond interactions to Glu61, Asn24, Tyr92, and Asn180. From k(cat)/K(M) values, single H-bonds account for 1.8-2.2 kcal mol(-)(1) transition-state (TS) stabilization, and a charged H-bond contributes up to 3.5 kcal mol(-)(1). Glu61 forms a bidentated H-bond in subsites -III and -II, and provides up to 6.5 kcal mol(-)(1) TS stabilization. With a disaccharide substrate that fills subsites -I and -II, activation kinetics were observed for the wild-type and mutant enzymes except for mutations on Glu61, pointing to an important role of the bidentate interaction of Glu61 in two subsites. Whereas removal of the hydroxyl group of Tyr121, initially proposed to hydrogen-bond with the 2OH of Glcp-I, has essentially no effect (Y121F mutant), side-chain removal (Y121A mutant) gave a 100-fold reduction in k(cat)/K(M) and a 10-fold lower K(I) value with a competitive inhibitor. In subsite -IV, only a stacking interaction with Tyr22 (0.7 kcal mol(-)(1) TS stabilization) is observed. PMID:10587432

  5. Soluble Carbohydrates Regulate Auxin Biosynthesis via PIF Proteins in Arabidopsis[W][OA

    PubMed Central

    Sairanen, Ilkka; Novák, Ondřej; Pěnčík, Aleš; Ikeda, Yoshihisa; Jones, Brian; Sandberg, Göran; Ljung, Karin

    2012-01-01

    Plants are necessarily highly competitive and have finely tuned mechanisms to adjust growth and development in accordance with opportunities and limitations in their environment. Sugars from photosynthesis form an integral part of this growth control process, acting as both an energy source and as signaling molecules in areas targeted for growth. The plant hormone auxin similarly functions as a signaling molecule and a driver of growth and developmental processes. Here, we show that not only do the two act in concert but that auxin metabolism is itself regulated by the availability of free sugars. The regulation of the biosynthesis and degradation of the main auxin, indole-3-acetic acid (IAA), by sugars requires changes in the expression of multiple genes and metabolites linked to several IAA biosynthetic pathways. The induction also involves members of the recently described central regulator PHYTOCHROME-INTERACTING FACTOR transcription factor family. Linking these three known regulators of growth provides a model for the dynamic coordination of responses to a changing environment. PMID:23209113

  6. Content of short-chain fatty acids in the hindgut of rats fed processed bean (Phaseolus vulgaris) flours varying in distribution and content of indigestible carbohydrates.

    PubMed

    Henningsson, A M; Nyman, E M; Björck, I M

    2001-09-01

    Red kidney beans (Phaseolus vulgaris) processed to differ in distribution and content of indigestible carbohydrates were used to study hindgut fermentability and production of short-chain fatty acids (SCFA). Bean flours with low or high content of resistant starch (RS), mainly raw and physically-inaccessible starch, were obtained by milling the beans before or after boiling. Flours containing retrograded starch and with a high or low content of oligosaccharides were prepared by autoclaving followed by freeze-drying with or without the boiling water. Six diets were prepared from these flours yielding a total concentration of indigestible carbohydrates of 90 or 120 g/kg (dry weight basis). The total fermentability of the indigestible carbohydrates was high with all diets (80-87 %). Raw and physically-inaccessible starch was more readily fermented than retrograded starch (97-99 % v. 86-95 %; ). Non-starch glucans were fermented to a lesser extent than RS, but the fermentability was higher in the case of autoclaved (50-54 %) than boiled beans (37-41 %). The distribution between acetic, propionic and butyric acid in the caecum was similar for all diets, with a comparatively high percentage of butyric acid (approximately 18). However, with diets containing the high amounts of RS, the butyric acid concentration was significantly higher in the distal colon than in the proximal colon ( and for the high- and low-level diets respectively), whereas it remained constant, or decreased along the colon in the case of the other diets. Furthermore, the two diets richest in RS also promoted the highest percentages of butyric acid in the distal colon (24 and 17 v. 12 and 12-16 for the high- and low-level diets respectively). PMID:11570990

  7. Drought adaptation in plants with crassulacean acid metabolism involves the flexible use of different storage carbohydrate pools

    PubMed Central

    Borland, Anne M; De Proft, Maurice P

    2009-01-01

    Nocturnal CO2 uptake in CAM plants is sustained by the degradation of storage carbohydrate which provides the acceptor (PEP) for the nocturnal carboxylase (PEPC). The investment of resources into a transient storage carbohydrate pool unavoidably places restriction on other metabolic activities including dark respiration, growth and acclimation to abiotic stress. In our recent report the flexible use of different storage carbohydrate pools is shown to be involved in the acclimation process to drought and recovery from dehydration. While starch breakdown stoichiometrically accounts for nocturnal CO2 uptake under well-watered conditions, the sucrose pool is maintained in preference to starch during progressing drought and sucrose becomes the major source of carbon fuelling the dark reactions after 45 days of water deprivation. Re-watering plants results in a recovery to the original situation, with starch constituting the main carbohydrate reserve for nocturnal provision of PEP. However, substantial amounts of starch are also retained in the leaves of re-watered plants by restricting export/respiration and thus provides a potential buffer capacity against a return to water deprivation. This significant conservation of starch suggests the ability to perceive, remember and anticipate the formerly encountered drought stress in some way, with the adaptation of the equilibrium of carbohydrate balance as a central factor underpinning the physiological homeostasis of CAM plants. PMID:19721752

  8. Carbohydrates as a tool for oriented immobilization of antigens and antibodies.

    PubMed

    Turková, J; Petkov, L; Sajdok, J; Kás, J; Benes, M J

    1990-02-01

    A biospecific sorbent for the isolation of ovalbumin antibodies was prepared by coupling of ovalbumin via its periodate-oxidized carbohydrate moiety to bead cellulose modified with adipic acid dihydrazide. The anti-ovalbumin IgG fraction isolated on this sorbent from immune rabbit serum contained only antibodies against protein determinants of ovalbumin. Thus, when these IgG were immobilized through their carbohydrate moieties to cellulose beads it became possible to prepare a biospecific sorbent for concanavalin A by oriented adsorption of ovalbumin. Ovalbumin was specifically adsorbed via its protein moiety and its carbohydrate part remained free for interaction with concanavalin A. PMID:2329151

  9. Alterations in protein, carbohydrate, and fat metabolism in injured and septic patients.

    PubMed

    Wilmore, D W

    1983-01-01

    The physiological and biochemical responses of the body following major injury or severe infection are characterized by hypermetabolism, accelerated gluconeogenesis, and the mobilization of substrates from the carcass to be utilized by visceral organs. These responses in the febrile patient are supported by an elevated cardiac output which insures perfusion of vital organs and provides additional bloodflow to the area of inflammation and/or injury. Because of the accelerated substrate flux and increased catabolism, weight loss and negative nitrogen balance are profound. Cumulative losses rapidly approach near-lethal limits if adequate nutritional support is not instituted. Nutritional maintenance will support the febrile response, maintain body nitrogen and acute phase protein synthesis, and assure an ongoing energy supply. Reparative tissue appears to preferentially utilize substrate, but if malnutrition occurs, wound healing and tissue repair may be limited. The effects of nutritional support on immunological function in these critically ill patients are only now being dissected. Clearly, immunosuppression is related to the initial insult and abnormalities in host defense mechanisms occur almost immediately in patients well nourished before illness. In addition, nutrient depletion and erosion of body mass are also associated with immunological dysfunction so that these two factors combine to impair the patient's resistance to subsequent infection. Present therapy should maintain balance of essential nutrients while complications associated with specialized techniques of nutrient support are minimized. Control of the patient's environment, minimizing pain and discomfort, preventing "bad rest" effect through exercise are all techniques of supportive care, but responses are ablated with resolution of the infection or wound closure, and every effort should be directed toward this goal. PMID:6886243

  10. Increase in the carbohydrate content of the microalgae Spirulina in culture by nutrient starvation and the addition of residues of whey protein concentrate.

    PubMed

    Vieira Salla, Ana Cláudia; Margarites, Ana Cláudia; Seibel, Fábio Ivan; Holz, Luiz Carlos; Brião, Vandré Barbosa; Bertolin, Telma Elita; Colla, Luciane Maria; Costa, Jorge Alberto Vieira

    2016-06-01

    Non-renewable sources that will end with time are the largest part of world energy consumption, which emphasizes the necessity to develop renewable sources of energy. This necessity has created opportunities for the use of microalgae as a biofuel. The use of microalgae as a feedstock source for bioethanol production requires high yields of both biomass and carbohydrates. With mixotrophic cultures, wastewater can be used to culture algae. The aim of the study was to increase the carbohydrate content in the microalgae Spirulina with the additions of residues from the ultra and nanofiltration of whey protein. The nutrient deficit in the Zarrouk medium diluted to 20% and the addition of 2.5% of both residue types led to high carbohydrate productivity (60 mg L(-1) d(-1)). With these culture conditions, the increase in carbohydrate production in Spirulina indicated that the conditions were appropriate for use with microalgae as a feedstock in the production of bioethanol. PMID:26967336

  11. Simple fabrication of hydrophobic surface target for increased sensitivity and homogeneity in matrix-assisted laser desorption/ionization time-of-flight mass spectrometry analysis of peptides, phosphopeptides, carbohydrates and proteins.

    PubMed

    Chen, Chao-Jung; Lai, Chien-Chen; Tseng, Mei-Chun; Liu, Yu-Ching; Lin, Shih-Yi; Tsai, Fuu-Jen

    2013-06-14

    To enhance sample signals and improve homogeneity in matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF) analysis, a simple, rapid, and efficient sample preparation method was developed in this study. Polydimethylsiloxane (PDMS) was coated on a stainless steel MALDI plate, forming a transparent, hydrophobic surface that enhanced sample signals without producing observable background signals. Compared to the use of an unmodified commercial metal MALDI plate, peptide signals were enhanced by ~7.1-11.0-fold due to the reduced sample spot area of the PDMS-coated plate, and showed improved peptide mass fingerprinting (PMF) and MS/MS peptide sequencing results. In the analysis of phosphopeptides and carbohydrates with a 2,5-dihydroxybenzoic acid (DHB) matrix, the PDMS-coated plate showed improved sample homogeneity and signal enhancements of ~5.2-8.2-fold and ~2.8-3.2-fold, respectively. Improved sensitivity in the observation of more unique fragment ions by MS/MS analysis, to successfully distinguish isomeric carbohydrates, was also illustrated. In protein analysis with a sinapinic acid (SA) matrix, a ~3.4-fold signal enhancement was observed. The PDMS film coating was easily removed and refabricated to avoid sample carryover, and was applicable to diverse commercial MALDI plates. The PDMS-coated approach is a simple, practical, and attractive method for enhancing analyte signals and homogeneity. PMID:23726097

  12. Effect of Carbohydrate Position on Lysosomal Transport of Procathepsin L

    PubMed Central

    Lingeman, Robert G.; Joy, Darrin S.; Sherman, Mark A.; Kane, Susan E.

    1998-01-01

    To study the role of carbohydrate in lysosomal protein transport, we engineered two novel glycosylation signals (Asn-X-Ser/Thr) into the cDNA of human procathepsin L, a lysosomal acid protease. We constructed six mutant cDNAs encoding glycosylation signals at mutant sites Asn-138, Asn-175, or both sites together, in the presence or absence of the wild-type Asn-204 site. We stably transfected wild-type and mutant cDNAs into NIH3T3 mouse fibroblasts and then used species-specific antibodies to determine the glycosylation status, phosphorylation, localization, and transport kinetics of recombinant human procathepsin L containing one, two, or three glycosylation sites. Both novel glycosylation sites were capable of being glycosylated, although Asn-175 was utilized only 30–50% of the time. Like the wild-type glycosylation at Asn-204, carbohydrates at Asn-138 and Asn-175 were completely sensitive to endoglycosidase H, and they were phosphorylated. Mutant proteins containing two carbohydrates were capable of being delivered to lysosomes, but there was not a consistent relationship between the efficiency of lysosomal delivery and carbohydrate content of the protein. Pulse-chase labeling revealed a unique biosynthetic pattern for proteins carrying the Asn-175 glycosylation sequence. Whereas wild-type procathepsin L and mutants bearing carbohydrate at Asn-138 appeared in lysosomes by about 60 min, proteins with carbohydrate at Asn-175 were processed to a lysosome-like polypeptide within 15 min. Temperature shift, brefeldin A, and NH4Cl experiments suggested that the rapid processing did not occur in the endoplasmic reticulum and that Asn-175 mutants could interact with the mannose 6-phosphate receptor. Taken together, our results are consistent with the interpretation that Asn-175 carbohydrate confers rapid transport to lysosomes. We may have identified a recognition domain in procathepsin L that is important for its interactions with the cellular transport machinery. PMID

  13. Effects of a carbohydrate-, protein-, and ribose-containing repletion drink during 8 weeks of endurance training on aerobic capacity, endurance performance, and body composition.

    PubMed

    Cramer, Joel T; Housh, Terry J; Johnson, Glen O; Coburn, Jared W; Stout, Jeffrey R

    2012-08-01

    This study compared a carbohydrate-, protein-, and ribose-containing repletion drink vs. carbohydrates alone during 8 weeks of aerobic training. Thirty-two men (age, mean ± SD = 23 ± 3 years) performed tests for aerobic capacity (V(O2)peak), time to exhaustion (TTE) at 90% V(O2)peak, and percent body fat (%fat), and fat-free mass (FFM). Testing was conducted at pre-training (PRE), mid-training at 3 weeks (MID3), mid-training at 6 weeks (MID6), and post-training (POST). Cycle ergometry training was performed at 70% V(O2)peak for 1 hours per day, 5 days per week for 8 weeks. Participants were assigned to a test drink (TEST; 370 kcal, 76 g carbohydrate, 14 g protein, 2.2 g d-ribose; n = 15) or control drink (CON; 370 kcal, 93 g carbohydrate; n = 17) ingested immediately after training. Body weight (BW; 1.8% decrease CON; 1.3% decrease TEST from PRE to POST), %fat (5.5% decrease CON; 3.9% decrease TEST), and FFM (0.1% decrease CON; 0.6% decrease TEST) decreased (p ≤ 0.05), whereas V(O2)peak (19.1% increase CON; 15.8% increase TEST) and TTE (239.1% increase CON; 377.3% increase TEST) increased (p ≤ 0.05) throughout the 8 weeks of training. Percent decreases in %fat from PRE to MID3 and percent increases in FFM from PRE to MID3 and MID6 were greater (p ≤ 0.05) for TEST than CON. Overall, even though the TEST drink did not augment BW, V(O2)peak, or TTE beyond carbohydrates alone, it did improve body composition (%fat and FFM) within the first 3-6 weeks of supplementation, which may be helpful for practitioners to understand how carbohydrate-protein recovery drinks can and cannot improve performance in their athletes. PMID:22692117

  14. Isolation of carbohydrate-metabolizing, extremely halophilic bacteria.

    NASA Technical Reports Server (NTRS)

    Tomlinson, G. A.; Hochstein, L. I.

    1972-01-01

    Four previously unrecognized strains of extremely halophilic bacteria that utilize carbohydrates have been isolated. Gas production proved an unreliable index of carbohydrate metabolism; therefore, carbohydrate utilization was measured by determining acid formation and sugar disappearance during growth. By these procedures, carbohydrate utilization was readily detected. The results suggest that carbohydrate dissimilation by extremely halophilic bacteria may be more common than previously thought and that the apparent rarity of carbohydrate-metabolizing halophiles may be an artifact of the isolation procedures used.

  15. Relationship between population growth of the red flour beetle Tribolium castaneum and protein and carbohydrate content in flour and starch.

    PubMed

    Wong, Nellie; Lee, Chow-Yang

    2011-12-01

    The effects of eight diets (atta flour, wheat flour, self-rising flour, rice flour, custard powder, corn flour, tapioca starch, and potato starch) on the development of the red flour beetle, Tribolium castaneum (Herbst), reared at 29-31 degrees C and 66-70% RH were assessed. Five pairs of male and female T. castaneum were reared on the respective diets for 28 d before the experimental setup was dismantled and adult counts were recorded. In another experiment, the insects were allowed to mate and oviposit in each flour or starch type over a period of 7 d before being removed. The counting of pupae and adult emergence began on the day of emergence and was continued on a daily basis until day 140. Proximate analysis was performed for chemical composition of each diet, and the numbers of new adults that developed were found to be positively correlated (r2 = 0.97; P < 0.05) with the protein content and negatively correlated (r2 = 0.93; P < 0.05) with the carbohydrate content. For T. castaneum, the suitable diets were ranked as follows: atta flour > wheat flour > self-rising flour > rice flour > custard powder > corn flour > tapioca starch > potato starch. T. castaneum larval development to the pupal and adult stages developed significantly faster in atta flour (P < 0.05) than in the other diets, and the greatest number of progeny was produced from beetles reared on atta flour. Fewer adults emerged from wheat flour, self-rising flour, and rice flour, and no new emergences were recorded for the remaining diets. Developmental rate was much slower in beetles reared on diets in which a low number in progeny was produced. These data illustrate that different diets can influence the sustainability of these insects and affect their development and growth. PMID:22299375

  16. Sex-specific effects of protein and carbohydrate intake on reproduction but not lifespan in Drosophila melanogaster

    PubMed Central

    Jensen, Kim; McClure, Colin; Priest, Nicholas K; Hunt, John

    2015-01-01

    Modest dietary restriction extends lifespan (LS) in a diverse range of taxa and typically has a larger effect in females than males. Traditionally, this has been attributed to a stronger trade-off between LS and reproduction in females than in males that is mediated by the intake of calories. Recent studies, however, suggest that it is the intake of specific nutrients that extends LS and mediates this trade-off. Here, we used the geometric framework (GF) to examine the sex-specific effects of protein (P) and carbohydrate (C) intake on LS and reproduction in Drosophila melanogaster. We found that LS was maximized at a high intake of C and a low intake of P in both sexes, whereas nutrient intake had divergent effects on reproduction. Male offspring production rate and LS were maximized at the same intake of nutrients, whereas female egg production rate was maximized at a high intake of diets with a P:C ratio of 1:2. This resulted in larger differences in nutrient-dependent optima for LS and reproduction in females than in males, as well as an optimal intake of nutrients for lifetime reproduction that differed between the sexes. Under dietary choice, the sexes followed similar feeding trajectories regulated around a P:C ratio of 1:4. Consequently, neither sex reached their nutritional optimum for lifetime reproduction, suggesting intralocus sexual conflict over nutrient optimization. Our study shows clear sex differences in the nutritional requirements of reproduction in D. melanogaster and joins the growing list of studies challenging the role of caloric restriction in extending LS. PMID:25808180

  17. Co-Ingestion of Whey Protein with a Carbohydrate-Rich Breakfast Does Not Affect Glycemia, Insulinemia or Subjective Appetite Following a Subsequent Meal in Healthy Males

    PubMed Central

    Allerton, Dean M.; Campbell, Matthew D.; Gonzalez, Javier T.; Rumbold, Penny L. S.; West, Daniel J.; Stevenson, Emma J.

    2016-01-01

    We aimed to assess postprandial metabolic and appetite responses to a mixed-macronutrient lunch following prior addition of whey protein to a carbohydrate-rich breakfast. Ten healthy males (age: 24 ± 1 years; body mass index (BMI): 24.5 ± 0.7 kg/m2) completed three trials in a non-isocaloric, crossover design. A carbohydrate-rich breakfast (93 g carbohydrate; 1799 kJ) was consumed with (CHO + WP) or without (CHO) 20 g whey protein isolate (373 kJ), or breakfast was omitted (NB). At 180 min, participants consumed a mixed-macronutrient lunch meal. Venous blood was sampled at 15 min intervals following each meal and every 30 min thereafter, while subjective appetite sensations were collected every 30 min throughout. Post-breakfast insulinemia was greater after CHO + WP (time-averaged area under the curve (AUC0–180 min): 193.1 ± 26.3 pmol/L), compared to CHO (154.7 ± 18.5 pmol/L) and NB (46.1 ± 8.0 pmol/L; p < 0.05), with no difference in post-breakfast (0–180 min) glycemia (CHO + WP, 3.8 ± 0.2 mmol/L; CHO, 4.2 ± 0.2 mmol/L; NB, 4.2 ± 0.1 mmol/L; p = 0.247). There were no post-lunch (0–180 min) effects of condition on glycemia (p = 0.492), insulinemia (p = 0.338) or subjective appetite (p > 0.05). Adding whey protein to a carbohydrate-rich breakfast enhanced the acute postprandial insulin response, without influencing metabolic or appetite responses following a subsequent mixed-macronutrient meal. PMID:26927166

  18. Co-Ingestion of Whey Protein with a Carbohydrate-Rich Breakfast Does Not Affect Glycemia, Insulinemia or Subjective Appetite Following a Subsequent Meal in Healthy Males.

    PubMed

    Allerton, Dean M; Campbell, Matthew D; Gonzalez, Javier T; Rumbold, Penny L S; West, Daniel J; Stevenson, Emma J

    2016-01-01

    We aimed to assess postprandial metabolic and appetite responses to a mixed-macronutrient lunch following prior addition of whey protein to a carbohydrate-rich breakfast. Ten healthy males (age: 24 ± 1 years; body mass index (BMI): 24.5 ± 0.7 kg/m²) completed three trials in a non-isocaloric, crossover design. A carbohydrate-rich breakfast (93 g carbohydrate; 1799 kJ) was consumed with (CHO + WP) or without (CHO) 20 g whey protein isolate (373 kJ), or breakfast was omitted (NB). At 180 min, participants consumed a mixed-macronutrient lunch meal. Venous blood was sampled at 15 min intervals following each meal and every 30 min thereafter, while subjective appetite sensations were collected every 30 min throughout. Post-breakfast insulinemia was greater after CHO + WP (time-averaged area under the curve (AUC0--180 min): 193.1 ± 26.3 pmol/L), compared to CHO (154.7 ± 18.5 pmol/L) and NB (46.1 ± 8.0 pmol/L; p < 0.05), with no difference in post-breakfast (0-180 min) glycemia (CHO + WP, 3.8 ± 0.2 mmol/L; CHO, 4.2 ± 0.2 mmol/L; NB, 4.2 ± 0.1 mmol/L; p = 0.247). There were no post-lunch (0-180 min) effects of condition on glycemia (p = 0.492), insulinemia (p = 0.338) or subjective appetite (p > 0.05). Adding whey protein to a carbohydrate-rich breakfast enhanced the acute postprandial insulin response, without influencing metabolic or appetite responses following a subsequent mixed-macronutrient meal. PMID:26927166

  19. Fluorous-based carbohydrate quartz crystal microbalance.

    PubMed

    Chen, Lei; Sun, Pengfei; Chen, Guosong

    2015-03-20

    Fluorous chemistry has brought many applications from catalysis to separation science, from supramolecular materials to analytical chemistry. However, fluorous-based quartz crystal microbalance (QCM) has not been reported so far. In the current paper, fluorous interaction has been firstly utilized in QCM, and carbohydrate-protein interaction and carbohydrate-carbohydrate interaction have been detected afterward. PMID:25541017

  20. Healthy carbohydrates

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Functional foods include dietary fiber consisting of health-promoting carbohydrates. We have produced novel prebiotics from orange peel and observed that they extend the shelf life of probiotic bacteria in synbiotics. Some pectic-oligosaccharides and xyloglucan-oligosaccharides also have anti-adhesi...

  1. High or low dietary carbohydrate:protein ratios during first-feeding affect glucose metabolism and intestinal microbiota in juvenile rainbow trout.

    PubMed

    Geurden, I; Mennigen, J; Plagnes-Juan, E; Veron, V; Cerezo, T; Mazurais, D; Zambonino-Infante, J; Gatesoupe, J; Skiba-Cassy, S; Panserat, S

    2014-10-01

    Based on the concept of nutritional programming in mammals, we tested whether an acute hyperglucidic-hypoproteic stimulus during first feeding could induce long-term changes in nutrient metabolism in rainbow trout. Trout alevins received during the five first days of exogenous feeding either a hyperglucidic (40% gelatinized starch + 20% glucose) and hypoproteic (20%) diet (VLP diet) or a high-protein (60%) glucose-free diet (HP diet, control). Following a common 105-day period on a commercial diet, both groups were then challenged (65 days) with a carbohydrate-rich diet (28%). Short- and long-term effects of the early stimuli were evaluated in terms of metabolic marker gene expressions and intestinal microbiota as initial gut colonisation is essential for regulating the development of the digestive system. In whole alevins (short term), diet VLP relative to HP rapidly increased gene expressions of glycolytic enzymes, while those involved in gluconeogenesis and amino acid catabolism decreased. However, none of these genes showed persistent molecular adaptation in the liver of challenged juveniles (long term). By contrast, muscle of challenged juveniles subjected previously to the VLP stimulus displayed downregulated expression of markers of glycolysis and glucose transport (not seen in the short term). These fish also had higher plasma glucose (9 h postprandial), suggesting impaired glucose homeostasis induced by the early stimulus. The early stimulus did not modify the expression of the analysed metabolism-related microRNAs, but had short- and long-term effects on intestinal fungi (not bacteria) profiles. In summary, our data show that a short hyperglucidic-hypoproteic stimulus during early life may have a long-term influence on muscle glucose metabolism and intestinal microbiota in trout. PMID:25274323

  2. Arabinoxylan‐oligosaccharides (AXOS) affect the protein/carbohydrate fermentation balance and microbial population dynamics of the Simulator of Human Intestinal Microbial Ecosystem

    PubMed Central

    Sanchez, J. I.; Marzorati, M.; Grootaert, C.; Baran, M.; Van Craeyveld, V.; Courtin, C. M.; Broekaert, W. F.; Delcour, J. A.; Verstraete, W.; Van de Wiele, T.

    2009-01-01

    Summary Arabinoxylan‐oligosaccharides (AXOS) are a recently newly discovered class of candidate prebiotics as – depending on their structure – they are fermented in different regions of gastrointestinal tract. This can have an impact on the protein/carbohydrate fermentation balance in the large intestine and, thus, affect the generation of potentially toxic metabolites in the colon originating from proteolytic activity. In this study, we screened different AXOS preparations for their impact on the in vitro intestinal fermentation activity and microbial community structure. Short‐term fermentation experiments with AXOS with an average degree of polymerization (avDP) of 29 allowed part of the oligosaccharides to reach the distal colon, and decreased the concentration of proteolytic markers, whereas AXOS with lower avDP were primarily fermented in the proximal colon. Additionally, prolonged supplementation of AXOS with avDP 29 to the Simulator of Human Intestinal Microbial Ecosystem (SHIME) reactor decreased levels of the toxic proteolytic markers phenol and p‐cresol in the two distal colon compartments and increased concentrations of beneficial short‐chain fatty acids (SCFA) in all colon vessels (25–48%). Denaturant gradient gel electrophoresis (DGGE) analysis indicated that AXOS supplementation only slightly modified the total microbial community, implying that the observed effects on fermentation markers are mainly caused by changes in fermentation activity. Finally, specific quantitative PCR (qPCR) analysis showed that AXOS supplementation significantly increased the amount of health‐promoting lactobacilli as well as of Bacteroides–Prevotella and Clostridium coccoides–Eubacterium rectale groups. These data allow concluding that AXOS are promising candidates to modulate the microbial metabolism in the distal colon. PMID:21261885

  3. Fluorinated amino acids: compatibility with native protein structures and effects on protein-protein interactions.

    PubMed

    Salwiczek, Mario; Nyakatura, Elisabeth K; Gerling, Ulla I M; Ye, Shijie; Koksch, Beate

    2012-03-21

    Fluorinated analogues of the canonical α-L-amino acids have gained widespread attention as building blocks that may endow peptides and proteins with advantageous biophysical, chemical and biological properties. This critical review covers the literature dealing with investigations of peptides and proteins containing fluorinated analogues of the canonical amino acids published over the course of the past decade including the late nineties. It focuses on side-chain fluorinated amino acids, the carbon backbone of which is identical to their natural analogues. Each class of amino acids--aliphatic, aromatic, charged and polar as well as proline--is presented in a separate section. General effects of fluorine on essential properties such as hydrophobicity, acidity/basicity and conformation of the specific side chains and the impact of these altered properties on stability, folding kinetics and activity of peptides and proteins are discussed (245 references). PMID:22130572

  4. Dietary protein-to-carbohydrate ratio and added sugar as determinants of excessive gestational weight gain: a prospective cohort study

    PubMed Central

    Maslova, Ekaterina; Halldorsson, Thorhallur I; Astrup, Arne; Olsen, Sjurdur F

    2015-01-01

    Objective To examine the relation between the protein:carbohydrate (P/C) ratio and added sugar intake in pregnancy and gestational weight gain (GWG). Design A prebirth cohort including 103 119 pregnancies enrolled between 1996 and 2003. Setting All women in Denmark were eligible to participate if they spoke Danish and were planning to carry to term.The pregnant women were recruited and enrolled during their first antenatal visit (6–10 weeks of gestation). Participants Participants included women with live-born singletons and complete data on dietary intake and GWG, leaving 46 262 women for the analysis. Exposure Macronutrient intake was quantified using a validated food frequency questionnaire administered in the 25th week of gestation. The P/C ratio and added sugar intake were examined in quintiles. Primary outcome measures GWG was based on self-reported weight in gestational weeks 12 and 30 and defined as gain in g/week. We used multivariable linear regression, including adjusting for pre-pregnancy body mass index, to calculate relative change in GWG and 95% CI. Results Average GWG was 471(224) g/week. The adjusted weight gain was 16 g/week lower (95% CI 9 to 22, p for trend <0.001) in the highest (Q5) versus lowest (Q1) quintile of the P/C ratio (∼3% average reduction across the entire pregnancy). Weight gain for those with >20%E vs <12%E from protein was 36 g/week lower (95% CI 20 to 53, p for trend <0.0001; ∼8% average reduction). A high P/C ratio was inversely related to intake of added sugars. Added sugar consumption was strongly associated with GWG (Q5 vs Q1: 34, 95% CI 28 to 40 g/week, p for trend <0.0001). Conclusions A high P/C ratio was associated with reduced GWG. This association appeared to be partly driven by a decrease in intake of added sugar. These results are consistent with randomised trials in non-pregnant participants. A dietary intervention targeting an increased P/C ratio with emphasis on reducing added sugar can

  5. Abuse potential of carbohydrates for overweight carbohydrate cravers

    PubMed Central

    Spring, Bonnie; Schneider, Kristin; Smith, Malaina; Kendzor, Darla; Appelhans, Bradley; Hedeker, Donald; Pagoto, Sherry

    2010-01-01

    Rationale The long-rejected construct of food addiction is undergoing re-examination. Objectives . To evaluate whether a novel carbohydrate food shows abuse potential for rigorously defined carbohydrate cravers, as evidenced by selective self-administration and mood enhancement during double-blind discrimination testing. Methods Discrete trials choice testing was performed with 61 overweight (BMI m=27.64, SD=2.59) women (ages 18–45; 19.70% African American) whose diet records showed >4 weekly afternoon/evening emotional eating episodes confined to snacks with carbohydrate:protein ≥ 6:1. After being induced into a sad mood, participants were exposed, double-blind and in counterbalanced order, to taste-matched carbohydrate and protein beverages. They were asked to choose and self-administer the drink that made them feel better. Results Women overwhelmingly chose the carbohydrate beverage, even though blinded. Mixed-effects regression modeling, controlling for beverage order, revealed greater liking and greater reduction in dysphoria following the carbohydrate beverage compared to the protein beverage, but no differential effect on vigor. Conclusion For women who crave them, carbohydrates appear to display abuse potential, plausibly contributing to overconsumption and overweight. PMID:18273603

  6. Learning about Carbohydrates

    MedlinePlus

    ... Here's Help White House Lunch Recipes Learning About Carbohydrates KidsHealth > For Kids > Learning About Carbohydrates Print A ... of energy for the body. Two Types of Carbohydrates There are two major types of carbohydrates (or ...

  7. Nucleic acids encoding human trithorax protein

    DOEpatents

    Evans, Glen A.; Djabali, Malek; Selleri, Licia; Parry, Pauline

    2001-01-01

    In accordance with the present invention, there is provided an isolated peptide having the characteristics of human trithorax protein (as well as DNA encoding same, antisense DNA derived therefrom and antagonists therefor). The invention peptide is characterized by having a DNA binding domain comprising multiple zinc fingers and at least 40% amino acid identity with respect to the DNA binding domain of Drosophila trithorax protein and at least 70% conserved sequence with respect to the DNA binding domain of Drosophila trithorax protein, and wherein said peptide is encoded by a gene located at chromosome 11 of the human genome at q23. Also provided are methods for the treatment of subject(s) suffering from immunodeficiency, developmental abnormality, inherited disease, or cancer by administering to said subject a therapeutically effective amount of one of the above-described agents (i.e., peptide, antagonist therefor, DNA encoding said peptide or antisense DNA derived therefrom). Also provided is a method for the diagnosis, in a subject, of immunodeficiency, developmental abnormality, inherited disease, or cancer associated with disruption of chromosome 11 at q23.

  8. Site specific incorporation of keto amino acids into proteins

    DOEpatents

    Schultz, Peter G.; Wang, Lei

    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.

  9. Site specific incorporation of keto amino acids into proteins

    DOEpatents

    Schultz, Peter G.; Wang, Lei

    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

    DOEpatents

    Schultz, Peter G.; Wang, Lei

    2008-10-07

    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. Site specific incorporation of keto amino acids into proteins

    DOEpatents

    Schultz, Peter G.; Wang, Lei

    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.

  12. Site specific incorporation of keto amino acids into proteins

    DOEpatents

    Schultz, Peter G.; Wang, Lei

    2009-04-28

    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.

  13. Carbohydrate intake.

    PubMed

    Leturque, Armelle; Brot-Laroche, Edith; Le Gall, Maude

    2012-01-01

    Carbohydrates represent more than 50% of the energy sources present in most human diets. Sugar intake is regulated by metabolic, neuronal, and hedonic factors, and gene polymorphisms are involved in determining sugar preference. Nutrigenomic adaptations to carbohydrate availability have been evidenced in metabolic diseases, in the persistence of lactose digestion, and in amylase gene copy number. Furthermore, dietary oligosaccharides, fermentable by gut flora, can modulate the microbiotal diversity to the benefit of the host. Genetic diseases linked to mutations in the disaccharidase genes (sucrase-isomaltase, lactase) and in sugar transporter genes (sodium/glucose cotransporter 1, glucose transporters 1 and 2) severely impact carbohydrate intake. These diseases are revealed upon exposure to food containing the offending sugar, and withdrawal of this sugar from the diet prevents disease symptoms, failure to thrive, and premature death. Tailoring the sugar composition of diets to optimize wellness and to prevent the chronic occurrence of metabolic diseases is a future goal that may yet be realized through continued development of nutrigenetics and nutrigenomics approaches. PMID:22656375

  14. Paradigm for Improving Catalytic Ability of Industrial Enzymes: Linkage Distortions of Carbohydrates in Complexes with Crystalline Proteins

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Future innovations in applications of industrial enzymes to carbohydrates will require improved knowledge of the mode of action. This chapter explores whether one aspect of enzymatic hydrolysis of saccharides is a twisting distortion of the bonds between adjacent monosaccharides in larger carbohydra...

  15. Terrestrial carbohydrates support freshwater zooplankton during phytoplankton deficiency

    PubMed Central

    Taipale, Sami J.; Galloway, Aaron W. E.; Aalto, Sanni L.; Kahilainen, Kimmo K.; Strandberg, Ursula; Kankaala, Paula

    2016-01-01

    Freshwater food webs can be partly supported by terrestrial primary production, often deriving from plant litter of surrounding catchment vegetation. Although consisting mainly of poorly bioavailable lignin, with low protein and lipid content, the carbohydrates from fallen tree leaves and shoreline vegetation may be utilized by aquatic consumers. Here we show that during phytoplankton deficiency, zooplankton (Daphnia magna) can benefit from terrestrial particulate organic matter by using terrestrial-origin carbohydrates for energy and sparing essential fatty acids and amino acids for somatic growth and reproduction. Assimilated terrestrial-origin fatty acids from shoreline reed particles exceeded available diet, indicating that Daphnia may convert a part of their dietary carbohydrates to saturated fatty acids. This conversion was not observed with birch leaf diets, which had lower carbohydrate content. Subsequent analysis of 21 boreal and subarctic lakes showed that diet of herbivorous zooplankton is mainly based on high-quality phytoplankton rich in essential polyunsaturated fatty acids. The proportion of low-quality diets (bacteria and terrestrial particulate organic matter) was <28% of the assimilated carbon. Taken collectively, the incorporation of terrestrial carbon into zooplankton was not directly related to the concentration of terrestrial organic matter in experiments or lakes, but rather to the low availability of phytoplankton. PMID:27510848

  16. Terrestrial carbohydrates support freshwater zooplankton during phytoplankton deficiency.

    PubMed

    Taipale, Sami J; Galloway, Aaron W E; Aalto, Sanni L; Kahilainen, Kimmo K; Strandberg, Ursula; Kankaala, Paula

    2016-01-01

    Freshwater food webs can be partly supported by terrestrial primary production, often deriving from plant litter of surrounding catchment vegetation. Although consisting mainly of poorly bioavailable lignin, with low protein and lipid content, the carbohydrates from fallen tree leaves and shoreline vegetation may be utilized by aquatic consumers. Here we show that during phytoplankton deficiency, zooplankton (Daphnia magna) can benefit from terrestrial particulate organic matter by using terrestrial-origin carbohydrates for energy and sparing essential fatty acids and amino acids for somatic growth and reproduction. Assimilated terrestrial-origin fatty acids from shoreline reed particles exceeded available diet, indicating that Daphnia may convert a part of their dietary carbohydrates to saturated fatty acids. This conversion was not observed with birch leaf diets, which had lower carbohydrate content. Subsequent analysis of 21 boreal and subarctic lakes showed that diet of herbivorous zooplankton is mainly based on high-quality phytoplankton rich in essential polyunsaturated fatty acids. The proportion of low-quality diets (bacteria and terrestrial particulate organic matter) was <28% of the assimilated carbon. Taken collectively, the incorporation of terrestrial carbon into zooplankton was not directly related to the concentration of terrestrial organic matter in experiments or lakes, but rather to the low availability of phytoplankton. PMID:27510848

  17. Yuanhuapine-induced intestinal and hepatotoxicity were correlated with disturbance of amino acids, lipids, carbohydrate metabolism and gut microflora function: A rat urine metabonomic study.

    PubMed

    Chen, Yanyan; Duan, Jin-Ao; Guo, Jianming; Shang, Erxin; Tang, Yuping; Qian, Yefei; Tao, Weiwei; Liu, Pei

    2016-07-15

    This research was designed to study metabonomic characteristics of the toxicity induced by yuanhuapine, a major bioactive diterpenoid in a well-known traditional Chinese medicine-Genkwa Flos. General observation, blood biochemistry and histopathological examination were used to reflect yuanhuapine-induced toxicity. Urine samples from rats in control and yuanhuapine treated rats were analyzed by ultra-performance liquid chromatography tandem quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF/MS). Pattern recognition methods including principal components analysis (PCA), partial least-squared discriminant analysis (PLS-DA), orthogonal partial least-squared discriminant analysis (OPLS-DA) and computational system analysis were integrated to obtain comprehensive metabonomic profiling and pathways of the biological data sets. The results suggested that yuanhuapine could induce intestinal and liver damage. And 14 endogenous metabolites as biomarkers related to the amino acids metabolism, lipids metabolism, carbohydrate metabolism and gut microflora were significantly changed in the urine of yuanhuapine treated rats, which were firstly constructed the metabolomic feature profiling and metabolite interaction network of yuanhuapine-induced injury using pattern recognition methods and Ingenuity Pathway Analysis (IPA) approach. The present study showed that yuanhuapine-induced intestinal and hepatic toxicity were correlated with disturbance of amino acids metabolism, lipids metabolism, carbohydrate metabolism and gut microflora. PMID:26341729

  18. The Effects of Breakfast Consumption and Composition on Metabolic Wellness with a Focus on Carbohydrate Metabolism.

    PubMed

    Maki, Kevin C; Phillips-Eakley, Alyssa K; Smith, Kristen N

    2016-05-01

    Findings from epidemiologic studies indicate that there are associations between breakfast consumption and a lower risk of type 2 diabetes mellitus (T2DM) and metabolic syndrome, prompting interest in the influence of breakfast on carbohydrate metabolism and indicators of T2DM risk. The objective of this review was to summarize the available evidence from randomized controlled trials assessing the impact of breakfast on variables related to carbohydrate metabolism and metabolic wellness. Consuming compared with skipping breakfast appeared to improve glucose and insulin responses throughout the day. Breakfast composition may also be important. Dietary patterns high in rapidly available carbohydrate were associated with elevated T2DM risk. Therefore, partial replacement of rapidly available carbohydrate with other dietary components, such as whole grains and cereal fibers, proteins, and unsaturated fatty acids (UFAs), at breakfast may be a useful strategy for producing favorable metabolic outcomes. Consumption of fermentable and viscous dietary fibers at breakfast lowers glycemia and insulinemia. Fermentable fibers likely act through enhancing insulin sensitivity later in the day, and viscous fibers have an acute effect to slow the rate of carbohydrate absorption. Partially substituting protein for rapidly available carbohydrate enhances satiety and diet-induced thermogenesis, and also favorably affects lipoprotein lipids and blood pressure. Partially substituting UFA for carbohydrate has been associated with improved insulin sensitivity, lipoprotein lipids, and blood pressure. Overall, the available evidence suggests that consuming breakfast foods high in whole grains and cereal fiber, while limiting rapidly available carbohydrate, is a promising strategy for metabolic health promotion. PMID:27184288

  19. [Acid-soluble collagen in the skin of rats who received a tryptophan load and were kept on a protein-free diet].

    PubMed

    Pechenova, T N; Gulyĭ, M F; Volodina, T T; Solodova, E V; Popova, N N

    1983-01-01

    Crystalline preparations of acid-soluble collagen of rat skin in norm and with tryptophan load against a background of the protein-free diet were fractionated by differential salting out using NaCl in concentrations corresponding to precipitation zones of collagen 1,3 and 4. Amino acid composition, electrophoretic mobility in polyacrylamide gel, profiles of elution from CM-cellulose, content of the carbohydrate component and--S--S-bonds were studied in proteins of the mentioned fractions and in the precipitate insoluble after the pepsin action. Essential differences as compared to the normal level in the amino acid composition and elution profiles were detected in the fraction corresponding to collagen I. Quantitative changes in the carbohydrate component and--S--S-bonds occur due to the fraction inaccessible to the persin action. PMID:6829075

  20. Daily Overfeeding from Protein and/or Carbohydrate Supplementation for Eight Weeks in Conjunction with Resistance Training Does not Improve Body Composition and Muscle Strength or Increase Markers Indicative of Muscle Protein Synthesis and Myogenesis in Resistance-Trained Males

    PubMed Central

    Spillane, Mike; Willoughby, Darryn S.

    2016-01-01

    This study determined the effects of heavy resistance training and daily overfeeding with carbohydrate and/or protein on blood and skeletal muscle markers of protein synthesis (MPS), myogenesis, body composition, and muscle performance. Twenty one resistance-trained males were randomly assigned to either a protein + carbohydrate [HPC (n = 11)] or a carbohydrate [HC (n = 10)] supplement group in a double-blind fashion. Body composition and muscle performance were assessed, and venous blood samples and muscle biopsies were obtained before and after eight weeks of resistance training and supplementation. Data were analyzed by two-way ANOVA (p ≤ 0.05). Total body mass, body water, and fat mass were significantly increased in both groups in response to resistance training, but not supplementation (p < 0.05); however, lean mass was not significantly increased in either group (p = 0.068). Upper- (p = 0.024) and lower-body (p = 0.001) muscle strength and myosin heavy chain (MHC) 1 (p = 0.039) and MHC 2A (p = 0.027) were also significantly increased with resistance training. Serum IGF-1, GH, and HGF were not significantly affected (p > 0.05). Muscle total DNA, total protein, and c-Met were not significantly affected (p > 0.05). In conjunction with resistance training, the peri-exercise and daily overfeeding of protein and/or carbohydrate did not preferentially improve body composition, muscle performance, and markers indicative of MPS and myogenic activation. Key points In response to 56 days of heavy resistance training and HC or HPC supplementation, similar increases in muscle mass and strength in both groups occurred; however, the increases were not different between supplement groups. The supplementation of HPC had no preferential effect on augmenting serum IGF-1 GH, or HGF. The supplementation of HPC had no preferential effect on augmenting increases in total muscle protein content or the myogenic markers, total DNA and muscle cMet content. In response to 56 days of

  1. Daily Overfeeding from Protein and/or Carbohydrate Supplementation for Eight Weeks in Conjunction with Resistance Training Does not Improve Body Composition and Muscle Strength or Increase Markers Indicative of Muscle Protein Synthesis and Myogenesis in Resistance-Trained Males.

    PubMed

    Spillane, Mike; Willoughby, Darryn S

    2016-03-01

    This study determined the effects of heavy resistance training and daily overfeeding with carbohydrate and/or protein on blood and skeletal muscle markers of protein synthesis (MPS), myogenesis, body composition, and muscle performance. Twenty one resistance-trained males were randomly assigned to either a protein + carbohydrate [HPC (n = 11)] or a carbohydrate [HC (n = 10)] supplement group in a double-blind fashion. Body composition and muscle performance were assessed, and venous blood samples and muscle biopsies were obtained before and after eight weeks of resistance training and supplementation. Data were analyzed by two-way ANOVA (p ≤ 0.05). Total body mass, body water, and fat mass were significantly increased in both groups in response to resistance training, but not supplementation (p < 0.05); however, lean mass was not significantly increased in either group (p = 0.068). Upper- (p = 0.024) and lower-body (p = 0.001) muscle strength and myosin heavy chain (MHC) 1 (p = 0.039) and MHC 2A (p = 0.027) were also significantly increased with resistance training. Serum IGF-1, GH, and HGF were not significantly affected (p > 0.05). Muscle total DNA, total protein, and c-Met were not significantly affected (p > 0.05). In conjunction with resistance training, the peri-exercise and daily overfeeding of protein and/or carbohydrate did not preferentially improve body composition, muscle performance, and markers indicative of MPS and myogenic activation. Key pointsIn response to 56 days of heavy resistance training and HC or HPC supplementation, similar increases in muscle mass and strength in both groups occurred; however, the increases were not different between supplement groups.The supplementation of HPC had no preferential effect on augmenting serum IGF-1 GH, or HGF.The supplementation of HPC had no preferential effect on augmenting increases in total muscle protein content or the myogenic markers, total DNA and muscle cMet content.In response to 56 days of a

  2. Determination of carboxylic acids, carbohydrates, glycerol, ethanol, and 5-HMF in beer by high-performance liquid chromatography and UV-refractive index double detection.

    PubMed

    Castellari, M; Sartini, E; Spinabelli, U; Riponi, C; Galassi, S

    2001-06-01

    A high-performance liquid chromatographic method is proposed for the simultaneous separation of main carboxylic acids, carbohydrates, ethanol, glycerol, and 5-HMF in beer by direct injection. A column packed with a sulfonated divinyl benzene-styrene copolymer and an isocratic elution with 0.0045N sulfuric acid and acetonitrile (6%, v/v) are employed. UV and refractive index detectors connected in series are also used to reduce the matrix interference of phenolic compounds. In conditions described, nine compounds are quantitated in a single chromatographic run without any pretreatment except for sample dilution and filtration before injection. Precision, accuracy, linearity of response, limit of detection, and limit of quantitation are also evaluated for each compound. Satisfactory results are obtained to justify the application of this method to all phases of beer production for process and quality control. PMID:11396687

  3. Carbohydrate Recognition Properties of Human Ficolins

    PubMed Central

    Gout, Evelyne; Garlatti, Virginie; Smith, David F.; Lacroix, Monique; Dumestre-Pérard, Chantal; Lunardi, Thomas; Martin, Lydie; Cesbron, Jean-Yves; Arlaud, Gérard J.; Gaboriaud, Christine; Thielens, Nicole M.

    2010-01-01

    Ficolins are oligomeric innate immune recognition proteins consisting of a collagen-like region and a fibrinogen-like recognition domain that bind to pathogen- and apoptotic cell-associated molecular patterns. To investigate their carbohydrate binding specificities, serum-derived L-ficolin and recombinant H- and M-ficolins were fluorescently labeled, and their carbohydrate binding ability was analyzed by glycan array screening. L-ficolin preferentially recognized disulfated N-acetyllactosamine and tri- and tetrasaccharides containing terminal galactose or N-acetylglucosamine. Binding was sensitive to the position and orientation of the bond between N-acetyllactosamine and the adjacent carbohydrate. No significant binding of H-ficolin to any of the 377 glycans probed could be detected, providing further evidence for its poor lectin activity. M-ficolin bound preferentially to 9-O-acetylated 2-6-linked sialic acid derivatives and to various glycans containing sialic acid engaged in a 2-3 linkage. To further investigate the structural basis of sialic acid recognition by M-ficolin, point mutants were produced in which three residues of the fibrinogen domain were replaced by their counterparts in L-ficolin. Mutations G221F and A256V inhibited binding to the 9-O-acetylated sialic acid derivatives, whereas Y271F abolished interaction with all sialic acid-containing glycans. The crystal structure of the Y271F mutant fibrinogen domain was solved, showing that the mutation does not alter the structure of the ligand binding pocket. These analyses reveal novel ficolin ligands such as sulfated N-acetyllactosamine (L-ficolin) and gangliosides (M-ficolin) and provide precise insights into the sialic acid binding specificity of M-ficolin, emphasizing the essential role of Tyr271 in this respect. PMID:20032467

  4. Microspectrophotometric quantitation of nucleic acid and protein in irradiated epidermis.

    PubMed

    Conti, C J; Giménez, I B; Cabrini, R L

    1976-03-01

    Nucleic acid and proteins of newborn rat tail subjected to local X-irradiation were microspectrophotometrically studied. Feulgen, gallocyanine chrom-alum and naphthol yellow S methods were performed for demonstration of DNA, total nucleic acid and proteins respectively. The amount of proteins and total nucleic acid increases concomitantly with reactional acanthosis. However, the proteins and nucleic acid decrease as from day 3 post-irradiation. A tentative interpretation of the results would point to a giantization of the epidermic cells not only caused by aqueous imbition but also by an actual increase of the cellular protoplasm. PMID:1258094

  5. Relatedness of acyl carrier proteins shown by amino acid compositions.

    PubMed

    Walker, T A; Ernst-Fonberg, M L

    1982-01-01

    1. Relatedness among the following carrier proteins was assessed on the basis of amino acid compositions: eight acyl carrier proteins (ACP's) associated with fatty acid synthesis, ACP's associated with citrate lyase and citramalate lyase, a biotin carboxyl carrier protein and cytochrome 552. Two independent indices of amino acid composition were used. 2. The fatty acid synthesis-associated ACP's of many organisms and the lyase-associated ACP's show a high degree of relatedness among one another. 3. The ACP's show no relatedness to biotin carboxyl carrier protein or cytochrome 552. PMID:7128903

  6. AMP-activated protein kinase and ATP-citrate lyase are two distinct molecular targets for ETC-1002, a novel small molecule regulator of lipid and carbohydrate metabolism[S

    PubMed Central

    Pinkosky, Stephen L.; Filippov, Sergey; Srivastava, Rai Ajit K.; Hanselman, Jeffrey C.; Bradshaw, Cheryl D.; Hurley, Timothy R.; Cramer, Clay T.; Spahr, Mark A.; Brant, Ashley F.; Houghton, Jacob L.; Baker, Chris; Naples, Mark; Adeli, Khosrow; Newton, Roger S.

    2013-01-01

    ETC-1002 (8-hydroxy-2,2,14,14-tetramethylpentadecanedioic acid) is a novel investigational drug being developed for the treatment of dyslipidemia and other cardio-metabolic risk factors. The hypolipidemic, anti-atherosclerotic, anti-obesity, and glucose-lowering properties of ETC-1002, characterized in preclinical disease models, are believed to be due to dual inhibition of sterol and fatty acid synthesis and enhanced mitochondrial long-chain fatty acid β-oxidation. However, the molecular mechanism(s) mediating these activities remained undefined. Studies described here show that ETC-1002 free acid activates AMP-activated protein kinase in a Ca2+/calmodulin-dependent kinase β-independent and liver kinase β 1-dependent manner, without detectable changes in adenylate energy charge. Furthermore, ETC-1002 is shown to rapidly form a CoA thioester in liver, which directly inhibits ATP-citrate lyase. These distinct molecular mechanisms are complementary in their beneficial effects on lipid and carbohydrate metabolism in vitro and in vivo. Consistent with these mechanisms, ETC-1002 treatment reduced circulating proatherogenic lipoproteins, hepatic lipids, and body weight in a hamster model of hyperlipidemia, and it reduced body weight and improved glycemic control in a mouse model of diet-induced obesity. ETC-1002 offers promise as a novel therapeutic approach to improve multiple risk factors associated with metabolic syndrome and benefit patients with cardiovascular disease. PMID:23118444

  7. Effect of carbohydrate source and cottonseed meal level in the concentrate on feed intake, nutrient digestibility, rumen fermentation and microbial protein synthesis in swamp buffaloes.

    PubMed

    Wanapat, M; Pilajun, R; Polyorach, S; Cherdthong, A; Khejornsart, P; Rowlinson, P

    2013-07-01

    The objective of this study was to investigate the effect of carbohydrate source and cottonseed meal level in the concentrate on feed intake, nutrient digestibility, rumen fermentation and microbial protein synthesis in swamp buffaloes. Four, 4-yr old rumen fistulated swamp buffaloes were randomly assigned to receive four dietary treatments according to a 2×2 factorial arrangement in a 4×4 Latin square design. Factor A was carbohydrate source; cassava chip (CC) and CC+rice bran at a ratio 3:1 (CR3:1), and factor B was level of cottonseed meal (CM); 109 g CP/kg (LCM) and 328 g CP/kg (HCM) in isonitrogenous diets (490 g CP/kg). Buffaloes received urea-treated rice straw ad libitum and supplemented with 5 g concentrate/kg BW. It was found that carbohydrate source did not affect feed intake, nutrient intake, digested nutrients, nutrient digestibility, ammonia nitrogen concentration, fungi and bacterial populations, or microbial protein synthesis (p>0.05). Ruminal pH at 6 h after feeding and the population of protozoa at 4 h after feeding were higher when buffalo were fed with CC than in the CR3:1 treatment (p<0.05). Buffalo fed with HCM had a lower roughage intake, nutrient intake, population of total viable and cellulolytic bacteria and microbial nitrogen supply than the LCM fed group (p<0.05). However, nutrient digestibility, ruminal pH, ammonia concentration, population of protozoa and fungi, and efficiency of microbial protein synthesis were not affected by cottonseed meal levels (p>0.05). Based on this experiment, concentrate with a low level of cottonseed meal could be fed with cassava chips as an energy source in swamp buffalo receiving rice straw. PMID:25049873

  8. Role of choline deficiency in the Fatty liver phenotype of mice fed a low protein, very low carbohydrate ketogenic diet.

    PubMed

    Schugar, Rebecca C; Huang, Xiaojing; Moll, Ashley R; Brunt, Elizabeth M; Crawford, Peter A

    2013-01-01

    Though widely employed for clinical intervention in obesity, metabolic syndrome, seizure disorders and other neurodegenerative diseases, the mechanisms through which low carbohydrate ketogenic diets exert their ameliorative effects still remain to be elucidated. Rodent models have been used to identify the metabolic and physiologic alterations provoked by ketogenic diets. A commonly used rodent ketogenic diet (Bio-Serv F3666) that is very high in fat (~94% kcal), very low in carbohydrate (~1% kcal), low in protein (~5% kcal), and choline restricted (~300 mg/kg) provokes robust ketosis and weight loss in mice, but through unknown mechanisms, also causes significant hepatic steatosis, inflammation, and cellular injury. To understand the independent and synergistic roles of protein restriction and choline deficiency on the pleiotropic effects of rodent ketogenic diets, we studied four custom diets that differ only in protein (5% kcal vs. 10% kcal) and choline contents (300 mg/kg vs. 5 g/kg). C57BL/6J mice maintained on the two 5% kcal protein diets induced the most significant ketoses, which was only partially diminished by choline replacement. Choline restriction in the setting of 10% kcal protein also caused moderate ketosis and hepatic fat accumulation, which were again attenuated when choline was replete. Key effects of the 5% kcal protein diet - weight loss, hepatic fat accumulation, and mitochondrial ultrastructural disarray and bioenergetic dysfunction - were mitigated by choline repletion. These studies indicate that synergistic effects of protein restriction and choline deficiency influence integrated metabolism and hepatic pathology in mice when nutritional fat content is very high, and support the consideration of dietary choline content in ketogenic diet studies in rodents to limit hepatic mitochondrial dysfunction and fat accumulation. PMID:24009777

  9. Role of Choline Deficiency in the Fatty Liver Phenotype of Mice Fed a Low Protein, Very Low Carbohydrate Ketogenic Diet

    PubMed Central

    Schugar, Rebecca C.; Huang, Xiaojing; Moll, Ashley R.; Brunt, Elizabeth M.; Crawford, Peter A.

    2013-01-01

    Though widely employed for clinical intervention in obesity, metabolic syndrome, seizure disorders and other neurodegenerative diseases, the mechanisms through which low carbohydrate ketogenic diets exert their ameliorative effects still remain to be elucidated. Rodent models have been used to identify the metabolic and physiologic alterations provoked by ketogenic diets. A commonly used rodent ketogenic diet (Bio-Serv F3666) that is very high in fat (~94% kcal), very low in carbohydrate (~1% kcal), low in protein (~5% kcal), and choline restricted (~300 mg/kg) provokes robust ketosis and weight loss in mice, but through unknown mechanisms, also causes significant hepatic steatosis, inflammation, and cellular injury. To understand the independent and synergistic roles of protein restriction and choline deficiency on the pleiotropic effects of rodent ketogenic diets, we studied four custom diets that differ only in protein (5% kcal vs. 10% kcal) and choline contents (300 mg/kg vs. 5 g/kg). C57BL/6J mice maintained on the two 5% kcal protein diets induced the most significant ketoses, which was only partially diminished by choline replacement. Choline restriction in the setting of 10% kcal protein also caused moderate ketosis and hepatic fat accumulation, which were again attenuated when choline was replete. Key effects of the 5% kcal protein diet – weight loss, hepatic fat accumulation, and mitochondrial ultrastructural disarray and bioenergetic dysfunction – were mitigated by choline repletion. These studies indicate that synergistic effects of protein restriction and choline deficiency influence integrated metabolism and hepatic pathology in mice when nutritional fat content is very high, and support the consideration of dietary choline content in ketogenic diet studies in rodents to limit hepatic mitochondrial dysfunction and fat accumulation. PMID:24009777

  10. Nonfeed application of rendered animal proteins for microbial production of eicosapentaenoic acid by the fungus Pythium irregulare.

    PubMed

    Liang, Yi; Garcia, Rafael A; Piazza, George J; Wen, Zhiyou

    2011-11-23

    Rendered animal proteins are well suited for animal nutrition applications, but the market is maturing, and there is a need to develop new uses for these products. The objective of this study is to explore the possibility of using animal proteins as a nutrient source for microbial production of omega-3 polyunsaturated fatty acids by the microalga Schizochytrium limacinum and the fungus Pythium irregulare. To be absorbed by the microorganisms, the proteins needed to be hydrolyzed into small peptides and free amino acids. The utility of the protein hydrolysates for microorganisms depended on the hydrolysis method used and the type of microorganism. The enzymatic hydrolysates supported better cell growth performance than the alkali hydrolysates did. P. irregulare displayed better overall growth performance on the experimental hydrolysates compared to S. limacinum. When P. irregulare was grown in medium containing 10 g/L enzymatic hydrolysate derived from meat and bone meal or feather meal, the performance of cell growth, lipid synthesis, and omega-3 fatty acid production was comparable to the that of culture using commercial yeast extract. The fungal biomass derived from the animal proteins had 26-29% lipid, 32-34% protein, 34-39% carbohydrate, and <2% ash content. The results show that it is possible to develop a nonfeed application for rendered animal protein by hydrolysis of the protein and feeding to industrial microorganisms which can produce omega-3 fatty acids for making omega-3-fortified foods or feeds. PMID:22010831

  11. Protein turnover, amino acid requirements and recommendations for athletes and active populations.

    PubMed

    Poortmans, J R; Carpentier, A; Pereira-Lancha, L O; Lancha Jr, A

    2012-10-01

    Skeletal muscle is the major deposit of protein molecules. As for any cell or tissue, total muscle protein reflects a dynamic turnover between net protein synthesis and degradation. Noninvasive and invasive techniques have been applied to determine amino acid catabolism and muscle protein building at rest, during exercise and during the recovery period after a single experiment or training sessions. Stable isotopic tracers ((13)C-lysine, (15)N-glycine, ²H5-phenylalanine) and arteriovenous differences have been used in studies of skeletal muscle and collagen tissues under resting and exercise conditions. There are different fractional synthesis rates in skeletal muscle and tendon tissues, but there is no major difference between collagen and myofibrillar protein synthesis. Strenuous exercise provokes increased proteolysis and decreased protein synthesis, the opposite occurring during the recovery period. Individuals who exercise respond differently when resistance and endurance types of contractions are compared. Endurance exercise induces a greater oxidative capacity (enzymes) compared to resistance exercise, which induces fiber hypertrophy (myofibrils). Nitrogen balance (difference between protein intake and protein degradation) for athletes is usually balanced when the intake of protein reaches 1.2 g · kg(-1) · day(-1) compared to 0.8 g · kg(-1) · day(-1) in resting individuals. Muscular activities promote a cascade of signals leading to the stimulation of eukaryotic initiation of myofibrillar protein synthesis. As suggested in several publications, a bolus of 15-20 g protein (from skimmed milk or whey proteins) and carbohydrate (± 30 g maltodextrine) drinks is needed immediately after stopping exercise to stimulate muscle protein and tendon collagen turnover within 1 h. PMID:22666780

  12. Protein turnover, amino acid requirements and recommendations for athletes and active populations

    PubMed Central

    Poortmans, J.R.; Carpentier, A.; Pereira-Lancha, L.O.; Lancha, A.

    2012-01-01

    Skeletal muscle is the major deposit of protein molecules. As for any cell or tissue, total muscle protein reflects a dynamic turnover between net protein synthesis and degradation. Noninvasive and invasive techniques have been applied to determine amino acid catabolism and muscle protein building at rest, during exercise and during the recovery period after a single experiment or training sessions. Stable isotopic tracers (13C-lysine, 15N-glycine, 2H5-phenylalanine) and arteriovenous differences have been used in studies of skeletal muscle and collagen tissues under resting and exercise conditions. There are different fractional synthesis rates in skeletal muscle and tendon tissues, but there is no major difference between collagen and myofibrillar protein synthesis. Strenuous exercise provokes increased proteolysis and decreased protein synthesis, the opposite occurring during the recovery period. Individuals who exercise respond differently when resistance and endurance types of contractions are compared. Endurance exercise induces a greater oxidative capacity (enzymes) compared to resistance exercise, which induces fiber hypertrophy (myofibrils). Nitrogen balance (difference between protein intake and protein degradation) for athletes is usually balanced when the intake of protein reaches 1.2 g·kg−1·day−1 compared to 0.8 g·kg−1·day−1 in resting individuals. Muscular activities promote a cascade of signals leading to the stimulation of eukaryotic initiation of myofibrillar protein synthesis. As suggested in several publications, a bolus of 15-20 g protein (from skimmed milk or whey proteins) and carbohydrate (± 30 g maltodextrine) drinks is needed immediately after stopping exercise to stimulate muscle protein and tendon collagen turnover within 1 h. PMID:22666780

  13. Post-exercise whey protein hydrolysate supplementation induces a greater increase in muscle protein synthesis than its constituent amino acid content.

    PubMed

    Kanda, Atsushi; Nakayama, Kyosuke; Fukasawa, Tomoyuki; Koga, Jinichiro; Kanegae, Minoru; Kawanaka, Kentaro; Higuchi, Mitsuru

    2013-09-28

    It is well known that ingestion of a protein source is effective in stimulating muscle protein synthesis after exercise. In addition, there are numerous reports on the impact of leucine and leucine-rich whey protein on muscle protein synthesis and mammalian target of rapamycin (mTOR) signalling. However, there is only limited information on the effects of whey protein hydrolysates (WPH) on muscle protein synthesis and mTOR signalling. The aim of the present study was to compare the effects of WPH and amino acids on muscle protein synthesis and the initiation of translation in skeletal muscle during the post-exercise phase. Male Sprague–Dawley rats swam for 2 h to depress muscle protein synthesis. Immediately after exercise, the animals were administered either carbohydrate (CHO), CHO plus an amino acid mixture (AA) or CHO plus WPH. At 1 h after exercise, the supplements containing whey-based protein (AA and WPH) caused a significant increase in the fractional rate of protein synthesis (FSR) compared with CHO. WPH also caused a significant increase in FSR compared with AA. Post-exercise ingestion of WPH caused a significant increase in the phosphorylation of mTOR levels compared with AA or CHO. In addition, WPH caused greater phosphorylation of ribosomal protein S6 kinase and eukaryotic initiation factor 4E-binding protein 1 than AA and CHO. In contrast, there was no difference in plasma amino acid levels following supplementation with either AA or WPH. These results indicate that WPH may include active components that are superior to amino acids for stimulating muscle protein synthesis and initiating translation. PMID:23388415

  14. Strained cycloalkynes as new protein sulfenic acid traps.

    PubMed

    Poole, Thomas H; Reisz, Julie A; Zhao, Weiling; Poole, Leslie B; Furdui, Cristina M; King, S Bruce

    2014-04-30

    Protein sulfenic acids are formed by the reaction of biologically relevant reactive oxygen species with protein thiols. Sulfenic acid formation modulates the function of enzymes and transcription factors either directly or through the subsequent formation of protein disulfide bonds. Identifying the site, timing, and conditions of protein sulfenic acid formation remains crucial to understanding cellular redox regulation. Current methods for trapping and analyzing sulfenic acids involve the use of dimedone and other nucleophilic 1,3-dicarbonyl probes that form covalent adducts with cysteine-derived protein sulfenic acids. As a mechanistic alternative, the present study describes highly strained bicyclo[6.1.0]nonyne (BCN) derivatives as concerted traps of sulfenic acids. These strained cycloalkynes react efficiently with sulfenic acids in proteins and small molecules yielding stable alkenyl sulfoxide products at rates more than 100× greater than 1,3-dicarbonyl reagents enabling kinetic competition with physiological sulfur chemistry. Similar to the 1,3-dicarbonyl reagents, the BCN compounds distinguish the sulfenic acid oxoform from the thiol, disulfide, sulfinic acid, and S-nitrosated forms of cysteine while displaying an acceptable cell toxicity profile. The enhanced rates demonstrated by these strained alkynes identify them as new bioorthogonal probes that should facilitate the discovery of previously unknown sulfenic acid sites and their parent proteins. PMID:24724926

  15. Antitussive Activity of the Water-Extracted Carbohydrate Polymer from Terminalia chebula on Citric Acid-Induced Cough

    PubMed Central

    Chatterjee, Udipta Ranjan; Majee, Sujay Kumar; Ray, Bimalendu

    2013-01-01

    Terminalia chebula, a medicinal plant, is widely used in the management of various diseases. As the water extract of its dried ripe fruit is a frequently used preparation, we decided to look for bioactive polysaccharide in this extract. We demonstrate that the obtained polysaccharide fraction, CP, contained a highly branched arabinogalactan protein having a (1 → 3)-, (1 → 6)- and (1 → 3, 6)-linked β-D-Galp together with (1 → 5)- and (1 → 3)-linked α-L-Araf and nonreducing end units of α-L-Araf. This polymer possesses strong antitussive property. Our results showed that the number of citric acid-induced cough efforts decreased significantly after the oral application of polysaccharide fraction in a dose of 50 mg kg−1 body weight. Its antitussive efficacy was higher than cough suppressive effect of standard drug codeine. Therefore, traditional aqueous extraction method provides a major polysaccharide, which induces a pharmacological effect: this could represent an attractive approach in phytotherapeutic managements. PMID:23878602

  16. iTRAQ-based quantitative proteomics analysis revealed alterations of carbohydrate metabolism pathways and mitochondrial proteins in a male sterile cybrid pummelo.

    PubMed

    Zheng, Bei-Bei; Fang, Yan-Ni; Pan, Zhi-Yong; Sun, Li; Deng, Xiu-Xin; Grosser, Jude W; Guo, Wen-Wu

    2014-06-01

    Comprehensive and quantitative proteomic information on citrus floral bud is significant for understanding male sterility of the cybrid pummelo (G1+HBP) with nuclear genome of HBP and foreign mitochondrial genome of G1. Scanning electron microscopy and transmission electron microscopy analyses of the anthers showed that the development of pollen wall in G1+HBP was severely defective with a lack of exine and sporopollenin formation. Proteomic analysis was used to identify the differentially expressed proteins between male sterile G1+HBP and fertile type (HBP) with the aim to clarify their potential roles in anther development and male sterility. On the basis of iTRAQ quantitative proteomics, we identified 2235 high-confidence protein groups, 666 of which showed differentially expressed profiles in one or more stages. Proteins up- or down-regulated in G1+HBP were mainly involved in carbohydrate and energy metabolism (e.g., pyruvate dehydrogenase, isocitrate dehydrogenase, ATP synthase, and malate dehydrogenase), nucleotide binding (RNA-binding proteins), protein synthesis and degradation (e.g., ribosome proteins and proteasome subunits). Additionally, the proteins located in mitochondria also showed changed expression patterns. These findings provide a valuable inventory of proteins involved in floral bud development and contribute to elucidate the mechanism of cytoplasmic male sterility in the cybrid pummelo. PMID:24824475

  17. Role of different additives and metallic micro minerals on the enhanced citric acid production by Aspergillus niger MNNG-115 using different carbohydrate materials.

    PubMed

    Ali, Sikander; Haq, Ikram-ul

    2005-01-01

    The present investigation deals with the promotry effect of different additives and metallic micro minerals on citric acid production by Aspergillus niger MNNG-115 using different carbohydrate materials. For this, sugar cane bagasse was fortified with sucrose salt medium. Ethanol and coconut oil at 3.0% (v/w) level increased citric acid productivity. Fluoroacetate at a concentration of 1.0 mg/ml bagasse enhanced the yield of citric acid significantly. However, the addition of ethanol and fluoroacetate after 6 h of growth gave the maximum conversion of available sugar to citric acid. In another study, influence of some metallic micro-minerals viz. copper sulphate, molybdenum sulphate, zinc sulphate and cobalt sulphate on microbial synthesis of citric acid using molasses medium was also carried out. It was found that copper sulphate and molybdenum sulphate remarkably enhanced the production of citric acid while zinc sulphate was not so effective. However, cobalt sulphate was the least effective for microbial biosynthesis of citric acid under the same experimental conditions. In case of CuSO(4), the strain of Aspergillus niger MNNG-115 showed enhanced citric productivity with experimental (9.80%) over the control (7.54%). In addition, the specific productivity of the culture at 30 ppm CuSO(4) (Q(p) = 0.012a g/g cells/h) was several folds higher than other all other concentrations. All kinetic parameters including yield coefficients and volumetric rates revealed the hyper productivity of citric acid by CuSO(4) using blackstrap molasses as the basal carbon source. PMID:15678560

  18. Echinococcus granulosus fatty acid binding proteins subcellular localization.

    PubMed

    Alvite, Gabriela; Esteves, Adriana

    2016-05-01

    Two fatty acid binding proteins, EgFABP1 and EgFABP2, were isolated from the parasitic platyhelminth Echinococcus granulosus. These proteins bind fatty acids and have particular relevance in flatworms since de novo fatty acids synthesis is absent. Therefore platyhelminthes depend on the capture and intracellular distribution of host's lipids and fatty acid binding proteins could participate in lipid distribution. To elucidate EgFABP's roles, we investigated their intracellular distribution in the larval stage by a proteomic approach. Our results demonstrated the presence of EgFABP1 isoforms in cytosolic, nuclear, mitochondrial and microsomal fractions, suggesting that these molecules could be involved in several cellular processes. PMID:26873273

  19. Role of Ingested Amino Acids and Protein in the Promotion of Resistance Exercise-Induced Muscle Protein Anabolism.

    PubMed

    Reidy, Paul T; Rasmussen, Blake B

    2016-02-01

    The goal of this critical review is to comprehensively assess the evidence for the molecular, physiologic, and phenotypic skeletal muscle responses to resistance exercise (RE) combined with the nutritional intervention of protein and/or amino acid (AA) ingestion in young adults. We gathered the literature regarding the translational response in human skeletal muscle to acute exposure to RE and protein/AA supplements and the literature describing the phenotypic skeletal muscle adaptation to RE and nutritional interventions. Supplementation of protein/AAs with RE exhibited clear protein dose-dependent effects on translational regulation (protein synthesis) through mammalian target of rapamycin complex 1 (mTORC1) signaling, which was most apparent through increases in p70 ribosomal protein S6 kinase 1 (S6K1) phosphorylation, compared with postexercise recovery in the fasted or carbohydrate-fed state. These acute findings were critically tested via long-term exposure to RE training (RET) and protein/AA supplementation, and it was determined that a diminishing protein/AA supplement effect occurs over a prolonged exposure stimulus after exercise training. Furthermore, we found that protein/AA supplements, combined with RET, produced a positive, albeit minor, effect on the promotion of lean mass growth (when assessed in >20 participants/treatment); a negligible effect on muscle mass; and a negligible to no additional effect on strength. A potential concern we discovered was that the majority of the exercise training studies were underpowered in their ability to discern effects of protein/AA supplementation. Regardless, even when using optimal methodology and large sample sizes, it is clear that the effect size for protein/AA supplementation is low and likely limited to a subset of individuals because the individual variability is high. With regard to nutritional intakes, total protein intake per day, rather than protein timing or quality, appears to be more of a factor on

  20. Photoaffinity labeling of retinoic acid-binding proteins.

    PubMed Central

    Bernstein, P S; Choi, S Y; Ho, Y C; Rando, R R

    1995-01-01

    Retinoid-binding proteins are essential mediators of vitamin A function in vertebrate organisms. They solubilize and stabilize retinoids, and they direct the intercellular and intracellular trafficking, transport, and metabolic function of vitamin A compounds in vision and in growth and development. Although many soluble retinoid-binding proteins and receptors have been purified and extensively characterized, relatively few membrane-associated enzymes and other proteins that interact with retinoids have been isolated and studied, due primarily to their inherent instabilities during purification. In an effort to identify and purify previously uncharacterized retinoid-binding proteins, it is shown that radioactively labeled all-trans-retinoic acid can be used as a photoaffinity labeling reagent to specifically tag two known retinoic acid-binding proteins, cellular retinoic acid-binding protein and albumin, in complex mixtures of cytosolic proteins. Additionally, a number of other soluble and membrane-associated proteins that bind all-trans-[11,12-3H]retinoic acid with high specificity are labeled utilizing the same photoaffinity techniques. Most of these labeled proteins have molecular weights that do not correspond to any known retinoid-binding proteins. Thus, photoaffinity labeling with all-trans-retinoic acid and related photoactivatable retinoids is a method that should prove extremely useful in the identification and purification of novel soluble and membrane-associated retinoid-binding proteins from ocular and nonocular tissues. Images Fig. 1 Fig. 2 Fig. 3 Fig. 4 PMID:7846032

  1. Molecular recognition of surface-immobilized carbohydrates by a synthetic lectin

    PubMed Central

    Rauschenberg, Melanie; Fritz, Eva-Corrina; Schulz, Christian; Kaufmann, Tobias

    2014-01-01

    Summary The molecular recognition of carbohydrates and proteins mediates a wide range of physiological processes and the development of synthetic carbohydrate receptors (“synthetic lectins”) constitutes a key advance in biomedical technology. In this article we report a synthetic lectin that selectively binds to carbohydrates immobilized in a molecular monolayer. Inspired by our previous work, we prepared a fluorescently labeled synthetic lectin consisting of a cyclic dimer of the tripeptide Cys-His-Cys, which forms spontaneously by air oxidation of the monomer. Amine-tethered derivatives of N-acetylneuraminic acid (NANA), β-D-galactose, β-D-glucose and α-D-mannose were microcontact printed on epoxide-terminated self-assembled monolayers. Successive prints resulted in simple microarrays of two carbohydrates. The selectivity of the synthetic lectin was investigated by incubation on the immobilized carbohydrates. Selective binding of the synthetic lectin to immobilized NANA and β-D-galactose was observed by fluorescence microscopy. The selectivity and affinity of the synthetic lectin was screened in competition experiments. In addition, the carbohydrate binding of the synthetic lectin was compared with the carbohydrate binding of the lectins concanavalin A and peanut agglutinin. It was found that the printed carbohydrates retain their characteristic selectivity towards the synthetic and natural lectins and that the recognition of synthetic and natural lectins is strictly orthogonal. PMID:24991289

  2. Avian serum. cap alpha. /sub 1/-glycoprotein, hemopexin, differing significantly in both amino acid and carbohydrate composition from mammalian (. beta. -glycoprotein) counter parts

    SciTech Connect

    Goldfarb, V.; Trimble, R.B.; Falco, M.D.; Liem, H.H.; Metcalfe, S.A.; Wellner, D.; Muller-Eberhard, U.

    1986-10-21

    The physicochemical characteristics of chicken hemopexin, which can be isolated by heme-agarose affinity chromatography, is compared with representative mammalian hemopexins of rat, rabbit, and human. The avian polypeptide chain appears to be slightly longer (52 kDa) than the human, rat, or rabbit forms (49 kDa), and also the glycoprotein differs from the mammalian hemopexins in being an ..cap alpha../sub 1/-glycoprotein instead of a ..beta../sub 1/-glycoprotein. The distinct electrophoretic mobility probably arises from significant differences in the amino acid composition of the chicken form, which, although lower in serine and particularly in lysine, has a much higher glutamine/glutamate and agrinine content, and also a higher proline, glycine, and histidine content, than the mammalian hemopexins. Compositional analyses and /sup 125/I concanavalin A and /sup 125/I wheat germ agglutinin binding suggest that chicken hemopexin has a mixture of three fucose-free N-linked bi- and triantennary oligosaccharides. In contrast, human hemopexin has give N-linked oligosaccharides and an additional O-linked glycan blocking the N-terminal threonine residue, while the rabbit form has four N-linked oligosaccharides. In keeping with the finding of a simpler carbohydrate structure, the avian hemopexin shows only a single band on polyacrylamide gel electrophoresis under both nondenaturing and denaturing conditions, whereas the hemopexins of the three mammalian species tested show several bands. In contrast, the isoelectric focusing pattern of chicken hemopexin is very complex, revealing at least nine bands between pH 4.0 and pH band 5.0, while the other hemopexins show a broad smear of multiple ill-defined bands in the same region.Results indicate the hemopexin of avians differs substantially from the hemopexins of mammals, which show a notable similarity with regard to carbohydrate structure and amino acid composition.

  3. Amino acid metabolism and protein synthesis in malarial parasites*

    PubMed Central

    Sherman, I. W.

    1977-01-01

    Malaria-infected red cells and free parasites have limited capabilities for the biosynthesis of amino acids. Therefore, the principal amino acid sources for parasite protein synthesis are the plasma free amino acids and host cell haemoglobin. Infected cells and plasmodia incorporate exogenously supplied amino acids into protein. However, the hypothesis that amino acid utilization (from an external source) is related to availability of that amino acid in haemoglobin is without universal support: it is true for isoleucine and for Plasmodium knowlesi and P. falciparum, but not for methionine, cysteine, and other amino acids, and it does not apply to P. lophurae. More by default than by direct evidence, haemoglobin is believed to be the main amino acid reservoir available to the intraerythrocytic plasmodium. Haemoglobin, ingested via the cytostome, is held in food vacuoles where auto-oxidation takes place. As a consequence, haem is released and accumulates in the vacuole as particulate haemozoin (= malaria pigment). Current evidence favours the view that haemozoin is mainly haematin. Acid and alkaline proteases (identified in crude extracts from mammalian and avian malarias) are presumably secreted directly into the food vacuole. They then digest the denatured globin and the resulting amino acids are incorporated into parasite protein. Cell-free protein synthesizing systems have been developed using P. knowlesi and P. lophurae ribosomes. In the main these systems are typically eukaryotic. Studies of amino acid metabolism are exceedingly limited. Arginine, lysine, methionine, and proline are incorporated into protein, whereas glutamic acid is metabolized via an NADP-specific glutamic dehydrogenase. Glutamate oxidation generates NADPH and auxiliary energy (in the form of α-ketoglutarate). The role of red cell glutathione in the economy of the parasite remains obscure. Important goals for future research should be: quantitative assessment of the relative importance of

  4. Phosphate acceptor amino acid residues in structural proteins of rhabdoviruses.

    PubMed

    Sokol, F; Tan, K B; McFalls, M L; Madore, P

    1974-07-01

    Partial acid hydrolysates of the [(32)P]phosphate- or [(3)H]serine-labeled proteins of purified vesicular stomatitis, rabies, Lagos bat, Mokola, or spring viremia of carp virions and of purified intracellular nucleocapsids of these viruses have been analyzed by paper electrophoresis for the presence of phosphorylated amino acids. Both phosphoserine and phosphothreonine, with the former predominant, were present in virion and nucleocapsid preparations that contained phosphoproteins. An exception was the fish rhabdovirus, which contained only phosphoserine. When vesicular stomatitis or rabies virus proteins were phosphorylated in a cell-free system by the virion-associated protein kinase and analyzed for the presence of phosphorylated amino acid residues, phosphoserine was again found to be more abundant than phosphothreonine. After in vitro protein phosphorylation, another phospho-compound, possibly a third phosphoamino acid, was detected in the partial acid hydrolysates of these viruses. PMID:4365328

  5. Protein and amino acid metabolism and requirements

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Proteins are the major structural and functional components of all cells of the body. Enzymes, membrane carriers, blood transport molecules, intracellular matrix, and even hair and fingernails are proteins, as are many hormones. Proteins also constitute a major portion of all membranes, and the cons...

  6. Interaction of milk whey protein with common phenolic acids

    NASA Astrophysics Data System (ADS)

    Zhang, Hao; Yu, Dandan; Sun, Jing; Guo, Huiyuan; Ding, Qingbo; Liu, Ruihai; Ren, Fazheng

    2014-01-01

    Phenolics-rich foods such as fruit juices and coffee are often consumed with milk. In this study, the interactions of α-lactalbumin and β-lactoglobulin with the phenolic acids (chlorogenic acid, caffeic acid, ferulic acid, and coumalic acid) were examined. Fluorescence, CD, and FTIR spectroscopies were used to analyze the binding modes, binding constants, and the effects of complexation on the conformation of whey protein. The results showed that binding constants of each whey protein-phenolic acid interaction ranged from 4 × 105 to 7 × 106 M-n and the number of binding sites n ranged from 1.28 ± 0.13 to 1.54 ± 0.34. Because of these interactions, the conformation of whey protein was altered, with a significant reduction in the amount of α-helix and an increase in the amounts of β-sheet and turn structures.

  7. Carbohydrate–Aromatic Interactions in Proteins

    PubMed Central

    2015-01-01

    Protein–carbohydrate interactions play pivotal roles in health and disease. However, defining and manipulating these interactions has been hindered by an incomplete understanding of the underlying fundamental forces. To elucidate common and discriminating features in carbohydrate recognition, we have analyzed quantitatively X-ray crystal structures of proteins with noncovalently bound carbohydrates. Within the carbohydrate-binding pockets, aliphatic hydrophobic residues are disfavored, whereas aromatic side chains are enriched. The greatest preference is for tryptophan with an increased prevalence of 9-fold. Variations in the spatial orientation of amino acids around different monosaccharides indicate specific carbohydrate C–H bonds interact preferentially with aromatic residues. These preferences are consistent with the electronic properties of both the carbohydrate C–H bonds and the aromatic residues. Those carbohydrates that present patches of electropositive saccharide C–H bonds engage more often in CH−π interactions involving electron-rich aromatic partners. These electronic effects are also manifested when carbohydrate–aromatic interactions are monitored in solution: NMR analysis indicates that indole favorably binds to electron-poor C–H bonds of model carbohydrates, and a clear linear free energy relationships with substituted indoles supports the importance of complementary electronic effects in driving protein–carbohydrate interactions. Together, our data indicate that electrostatic and electronic complementarity between carbohydrates and aromatic residues play key roles in driving protein–carbohydrate complexation. Moreover, these weak noncovalent interactions influence which saccharide residues bind to proteins, and how they are positioned within carbohydrate-binding sites. PMID:26561965

  8. Comparative proteomic analysis of oil palm leaves infected with Ganoderma boninense revealed changes in proteins involved in photosynthesis, carbohydrate metabolism, and immunity and defense.

    PubMed

    Jeffery Daim, Leona Daniela; Ooi, Tony Eng Keong; Ithnin, Nalisha; Mohd Yusof, Hirzun; Kulaveerasingam, Harikrishna; Abdul Majid, Nazia; Karsani, Saiful Anuar

    2015-08-01

    The basidiomycete fungal pathogen Ganoderma boninense is the causative agent for the incurable basal stem rot (BSR) disease in oil palm. This disease causes significant annual crop losses in the oil palm industry. Currently, there is no effective method for disease control and elimination, nor is any molecular marker for early detection of the disease available. An understanding of how BSR affects protein expression in plants may help identify and/or assist in the development of an early detection protocol. Although the mode of infection of BSR disease is primarily via the root system, defense-related genes have been shown to be expressed in both the root and leafs. Thus, to provide an insight into the changes in the global protein expression profile in infected plants, comparative 2DE was performed on leaf tissues sampled from palms with and without artificial inoculation of the Ganoderma fungus. Comparative 2DE revealed that 54 protein spots changed in abundance. A total of 51 protein spots were successfully identified by LC-QTOF MS/MS. The majority of these proteins were those involved in photosynthesis, carbohydrate metabolism as well as immunity and defense. PMID:25930948

  9. [Functionalized Metal Chelates Based on Diethylenetriaminetetraacetic Acids for Chemical Modification of Proteins and Small Biomolecules].

    PubMed

    Kuprienko, O S; Dubovskaya, L V; Shabunya, P S; Fatykhava, S A; Sviridov, O V

    2015-01-01

    Bifunctional reagents based on diethylenetriaminetetraacetic acid containing a bound metal ion and a reactive functional group for the interaction with proteins and low-molecular-weight substances have been synthesized. An Amino-derivative of a complexonate was obtained by acylation of monosubstituted diamine with diethylenetriaminepentaacetic acid dianhydride followed by deprotection ofthe amino group, purification by anion exchange chromatography and chelation of Eu3+. This metal chelate derivative was used for labeling 17α-hydroxyprogesterone 3-(O-carboxymethyl)oxime and horseradish peroxidase. The enzyme modified with the Eu3+ complexonate at the carbohydrate component and with a cortisol derivative at the polypeptide chain was used in a dissociation-enhanced lanthanide fluorescent immunoassay (DELFIA) as well as in an enzyme immunoassay of the steroid hormone. DELFIA showed that labeled 17α-hydroxyprogesterone retained the affinity for corresponding antibodies. A Eu(3+)-complexonate carboxy-derivative N-succinimide ester was obtained by acylation of the aminochelate with p-phthalic acid di-N-succinimide ester. It was used for modification of amino groups of lysine residues in polypeptide chains of human serum albumin and some immunoglobulins G. Purification of Eu3+ complexonate-protein conjugates by gel-chromatography on a Superose- 12 column allowed to separate the modified proteins from unreacted low molecular weight Eu(3+)-derivatives and to determine a degree of lanthanide inclusion into a protein. The amount of Eu3+ covalently attached to a protein was determined by measuring the fluorescence of a conjugate in the dissociative-enhancement solution. The obtained values correlated well with the results of ICP-MS determination of Eu3+ concentration in a conjugate solution. It was shown that conjugates of monoclonal antibodies obtained by the proposed method possessed the required characteristics of fluorescence intensity, signal-to-noise ratio, sensitivity

  10. Real-time and label-free analysis of binding thermodynamics of carbohydrate-protein interactions on unfixed cancer cell surfaces using a QCM biosensor

    PubMed Central

    Li, Xueming; Song, Siyu; Shuai, Qi; Pei, Yihan; Aastrup, Teodor; Pei, Yuxin; Pei, Zhichao

    2015-01-01

    A novel approach to the study of binding thermodynamics and kinetics of carbohydrate-protein interactions on unfixed cancer cell surfaces using a quartz crystal microbalance (QCM) biosensor was developed, in which binding events take place at the cell surface, more closely mimicking a biologically relevant environment. In this study, colon adenocarcinoma cells (KM-12) and ovary adenocarcinoma cells (SKOV-3) grew on the optimized polystyrene-coated biosensor chip without fixation. The association and dissociation between the cell surface carbohydrates and a range of lectins, including WGA, Con A, UEA-I, GS-II, PNA and SBA, were monitored in real time and without label for evaluation of cell surface glycosylation. Furthermore, the thermodynamic and kinetic parameters of the interaction between lectins and cell surface glycan were studied, providing detailed information about the interactions, such as the association rate constant, dissociation rate constant, affinity constant, as well as the changes of entropy, enthalpy and Gibbs free energy. This application provides an insight into the cell surface glycosylation and the complex molecular recognition on the intact cell surface, which may have impacts on disease diagnosis and drug discovery. PMID:26369583

  11. Adding protein to a carbohydrate supplement provided after endurance exercise enhances 4E-BP1 and RPS6 signaling in skeletal muscle.

    PubMed

    Morrison, Paul J; Hara, Daisuke; Ding, Zhenping; Ivy, John L

    2008-04-01

    To examine the role of both endurance exercise and nutrient supplementation on the activation of mRNA translation signaling pathways postexercise, rats were subjected to a 3-h swimming protocol. Immediately following exercise, the rats were provided with a solution containing either 23.7% wt/vol carbohydrates (CHO), 7.9% wt/vol protein (Pro), 31.6% wt/vol (23.7% wt/vol CHO + 7.9% wt/vol Pro) carbohydrates and Pro (CP), or a placebo (EX). The rats were then killed at 0, 30, and 90 min postexercise, and phosphorylation states of mammalian target of rapamycin (mTOR), ribosomal S6 kinase (p70(S6K)), ribosomal protein S6 (rpS6), and 4E-binding protein 1 (4E-BP1), were analyzed by immunoblot analysis in the red and white quadriceps muscle. Results demonstrated that rat groups provided with any of the three nutritional supplements (CHO, Pro, CP) transiently increased the phosphorylation states of mTOR, 4E-BP1, rpS6, and p70(S6K) compared with EX rats. Although CHO, Pro, and CP supplements phosphorylated mTOR and p70(S6K) after exercise, only CP elevated the phosphorylation of rpS6 above all other supplements 30 min postexercise and 4E-BP1 30 and 90 min postexercise. Furthermore, the phosphorylation states of 4E-BP1 (r(2) = 0.7942) and rpS6 (r(2) = 0.760) were highly correlated to insulin concentrations in each group. These results suggest that CP supplementation may be most effective in activating the mTOR-dependent signaling pathway in the postprandial state postexercise, and that there is a strong relationship between the insulin concentration and the activation of enzymes critical for mRNA translation. PMID:18239077

  12. Measuring protein-protein and protein-nucleic Acid interactions by biolayer interferometry.

    PubMed

    Sultana, Azmiri; Lee, Jeffrey E

    2015-01-01

    Biolayer interferometry (BLI) is a simple, optical dip-and-read system useful for measuring interactions between proteins, peptides, nucleic acids, small molecules, and/or lipids in real time. In BLI, a biomolecular bait is immobilized on a matrix at the tip of a fiber-optic sensor. The binding between the immobilized ligand and another molecule in an analyte solution produces a change in optical thickness at the tip and results in a wavelength shift proportional to binding. BLI provides direct binding affinities and rates of association and dissociation. This unit describes an efficient approach using streptavidin-based BLI to analyze DNA-protein and protein-protein interactions. A quantitative set of equilibrium binding affinities (K(d)) and rates of association and dissociation (k(a)/k(d)) can be measured in minutes using nanomole quantities of sample. PMID:25640894

  13. High Carbohydrate-Fiber Nutrition for Running and Health.

    ERIC Educational Resources Information Center

    Battinelli, Thomas

    1983-01-01

    The roles of carbohydrates, fats, proteins, and fiber in producing energy for health and exercise are discussed. Long-distance runners should have a high intake of complex carbohydrates and fiber. (PP)

  14. The effect of all-trans-retinoic acid on the synthesis of epidermal cell-surface-associated carbohydrates

    PubMed Central

    King, Ian A.; Tabiowo, Anne

    1981-01-01

    1. all-trans-Retinoic acid at concentrations greater than 10−7m stimulated the incorporation of d-[3H]glucosamine into 8m-urea/5% (w/v) sodium dodecyl sulphate extracts of 1m-CaCl2-separated epidermis from pig ear skin slices cultured for 18h. The incorporation of 35SO42−, l-[14C]fucose and U-14C-labelled l-amino acids was not significantly affected. 2. Electrophoresis of the solubilized epidermis showed increased incorporation of d-[3H]glucosamine into a high-molecular-weight glycosaminoglycan-containing peak when skin slices were cultured in the presence of 10−5m-all-trans-retinoic acid. The labelling of other epidermal components with d-[3H]glucosamine, 35SO42−, l-[14C]fucose and U-14C-labelled l-amino acids was not significantly affected by 10−5m-all-trans-retinoic acid. 3. Trypsinization dispersed the epidermal cells and released 75–85% of the total d-[3H]glucosamine-labelled material in the glycosaminoglycan peak. Thus most of this material was extracellular in both control and 10−5m-all-trans-retinoic acid-treated epidermis. 4. Increased labelling of extracellular epidermal glycosaminoglycans was also observed when human skin slices were treated with all-trans-retinoic acid, indicating a similar mechanism in both tissues. Increased labelling was also found when the epidermis was cultured in the absence of the dermis, suggesting a direct effect of all-trans-retinoic acid on the epidermis. 5. Increased incorporation of d-[3H]-glucosamine into extracellular epidermal glycosaminoglycans in 10−5m-all-trans-retinoic acid-treated skin slices was apparent after 4–8h in culture and continued up to 48h. all-trans-Retinoic acid (10−5m) did not affect the rate of degradation of this material in cultures `chased' with 5mm-unlabelled glucosamine after 4 or 18h. 6. Cellulose acetate electrophoresis at pH7.2 revealed that hyaluronic acid was the major labelled glycosaminoglycan (80–90%) in both control and 10−5m-all-trans-retinoic acid

  15. Carbohydrates as synthetic tools in organic chemistry.

    PubMed

    Boysen, Mike M K

    2007-01-01

    While amino acids, terpenes and alkaloids have found broad application as tools in stereoselective organic synthesis, carbohydrates have only lately been recognised as versatile starting materials for chiral auxiliaries, reagents, ligands and organocatalysts. The structural diversity of carbohydrates and the high density of functional groups offer a wide variety of opportunities for derivatization and tailoring of synthetic tools to a specific problem. PMID:17712826

  16. Carbohydrates and Diabetes

    MedlinePlus

    ... How Can I Help a Friend Who Cuts? Carbohydrates and Diabetes KidsHealth > For Teens > Carbohydrates and Diabetes Print A A A Text Size ... that you should keep track of how many carbohydrates (carbs) you eat. But what exactly are carbohydrates ...

  17. Pre-operative nutrition and carbohydrate loading.

    PubMed

    Kratzing, Caroline

    2011-08-01

    An optimal nutritional state is an important consideration in providing successful operative outcomes. Unfortunately, many aspects of surgery are not constructive to providing this. In addition, the metabolic and immune response to injury induces a catabolic state and insulin resistance, a known risk factor of post-operative complications. Aggressive insulin therapy post-operatively has been shown to reduce morbidity and mortality but similar results can be achieved when insulin resistance is lessened by the use of pre-operative carbohydrate loading. Consuming carbohydrate-containing drinks up to 2 h before surgery has been found to be an effective way to attenuate insulin resistance, minimise protein losses, reduce hospital stays and improve patient comfort without adversely affecting gastric emptying. Enhanced recovery programmes have employed carbohydrate loading as one of several strategies aimed at reducing post-operative stress and improving the recovery process. Studies examining the benefits of these programmes have demonstrated significantly shorter post-operative hospital stays, faster return to normal functions and lower occurrences of surgical complications. As a consequence of the favourable evidence they are now being implemented in many surgical units. Further benefit to post-operative recovery may be found with the use of immune-enhancing diets, i.e. supplementation with n-3 fatty acids, arginine, glutamine and/or nucleotides. These have the potential to boost the immune system, improve wound healing and reduce inflammatory markers. Research exploring the benefits of immunonutrition and solidifying the use of carbohydrate loading is ongoing; however, there is strong evidence to link good pre-operative nutrition and improved surgical outcomes. PMID:21781358

  18. The developmental regulation of the L2/HNK-1 and L3 carbohydrate epitopes in mouse brain. Evidence for separate control of lipid- and protein-bound epitopes.

    PubMed

    Breen, K C

    1989-04-10

    The carbohydrate epitopes L2/HNK-1 and L3 have previously been identified on various neural cell adhesion molecules and have been suggested to play a role in the mediation of cell-cell adhesion. In this study, the developmental expression of the two epitopes in soluble, membrane-bound and chloroform/methanol-extracted fractions of the constituent mouse brain regions was examined by enzyme-linked immunosorbent assay (ELISA). The protein-bound epitopes were shown to be uniformly developmentally regulated, with levels peaking at postnatal day 20 (P20). The epitopes in a crude chloroform/methanol fraction, however, demonstrated a different pattern, with L2 peaking earlier at postnatal day zero (P0). These results suggest a possible interaction between the control of the two pools of the epitope. PMID:2468531

  19. Display of alpha-amylase on the surface of Lactobacillus casei cells by use of the PgsA anchor protein, and production of lactic acid from starch.

    PubMed

    Narita, Junya; Okano, Kenji; Kitao, Tomoe; Ishida, Saori; Sewaki, Tomomitsu; Sung, Moon-Hee; Fukuda, Hideki; Kondo, Akihiko

    2006-01-01

    We developed a new cell surface engineering system based on the PgsA anchor protein from Bacillus subtilis. In this system, the N terminus of the target protein was fused to the PgsA protein and the resulting fusion protein was expressed on the cell surface. Using this new system, we constructed a novel starch-degrading strain of Lactobacillus casei by genetically displaying alpha-amylase from the Streptococcus bovis strain 148 with a FLAG peptide tag (AmyAF). Localization of the PgsA-AmyA-FLAG fusion protein on the cell surface was confirmed by immunofluorescence microscopy and flow cytometric analysis. The lactic acid bacteria which displayed AmyAF showed significantly elevated hydrolytic activity toward soluble starch. By fermentation using AmyAF-displaying L. casei cells, 50 g/liter of soluble starch was reduced to 13.7 g/liter, and 21.8 g/liter of lactic acid was produced within about 24 h. The yield in terms of grams of lactic acid produced per gram of carbohydrate utilized was 0.60 g per g of carbohydrate consumed at 24 h. Since AmyA was immobilized on the cells, cells were recovered after fermentation and used repeatedly. During repeated utilization of cells, the lactic acid yield was improved to 0.81 g per g of carbohydrate consumed at 72 h. These results indicate that efficient simultaneous saccharification and fermentation from soluble starch to lactic acid were carried out by recombinant L. casei cells with cell surface display of AmyA. PMID:16391053

  20. Display of α-Amylase on the Surface of Lactobacillus casei Cells by Use of the PgsA Anchor Protein, and Production of Lactic Acid from Starch

    PubMed Central

    Narita, Junya; Okano, Kenji; Kitao, Tomoe; Ishida, Saori; Sewaki, Tomomitsu; Sung, Moon-Hee; Fukuda, Hideki; Kondo, Akihiko

    2006-01-01

    We developed a new cell surface engineering system based on the PgsA anchor protein from Bacillus subtilis. In this system, the N terminus of the target protein was fused to the PgsA protein and the resulting fusion protein was expressed on the cell surface. Using this new system, we constructed a novel starch-degrading strain of Lactobacillus casei by genetically displaying α-amylase from the Streptococcus bovis strain 148 with a FLAG peptide tag (AmyAF). Localization of the PgsA-AmyA-FLAG fusion protein on the cell surface was confirmed by immunofluorescence microscopy and flow cytometric analysis. The lactic acid bacteria which displayed AmyAF showed significantly elevated hydrolytic activity toward soluble starch. By fermentation using AmyAF-displaying L. casei cells, 50 g/liter of soluble starch was reduced to 13.7 g/liter, and 21.8 g/liter of lactic acid was produced within about 24 h. The yield in terms of grams of lactic acid produced per gram of carbohydrate utilized was 0.60 g per g of carbohydrate consumed at 24 h. Since AmyA was immobilized on the cells, cells were recovered after fermentation and used repeatedly. During repeated utilization of cells, the lactic acid yield was improved to 0.81 g per g of carbohydrate consumed at 72 h. These results indicate that efficient simultaneous saccharification and fermentation from soluble starch to lactic acid were carried out by recombinant L. casei cells with cell surface display of AmyA. PMID:16391053

  1. Cancer Vaccines and Carbohydrate Epitopes

    PubMed Central

    Heimburg-Molinaro, Jamie; Lum, Michelle; Vijay, Geraldine; Jain, Miten; Almogren, Adel; Rittenhouse-Olson, Kate

    2011-01-01

    Tumor-associated carbohydrate antigens (TACA) result from the aberrant glycosylation that is seen with transformation to a tumor cell. The carbohydrate antigens that have been found to be tumor-associated include the mucin related Tn, Sialyl Tn, and Thomsen-Friedenreich antigens, the blood group Lewis related LewisY, Sialyl LewisX and Sialyl LewisA, and LewisX, (also known as stage-specific embryonic antigen-1, SSEA-1), the glycosphingolipids Globo H and stage-specific embryonic antigen-3 (SSEA-3), the sialic acid containing glycosphingolipids, the gangliosides GD2, GD3, GM2, fucosyl GM1, and Neu5GcGM3, and polysialic acid. Recent developments have furthered our understanding of the T-independent type II response that is seen in response to carbohydrate antigens. The selection of a vaccine target antigen is based on not only the presence of the antigen in a variety of tumor tissues but also on the role this antigen plays in tumor growth and metastasis. These roles for TACAs are being elucidated. Newly acquired knowledge in understanding the T-independent immune response and in understanding the key roles that carbohydrates play in metastasis are being applied in attempts to develop an effective vaccine response to TACAs. The role of each of the above mentioned carbohydrate antigens in cancer growth and metastasis and vaccine attempts using these antigens will be described. PMID:21964054

  2. Coordinate regulation/localization of the carbohydrate responsive binding protein (ChREBP) by two nuclear export signal sites: Discovery of a new leucine-rich nuclear export signal site

    SciTech Connect

    Fukasawa, Masashi; Ge, Qing; Wynn, R. Max; Ishii, Seiji; Uyeda, Kosaku

    2010-01-08

    Carbohydrate response element binding protein (ChREBP) is responsible for conversion of dietary carbohydrate to storage fat in liver by coordinating expression of the enzymes that channel glycolytic pyruvate into lipogenesis. The activation of ChREBP in response to high glucose is nuclear localization and transcription, and the inactivation of ChREBP under low glucose involves export from the nucleus to the cytosol. Here we report a new nuclear export signal site ('NES1') of ChREBP. Together these signals provide ChREBP with two NES sequences, both the previously reported NES2 and now the new NES1 coordinate to interact together with CRM1 (exportin) for nuclear export of the carbohydrate response element binding protein.

  3. Non-protein amino acids and neurodegeneration: the enemy within.

    PubMed

    Rodgers, Kenneth J

    2014-03-01

    Animals, in common with plants and microorganisms, synthesise proteins from a pool of 20 protein amino acids (plus selenocysteine and pyrolysine) (Hendrickson et al., 2004). This represents a small proportion (~2%) of the total number of amino acids known to exist in nature (Bell, 2003). Many 'non-protein' amino acids are synthesised by plants, and in some cases constitute part of their chemical armoury against pathogens, predators or other species competing for the same resources (Fowden et al., 1967). Microorganisms can also use selectively toxic amino acids to gain advantage over competing organisms (Nunn et al., 2010). Since non-protein amino acids (and imino acids) are present in legumes, fruits, seeds and nuts, they are ubiquitous in the diets of human populations around the world. Toxicity to humans is unlikely to have been the selective force for their evolution, but they have the clear potential to adversely affect human health. In this review we explore the links between exposure to non-protein amino acids and neurodegenerative disorders in humans. Environmental factors play a major role in these complex disorders which are predominantly sporadic (Coppede et al., 2006). The discovery of new genes associated with neurodegenerative diseases, many of which code for aggregation-prone proteins, continues at a spectacular pace but little progress is being made in identifying the environmental factors that impact on these disorders. We make the case that insidious entry of non-protein amino acids into the human food chain and their incorporation into protein might be contributing significantly to neurodegenerative damage. PMID:24374297

  4. Heat capacities of amino acids, peptides and proteins.

    PubMed

    Makhatadze, G I

    1998-04-20

    The heat capacity is one of the fundamental parameters describing thermodynamic properties of a system. It has wide applications in a number of areas such as polymer chemistry, protein folding and DNA stability. To aid the scientific community in the analysis of such data, I have compiled a database on the experimentally measured heat capacities of amino acids, polyamino acids, peptides, and proteins in solid state and in aqueous solutions. PMID:9648205

  5. Aspartame ingestion with and without carbohydrate in phenylketonuric and normal subjects: effect on plasma concentrations of amino acids, glucose, and insulin.

    PubMed

    Wolf-Novak, L C; Stegink, L D; Brummel, M C; Persoon, T J; Filer, L J; Bell, E F; Ziegler, E E; Krause, W L

    1990-04-01

    Seven subjects homozygous for phenylketonuria (PKU) and seven normal subjects were administered four beverage regimens after an overnight fast: unsweetened beverage, beverage providing carbohydrate (CHO), beverage providing aspartame (APM), and beverage providing APM plus CHO. The APM dose (200 mg) was the amount provided in 12 oz of diet beverage; the CHO was partially hydrolyzed starch (60 g). Plasma amino acid concentrations were determined after dosing and the molar plasma phenylalanine (Phe) to large neutral amino acid (LNAA) ratio calculated. APM administration without CHO did not increase plasma Phe concentrations over baseline values in either normal or PKU subjects (5.48 +/- 0.85 and 150 +/- 23.0 mumols/dL, respectively). Similarly, the Phe/LNAA did not increase significantly. Ingestion of beverage providing APM and CHO did not significantly increase plasma Phe concentrations over baseline values in either normal or PKU subjects. However, ingestion of beverage providing CHO (with or without APM) significantly decreased plasma levels of valine, isoleucine, and leucine 1.5 to 4 hours after dosing in both normal and PKU subjects, thereby increasing the Phe/LNAA ratio significantly. These data indicate that changes noted in Phe/LNAA values after ingestion of beverage providing APM plus CHO were due to CHO. The plasma insulin response to beverage providing CHO (with or without APM) was significantly higher in PKU subjects than in normals. PMID:2182973

  6. The Multiple DSF-family QS Signals are Synthesized from Carbohydrate and Branched-chain Amino Acids via the FAS Elongation Cycle

    PubMed Central

    Zhou, Lian; Yu, Yonghong; Chen, Xiping; Diab, Abdelgader Abdeen; Ruan, Lifang; He, Jin; Wang, Haihong; He, Ya-Wen

    2015-01-01

    Members of the diffusible signal factor (DSF) family are a novel class of quorum sensing (QS) signals in diverse Gram-negative bacteria. Although previous studies have identified RpfF as a key enzyme for the biosynthesis of DSF family signals, many questions in their biosynthesis remain to be addressed. In this study with the phytopathogen Xanthomonas campestris pv. campestris (Xcc), we show that Xcc produces four DSF-family signals (DSF, BDSF, CDSF and IDSF) during cell culture, and that IDSF is a new functional signal characterized as cis-10-methyl-2-dodecenoic acid. Using a range of defined media, we further demonstrate that Xcc mainly produces BDSF in the presence of carbohydrates; leucine and valine are the primary precursor for DSF biosynthesis; isoleucine is the primary precursor for IDSF biosynthesis. Furthermore, our biochemical analyses show that the key DSF synthase RpfF has both thioesterase and dehydratase activities, and uses 3-hydroxydedecanoyl-ACP as a substrate to produce BDSF. Finally, our results show that the classic fatty acid synthesis elongation cycle is required for the biosynthesis of DSF-family signals. Taken all together, these findings establish a general biosynthetic pathway for the DSF-family quorum sensing signals. PMID:26289160

  7. Glucose uptake by the brain on chronic high-protein weight-loss diets with either moderate or low amounts of carbohydrate.

    PubMed

    Lobley, Gerald E; Johnstone, Alexandra M; Fyfe, Claire; Horgan, Graham W; Holtrop, Grietje; Bremner, David M; Broom, Iain; Schweiger, Lutz; Welch, Andy

    2014-02-01

    Previous work has shown that hunger and food intake are lower in individuals on high-protein (HP) diets when combined with low carbohydrate (LC) intakes rather than with moderate carbohydrate (MC) intakes and where a more ketogenic state occurs. The aim of the present study was to investigate whether the difference between HPLC and HPMC diets was associated with changes in glucose and ketone body metabolism, particularly within key areas of the brain involved in appetite control. A total of twelve men, mean BMI 34·9 kg/m², took part in a randomised cross-over trial, with two 4-week periods when isoenergetic fixed-intake diets (8·3 MJ/d) were given, with 30% of the energy being given as protein and either (1) a very LC (22 g/d; HPLC) or (2) a MC (182 g/d; HPMC) intake. An ¹⁸fluoro-deoxyglucose positron emission tomography scan of the brain was conducted at the end of each dietary intervention period, following an overnight fast (n 4) or 4 h after consumption of a test meal (n 8). On the next day, whole-body ketone and glucose metabolism was quantified using [1,2,3,4-¹³C]acetoacetate, [2,4-¹³C]3-hydroxybutyrate and [6,6-²H₂]glucose. The composite hunger score was 14% lower (P= 0·013) for the HPLC dietary intervention than for the HPMC diet. Whole-body ketone flux was approximately 4-fold greater for the HPLC dietary intervention than for the HPMC diet (P< 0·001). The 9-fold difference in carbohydrate intakes between the HPLC and HPMC dietary interventions led to a 5% lower supply of glucose to the brain. Despite this, the uptake of glucose by the fifty-four regions of the brain analysed remained similar for the two dietary interventions. In conclusion, differences in the composite hunger score observed for the two dietary interventions are not associated with the use of alternative fuels by the brain. PMID:24528939

  8. [Carbohydrates and fiber].

    PubMed

    Lajolo, F M; de Menezes, E W; Filisetti-Cozzi, T M

    1988-09-01

    ) the proportion of "crude fiber" (as measured by acid and alkaline digestion) leads to an over-estimation of the proportion of digestible carbohydrates calculated by difference; 2) fiber may alter the polysaccharide utilization of some foods, as shown by the "glycemic index". It is difficult to make recommendations on dietary fiber due to insufficient data on intake, fiber composition, its physiological effects, and epidemiological studies. However, a preliminary evaluation of the diets from most Latin American countries shows large intakes of vegetable foods and, consequently, an adequate fiber intake may be expected. PMID:2856370

  9. Phthalic acid chemical probes synthesized for protein-protein interaction analysis.

    PubMed

    Liang, Shih-Shin; Liao, Wei-Ting; Kuo, Chao-Jen; Chou, Chi-Hsien; Wu, Chin-Jen; Wang, Hui-Min

    2013-01-01

    Plasticizers are additives that are used to increase the flexibility of plastic during manufacturing. However, in injection molding processes, plasticizers cannot be generated with monomers because they can peel off from the plastics into the surrounding environment, water, or food, or become attached to skin. Among the various plasticizers that are used, 1,2-benzenedicarboxylic acid (phthalic acid) is a typical precursor to generate phthalates. In addition, phthalic acid is a metabolite of diethylhexyl phthalate (DEHP). According to Gene_Ontology gene/protein database, phthalates can cause genital diseases, cardiotoxicity, hepatotoxicity, nephrotoxicity, etc. In this study, a silanized linker (3-aminopropyl triethoxyslane, APTES) was deposited on silicon dioxides (SiO2) particles and phthalate chemical probes were manufactured from phthalic acid and APTES-SiO2. These probes could be used for detecting proteins that targeted phthalic acid and for protein-protein interactions. The phthalic acid chemical probes we produced were incubated with epithelioid cell lysates of normal rat kidney (NRK-52E cells) to detect the interactions between phthalic acid and NRK-52E extracted proteins. These chemical probes interacted with a number of chaperones such as protein disulfide-isomerase A6, heat shock proteins, and Serpin H1. Ingenuity Pathways Analysis (IPA) software showed that these chemical probes were a practical technique for protein-protein interaction analysis. PMID:23797655

  10. A holistic view of dietary carbohydrate utilization in lobster: digestion, postprandial nutrient flux, and metabolism.

    PubMed

    Rodríguez-Viera, Leandro; Perera, Erick; Casuso, Antonio; Perdomo-Morales, Rolando; Gutierrez, Odilia; Scull, Idania; Carrillo, Olimpia; Martos-Sitcha, Juan A; García-Galano, Tsai; Mancera, Juan Miguel

    2014-01-01

    Crustaceans exhibit a remarkable variation in their feeding habits and food type, but most knowledge on carbohydrate digestion and utilization in this group has come from research on few species. The aim of this study was to make an integrative analysis of dietary carbohydrate utilization in the spiny lobster Panulirus argus. We used complementary methodologies such as different assessments of digestibility, activity measurements of digestive and metabolic enzymes, and post-feeding flux of nutrients and metabolites. Several carbohydrates were well digested by the lobster, but maize starch was less digestible than all other starches studied, and its inclusion in diet affected protein digestibility. Most intense hydrolysis of carbohydrates in the gastric chamber of lobster occurred between 2-6 h after ingestion and afterwards free glucose increased in hemolymph. The inclusion of wheat in diet produced a slow clearance of glucose from the gastric fluid and a gradual increase in hemolymph glucose. More intense hydrolysis of protein in the gastric chamber occurred 6-12 h after ingestion and then amino acids tended to increase in hemolymph. Triglyceride concentration in hemolymph rose earlier in wheat-fed lobsters than in lobsters fed other carbohydrates, but it decreased the most 24 h later. Analyses of metabolite levels and activities of different metabolic enzymes revealed that intermolt lobsters had a low capacity to store and use glycogen, although it was slightly higher in wheat-fed lobsters. Lobsters fed maize and rice diets increased amino acid catabolism, while wheat-fed lobsters exhibited higher utilization of fatty acids. Multivariate analysis confirmed that the type of carbohydrate ingested had a profound effect on overall metabolism. Although we found no evidence of a protein-sparing effect of dietary carbohydrate, differences in the kinetics of their digestion and absorption impacted lobster metabolism determining the fate of other nutrients. PMID:25268641

  11. A Holistic View of Dietary Carbohydrate Utilization in Lobster: Digestion, Postprandial Nutrient Flux, and Metabolism

    PubMed Central

    Casuso, Antonio; Perdomo-Morales, Rolando; Gutierrez, Odilia; Scull, Idania; Carrillo, Olimpia; Martos-Sitcha, Juan A.; García-Galano, Tsai; Mancera, Juan Miguel

    2014-01-01

    Crustaceans exhibit a remarkable variation in their feeding habits and food type, but most knowledge on carbohydrate digestion and utilization in this group has come from research on few species. The aim of this study was to make an integrative analysis of dietary carbohydrate utilization in the spiny lobster Panulirus argus. We used complementary methodologies such as different assessments of digestibility, activity measurements of digestive and metabolic enzymes, and post-feeding flux of nutrients and metabolites. Several carbohydrates were well digested by the lobster, but maize starch was less digestible than all other starches studied, and its inclusion in diet affected protein digestibility. Most intense hydrolysis of carbohydrates in the gastric chamber of lobster occurred between 2–6 h after ingestion and afterwards free glucose increased in hemolymph. The inclusion of wheat in diet produced a slow clearance of glucose from the gastric fluid and a gradual increase in hemolymph glucose. More intense hydrolysis of protein in the gastric chamber occurred 6–12 h after ingestion and then amino acids tended to increase in hemolymph. Triglyceride concentration in hemolymph rose earlier in wheat-fed lobsters than in lobsters fed other carbohydrates, but it decreased the most 24 h later. Analyses of metabolite levels and activities of different metabolic enzymes revealed that intermolt lobsters had a low capacity to store and use glycogen, although it was slightly higher in wheat-fed lobsters. Lobsters fed maize and rice diets increased amino acid catabolism, while wheat-fed lobsters exhibited higher utilization of fatty acids. Multivariate analysis confirmed that the type of carbohydrate ingested had a profound effect on overall metabolism. Although we found no evidence of a protein-sparing effect of dietary carbohydrate, differences in the kinetics of their digestion and absorption impacted lobster metabolism determining the fate of other nutrients. PMID

  12. HALOACETIC ACIDS PERTURB PROTEIN PHOSPHORYLATION IN MOUSE EMBRYOS IN VITRO

    EPA Science Inventory

    HALOACETIC ACIDS PERTURB PROTEIN PHOSPHORYLATION IN MOUSE EMBRYOS IN VITRO. MR Blanton and ES Hunter. Reproductive Toxicology Division, NHEERL, ORD, US EPA, RTP, NC, USA.
    Sponsor: JM Rogers.
    Haloacetic Acids (HAAs) formed during the disinfection process are present in drin...

  13. Conformational Entropy of Intrinsically Disordered Proteins from Amino Acid Triads

    PubMed Central

    Baruah, Anupaul; Rani, Pooja; Biswas, Parbati

    2015-01-01

    This work quantitatively characterizes intrinsic disorder in proteins in terms of sequence composition and backbone conformational entropy. Analysis of the normalized relative composition of the amino acid triads highlights a distinct boundary between globular and disordered proteins. The conformational entropy is calculated from the dihedral angles of the middle amino acid in the amino acid triad for the conformational ensemble of the globular, partially and completely disordered proteins relative to the non-redundant database. Both Monte Carlo (MC) and Molecular Dynamics (MD) simulations are used to characterize the conformational ensemble of the representative proteins of each group. The results show that the globular proteins span approximately half of the allowed conformational states in the Ramachandran space, while the amino acid triads in disordered proteins sample the entire range of the allowed dihedral angle space following Flory’s isolated-pair hypothesis. Therefore, only the sequence information in terms of the relative amino acid triad composition may be sufficient to predict protein disorder and the backbone conformational entropy, even in the absence of well-defined structure. The predicted entropies are found to agree with those calculated using mutual information expansion and the histogram method. PMID:26138206

  14. The differential effects of a complex protein drink versus isocaloric carbohydrate drink on performance indices following high-intensity resistance training: a two arm crossover design

    PubMed Central

    2013-01-01

    Background Post-workout nutrient timing and macronutrient selection are essential for recovery, glycogen replenishment and muscle protein synthesis (MPS). Performance repeatability, particularly after strenuous activity, can be influenced by substrate availability, recovery markers and perceived rate of exertion. This study compared the differential effects of a complex protein ready-to-drink beverage (VPX) and isocaloric carbohydrate beverage (iCHO) on performance—agility T-test, push-up test, 40-yard sprint, and rate of perceived exertion (RPE), following high-intensity resistance training (HIRT). Methods In a randomized, double blind two-arm crossover controlled trial, 15 subjects performed a 15–18 minute (2:1 work to rest) HIRT and then immediately drank one of the two treatments. After a 2-hour fast, subjects returned to execute the field tests and report RPE. The protocol was repeated one week later with the other treatment. Results There were no significant main effect differences in the agility T-test (p = 0.83), push-up (p = 0.21) sprint (p = 0.12), average agility RPE (p = 0.83), average push-up RPE (p = 0.81) or average sprint RPE (p = 0.66) between the two trials and the two treatments. The multivariate analysis yielded a cumulative significant interaction effect amongst the three performance variables after consuming VPX (p < 0.01). These results suggest a complex protein beverage is a better post-workout choice compared to an isocaloric carbohydrate beverage for repeated performance for activities that require multiple energy demands and athletic skills; however, this outcome was not observed for each single performance event or RPE. Conclusion When considering the collective physical effects of the agility T-test, push-up and sprint tests, a complex protein beverage may provide a recovery advantage as it relates to repeated-bout performance compared to an iCHO-only beverage. Additional research examining the chronic effects of post

  15. IMPLICATIONS OF A CARBON BALANCE STUDY: ORGANIC ACID AND PROTEIN SUPPLIES CHANGE WITH FERMENTABLE CARBOHYDRATE:PROTEIN RATIO

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Three concentrations of sucrose (Suc, trt) with one of isolated neutral detergent fiber (isolNDF) from bermudagrass were fermented together in vitro with rumen inoculum to evaluate the effects of Suc concentration on partition of carbon (C) in Suc into fermentation products. Nitrogen sources were in...

  16. A Soluble, Folded Protein without Charged Amino Acid Residues.

    PubMed

    Højgaard, Casper; Kofoed, Christian; Espersen, Roall; Johansson, Kristoffer Enøe; Villa, Mara; Willemoës, Martin; Lindorff-Larsen, Kresten; Teilum, Kaare; Winther, Jakob R

    2016-07-19

    Charges are considered an integral part of protein structure and function, enhancing solubility and providing specificity in molecular interactions. We wished to investigate whether charged amino acids are indeed required for protein biogenesis and whether a protein completely free of titratable side chains can maintain solubility, stability, and function. As a model, we used a cellulose-binding domain from Cellulomonas fimi, which, among proteins of more than 100 amino acids, presently is the least charged in the Protein Data Bank, with a total of only four titratable residues. We find that the protein shows a surprising resilience toward extremes of pH, demonstrating stability and function (cellulose binding) in the pH range from 2 to 11. To ask whether the four charged residues present were required for these properties of this protein, we altered them to nontitratable ones. Remarkably, this chargeless protein is produced reasonably well in Escherichia coli, retains its stable three-dimensional structure, and is still capable of strong cellulose binding. To further deprive this protein of charges, we removed the N-terminal charge by acetylation and studied the protein at pH 2, where the C-terminus is effectively protonated. Under these conditions, the protein retains its function and proved to be both soluble and have a reversible folding-unfolding transition. To the best of our knowledge, this is the first time a soluble, functional protein with no titratable side chains has been produced. PMID:27307139

  17. C-type lectin-like carbohydrate recognition of the hemolytic lectin CEL-III containing ricin-type -trefoil folds.

    PubMed

    Hatakeyama, Tomomitsu; Unno, Hideaki; Kouzuma, Yoshiaki; Uchida, Tatsuya; Eto, Seiichiro; Hidemura, Haruki; Kato, Norihisa; Yonekura, Masami; Kusunoki, Masami

    2007-12-28

    CEL-III is a Ca(2+)-dependent hemolytic lectin, isolated from the marine invertebrate Cucumaria echinata. The three-dimensional structure of CEL-III/GalNAc and CEL-III/methyl alpha-galactoside complexes was solved by x-ray crystallographic analysis. In these complexes, five carbohydrate molecules were found to be bound to two carbohydrate-binding domains (domains 1 and 2) located in the N-terminal 2/3 portion of the polypeptide and that contained beta-trefoil folds similar to ricin B-chain. The 3-OH and 4-OH of bound carbohydrate molecules were coordinated with Ca(2+) located at the subdomains 1alpha, 1gamma, 2alpha, 2beta, and 2gamma, simultaneously forming hydrogen bond networks with nearby amino acid side chains, which is similar to carbohydrate binding in C-type lectins. The binding of carbohydrates was further stabilized by aromatic amino acid residues, such as tyrosine and tryptophan, through a stacking interaction with the hydrophobic face of carbohydrates. The importance of amino acid residues in the carbohydrate-binding sites was confirmed by the mutational analyses. The orientation of bound GalNAc and methyl alpha-galactoside was similar to the galactose moiety of lactose bound to the carbohydrate-binding site of the ricin B-chain, although the ricin B-chain does not require Ca(2+) ions for carbohydrate binding. The binding of the carbohydrates induced local structural changes in carbohydrate-binding sites in subdomains 2alpha and 2beta. Binding of GalNAc also induced a slight change in the main chain structure of domain 3, which could be related to the conformational change upon binding of specific carbohydrates to induce oligomerization of the protein. PMID:17977832

  18. Secretion of whey acidic protein and cystatin is down regulated at mid-lactation in the red kangaroo (Macropus rufus)

    USGS Publications Warehouse

    Nicholas, K.R.; Fisher, J.A.; Muths, E.; Trott, J.; Janssens, P.A.; Reich, C.; Shaw, D.C.

    2001-01-01

    Milk collected from the red kangaroo (Macropus rufus) between day 100 and 260 of lactation showed major changes in milk composition at around day 200 of lactation, the time at which the pouch young begins to temporarily exit the pouch and eat herbage. The carbohydrate content of milk declined abruptly at this time and although there was only a small increase in total protein content, SDS PAGE analysis of milk revealed asynchrony in the secretory pattern of individual proteins. The levels of ??-lactalbumin, ??-lactoglobulin, serum albumin and transferrin remain unchanged during lactation. In contrast, the protease inhibitor cystatin, and the putative protease inhibitor whey acidic protein (WAP) first appeared in milk at elevated concentrations after approximately 150 days of lactation and then ceased to be secreted at approximately 200 days. In addition, a major whey protein, late lactation protein, was first detected in milk around the time whey acidic protein and cystatin cease to be secreted and was present at least until day 260 of lactation. The co-ordinated, but asynchronous secretion of putative protease inhibitors in milk may have several roles during lactation including tissue remodelling in the mammary gland and protecting specific proteins in milk required for physiological development of the dependent young. ?? 2001 Elsevier Science Inc.

  19. Properties of low-moisture viscoplastic materials consisting of oil droplets dispersed in a protein-carbohydrate-glycerol matrix: effect of oil concentration.

    PubMed

    Gu, Yeun Suk; Corradini, Maria G; McClements, D Julian; DesRochers, Julia

    2007-10-31

    The influence of oil concentration and baking on the properties of low-moisture composites consisting of oil droplets dispersed in a protein-carbohydrate-glycerol matrix was investigated. These composites were produced by blending canola oil, whey protein concentrate (WPC), corn syrup, and glycerol together using a high-speed mixer. The resulting system consisted of oil droplets dispersed in a polar matrix. Some composites were analyzed directly after preparation, while others were analyzed after being heated at 176 degrees C for 10 min to simulate baking. The "lightness" of the composites was greater before baking (higher L value), but the color was more intense after baking (higher a and b values). The lightness and color intensity of the composites decreased as the oil concentration increased, with the effects being more pronounced in the baked samples. The zeta potential of the oil droplets (measured after dilution at pH 6) was highly negative (approximately -40 mV), indicating that whey protein was adsorbed to the droplet surfaces. The mean particle diameter (measured after dilution at pH 6) increased appreciably after baking, which was attributed to droplet flocculation. The rheological properties of the unbaked and baked materials were characterized by squeezing flow viscometry, which showed that the measurements associated with consistency and yield stress increased with increasing oil concentration and with baking. PMID:17902626

  20. Role of carbohydrate response element-binding protein (ChREBP) in generating an aerobic metabolic phenotype and in breast cancer progression

    PubMed Central

    Airley, R E; McHugh, P; Evans, A R; Harris, B; Winchester, L; Buffa, F M; Al-Tameemi, W; Leek, R; Harris, A L

    2014-01-01

    Background: The lipogenic transcription factor carbohydrate response element-binding protein (ChREBP) may play a key role in malignant progression of breast cancer by allowing metabolic adaptations to take place in response to changes in oxygenation. Methods: Immunohistochemical analysis of ChREBP was carried out in human breast tumour tissue microarrays representative of malignant progression from normal breast through to metastatic cancer. The ChREBP protein and mRNA expressions were then analysed in a series of breast cancers for correlative analysis with common and breast-specific hypoxia signatures, and survival. Results: In invasive ductal carcinoma, ChREBP correlated significantly with mean ‘downregulated' hypoxia scores (r=0.3, P<0.015, n=67) and in two distinct breast progression arrays, ChREBP protein also increased with malignant progression (P<0.001). However, bioinformatic analysis of a large data set (2136 cases) revealed an apparent reversal in the relationship between ChREBP mRNA level and clinical outcome – not only being significantly correlated with increased survival (log rank P<0.001), but also downregulated in malignant tissue compared with adjacent normal tissue. Conclusion: The ChREBP expression may be reflective of an aerobic metabolic phenotype that may conflict with hypoxia-induced signalling but provide a mechanism for growth at the oxygenated edge of the tumours. PMID:24366300

  1. Probing of exopolysaccharides with green fluorescence protein-labeled carbohydrate-binding module in Escherichia coli biofilms and flocs induced by bcsB overexpression.

    PubMed

    Nguyen, Minh Hong; Ojima, Yoshihiro; Sakka, Makiko; Sakka, Kazuo; Taya, Masahito

    2014-10-01

    Polysaccharides are major structural constituents to develop the three-dimensional architecture of Escherichia coli biofilms. In this study, confocal laser scanning microscopy was applied in combination with a fluorescent probe to analyze the location and arrangement of exopolysaccharide (EPSh) in microcolonies of E. coli K-12 derived strains, formed as biofilms on solid surfaces and flocs in the liquid phase. For this purpose, a novel fluorescent probe was constructed by conjugating a carbohydrate-binding module 3, from Paenibacillus curdlanolyticus, with the green fluorescence protein (GFP-CBM3). The GFP-CBM3 fused protein exhibited strong affinity to microcrystalline cellulose. Moreover, GFP-CBM3 specifically bound to cell-dense microcolonies in the E. coli biofilms, and to their flocs induced by bcsB overexpression. Therefore, the fused protein presents as a novel marker for EPSh produced by E. coli cells. Overexpression of bcsB was associated with abundant EPSh production and enhanced E. coli biofilm formation, which was similarly detectable by GFP-CBM3 probing. PMID:24746734

  2. Some non-anomerically C-C-linked carbohydrate amino acids related to leucine-synthesis and structure determination.

    PubMed

    Steiner, Bohumil; Micová, Júlia; Koós, Miroslav; Langer, Vratislav; Gyepesová, Dalma

    2003-06-23

    (5'R)-5'-Isobutyl-5'-[methyl (4R)-2,3-O-isopropylidene-beta-L-erythrofuranosid-4-C-yl]-imidazolidin-2',4'-dione was synthesised starting from methyl 2,3-O-isopropylidene-alpha-D-lyxo-pentodialdo-1,4-furanoside via methyl 6-deoxy-6-isopropyl-2,3-O-isopropylidene-alpha-D-lyxo-hexofuranosid-5-ulose applying the Bucherer-Bergs reaction. Its 5'-R configuration was confirmed by X-ray crystallography. Corresponding alpha-amino acid-methyl (5R)-5-amino-5-C-carboxy-5,6-dideoxy-6-isopropyl-alpha-D-lyxo-hexofuranoside (alternative name: 2-[methyl (4R)-beta-L-erythrofuranosid-4-C-yl]-D-leucine) was obtained from the above hydantoin by acid hydrolysis of the isopropylidene group followed by basic hydrolysis of the hydantoin ring. Analogous derivatives with 5S configuration, formed in a minority, were also isolated and characterised. PMID:12801708

  3. Recombinant Trichoderma harzianum endoglucanase I (Cel7B) is a highly acidic and promiscuous carbohydrate-active enzyme.

    PubMed

    Pellegrini, Vanessa O A; Serpa, Viviane Isabel; Godoy, Andre S; Camilo, Cesar M; Bernardes, Amanda; Rezende, Camila A; Junior, Nei Pereira; Franco Cairo, João Paulo L; Squina, Fabio M; Polikarpov, Igor

    2015-11-01

    Trichoderma filamentous fungi have been investigated due to their ability to secrete cellulases which find various biotechnological applications such as biomass hydrolysis and cellulosic ethanol production. Previous studies demonstrated that Trichoderma harzianum IOC-3844 has a high degree of cellulolytic activity and potential for biomass hydrolysis. However, enzymatic, biochemical, and structural studies of cellulases from T. harzianum are scarce. This work reports biochemical characterization of the recombinant endoglucanase I from T. harzianum, ThCel7B, and its catalytic core domain. The constructs display optimum activity at 55 °C and a surprisingly acidic pH optimum of 3.0. The full-length enzyme is able to hydrolyze a variety of substrates, with high specific activity: 75 U/mg for β-glucan, 46 U/mg toward xyloglucan, 39 U/mg for lichenan, 26 U/mg for carboxymethyl cellulose, 18 U/mg for 4-nitrophenyl β-D-cellobioside, 16 U/mg for rye arabinoxylan, and 12 U/mg toward xylan. The enzyme also hydrolyzed filter paper, phosphoric acid swollen cellulose, Sigmacell 20, Avicel PH-101, and cellulose, albeit with lower efficiency. The ThCel7B catalytic domain displays similar substrate diversity. Fluorescence-based thermal shift assays showed that thermal stability is highest at pH 5.0. We determined kinetic parameters and analyzed a pattern of oligosaccharide substrates hydrolysis, revealing cellobiose as a final product of C6 degradation. Finally, we visualized effects of ThCel7B on oat spelt using scanning electron microscopy, demonstrating the morphological changes of the substrate during the hydrolysis. The acidic behavior of ThCel7B and its considerable thermostability hold a promise of its industrial applications and other biotechnological uses under extremely acidic conditions. PMID:26156238

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

    PubMed Central

    2012-01-01

    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 < 0.05). The insulin response was increased following all test meals, although only significantly higher after whey. Plasma amino acids were correlated to insulin and incretin secretion (iAUC 0–60 min) (P ≤ 0.05). The lowered glycemia with the test meals (iAUC 0–90 min) was inversely correlated to GLP-1 (iAUC 0–30 min) (P ≤ 0.05). 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. PMID:23057765

  5. Short-chain fatty acids regulate IGF-binding protein secretion by intestinal epithelial cells.

    PubMed

    Nishimura, A; Fujimoto, M; Oguchi, S; Fusunyan, R D; MacDermott, R P; Sanderson, I R

    1998-07-01

    Gastrointestinal epithelial cells secrete insulin-like growth factor (IGF)-binding proteins (IGFBPs), which modulate the actions of IGFs on cell proliferation and differentiation. Short-chain fatty acids are bacterial metabolites from unabsorbed carbohydrate (including fiber). We hypothesized that they may alter the pattern of IGFBPs secreted by epithelial cells as part of a wider phenomenon by which luminal molecules regulate gastrointestinal epithelial cell signaling. The intestinal epithelial cell line, Caco-2, predominantly secretes IGFBP-3; however, butyrate increased the secretion of IGFBP-2 in a dose-dependent and reversible manner. Butyrate decreased the secretion of IGFBP-3. Butyrate altered only the synthesis and not the cell sorting of IGFBPs because 1) the secretion of IGFBPs remained polarized despite changes in their rates of production, and 2) IGFBP secretion corresponded to mRNA accumulation. The ability of short-chain fatty acids or the fungicide trichostatin A to stimulate IGFBP-2 correlated with their actions on histone acetylation. In conclusion, intestinal epithelial cells respond to short-chain fatty acids by altering secretion of IGFBPs. PMID:9688874

  6. Manipulating Fatty Acid Biosynthesis in Microalgae for Biofuel through Protein-Protein Interactions

    PubMed Central

    Blatti, Jillian L.; Beld, Joris; Behnke, Craig A.; Mendez, Michael; Mayfield, Stephen P.; Burkart, Michael D.

    2012-01-01

    Microalgae are a promising feedstock for renewable fuels, and algal metabolic engineering can lead to crop improvement, thus accelerating the development of commercially viable biodiesel production from algae biomass. We demonstrate that protein-protein interactions between the fatty acid acyl carrier protein (ACP) and thioesterase (TE) govern fatty acid hydrolysis within the algal chloroplast. Using green microalga Chlamydomonas reinhardtii (Cr) as a model, a structural simulation of docking CrACP to CrTE identifies a protein-protein recognition surface between the two domains. A virtual screen reveals plant TEs with similar in silico binding to CrACP. Employing an activity-based crosslinking probe designed to selectively trap transient protein-protein interactions between the TE and ACP, we demonstrate in vitro that CrTE must functionally interact with CrACP to release fatty acids, while TEs of vascular plants show no mechanistic crosslinking to CrACP. This is recapitulated in vivo, where overproduction of the endogenous CrTE increased levels of short-chain fatty acids and engineering plant TEs into the C. reinhardtii chloroplast did not alter the fatty acid profile. These findings highlight the critical role of protein-protein interactions in manipulating fatty acid biosynthesis for algae biofuel engineering as illuminated by activity-based probes. PMID:23028438

  7. Carbohydrate-interactive pDNA and siRNA gene vectors based on boronic acid functionalized poly(amido amine)s.

    PubMed

    Piest, Martin; Ankoné, Marc; Engbersen, Johan F J

    2013-08-10

    In order to evaluate the influence of incorporation of boronic acid groups on the properties of poly(amido amine)s as gene vectors, a novel poly(amido amine) copolymer p(CBA-ABOL/2AMPBA) containing ortho-aminomethylphenylboronic acid (2AMPBA) moieties was prepared by Michael-type polyaddition of a mixture of 1,4-aminobutanol (ABOL) and 2-((4-aminobutylamino)methyl)phenyl boronic acid to N,N'-cystamine bisacrylamide (CBA). It appeared that the presence of the boronic acid moieties as side groups along the polymer chain strongly enhances the stability of the self-assembled nanoparticles and nanosized polyplexes formed from this polymer; no aggregation was observed after storage for 6days at 37°C. This strong stabilization can be attributed to intermolecular Lewis acid-base interactions between the 2AMPBA groups and the alcohol and amine groups present in the polymer, leading to dynamical (reversible) crosslinking in the nanoparticles. Moreover, since the boronic acids can reversibly form boronic esters with vicinal diol groups, the presence of the 2AMPBA groups add carbohydrate-interactive properties to these polymers that strongly influence their behavior as gene delivery vectors. DNA transfection with p(CBA-ABOL/2AMPBA) polyplexes gave transfection efficiencies that were approximately similar to commercial PEI in different cell lines (COS-7, HUH-6 and H1299-Fluc), but lower than those obtained with reference polyplexes from p(CBA-ABOL). It is hypothesized that the uptake of the boronated polyplexes is suppressed by binding to the glycocalyx of the cells. This is supported by the observation that addition of sorbitol or dextran to the transfection medium significantly enhances the transfection efficiency, which can be attributed to increased cellular uptake of the polyplexes due to boronic ester formation with these agents. AFM, SEM and confocal microscopy showed that polyplexes of p(CBA-ABOL/2AMPBA) become decorated with a dextran layer in the presence of 0.9% (w

  8. Predicting protein disorder by analyzing amino acid sequence

    PubMed Central

    Yang, Jack Y; Yang, Mary Qu

    2008-01-01

    Background Many protein regions and some entire proteins have no definite tertiary structure, presenting instead as dynamic, disorder ensembles under different physiochemical circumstances. These proteins and regions are known as Intrinsically Unstructured Proteins (IUP). IUP have been associated with a wide range of protein functions, along with roles in diseases characterized by protein misfolding and aggregation. Results Identifying IUP is important task in structural and functional genomics. We exact useful features from sequences and develop machine learning algorithms for the above task. We compare our IUP predictor with PONDRs (mainly neural-network-based predictors), disEMBL (also based on neural networks) and Globplot (based on disorder propensity). Conclusion We find that augmenting features derived from physiochemical properties of amino acids (such as hydrophobicity, complexity etc.) and using ensemble method proved beneficial. The IUP predictor is a viable alternative software tool for identifying IUP protein regions and proteins. PMID:18831799

  9. IR-UV photochemistry of protein-nucleic acid systems

    SciTech Connect

    Kozub, J.; Edwards, G.

    1995-12-31

    UV light has often been used to induce the formation of covalent bonds between DNA (or RNA) and tightly-bound protein molecules. However, the internal photoreactions of nucleic acids and proteins limit the yield and complicate the analysis of intermolecular crosslinks. In an ongoing search for improved reaction specificity or new photoreactions in these systems, we have employed UV photons from a Nd:YAG-pumped dye laser and mid-IR photons from the Vanderbilt FEL. Having crosslinked several protein-nucleic acid systems with nanosecond UV laser pulses, we are currently studying the effect of various IR wavelengths on a model system (gene 32 protein and poly[dT]). We have found that irradiation with sufficiently intense FEL macropulses creates an altered form of gene 32 protein which was not observed with UV-only irradiation. The electrophoretic nobility of the product is consistent with the formation of a specific protein-protein crosslink. No evidence of the non-specific protein damage typically induced by UV light is found. The yield of the new photoproduct is apparently enhanced by exposure to FEL macropulses which are synchronized with UV laser pulses. With ideal exposure parameters, the two-color reaction effectively competes with UV-only reactions. Experiments designed to determine the reaction mechanism and to demonstrate FEL-induced reactions in other protein-nucleic acid systems are currently underway.

  10. Modifications of proteins by polyunsaturated fatty acid peroxidation products

    NASA Astrophysics Data System (ADS)

    Refsgaard, Hanne H. F.; Tsai, Lin; Stadtman, Earl R.

    2000-01-01

    The ability of unsaturated fatty acid methyl esters to modify amino acid residues in bovine serum albumin (BSA), glutamine synthetase, and insulin in the presence of a metal-catalyzed oxidation system [ascorbate/Fe(III)/O2] depends on the degree of unsaturation of the fatty acid. The fatty acid-dependent generation of carbonyl groups and loss of lysine residues increased in the order methyl linoleate < methyl linolenate < methyl arachidonate. The amounts of alkyl hydroperoxides, malondialdehyde, and a number of other aldehydes that accumulated when polyunsaturated fatty acids were oxidized in the presence of BSA were significantly lower than that observed in the absence of BSA. Direct treatment of proteins with various lipid hydroperoxides led to a slight increase in the formation of protein carbonyl derivatives, whereas treatment with the hydroperoxides together with Fe(II) led to a substantial increase in the formation of protein carbonyls. These results are consistent with the proposition that metal-catalyzed oxidation of polyunsaturated fatty acids can contribute to the generation of protein carbonyls by direct interaction of lipid oxidation products (α,β-unsaturated aldehydes) with lysine residues (Michael addition reactions) and also by interactions with alkoxyl radicals obtained by Fe(II) cleavage of lipid hydroperoxides that are formed. In addition, saturated aldehydes derived from the polyunsaturated fatty acids likely react with lysine residues to form Schiff base adducts.

  11. Modifications of proteins by polyunsaturated fatty acid peroxidation products

    PubMed Central

    Refsgaard, Hanne H. F.; Tsai, Lin; Stadtman, Earl R.

    2000-01-01

    The ability of unsaturated fatty acid methyl esters to modify amino acid residues in bovine serum albumin (BSA), glutamine synthetase, and insulin in the presence of a metal-catalyzed oxidation system [ascorbate/Fe(III)/O2] depends on the degree of unsaturation of the fatty acid. The fatty acid-dependent generation of carbonyl groups and loss of lysine residues increased in the order methyl linoleate < methyl linolenate < methyl arachidonate. The amounts of alkyl hydroperoxides, malondialdehyde, and a number of other aldehydes that accumulated when polyunsaturated fatty acids were oxidized in the presence of BSA were significantly lower than that observed in the absence of BSA. Direct treatment of proteins with various lipid hydroperoxides led to a slight increase in the formation of protein carbonyl derivatives, whereas treatment with the hydroperoxides together with Fe(II) led to a substantial increase in the formation of protein carbonyls. These results are consistent with the proposition that metal-catalyzed oxidation of polyunsaturated fatty acids can contribute to the generation of protein carbonyls by direct interaction of lipid oxidation products (α,β-unsaturated aldehydes) with lysine residues (Michael addition reactions) and also by interactions with alkoxyl radicals obtained by Fe(II) cleavage of lipid hydroperoxides that are formed. In addition, saturated aldehydes derived from the polyunsaturated fatty acids likely react with lysine residues to form Schiff base adducts. PMID:10639127

  12. Carbon-13 nuclear magnetic resonance analysis, lignin content and carbohydrate composition of humic substances from salt marsh estuaries

    NASA Astrophysics Data System (ADS)

    Alberts, James J.; Hatcher, Patrick G.; Price, Mary T.; Filip, Zdenek

    13C nuclear magnetic resonance spectroscopy, CuO oxidation products of lignin and hydrolyzable carbohydrates were measured for fulvic and humic acids extracted from living and dead Spartina alterniflora and salt marsh sediments. With these methods, there was little evidence for early diagenetic alteration of the humic materials. No trends consistent for fulvic and humic acids were observed for either hydrolyzable carbohydrates or lignin derived phenols, and chemical measurements of these fractions did not agree with spectral estimates. Humic acids appear to contain secondary amide linkages typical of proteins and peptides.

  13. Effect of ketogenic mediterranean diet with phytoextracts and low carbohydrates/high-protein meals on weight, cardiovascular risk factors, body composition and diet compliance in Italian council employees

    PubMed Central

    2011-01-01

    Background There has been increased interest in recent years in very low carbohydrate ketogenic diets (VLCKD) that, even though they are much discussed and often opposed, have undoubtedly been shown to be effective, at least in the short to medium term, as a tool to tackle obesity, hyperlipidemia and some cardiovascular risk factors. For this reason the ketogenic diet represents an interesting option but unfortunately suffers from a low compliance. The aim of this pilot study is to ascertain the safety and effects of a modified ketogenic diet that utilizes ingredients which are low in carbohydrates but are formulated to simulate its aspect and taste and also contain phytoextracts to add beneficial effects of important vegetable components. Methods The study group consisted of 106 Rome council employees with a body mass index of ≥ 25, age between 18 and 65 years (19 male and 87 female; mean age 48.49 ± 10.3). We investigated the effects of a modified ketogenic diet based on green vegetables, olive oil, fish and meat plus dishes composed of high quality protein and virtually zero carbohydrate but which mimic their taste, with the addition of some herbal extracts (KEMEPHY ketogenic Mediterranean with phytoextracts). Calories in the diet were unlimited. Measurements were taken before and after 6 weeks of diet. Results There were no significant changes in BUN, ALT, AST, GGT and blood creatinine. We detected a significant (p < 0.0001) reduction in BMI (31.45 Kg/m2 to 29.01 Kg/m2), body weight (86.15 kg to 79.43 Kg), percentage of fat mass (41.24% to 34.99%), waist circumference (106.56 cm to 97.10 cm), total cholesterol (204 mg/dl to 181 mg/dl), LDLc (150 mg/dl to 136 mg/dl), triglycerides (119 mg/dl to 93 mg/dl) and blood glucose (96 mg/dl to 91 mg/dl). There was a significant (p < 0.0001) increase in HDLc (46 mg/dl to 52 mg/dl). Conclusions The KEMEPHY diet lead to weight reduction, improvements in cardiovascular risk markers, reduction in waist circumference and

  14. [Amino acid composition of rice grain proteins].

    PubMed

    Peruanskiĭ, Iu V; Savich, I M

    1976-01-01

    The composition of the major reserve proteins of rice grain--globulins, prolamines and glutelins--was examined in four rice varieties (Dubovsky 129, Kuban 3, Alakul, Ushtobinsky). Globulins proved to be most heterogeneous whereas glutelins appeared to be least heterogeneous. In regards to the ratio of components globulins showed high variability and glutelins displayed high stability. PMID:1005365

  15. Real-time Measurements of Amino Acid and Protein Hydroperoxides Using Coumarin Boronic Acid*

    PubMed Central

    Michalski, Radoslaw; Zielonka, Jacek; Gapys, Ewa; Marcinek, Andrzej; Joseph, Joy; Kalyanaraman, Balaraman

    2014-01-01

    Hydroperoxides of amino acid and amino acid residues (tyrosine, cysteine, tryptophan, and histidine) in proteins are formed during oxidative modification induced by reactive oxygen species. Amino acid hydroperoxides are unstable intermediates that can further propagate oxidative damage in proteins. The existing assays (oxidation of ferrous cation and iodometric assays) cannot be used in real-time measurements. In this study, we show that the profluorescent coumarin boronic acid (CBA) probe reacts with amino acid and protein hydroperoxides to form the corresponding fluorescent product, 7-hydroxycoumarin. 7-Hydroxycoumarin formation was catalase-independent. Based on this observation, we have developed a fluorometric, real-time assay that is adapted to a multiwell plate format. This is the first report showing real-time monitoring of amino acid and protein hydroperoxides using the CBA-based assay. This approach was used to detect protein hydroperoxides in cell lysates obtained from macrophages exposed to visible light and photosensitizer (rose bengal). We also measured the rate constants for the reaction between amino acid hydroperoxides (tyrosyl, tryptophan, and histidine hydroperoxides) and CBA, and these values (7–23 m−1 s−1) were significantly higher than that measured for H2O2 (1.5 m−1 s−1). Using the CBA-based competition kinetics approach, the rate constants for amino acid hydroperoxides with ebselen, a glutathione peroxidase mimic, were also determined, and the values were within the range of 1.1–1.5 × 103 m−1 s−1. Both ebselen and boronates may be used as small molecule scavengers of amino acid and protein hydroperoxides. Here we also show formation of tryptophan hydroperoxide from tryptophan exposed to co-generated fluxes of nitric oxide and superoxide. This observation reveals a new mechanism for amino acid and protein hydroperoxide formation in biological systems. PMID:24928516

  16. Co-ingestion of carbohydrate and whey protein isolates enhance PGC-1α mRNA expression: a randomised, single blind, cross over study

    PubMed Central

    2013-01-01

    Background Whey protein isolates (WPI) supplementation is known to improve resistance training adaptations. However, limited information is available on the effects of WPI plus carbohydrate (CHO) supplementation on endurance training adaptations. Method Six endurance trained male cyclists and triathletes (age 29 ± 4 years, weight 74 ± 2 kg, VO2 max 63 ± 3 ml oxygen. kg-1. Min-1, height 183 ± 5 cm; mean ± SEM) were randomly assigned to one of two dietary interventions in a single blind cross over design; CHO or CHO + WPI. Each dietary intervention was followed for 16 days which included the last 2 days having increased CHO content, representing a CHO loading phase. The dietary interventions were iso-caloric and carbohydrate content matched. On completion of the dietary intervention, participants performed an exercise bout, consisting of cycling for 60 min at 70% VO2 max, followed by time trial to exhaustion at 90% VO2 max and recovered in the laboratory for 6 hours. Blood samples and muscle biopsies were taken at various time points at rest and through the exercise trial and recovery. Results Compared to CHO, CHO + WPI increased plasma insulin during recovery at 180 mins (P < 0.05) and peroxisome proliferator-activated receptor gamma coactivator-1 alpha (PGC-1α) mRNA expression at the end of 6 hours of recovery (P < 0.05). Muscle glycogen did not differ between the two trials. Conclusion This study showed co-ingestion of CHO + WPI may have beneficial effects on recovery and adaptations to endurance exercise via, increased insulin response and up regulation of PGC-1α mRNA expression. PMID:23402493

  17. Nucleic acid compositions and the encoding proteins

    DOEpatents

    Preston, III, James F.; Chow, Virginia; Nong, Guang; Rice, John D.; St. John, Franz J.

    2014-09-02

    The subject invention provides at least one nucleic acid sequence encoding an aldouronate-utilization regulon isolated from Paenibacillus sp. strain JDR-2, a bacterium which efficiently utilizes xylan and metabolizes aldouronates (methylglucuronoxylosaccharides). The subject invention also provides a means for providing a coordinately regulated process in which xylan depolymerization and product assimilation are coupled in Paenibacillus sp. strain JDR-2 to provide a favorable system for the conversion of lignocellulosic biomass to biobased products. Additionally, the nucleic acid sequences encoding the aldouronate-utilization regulon can be used to transform other bacteria to form organisms capable of producing a desired product (e.g., ethanol, 1-butanol, acetoin, 2,3-butanediol, 1,3-propanediol, succinate, lactate, acetate, malate or alanine) from lignocellulosic biomass.

  18. Carbohydrate-Binding Module–Cyclodextrin Glycosyltransferase Fusion Enables Efficient Synthesis of 2-O-d-Glucopyranosyl-l-Ascorbic Acid with Soluble Starch as the Glycosyl Donor

    PubMed Central

    Han, Ruizhi; Li, Jianghua; Shin, Hyun-Dong; Chen, Rachel R.; Du, Guocheng

    2013-01-01

    In this study, we achieved the efficient synthesis of 2-O-d-glucopyranosyl-l-ascorbic acid (AA-2G) from soluble starch by fusing a carbohydrate-binding module (CBM) from Alkalimonas amylolytica α-amylase (CBMAmy) to cyclodextrin glycosyltransferase (CGTase) from Paenibacillus macerans. One fusion enzyme, CGT-CBMAmy, was constructed by fusing the CBMAmy to the C-terminal region of CGTase, and the other fusion enzyme, CGTΔE-CBMAmy, was obtained by replacing the E domain of CGTase with CBMAmy. The two fusion enzymes were then used to synthesize AA-2G from soluble starch as a cheap and easily soluble glycosyl donor. Under the optimal conditions, the AA-2G yields produced using CGTΔE-CBMAmy and CGT-CBMAmy were 2.01 g/liter and 3.03 g/liter, respectively, which were 3.94- and 5.94-fold of the yield from the wild-type CGTase (0.51 g/liter). The reaction kinetics of the two fusion enzymes were analyzed and modeled to confirm the enhanced specificity toward soluble starch. It was also found that, compared to the wild-type CGTase, the two fusion enzymes had relatively high hydrolysis and disproportionation activities, factors that favor AA-2G synthesis. Finally, it was speculated that the enhancement of soluble starch specificity may be related to the changes of substrate binding ability and the substrate binding sites between the CBM and the starch granule. PMID:23503312

  19. Induction of ketosis in rats fed low-carbohydrate, high-fat diets depends on the relative abundance of dietary fat and protein.

    PubMed

    Bielohuby, Maximilian; Menhofer, Dominik; Kirchner, Henriette; Stoehr, Barbara J M; Müller, Timo D; Stock, Peggy; Hempel, Madlen; Stemmer, Kerstin; Pfluger, Paul T; Kienzle, Ellen; Christ, Bruno; Tschöp, Matthias H; Bidlingmaier, Martin

    2011-01-01

    Low-carbohydrate/high-fat diets (LC-HFDs) in rodent models have been implicated with both weight loss and as a therapeutic approach to treat neurological diseases. LC-HFDs are known to induce ketosis; however, systematic studies analyzing the impact of the macronutrient composition on ketosis induction and weight loss success are lacking. Male Wistar rats were pair-fed for 4 wk either a standard chow diet or one of three different LC-HFDs, which only differed in the relative abundance of fat and protein (percentages of fat/protein in dry matter: LC-75/10; LC-65/20; LC-55/30). We subsequently measured body composition by nuclear magnetic resonance (NMR), analyzed blood chemistry and urine acetone content, evaluated gene expression changes of key ketogenic and gluconeogenic genes, and measured energy expenditure (EE) and locomotor activity (LA) during the first 4 days and after 3 wk on the respective diets. Compared with chow, rats fed with LC-75/10, LC-65/20, and LC-55/30 gained significantly less body weight. Reductions in body weight were mainly due to lower lean body mass and paralleled by significantly increased fat mass. Levels of β-hydroxybutyate were significantly elevated feeding LC-75/10 and LC-65/20 but decreased in parallel to reductions in dietary fat. Acetone was about 16-fold higher with LC-75/10 only (P < 0.001). In contrast, rats fed with LC-55/30 were not ketotic. Serum fibroblast growth factor-21, hepatic mRNA expression of hydroxymethylglutaryl-CoA-lyase, peroxisome proliferator-activated receptor-γ coactivator-1α, and peroxisome proliferator-activated receptor-γ coactivator-1β were increased with LC-75/10 only. Expression of phosphoenolpyruvate carboxykinase and glucose-6-phosphatase was downregulated by 50-70% in LC-HF groups. Furthermore, EE and LA were significantly decreased in all groups fed with LC-HFDs after 3 wk on the diets. In rats, the absence of dietary carbohydrates per se does not induce ketosis. LC-HFDs must be high in fat

  20. FLU, an amino acid substitution model for influenza proteins

    PubMed Central

    2010-01-01

    Background The amino acid substitution model is the core component of many protein analysis systems such as sequence similarity search, sequence alignment, and phylogenetic inference. Although several general amino acid substitution models have been estimated from large and diverse protein databases, they remain inappropriate for analyzing specific species, e.g., viruses. Emerging epidemics of influenza viruses raise the need for comprehensive studies of these dangerous viruses. We propose an influenza-specific amino acid substitution model to enhance the understanding of the evolution of influenza viruses. Results A maximum likelihood approach was applied to estimate an amino acid substitution model (FLU) from ~113, 000 influenza protein sequences, consisting of ~20 million residues. FLU outperforms 14 widely used models in constructing maximum likelihood phylogenetic trees for the majority of influenza protein alignments. On average, FLU gains ~42 log likelihood points with an alignment of 300 sites. Moreover, topologies of trees constructed using FLU and other models are frequently different. FLU does indeed have an impact on likelihood improvement as well as tree topologies. It was implemented in PhyML and can be downloaded from ftp://ftp.sanger.ac.uk/pub/1000genomes/lsq/FLU or included in PhyML 3.0 server at http://www.atgc-montpellier.fr/phyml/. Conclusions FLU should be useful for any influenza protein analysis system which requires an accurate description of amino acid substitutions. PMID:20384985

  1. Acid Cleavable Surface enhanced Raman Tagging for Protein Detection

    PubMed Central

    Zhang, Dongmao; Vangala, Karthikeshwar; Li, Shaoyong; Yanney, Michael; Xia, Hao; Zou, Sige; Sygula, Andrzej

    2010-01-01

    Dye conjugation is a common strategy improving the surface enhanced Raman detection sensitivity of biomolecules. Reported is a proof-of-concept study of a novel surface enhanced Raman spectroscopic tagging strategy termed as acid-cleavable SERS tag (ACST) method. Using Rhodamine B as the starting material, we prepared the first ACST prototype that consisted of, from the distal end, a SERS tag moiety (STM), an acid-cleavable linker, and a protein reactive moiety. Complete acid cleavage of the ACST tags was achieved at a very mild condition that is 1.5% trifluoroacetic acid (TFA) aqueous solution at room temperature. SERS detection of this ACST tagged protein was demonstrated using bovine serum albumin (BSA) as the model protein. While the SERS spectrum of intact ACST-BSA was entirely dominated by the fluorescent signal of STM, quality SERS spectra can be readily obtained with the acid cleaved ACST-BSA conjugates. Separation of the acid cleaved STM from protein further enhances the SERS sensitivity. Current SERS detection sensitivity, achieved with the acid cleaved ACST-BSA conjugate is ~5 nM in terms of the BSA concentration and ~1.5 nM in ACST content. The linear dynamic range of the cleaved ACST-BSA conjugate spans four orders of magnitudes from ~10 nM to ~100 μM in protein concentrations. Further improvement in the SERS sensitivity can be achieved with resonance Raman acquisition. This cleavable tagging strategy may also be used for elimination of protein interference in fluorescence based biomolecule detection. PMID:21109888

  2. Effects of Low Carbohydrate High Protein (LCHP) diet on atherosclerotic plaque phenotype in ApoE/LDLR−/− mice: FT-IR and Raman imaging

    PubMed Central

    Wrobel, T. P.; Marzec, K. M.; Chlopicki, S.; Maślak, E.; Jasztal, A.; Franczyk-Żarów, M.; Czyżyńska-Cichoń, I.; Moszkowski, T.; Kostogrys, R. B.; Baranska, M.

    2015-01-01

    Low Carbohydrate High Protein (LCHP) diet displays pro-atherogenic effects, however, the exact mechanisms involved are still unclear. Here, with the use of vibrational imaging, such as Fourier transform infrared (FT-IR) and Raman (RS) spectroscopies, we characterize biochemical content of plaques in Brachiocephalic Arteries (BCA) from ApoE/LDLR−/− mice fed LCHP diet as compared to control, recomended by American Institute of Nutrition, AIN diet. FT-IR images were taken from 6–10 sections of BCA from each mice and were complemented with RS measurements with higher spatial resolution of chosen areas of plaque sections. In aortic plaques from LCHP fed ApoE/LDLR−/− mice, the content of cholesterol and cholesterol esters was increased, while that of proteins was decreased as evidenced by global FT-IR analysis. High resolution imaging by RS identified necrotic core/foam cells, lipids (including cholesterol crystals), calcium mineralization and fibrous cap. The decreased relative thickness of the outer fibrous cap and the presence of buried caps were prominent features of the plaques in ApoE/LDLR−/− mice fed LCHP diet. In conclusion, FT-IR and Raman-based imaging provided a complementary insight into the biochemical composition of the plaque suggesting that LCHP diet increased plaque cholesterol and cholesterol esters contents of atherosclerotic plaque, supporting the cholesterol-driven pathogenesis of LCHP–induced atherogenesis. PMID:26391802

  3. Effect of temperature on lipids, proteins, and carbohydrates levels during development from egg extrusion to juvenile stage of Cherax quadricarinatus (Decapoda: Parastacidae).

    PubMed

    García-Guerrero, Marcelo; Villarreal, Humberto; Racotta, Ilie S

    2003-05-01

    The influence of temperature on biochemical composition, survival and duration of development of Cherax quadricarinatus from egg extrusion to juvenile was analyzed. Berried females were individually subjected to each of 22, 25, 28 and 31 degrees C (n=5 per temperature). Egg samples were obtained every 3 days from egg extrusion to juvenile stage for biochemical analysis. Duration of development and survival decreased with increasing temperature. At 22 and 25 degrees C half of the initial lipid content was consumed during development. At 28 and 31 degrees C, 80% of the initial amount of lipids was consumed. For proteins, depletion rate was significantly lower at 25 degrees C (36% of the initial amount) than at 22, 28 and 31 degrees C (61-65% of the initial amount). For carbohydrates, a significant consumption was observed only at 22 degrees C. Total energy consumption was lower at 22 and 25 degrees C than at 28 and 31 degrees C. We conclude that 22-25 degrees C is the optimal temperature range for C. quadricarinatus egg incubation, although 25 degrees C might be better in terms of development duration in terms of survival, energy cost and protein consumption. PMID:12727551

  4. Effects of Low Carbohydrate High Protein (LCHP) diet on atherosclerotic plaque phenotype in ApoE/LDLR-/- mice: FT-IR and Raman imaging.

    PubMed

    Wrobel, T P; Marzec, K M; Chlopicki, S; Maślak, E; Jasztal, A; Franczyk-Żarów, M; Czyżyńska-Cichoń, I; Moszkowski, T; Kostogrys, R B; Baranska, M

    2015-01-01

    Low Carbohydrate High Protein (LCHP) diet displays pro-atherogenic effects, however, the exact mechanisms involved are still unclear. Here, with the use of vibrational imaging, such as Fourier transform infrared (FT-IR) and Raman (RS) spectroscopies, we characterize biochemical content of plaques in Brachiocephalic Arteries (BCA) from ApoE/LDLR(-/-) mice fed LCHP diet as compared to control, recomended by American Institute of Nutrition, AIN diet. FT-IR images were taken from 6-10 sections of BCA from each mice and were complemented with RS measurements with higher spatial resolution of chosen areas of plaque sections. In aortic plaques from LCHP fed ApoE/LDLR(-/-) mice, the content of cholesterol and cholesterol esters was increased, while that of proteins was decreased as evidenced by global FT-IR analysis. High resolution imaging by RS identified necrotic core/foam cells, lipids (including cholesterol crystals), calcium mineralization and fibrous cap. The decreased relative thickness of the outer fibrous cap and the presence of buried caps were prominent features of the plaques in ApoE/LDLR(-/-) mice fed LCHP diet. In conclusion, FT-IR and Raman-based imaging provided a complementary insight into the biochemical composition of the plaque suggesting that LCHP diet increased plaque cholesterol and cholesterol esters contents of atherosclerotic plaque, supporting the cholesterol-driven pathogenesis of LCHP-induced atherogenesis. PMID:26391802

  5. Effect of period, water temperature and agitation on loss of water-soluble carbohydrates and protein from grass hay: implications for equine feeding management.

    PubMed

    Longland, A C; Barfoot, C; Harris, P A

    2014-01-18

    The effects of different water-soaking treatments on removal of water-soluble carbohydrates (WSC), WSC constituents and protein from four UK hays were determined. Hays were soaked in water for up to 16 hours at mean temperatures of 8°C, 16°C, in hot tap water (initially 49°C) or agitated and rinsed in clean water at 16°C. Initial hay WSC contents ranged from 154 to 216 g/kg dry matter. Losses of WSC from hays after 16 hours soaking at 8°C, 16°C, 16°C plus agitation and 49°C averaged 28, 46, 49 and 44 per cent, respectively. Corresponding percentage losses of fructan were 16, 37, 39 and 33. Percentage losses of sucrose averaged 55 (8°C), 86 (16°C), 91 (16°C+agitation) and 82 (initial temperature 49°C), those of glucose were 60, 85, 75 and 75, and of fructose were 41, 52, 54 and 46. Hay crude protein contents were not significantly changed by any of the soaking treatments. Soaking at 8°C generally resulted in reduced losses of WSC compared to when soaked at the higher temperatures. Thus, in cold weather using warmer water to soak hays may effect greater WSC loss, although very prolonged soaking at warm temperatures might encourage the proliferation of unwanted micro-organisms in the soak liquor. PMID:24336793

  6. Serum and salivary antibody responses in rats orally immunized with Streptococcus mutans carbohydrate protein conjugate associated with liposomes.

    PubMed Central

    Wachsmann, D; Klein, J P; Scholler, M; Ogier, J; Ackermans, F; Frank, R M

    1986-01-01

    In this study we describe the preparation of a Streptococcus mutans vaccine consisting of a purified polysaccharide antigen, derived from S. mutans OMZ175 serotype f, covalently coupled through reductive amination to a previously isolated 74,000-molecular-weight (74K) cell wall protein which interacts with saliva proteins (74K-SR). We also investigated the local and systemic immune response to the poly-74K-SR conjugate after oral administration of the conjugate associated with liposomes. Intragastric administration of liposome-associated poly-74K-SR conjugate in rats produced a local immunoglobulin A (IgA) response directed against the polysaccharide and the cell surface protein, whereas liposome-associated polysaccharide was unable to induce any detectable local IgA response. The antigenicity of the polysaccharide in the conjugate was not affected by the coupling reaction, while that of the cell surface protein was reduced. We showed that the immunogenicity of S. mutans polysaccharide could be improved by chemical coupling with a carrier cell surface protein. If such a conjugate were orally administered with liposomes it could constitute a potential vaccine against dental caries. Images PMID:3699888

  7. Effects of preoperative feeding with a whey protein plus carbohydrate drink on the acute phase response and insulin resistance. A randomized trial

    PubMed Central

    2011-01-01

    Background Prolonged preoperative fasting increases insulin resistance and current evidence recommends carbohydrate (CHO) drinks 2 hours before surgery. Our hypothesis is that the addition of whey protein to a CHO-based drink not only reduces the inflammatory response but also diminish insulin resistance. Methods Seventeen patients scheduled to cholecystectomy or inguinal herniorraphy were randomized and given 474 ml and 237 ml of water (CO group) or a drink containing CHO and milk whey protein (CHO-P group) respectively, 6 and 3 hours before operation. Blood samples were collected before surgery and 24 hours afterwards for biochemical assays. The endpoints of the study were the insulin resistance (IR), the prognostic inflammatory and nutritional index (PINI) and the C-reactive protein (CRP)/albumin ratio. A 5% level for significance was established. Results There were no anesthetic or postoperative complications. The post-operative IR was lower in the CHO-P group when compared with the CO group (2.75 ± 0.72 vs 5.74 ± 1.16; p = 0.03). There was no difference between the two groups in relation to the PINI. The CHO-P group showed a decrease in the both CRP elevation and CRP/albumin ratio (p < 0.05). The proportion of patients who showed CRP/albumin ratio considered normal was significantly greater (p < 0.05) in the CHO-P group (87.5%) than in the CO group (33.3%). Conclusions Shortening the pre-operative fasting using CHO and whey protein is safe and reduces insulin resistance and postoperative acute phase response in elective moderate operations. Trial registration ClinicalTrail.gov NCT01354249 PMID:21668975

  8. Properties of low moisture composite materials consisting of oil droplets dispersed in a protein-carbohydrate-glycerol matrix: effect of continuous phase composition.

    PubMed

    Gu, Yeun Suk; Corradini, Maria G; McClements, D Julian; Desrochers, Julia

    2006-01-25

    The influence of continuous phase composition on the properties of low moisture (<3% water) composite materials consisting of oil droplets dispersed in a protein-carbohydrate-glycerol matrix was investigated. These composites were produced by blending canola oil (62.3%), whey protein concentrate (1.7%, WPC), and corn syrup and glycerol together (36.0% combined) using a high speed mixer equipped with a whisk. The polyol composition was varied by changing the ratio of corn syrup to glycerol in the system while keeping the total concentration of these two polyol components constant. Some composites were analyzed directly after preparation ("unbaked"), while others were analyzed after heating at 176 degrees C for 10 min to simulate baking of a food product ("baked"). The "lightness" of the composites was greater before baking (higher L value), but the color intensity of the composites was greater after baking (higher b value), which was attributed to Maillard browning reactions. The brownness of the baked composites increased with increasing corn syrup concentration, which was attributed to Maillard browning reactions. Squeezing flow viscometry indicated that the consistency and yield stress of the composites increased with baking, which was attributed to whey protein unfolding and aggregation. These rheological parameters also increased with increasing corn syrup concentration, which was attributed to its influence on the continuous phase rheology and on the interactions between the whey proteins. This study shows that the continuous phase composition and thermal history of low moisture composite materials have a large impact on their final physicochemical properties. PMID:16417299

  9. Carbohydrate degrading polypeptide and uses thereof

    SciTech Connect

    Sagt, Cornelis Maria Jacobus; Schooneveld-Bergmans, Margot Elisabeth Francoise; Roubos, Johannes Andries; Los, Alrik Pieter

    2015-10-20

    The invention relates to a polypeptide having carbohydrate material degrading activity which comprises the amino acid sequence set out in SEQ ID NO: 2 or an amino acid sequence encoded by the nucleotide sequence of SEQ ID NO: 1 or SEQ ID NO: 4, or a variant polypeptide or variant polynucleotide thereof, wherein the variant polypeptide has at least 96% sequence identity with the sequence set out in SEQ ID NO: 2 or the variant polynucleotide encodes a polypeptide that has at least 96% sequence identity with the sequence set out in SEQ ID NO: 2. The invention features the full length coding sequence of the novel gene as well as the amino acid sequence of the full-length functional protein and functional equivalents of the gene or the amino acid sequence. The invention also relates to methods for using the polypeptide in industrial processes. Also included in the invention are cells transformed with a polynucleotide according to the invention suitable for producing these proteins.

  10. Proteins, Peptides and Amino Acids: Role in Infant Nutrition.

    PubMed

    Nutten, Sophie

    2016-01-01

    Proteins are polymers composed of 30 or more amino acids; some of them are essential dietary components, since they are not synthetized by human metabolic processes. They are crucial for healthy growth and development and influence major functions of the body. The infant's first year is a critical time of rapid growth and development, which must be supported by a high rate of protein synthesis. Breast milk, as a single specific food source in the first months of life, is providing the total protein and essential amino acids required. Infant formulas have been designed for infants who cannot be breastfed. They should be similar to breast milk in their composition and their functional outcomes, insuring appropriate growth, optimal development, maturation of the immune system, easy digestion and healthy metabolic programming. By modifying their protein components, specific infant formulas have also been developed for specific needs. For example, partially hydrolyzed (prevention of atopic dermatitis) and extensively hydrolyzed or amino-acid-based infant formulas (reduction in allergy symptoms) have been designed for the management of cow's milk protein allergy. In conclusion, proteins provided via breast milk or infant formula are essential components of the infant's diet; therefore, the specific quality, quantity and conformation of proteins are of utmost importance for healthy growth and development. PMID:27336588

  11. Lactivibrio alcoholicus gen. nov., sp. nov., an anaerobic, mesophilic, lactate-, alcohol-, carbohydrate- and amino-acid-degrading bacterium in the phylum Synergistetes.

    PubMed

    Qiu, Yan-Ling; Hanada, Satoshi; Kamagata, Yoichi; Guo, Rong-Bo; Sekiguchi, Yuji

    2014-06-01

    A mesophilic, obligately anaerobic, lactate-, alcohol-, carbohydrate- and amino-acid- degrading bacterium, designated strain 7WAY-8-7(T), was isolated from an upflow anaerobic sludge blanket reactor treating high-strength organic wastewater from isomerized sugar production processes. Cells of strain 7WAY-8-7(T) were motile, curved rods (0.7-1.0×5.0-8.0 µm). Spore formation was not observed. The strain grew optimally at 37 °C (range for growth was 25-40 °C) and pH 7.0 (pH 6.0-7.5), and could grow fermentatively on yeast extract, glucose, ribose, xylose, malate, tryptone, pyruvate, fumarate, Casamino acids, serine and cysteine. The main end-products of glucose fermentation were acetate and hydrogen. In co-culture with the hydrogenotrophic methanogen Methanospirillum hungatei DSM 864(T), strain 7WAY-8-7(T) could utilize lactate, glycerol, ethanol, 1-propanol, 1-butanol, L-glutamate, alanine, leucine, isoleucine, valine, histidine, asparagine, glutamine, arginine, lysine, threonine, 2-oxoglutarate, aspartate and methionine. A Stickland reaction was not observed with some pairs of amino acids. Yeast extract was required for growth. Nitrate, sulfate, thiosulfate, elemental sulfur, sulfite and Fe (III) were not used as terminal electron acceptors. The G+C content of the genomic DNA was 61.4 mol%. 16S rRNA gene sequence analysis revealed that the isolate belongs to the uncultured environmental clone clade (called 'PD-UASB-13' in the Greengenes database) in the bacterial phylum Synergistetes, showing less than 90% sequence similarity with closely related described species such as Aminivibrio pyruvatiphilus and Aminobacterium colombiense (89.7% and 88.7%, respectively). The major cellular fatty acids were iso-C(13 : 0), iso-C(15 : 0), anteiso-C(15 : 0), C(18 : 1), C(19 : 1), C(20 : 1) and C(21 : 1). A novel genus and species, Lactivibrio alcoholicus gen. nov., sp. nov. is proposed to accommodate strain 7WAY-8-7(T) ( = JCM 17151(T

  12. Fatty acid induced remodeling within the human liver fatty acid-binding protein.

    PubMed

    Sharma, Ashwani; Sharma, Amit

    2011-09-01

    We crystallized human liver fatty acid-binding protein (LFABP) in apo, holo, and intermediate states of palmitic acid engagement. Structural snapshots of fatty acid recognition, entry, and docking within LFABP support a heads-in mechanism for ligand entry. Apo-LFABP undergoes structural remodeling, where the first palmitate ingress creates the atomic environment for placement of the second palmitate. These new mechanistic insights will facilitate development of pharmacological agents against LFABP. PMID:21757748

  13. beta-1,3-Glucan recognition by an insect pathogen recognition domain causes self-association of protein: carbohydrate complex

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In response to invading microorganisms, insect beta-1,3-glucan recognition protein (beta-GRP), a soluble receptor in the hemolymph, binds to the surfaces of bacteria and fungi and activates serine protease cascades associated with the prophenoloxidase (proPO) and Toll pathways; it also agglutinates ...

  14. "Click" Chemistry-Tethered Hyaluronic Acid-Based Contact Lens Coatings Improve Lens Wettability and Lower Protein Adsorption.

    PubMed

    Deng, Xudong; Korogiannaki, Myrto; Rastegari, Banafsheh; Zhang, Jianfeng; Chen, Mengsu; Fu, Qiang; Sheardown, Heather; Filipe, Carlos D M; Hoare, Todd

    2016-08-31

    Improving the wettability of and reducing the protein adsorption to contact lenses may be beneficial for improving wearer comfort. Herein, we describe a simple "click" chemistry approach to surface functionalize poly(2-hydroxyethyl methacrylate) (pHEMA)-based contact lenses with hyaluronic acid (HA), a carbohydrate naturally contributing to the wettability of the native tear film. A two-step preparation technique consisting of laccase/TEMPO-mediated oxidation followed by covalent grafting of hydrazide-functionalized HA via simple immersion resulted in a model lens surface that is significantly more wettable, more water retentive, and less protein binding than unmodified pHEMA while maintaining the favorable transparency, refractive, and mechanical properties of a native lens. The dipping/coating method we developed to covalently tether the HA wetting agent is simple, readily scalable, and a highly efficient route for contact lens modification. PMID:27509015

  15. Carbohydrate digestion and absorption

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A variety of simple and complex carbohydrates are present in human diets. Food carbohydrates include the sugars, starches, and fibers found mainly in fruits, vegetables, grains, and milk products. Small amounts of digestible carbohydrates come from non-plant sources (e.g., trehalose in insects and...

  16. Challenges with nonfiber carbohydrate methods.

    PubMed

    Hall, M B

    2003-12-01

    Nonfiber carbohydrates (NFC) encompass a compositionally and nutritionally diverse group exclusive of those carbohydrates found in NDF. Their content in feeds has often been described as a single value estimated by difference as 100% of dry matter minus the percentages of CP, NDF (adjusted for CP in NDF), ether extract, and ash. A calculated value was used because of difficulties with assays for individual NFC, but it does not differentiate among nutritionally distinct NFC. Errors in NFC estimation can arise from not accounting for CP in NDF and when multipliers other than 6.25 are appropriate to estimate CP. Analyses that begin to distinguish among NFC are those for starch, soluble fiber (non-NDF, nonstarch polysaccharides), and low molecular weight carbohydrates (mono- and oligosaccharides). Many starch analyses quantify alpha-glucans through specific hydrolysis of alpha-(1 --> 4) and alpha-(1 --> 6) linkages in the glucan, and measurement of released glucose. Incomplete gelatinization and hydrolysis will lead to underestimation of starch content. Starch values are inflated by enzyme preparations that hydrolyze carbohydrates other than alpha-glucan, measurement of all released monosaccharides without specificity for glucose, and failure to exclude free glucose present in the unhydrolyzed sample. Soluble fiber analyses err in a fashion similar to NFC if estimation of CP requires multipliers other than 6.25, or if contaminants such as CP and starch have not been properly accounted. Depolymerization and incomplete precipitation can also decrease soluble fiber estimates. The low molecular weight carbohydrates have been defined as carbohydrates soluble in 78 to 80% ethanol, which separates them from polysaccharides. They can be measured in extracts using broad-spectrum colorimetric assays (phenol-sulfuric acid assay or reducing sugar analysis of acid hydrolyzed samples) or chromatographic methods. Limitations of the colorimetric assays include lack of differentiation

  17. A study of different indicators of Maillard reaction with whey proteins and different carbohydrates under adverse storage conditions.

    PubMed

    Leiva, Graciela E; Naranjo, Gabriela B; Malec, Laura S

    2017-01-15

    This study examined different indicators of each stage of Maillard reaction under adverse storage conditions in a system with whey proteins and lactose or glucose. The analysis of lysine loss by the o-phthaldialdehyde method can be considered a good indicator of the early stage, showing considerable differences in reactivity when systems with mono and disaccharides were analyzed. Capillary electrophoresis proved to be a sensitive method for evaluating the extent of glycosylation of the native proteins, providing valuable information when the loss of lysine was not significant. The estimation of the Amadori compound from the determination of total 5-hydroxymethyl-2-furfuraldehyde would have correlate well with reactive lysine content if the advanced stages of the reaction had not been reached. For assessing the occurrence of the intermediate and final stages, the measurement of free 5-hydroxymethyl-2-furfuraldehyde and color, proved not to be suitable for storage conditions. PMID:27542493

  18. Irradiation of Yarrowia lipolytica NRRL YB-567 creating novel strains with enhanced ammonia and oil production on protein and carbohydrate substrates.

    PubMed

    Lindquist, Mitch R; López-Núñez, Juan Carlos; Jones, Marjorie A; Cox, Elby J; Pinkelman, Rebecca J; Bang, Sookie S; Moser, Bryan R; Jackson, Michael A; Iten, Loren B; Kurtzman, Cletus P; Bischoff, Kenneth M; Liu, Siqing; Qureshi, Nasib; Tasaki, Kenneth; Rich, Joseph O; Cotta, Michael A; Saha, Badal C; Hughes, Stephen R

    2015-11-01

    Increased interest in sustainable production of renewable diesel and other valuable bioproducts is redoubling efforts to improve economic feasibility of microbial-based oil production. Yarrowia lipolytica is capable of employing a wide variety of substrates to produce oil and valuable co-products. We irradiated Y. lipolytica NRRL YB-567 with UV-C to enhance ammonia (for fertilizer) and lipid (for biodiesel) production on low-cost protein and carbohydrate substrates. The resulting strains were screened for ammonia and oil production using color intensity of indicators on plate assays. Seven mutant strains were selected (based on ammonia assay) and further evaluated for growth rate, ammonia and oil production, soluble protein content, and morphology when grown on liver infusion medium (without sugars), and for growth on various substrates. Strains were identified among these mutants that had a faster doubling time, produced higher maximum ammonia levels (enzyme assay) and more oil (Sudan Black assay), and had higher maximum soluble protein levels (Bradford assay) than wild type. When grown on plates with substrates of interest, all mutant strains showed similar results aerobically to wild-type strain. The mutant strain with the highest oil production and the fastest doubling time was evaluated on coffee waste medium. On this medium, the strain produced 0.12 g/L ammonia and 0.20 g/L 2-phenylethanol, a valuable fragrance/flavoring, in addition to acylglycerols (oil) containing predominantly C16 and C18 residues. These mutant strains will be investigated further for potential application in commercial biodiesel production. PMID:26272089

  19. A macromolecular delivery vehicle for protein-based vaccines: Acid-degradable protein-loaded microgels

    PubMed Central

    Murthy, Niren; Xu, Mingcheng; Schuck, Stephany; Kunisawa, Jun; Shastri, Nilabh; Fréchet, Jean M. J.

    2003-01-01

    The development of protein-based vaccines remains a major challenge in the fields of immunology and drug delivery. Although numerous protein antigens have been identified that can generate immunity to infectious pathogens, the development of vaccines based on protein antigens has had limited success because of delivery issues. In this article, an acid-sensitive microgel material is synthesized for the development of protein-based vaccines. The chemical design of these microgels is such that they degrade under the mildly acidic conditions found in the phagosomes of antigen-presenting cells (APCs). The rapid cleavage of the microgels leads to phagosomal disruption through a colloid osmotic mechanism, releasing protein antigens into the APC cytoplasm for class I antigen presentation. Ovalbumin was encapsulated in microgel particles, 200–500 nm in diameter, prepared by inverse emulsion polymerization with a synthesized acid-degradable crosslinker. Ovalbumin is released from the acid-degradable microgels in a pH-dependent manner; for example, microgels containing ovalbumin release 80% of their encapsulated proteins after 5 h at pH 5.0, but release only 10% at pH 7.4. APCs that phagocytosed the acid-degradable microgels containing ovalbumin were capable of activating ovalbumin-specific cytoxic T lymphocytes. The acid-degradable microgels developed in this article should therefore find applications as delivery vehicles for vaccines targeted against viruses and tumors, where the activation of cytoxic T lymphocytes is required for the development of immunity. PMID:12704236

  20. Nucleic Acid Programmable Protein Array: A Just-In-Time Multiplexed Protein Expression and Purification Platform

    PubMed Central

    Qiu, Ji; LaBaer, Joshua

    2012-01-01

    Systematic study of proteins requires the availability of thousands of proteins in functional format. However, traditional recombinant protein expression and purification methods have many drawbacks for such study at the proteome level. We have developed an innovative in situ protein expression and capture system, namely NAPPA (nucleic acid programmable protein array), where C-terminal tagged proteins are expressed using an in vitro expression system and efficiently captured/purified by antitag antibodies coprinted at each spot. The NAPPA technology presented in this chapter enable researchers to produce and display fresh proteins just in time in a multiplexed high-throughput fashion and utilize them for various downstream biochemical researches of interest. This platform could revolutionize the field of functional proteomics with it ability to produce thousands of spatially separated proteins in high density with narrow dynamic rand of protein concentrations, reproducibly and functionally. PMID:21943897

  1. Structure of Bacteroides thetaiotaomicron BT2081 at 2.05 Å resolution: the first structural representative of a new protein family that may play a role in carbohydrate metabolism

    PubMed Central

    Yeh, Andrew P.; Abdubek, Polat; Astakhova, Tamara; Axelrod, Herbert L.; Bakolitsa, Constantina; Cai, Xiaohui; Carlton, Dennis; Chen, Connie; Chiu, Hsiu-Ju; Chiu, Michelle; Clayton, Thomas; Das, Debanu; Deller, Marc C.; Duan, Lian; Ellrott, Kyle; Farr, Carol L.; Feuerhelm, Julie; Grant, Joanna C.; Grzechnik, Anna; Han, Gye Won; Jaroszewski, Lukasz; Jin, Kevin K.; Klock, Heath E.; Knuth, Mark W.; Kozbial, Piotr; Krishna, S. Sri; Kumar, Abhinav; Lam, Winnie W.; Marciano, David; McMullan, Daniel; Miller, Mitchell D.; Morse, Andrew T.; Nigoghossian, Edward; Nopakun, Amanda; Okach, Linda; Puckett, Christina; Reyes, Ron; Tien, Henry J.; Trame, Christine B.; van den Bedem, Henry; Weekes, Dana; Wooten, Tiffany; Xu, Qingping; Hodgson, Keith O.; Wooley, John; Elsliger, Marc-André; Deacon, Ashley M.; Godzik, Adam; Lesley, Scott A.; Wilson, Ian A.

    2010-01-01

    BT2081 from Bacteroides thetaiotaomicron (GenBank accession code NP_810994.1) is a member of a novel protein family consisting of over 160 members, most of which are found in the different classes of Bacteroidetes. Genome-context analysis lends support to the involvement of this family in carbohydrate metabolism, which plays a key role in B. thetaiotaomicron as a predominant bacterial symbiont in the human distal gut microbiome. The crystal structure of BT2081 at 2.05 Å resolution represents the first structure from this new protein family. BT2081 consists of an N-terminal domain, which adopts a β-sandwich immunoglobulin-like fold, and a larger C-terminal domain with a β-sandwich jelly-roll fold. Structural analyses reveal that both domains are similar to those found in various carbohydrate-active enzymes. The C-terminal β-jelly-roll domain contains a potential carbohydrate-binding site that is highly conserved among BT2081 homologs and is situated in the same location as the carbohydrate-binding sites that are found in structurally similar glycoside hydrolases (GHs). However, in BT2081 this site is partially occluded by surrounding loops, which results in a deep solvent-accessible pocket rather than a shallower solvent-exposed cleft. PMID:20944224

  2. Analysis and validation of carbohydrate three-dimensional structures

    SciTech Connect

    Lütteke, Thomas

    2009-02-01

    The article summarizes the information that is gained from and the errors that are found in carbohydrate structures in the Protein Data Bank. Validation tools that can locate these errors are described. Knowledge of the three-dimensional structures of the carbohydrate molecules is indispensable for a full understanding of the molecular processes in which carbohydrates are involved, such as protein glycosylation or protein–carbohydrate interactions. The Protein Data Bank (PDB) is a valuable resource for three-dimensional structural information on glycoproteins and protein–carbohydrate complexes. Unfortunately, many carbohydrate moieties in the PDB contain inconsistencies or errors. This article gives an overview of the information that can be obtained from individual PDB entries and from statistical analyses of sets of three-dimensional structures, of typical problems that arise during the analysis of carbohydrate three-dimensional structures and of the validation tools that are currently available to scientists to evaluate the quality of these structures.

  3. Amino acid repeats and the structure and evolution of proteins.

    PubMed

    Albà, M M; Tompa, P; Veitia, R A

    2007-01-01

    Many proteins have repeats or runs of single amino acids. The pathogenicity of some repeat expansions has fueled proteomic, genomic and structural explorations of homopolymeric runs not only in human but in a wide variety of other organisms. Other types of amino acid repetitive structures exhibit more complex patterns than homopeptides. Irrespective of their precise organization, repetitive sequences are defined as low complexity or simple sequences, as one or a few residues are particularly abundant. Prokaryotes show a relatively low frequency of simple sequences compared to eukaryotes. In the latter the percentage of proteins containing homopolymeric runs varies greatly from one group to another. For instance, within vertebrates, amino acid repeat frequency is much higher in mammals than in amphibians, birds or fishes. For some repeats, this is correlated with the GC-richness of the regions containing the corresponding genes. Homopeptides tend to occur in disordered regions of transcription factors or developmental proteins. They can trigger the formation of protein aggregates, particularly in 'disease' proteins. Simple sequences seem to evolve more rapidly than the rest of the protein/gene and may have a functional impact. Therefore, they are good candidates to promote rapid evolutionary changes. All these diverse facets of homopolymeric runs are explored in this review. PMID:18753788

  4. (-)-Hydroxycitric Acid Nourishes Protein Synthesis via Altering Metabolic Directions of Amino Acids in Male Rats.

    PubMed

    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. PMID:27145492

  5. Suppression of muscle protein turnover and amino acid degradation by dietary protein deficiency

    NASA Technical Reports Server (NTRS)

    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.

  6. Structural Assessment of the Effects of Amino Acid Substitutions on Protein Stability and Protein-Protein Interaction

    PubMed Central

    Teng, Shaolei; Wang, Liangjiang; Srivastava, Anand K.; Schwartz, Charles E.; Alexov, Emil

    2012-01-01

    A structure-based approach is described for predicting the effects of amino acid substitutions on protein function. Structures were predicted using a homology modelling method. Folding and binding energy differences between wild-type and mutant structures were computed to quantitatively assess the effects of amino acid substitutions on protein stability and protein–protein interaction, respectively. We demonstrated that pathogenic mutations at the interaction interface could affect binding energy and destabilise protein complex, whereas mutations at the non-interface might reduce folding energy and destabilise monomer structure. The results suggest that the structure-based analysis can provide useful information for understanding the molecular mechanisms of diseases. PMID:21297231

  7. Maximizing efficiency of rumen microbial protein production

    PubMed Central

    Hackmann, Timothy J.; Firkins, Jeffrey L.

    2015-01-01

    Rumen microbes produce cellular protein inefficiently partly because they do not direct all ATP toward growth. They direct some ATP toward maintenance functions, as long-recognized, but they also direct ATP toward reserve carbohydrate synthesis and energy spilling (futile cycles that dissipate heat). Rumen microbes expend ATP by vacillating between (1) accumulation of reserve carbohydrate after feeding (during carbohydrate excess) and (2) mobilization of that carbohydrate thereafter (during carbohydrate limitation). Protozoa account for most accumulation of reserve carbohydrate, and in competition experiments, protozoa accumulated nearly 35-fold more reserve carbohydrate than bacteria. Some pure cultures of bacteria spill energy, but only recently have mixed rumen communities been recognized as capable of the same. When these communities were dosed glucose in vitro, energy spilling could account for nearly 40% of heat production. We suspect that cycling of glycogen (a major reserve carbohydrate) is a major mechanism of spilling; such cycling has already been observed in single-species cultures of protozoa and bacteria. Interconversions of short-chain fatty acids (SCFA) may also expend ATP and depress efficiency of microbial protein production. These interconversions may involve extensive cycling of intermediates, such as cycling of acetate during butyrate production in certain butyrivibrios. We speculate this cycling may expend ATP directly or indirectly. By further quantifying the impact of reserve carbohydrate accumulation, energy spilling, and SCFA interconversions on growth efficiency, we can improve prediction of microbial protein production and guide efforts to improve efficiency of microbial protein production in the rumen. PMID:26029197

  8. Characterization and amino acid sequence of a fatty acid-binding protein from human heart.

    PubMed

    Offner, G D; Brecher, P; Sawlivich, W B; Costello, C E; Troxler, R F

    1988-05-15

    The complete amino acid sequence of a fatty acid-binding protein from human heart was determined by automated Edman degradation of CNBr, BNPS-skatole [3'-bromo-3-methyl-2-(2-nitrobenzenesulphenyl)indolenine], hydroxylamine, Staphylococcus aureus V8 proteinase, tryptic and chymotryptic peptides, and by digestion of the protein with carboxypeptidase A. The sequence of the blocked N-terminal tryptic peptide from citraconylated protein was determined by collisionally induced decomposition mass spectrometry. The protein contains 132 amino acid residues, is enriched with respect to threonine and lysine, lacks cysteine, has an acetylated valine residue at the N-terminus, and has an Mr of 14768 and an isoelectric point of 5.25. This protein contains two short internal repeated sequences from residues 48-54 and from residues 114-119 located within regions of predicted beta-structure and decreasing hydrophobicity. These short repeats are contained within two longer repeated regions from residues 48-60 and residues 114-125, which display 62% sequence similarity. These regions could accommodate the charged and uncharged moieties of long-chain fatty acids and may represent fatty acid-binding domains consistent with the finding that human heart fatty acid-binding protein binds 2 mol of oleate or palmitate/mol of protein. Detailed evidence for the amino acid sequences of the peptides has been deposited as Supplementary Publication SUP 50143 (23 pages) at the British Library Lending Division, Boston Spa, Yorkshire LS23 7BQ, U.K., from whom copies may be obtained as indicated in Biochem. J. (1988) 249, 5. PMID:3421901

  9. INCAP studies of energy, amino acids, and protein.

    PubMed

    Viteri, Fernando E

    2010-03-01

    This Special Issue summarizes the results of several studies aimed at providing information on a series of questions related to the adequate protein and energy intakes that allow adequate growth and function in children and work performance and productivity in adults. The effect of different sources of protein on nitrogen balance and the requirements of essential amino acids in young children were also explored in fully recovered, previously malnourished children housed in the Metabolic Ward of the Biomedical Division of INCAP. The following are the main results of these investigations: Animal experiments and studies in children recovering from protein-energy malnutrition (PEM) strongly suggest that even when requirements of all nutrients are satisfied, inactivity reduces the rate of linear growth and physical activity improves it as well as lean body mass repletion. The effects of different energy intakes on nitrogen balance demonstrated how energy intake modifies the need to ingest different amounts of protein to satisfy protein requirements. Insensible nitrogen losses in preschool children and their relation to protein intake was demonstrated. The quality of even "good protein sources" modifies the amount needed to satisfy nitrogen requirements, and corn and bean-based diets can satisfy protein needs for health and even growth of young children. Essential amino acid requirements of 2-year-old children was assessed by diverse measurements of nitrogen metabolism and amino acid levels in blood, and were found lower than those recommended by FAO-WHO. In rural adult populations the relationship between energy and protein intake, productivity and body composition, and the impact of environmental hygiene on nitrogen balance was demonstrated and measured. PMID:20461903

  10. General Properties, Occurrence, and Preparation of Carbohydrates

    NASA Astrophysics Data System (ADS)

    Robyt, John F.

    D-Glucose and its derivatives and analogues, N-acetyl-D-glucosamine, N-acetyl-D-muramic acid, D-glucopyranosyl uronic acid, and D-glucitol represent 99.9% of the carbohydrates on the earth. D-Glucose is found in the free state in human blood and in the combined state in disaccharides, sucrose, lactose, and α,α-trehalose, in cyclic dextrins, and in polysaccharides, starch, glycogen, cellulose, dextrans; N-acetyl-D-glucosamine and an analogue N-acetyl-D-muramic acid are found in bacterial cell wall polysaccharide, murein, along with teichoic acids made up of poly-glycerol or -ribitol phosphodiesters. Other carbohydrates, D-mannose, D-mannuronic acid, D-galactose, N-acetyl-D-galactosamine, D-galacturonic acid, D-iduronic acid, L-guluronic acid, L-rhamnose, L-fucose, D-xylose, and N-acetyl-D-neuraminic acid are found in glycoproteins, hemicelluloses, glycosaminoglycans, and polysaccharides of plant exudates, bacterial capsules, alginates, and heparin. D-Ribofuranose-5-phosphate is found in many coenzymes and is the backbone of RNAs (ribonucleic acid), and 2-deoxy-D-ribofuranose-5-phosphate is the backbone of DNA (deoxyribonucleic acid). D-Fructofuranose is found in sucrose, inulin, and levan. The general properties and occurrence of these carbohydrates and general methods of isolation and preparation of carbohydrates are presented.

  11. Studies on fatty acid-binding proteins. The diurnal variation shown by rat liver fatty acid-binding protein.

    PubMed Central

    Wilkinson, T C; Wilton, D C

    1987-01-01

    The concentration of fatty acid-binding protein in rat liver was examined by SDS/polyacrylamide-gel electrophoresis, by Western blotting and by quantifying the fluorescence enhancement achieved on the binding of the fluorescent probe 11-(dansylamino)undecanoic acid. A 2-3-fold increase in the concentration of this protein produced by treatment of rats with the peroxisome proliferator tiadenol was readily detected; however, only a small variation in the concentration of the protein due to a diurnal rhythm was observed. This result contradicts the 7-10-fold variation previously reported for this protein [Hargis, Olson, Clarke & Dempsey (1986) J. Biol. Chem. 261, 1988-1991]. Images Fig. 1. Fig. 3. PMID:3593284

  12. AMP-activated protein kinase: an emerging drug target to regulate imbalances in lipid and carbohydrate metabolism to treat cardio-metabolic diseases.

    PubMed

    Srivastava, Rai Ajit K; Pinkosky, Stephen L; Filippov, Sergey; Hanselman, Jeffrey C; Cramer, Clay T; Newton, Roger S

    2012-12-01

    The adenosine monophosphate-activated protein kinase (AMPK) is a metabolic sensor of energy metabolism at the cellular as well as whole-body level. It is activated by low energy status that triggers a switch from ATP-consuming anabolic pathways to ATP-producing catabolic pathways. AMPK is involved in a wide range of biological activities that normalizes lipid, glucose, and energy imbalances. These pathways are dysregulated in patients with metabolic syndrome (MetS), which represents a clustering of major cardiovascular risk factors including diabetes, lipid abnormalities, and energy imbalances. Clearly, there is an unmet medical need to find a molecule to treat alarming number of patients with MetS. AMPK, with multifaceted activities in various tissues, has emerged as an attractive drug target to manage lipid and glucose abnormalities and maintain energy homeostasis. A number of AMPK activators have been tested in preclinical models, but many of them have yet to reach to the clinic. This review focuses on the structure-function and role of AMPK in lipid, carbohydrate, and energy metabolism. The mode of action of AMPK activators, mechanism of anti-inflammatory activities, and preclinical and clinical findings as well as future prospects of AMPK as a drug target in treating cardio-metabolic disease are discussed. PMID:22798688

  13. Rice Bran Protein Hydrolysates Improve Insulin Resistance and Decrease Pro-inflammatory Cytokine Gene Expression in Rats Fed a High Carbohydrate-High Fat Diet

    PubMed Central

    Boonloh, Kampeebhorn; Kukongviriyapan, Veerapol; Kongyingyoes, Bunkerd; Kukongviriyapan, Upa; Thawornchinsombut, Supawan; Pannangpetch, Patchareewan

    2015-01-01

    A high carbohydrate-high fat (HCHF) diet causes insulin resistance (IR) and metabolic syndrome (MS). Rice bran has been demonstrated to have anti-dyslipidemic and anti-atherogenic properties in an obese mouse model. In the present study, we investigated the beneficial effects of rice bran protein hydrolysates (RBP) in HCHF-induced MS rats. After 12 weeks on this diet, the HCHF-fed group was divided into four subgroups, which were orally administered RBP 100 or 500 mg/kg, pioglitazone 10 mg/kg, or tap water for a further 6 weeks. Compared with normal diet control group, the MS rats had elevated levels of blood glucose, lipid, insulin, and HOMA-IR. Treatment with RBP significantly alleviated all those changes and restored insulin sensitivity. Additionally, RBP treatment increased adiponectin and suppressed leptin levels. Expression of Ppar-γ mRNA in adipose tissues was significantly increased whereas expression of lipogenic genes Srebf1 and Fasn was significantly decreased. Levels of mRNA of proinflammatory cytokines, Il-6, Tnf-α, Nos-2 and Mcp-1 were significantly decreased. In conclusion, the present findings support the consumption of RBP as a functional food to improve insulin resistance and to prevent the development of metabolic syndrome. PMID:26247962

  14. Rice Bran Protein Hydrolysates Improve Insulin Resistance and Decrease Pro-inflammatory Cytokine Gene Expression in Rats Fed a High Carbohydrate-High Fat Diet.

    PubMed

    Boonloh, Kampeebhorn; Kukongviriyapan, Veerapol; Kongyingyoes, Bunkerd; Kukongviriyapan, Upa; Thawornchinsombut, Supawan; Pannangpetch, Patchareewan

    2015-08-01

    A high carbohydrate-high fat (HCHF) diet causes insulin resistance (IR) and metabolic syndrome (MS). Rice bran has been demonstrated to have anti-dyslipidemic and anti-atherogenic properties in an obese mouse model. In the present study, we investigated the beneficial effects of rice bran protein hydrolysates (RBP) in HCHF-induced MS rats. After 12 weeks on this diet, the HCHF-fed group was divided into four subgroups, which were orally administered RBP 100 or 500 mg/kg, pioglitazone 10 mg/kg, or tap water for a further 6 weeks. Compared with normal diet control group, the MS rats had elevated levels of blood glucose, lipid, insulin, and HOMA-IR. Treatment with RBP significantly alleviated all those changes and restored insulin sensitivity. Additionally, RBP treatment increased adiponectin and suppressed leptin levels. Expression of Ppar-γ mRNA in adipose tissues was significantly increased whereas expression of lipogenic genes Srebf1 and Fasn was significantly decreased. Levels of mRNA of proinflammatory cytokines, Il-6, Tnf-α, Nos-2 and Mcp-1 were significantly decreased. In conclusion, the present findings support the consumption of RBP as a functional food to improve insulin resistance and to prevent the development of metabolic syndrome. PMID:26247962

  15. Cellulosilyticum ruminicola, a Newly Described Rumen Bacterium That Possesses Redundant Fibrolytic-Protein-Encoding Genes and Degrades Lignocellulose with Multiple Carbohydrate- Borne Fibrolytic Enzymes▿ †

    PubMed Central

    Cai, Shichun; Li, Jiabao; Hu, Fen Ze; Zhang, Kegui; Luo, Yuanming; Janto, Benjamin; Boissy, Robert; Ehrlich, Garth; Dong, Xiuzhu

    2010-01-01

    Cellulosilyticum ruminicola H1 is a newly described bacterium isolated from yak (Bos grunniens) rumen and is characterized by its ability to grow on a variety of hemicelluloses and degrade cellulosic materials. In this study, we performed the whole-genome sequencing of C. ruminicola H1 and observed a comprehensive set of genes encoding the enzymes essential for hydrolyzing plant cell wall. The corresponding enzymatic activities were also determined in strain H1; these included endoglucanases, cellobiohydrolases, xylanases, mannanase, pectinases, and feruloyl esterases and acetyl esterases to break the interbridge cross-link, as well as the enzymes that degrade the glycosidic bonds. This bacterium appears to produce polymer hydrolases that act on both soluble and crystal celluloses. Approximately half of the cellulytic activities, including cellobiohydrolase (50%), feruloyl esterase (45%), and one third of xylanase (31%) and endoglucanase (36%) activities were bound to cellulosic fibers. However, only a minority of mannase (6.78%) and pectinase (1.76%) activities were fiber associated. Strain H1 seems to degrade the plant-derived polysaccharides by producing individual fibrolytic enzymes, whereas the majority of polysaccharide hydrolases contain carbohydrate-binding module. Cellulosome or cellulosomelike protein complex was never isolated from this bacterium. Thus, the fibrolytic enzyme production of strain H1 may represent a different strategy in cellulase organization used by most of other ruminal microbes, but it applies the fungal mode of cellulose production. PMID:20400560

  16. AMP-activated protein kinase: an emerging drug target to regulate imbalances in lipid and carbohydrate metabolism to treat cardio-metabolic diseases

    PubMed Central

    Srivastava, Rai Ajit K.; Pinkosky, Stephen L.; Filippov, Sergey; Hanselman, Jeffrey C.; Cramer, Clay T.; Newton, Roger S.

    2012-01-01

    The adenosine monophosphate-activated protein kinase (AMPK) is a metabolic sensor of energy metabolism at the cellular as well as whole-body level. It is activated by low energy status that triggers a switch from ATP-consuming anabolic pathways to ATP-producing catabolic pathways. AMPK is involved in a wide range of biological activities that normalizes lipid, glucose, and energy imbalances. These pathways are dysregulated in patients with metabolic syndrome (MetS), which represents a clustering of major cardiovascular risk factors including diabetes, lipid abnormalities, and energy imbalances. Clearly, there is an unmet medical need to find a molecule to treat alarming number of patients with MetS. AMPK, with multifaceted activities in various tissues, has emerged as an attractive drug target to manage lipid and glucose abnormalities and maintain energy homeostasis. A number of AMPK activators have been tested in preclinical models, but many of them have yet to reach to the clinic. This review focuses on the structure-function and role of AMPK in lipid, carbohydrate, and energy metabolism. The mode of action of AMPK activators, mechanism of anti-inflammatory activities, and preclinical and clinical findings as well as future prospects of AMPK as a drug target in treating cardio-metabolic disease are discussed. PMID:22798688

  17. Editorial overview: Carbohydrate-protein interactions and glycosylation: Glycan synthesis and recognition: finding the perfect partner in a sugar-coated life.

    PubMed

    Feizi, Ten E N; Haltiwanger, Robert S

    2015-10-01

    Oligosaccharides expressed on the surface of cells and in biological fluids as glycoproteins, glycolipids, proteoglycans and polysaccharides can be recognized by partner proteins, and these interactions have been shown to mediate fundamental biological events such as occur in the immune system, signal transduction, development and cancer metastasis. The specificities of these partner proteins (lectins) for their glycan ligands are determined by factors such as glycan composition, shape and density of expression and the involvement of the aglycone moiety as part of the recognition motif. There is increasing knowledge on the mechanisms of these interactions as new secondary binding sites continue to be elucidated adding to the functional awareness of sugar-binding proteins. This issue focuses on recent advances in understanding how C-type lectins in the immune system work, how novel motifs involving asymmetric glycan branch recognition and protein-protein interactions influence critical biological functions including signal transduction and bactericidal pore formation, recent studies on novel glycan-binding proteins produced by bacteriophage, analysis of the interactions between heparin/heparan sulphate and their binding proteins, and recent findings on the molecular interactions between chondroitin-dermatan sulphate and various bioactive protein components. We conclude with a review on a recent fascinating class of processive enzymes responsible for synthesis of high-molecular weight extracellular polysaccharides such as hyaluronic acid, chitin and alginate. PMID:26613983

  18. Protein and amino acid metabolism in the human newborn

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Birth and adaptation to extrauterine life involve major shifts in the protein and energy metabolism of the human newborn. These include a shift from a state of continuous supply of nutrients including amino acids from the mother to cyclic periodic oral intake, a change in the redox state of organs, ...

  19. Vacuum ultraviolet photoionization of carbohydrates and nucleotides.

    PubMed

    Shin, Joong-Won; Bernstein, Elliot R

    2014-01-28

    Carbohydrates (2-deoxyribose, ribose, and xylose) and nucleotides (adenosine-, cytidine-, guanosine-, and uridine-5(')-monophosphate) are generated in the gas phase, and ionized with vacuum ultraviolet photons (VUV, 118.2 nm). The observed time of flight mass spectra of the carbohydrate fragmentation are similar to those observed [J.-W. Shin, F. Dong, M. Grisham, J. J. Rocca, and E. R. Bernstein, Chem. Phys. Lett. 506, 161 (2011)] for 46.9 nm photon ionization, but with more intensity in higher mass fragment ions. The tendency of carbohydrate ions to fragment extensively following ionization seemingly suggests that nucleic acids might undergo radiation damage as a result of carbohydrate, rather than nucleobase fragmentation. VUV photoionization of nucleotides (monophosphate-carbohydrate-nucleobase), however, shows that the carbohydrate-nucleobase bond is the primary fragmentation site for these species. Density functional theory (DFT) calculations indicate that the removed carbohydrate electrons by the 118.2 nm photons are associated with endocyclic C-C and C-O ring centered orbitals: loss of electron density in the ring bonds of the nascent ion can thus account for the observed fragmentation patterns following carbohydrate ionization. DFT calculations also indicate that electrons removed from nucleotides under these same conditions are associated with orbitals involved with the nucleobase-saccharide linkage electron density. The calculations give a general mechanism and explanation of the experimental results. PMID:25669546

  20. Vacuum ultraviolet photoionization of carbohydrates and nucleotides

    SciTech Connect

    Shin, Joong-Won; Bernstein, Elliot R.

    2014-01-28

    Carbohydrates (2-deoxyribose, ribose, and xylose) and nucleotides (adenosine-, cytidine-, guanosine-, and uridine-5{sup ′}-monophosphate) are generated in the gas phase, and ionized with vacuum ultraviolet photons (VUV, 118.2 nm). The observed time of flight mass spectra of the carbohydrate fragmentation are similar to those observed [J.-W. Shin, F. Dong, M. Grisham, J. J. Rocca, and E. R. Bernstein, Chem. Phys. Lett. 506, 161 (2011)] for 46.9 nm photon ionization, but with more intensity in higher mass fragment ions. The tendency of carbohydrate ions to fragment extensively following ionization seemingly suggests that nucleic acids might undergo radiation damage as a result of carbohydrate, rather than nucleobase fragmentation. VUV photoionization of nucleotides (monophosphate-carbohydrate-nucleobase), however, shows that the carbohydrate-nucleobase bond is the primary fragmentation site for these species. Density functional theory (DFT) calculations indicate that the removed carbohydrate electrons by the 118.2 nm photons are associated with endocyclic C–C and C–O ring centered orbitals: loss of electron density in the ring bonds of the nascent ion can thus account for the observed fragmentation patterns following carbohydrate ionization. DFT calculations also indicate that electrons removed from nucleotides under these same conditions are associated with orbitals involved with the nucleobase-saccharide linkage electron density. The calculations give a general mechanism and explanation of the experimental results.

  1. Short communication: Effect of dietary manipulation of crude protein content and nonfibrous-to-fibrous-carbohydrate ratio on energy balance in early-lactation dairy cows.

    PubMed

    Whelan, S J; Mulligan, F J; Gath, V; Flynn, B; Pierce, K M

    2014-11-01

    Disparities between nutrient intake and demand often result in a state of negative energy balance (EB) in the early-lactation dairy cow. Reducing dietary crude protein (CP) content and providing glucogenic nutrients may overcome this issue. This study evaluates whether or not offering a diet lower in CP and higher in nonfiber carbohydrates (LP-NFC) can improve EB and the metabolic status of the early-lactation dairy cow compared with a diet higher in CP and fibrous carbohydrates (HP-FC). Twenty Holstein-Friesian dairy cows were assigned to 1 of 2 dietary treatments in a randomized block design. Diets were isoenergetic (6.57 MJ of net energy for lactation) and formulated to contain 15% CP and 6% starch (HP-FC), or 12% CP and 28% starch (LP-NFC) and were offered for the first 63 d of lactation. Intake and milk yield were determined daily, whereas milk and blood samples, weights, and body condition scores were collected weekly. Intakes (mean ± standard errors of the mean, SEM) of dry matter (17.4 ± 0.6 kg/d) and energy (113.0 ± 4.6 MJ of net energy for lactation) were not different between treatments. However, the HP-FC group had a higher milk yield (31.8 vs. 28.9 ± 1.4 kg/d) and a lower EB compared with the LP-NFC group. Blood urea N concentration (3.5 vs. 1.8 ± 0.2 mmol/L) was higher, whereas bilirubin (6.0 vs. 6.7 ± 0.2 mmol/L) and β-hydroxybutyrate concentrations (0.7 vs. 0.8 ± 0.05 mmol/L) were lower in the HP-FC group compared with the LP-NFC group. These data suggest that EB can be improved during early lactation through the manipulation of milk output by offering a lower CP, higher NFC diet. PMID:25173467

  2. Understanding the differences in molecular conformation of carbohydrate and protein in endosperm tissues of grains with different biodegradation kinetics using advanced synchrotron technology

    NASA Astrophysics Data System (ADS)

    Yu, P.; Block, H. C.; Doiron, K.

    2009-01-01

    Conventional "wet" chemical analyses rely heavily on the use of harsh chemicals and derivatization, thereby altering native seed structures leaving them unable to detect any original inherent structures within an intact tissue sample. A synchrotron is a giant particle accelerator that turns electrons into light (million times brighter than sunlight) which can be used to study the structure of materials at the molecular level. Synchrotron radiation-based Fourier transform IR microspectroscopy (SR-FTIRM) has been developed as a rapid, direct, non-destructive and bioanalytical technique. This technique, taking advantage of the brightness of synchrotron light and a small effective source size, is capable of exploring the molecular chemistry within the microstructures of a biological tissue without the destruction of inherent structures at ultraspatial resolutions within cellular dimensions. This is in contrast to traditional 'wet' chemical methods, which, during processing for analysis, often result in the destruction of the intrinsic structures of feeds. To date there has been very little application of this technique to the study of plant seed tissue in relation to nutrient utilization. The objective of this study was to use novel synchrotron radiation-based technology (SR-FTIRM) to identify the differences in the molecular chemistry and conformation of carbohydrate and protein in various plant seed endosperms within intact tissues at cellular and subcellular level from grains with different biodegradation kinetics. Barley grain (cv. Harrington) with a high rate (31.3%/h) and extent (78%), corn grain (cv. Pioneer) with a low rate (9.6%/h) and extent of (57%), and wheat grain (cv. AC Barrie) with an intermediate rate (23%/h) and extent (72%) of ruminal DM degradation were selected for evaluation. SR-FTIRM evaluations were performed at the National Synchrotron Light Source at the Brookhaven National Laboratory (Brookhaven, NY). The molecular structure spectral analysis

  3. Carbohydrate metabolism of malarial parasites

    PubMed Central

    Homewood, C. A.

    1977-01-01

    The evidence for the pathways involved in the metabolism of carbohydrates by malarial parasites is critically reviewed. In all species studied, glucose is catabolized mainly by glycolysis with little participation of the pentose—phosphate pathway. It has not been proved conclusively that there is a functioning citric acid cycle in the intraerythrocytic stages of avian plasmodia, nor is it certain that these stages of any malarial parasites use oxygen. PMID:338181

  4. Nucleic acid-protein interactions: Wedding for love or circumstances?

    PubMed

    Lavelle, Christophe; Buckle, Malcolm

    2009-08-01

    The sixth Figeac meeting on nucleic acid-protein interactions was held in Figeac, France, from September 26th to October 1st, 2008. It was organized by the working group "nucleic acid-protein interactions and gene expression" from the French Society for Biochemistry and Molecular Biology. This report briefly summarizes the presentations by 40 speakers during the four plenary sessions, which were organised as follows: (1) nucleic acids: targets and tools, (2) RNA superstar, (3) nuclear structure and dynamics, and (4) new concepts - new approaches. A total of 22 plenary lectures, 18 oral communications and 40 posters were presented over the 5 days, providing a highly stimulating environment for scientific exchange between the approximately 80 participants (biochemists, physicists, bio-informaticians and molecular and cellular biologists). PMID:19422875

  5. Calculation of 29Si NMR shifts of silicate complexes with carbohydrates, amino acids, and muhicarboxylic acids: potential role in biological silica utilization

    NASA Astrophysics Data System (ADS)

    Sahai, Nita

    2004-01-01

    The existence of ether or ester-like complexes of silicate with organic compounds has long been debated in the literature on biological utilization of silicon. Comparison of theoretically calculated 29Si NMR chemical shifts for such complexes with experimentally measured values in biological systems could provide a diagnostic tool for identifying which, if any of these molecules exist under physiological conditions. Results are presented here for ab initio molecular orbital calculations of 29Si NMR shifts and formation energies of silicate complexes with polyalcohols, sugar-acids, pyranose sugars, amino acids and multicarboxylic acids. The effects of functional group and molecular structure including ligand size, denticity, ring size, silicon polymerization and coordination number on calculated 29Si shifts were considered. The potential role of such compounds in biological silica utilization pathways is discussed. 29Si NMR shifts and energies were calculated at the HF/6-311+G(2d,p)//HF/6-31G* level. The main result is that only five-membered rings containing penta- and hexa-coordinated Si can explain experimentally observed resonances at ˜ -101 and -141 ppm. Further, the heptet observed in 1H- 29Si coupled spectra can only be explained by structures where Si bonds to oxygens atoms in H-C-O-Si linkages with six symmetrically equivalent H atoms. While compounds containing quadra-coordinated silicon may exist in intracellular silicon storage pools within diatoms, calculated reaction energies suggest that the organism has no thermodynamic advantage in taking up extracellular organ-silicate compounds, instead of silicic acid, from the ambient aqueous environment. Hyper-coordinated complexes are deemed unlikely for transport and storage, though they may exist as transient reactive intermediates or activated complexes during enzymatically- catalyzed silica polymerization, as known previously from sol-gel silica synthesis studies.

  6. Effects of Salt Stress on Carbohydrate Metabolism of Lactobacillus plantarum ATCC 14917.

    PubMed

    Wang, Pingping; Wu, Zhen; Wu, Jing; Pan, Daodong; Zeng, Xiaoqun; Cheng, Kemeng

    2016-10-01

    Lactic acid bacteria are widely used in fermented foods, especially cheese products. In this study, we observed the salt tolerance of Lactobacillus plantarum ATCC 14917 after exposure to different concentrations of NaCl in MRS medium. Quantitative proteomic profiles using two-dimensional electrophoresis identified 384 proteins, of which 26 were upregulated and 31 downregulated. Matrix-Assisted Laser Desorption/Ionization Time of Flight Mass Spectrometry was then used to identify 11 proteins, of which three were linked to carbohydrate metabolism. The downregulation of carbamoyl phosphate synthase in carbohydrate metabolism revealed a bacterial regulation mechanism to save energy in order to survive during the salt tolerance. Other proteins were found involved in transcription-translation processes, fatty acid biosynthesis, and the primary metabolic process. PMID:27342422

  7. Night-time consumption of protein or carbohydrate results in increased morning resting energy expenditure in active college-aged men.

    PubMed

    Madzima, Takudzwa A; Panton, Lynn B; Fretti, Sarah K; Kinsey, Amber W; Ormsbee, Michael J

    2014-01-14

    The purpose of the present study was to investigate whether whey protein (WP), casein protein (CP), carbohydrate (CHO) or a non-energy-containing placebo (PLA) consumed before sleep alters morning appetite and resting energy expenditure (REE) in active men. A total of eleven men (age: 23·6 (sem 1·0) years; body fat: 16·3 (sem 2·5) %) participated in this randomised, double-blind, cross-over study. A single dose of WP (30 g), CP (30 g), CHO (33 g) or PLA was consumed 30 min before sleep, and each trial was separated by 48-72 h. The next morning (05.00-08.00 hours), measurements of satiety, hunger and desire to eat and REE were taken. After a 30 min equilibration period, REE in the supine position was measured for 60 min. An analysis of 10 min mean intervals over the final 50 min of the measurement period was conducted. Statistical analyses were conducted using repeated-measures ANOVA for metabolic variables, and a one-way ANOVA was used for measuring changes in appetite markers. Group differences were examined by Tukey's post hoc analysis. There were no significant differences in appetite measures among the groups. There was a main group effect for REE. The predicted REE was significantly greater after consumption of the WP (8151 (sem 67) kJ/d), CP (8126 (sem 67) kJ/d) and CHO (7988 (sem 67) kJ/d) than after that of the PLA (7716 (sem 67) kJ/d, P <0·0001). There were no significant differences between the WP and CP groups in any metabolic measurements. Night-time consumption of WP, CP or CHO, in the hours close to sleep, elicits favourable effects on the next-morning metabolism when compared with that of a PLA in active young men. PMID:23768612

  8. Tie-dyed1 Encodes a Novel, Phloem-Expressed Transmembrane Protein That Functions in Carbohydrate Partitioning1[C][W][OA

    PubMed Central

    Ma, Yi; Slewinski, Thomas L.; Baker, R. Frank; Braun, David M.

    2009-01-01

    Carbon is partitioned between export from the leaf and retention within the leaf, and this process is essential for all aspects of plant growth and development. In most plants, sucrose is loaded into the phloem of carbon-exporting leaves (sources), transported through the veins, and unloaded into carbon-importing tissues (sinks). We have taken a genetic approach to identify genes regulating carbon partitioning in maize (Zea mays). We identified a collection of mutants, called the tie-dyed (tdy) loci, that hyperaccumulate carbohydrates in regions of their leaves. To understand the molecular function of Tdy1, we cloned the gene. Tdy1 encodes a novel transmembrane protein present only in grasses, although two protein domains are conserved across angiosperms. We found that Tdy1 is expressed exclusively in phloem cells of both source and sink tissues, suggesting that Tdy1 may play a role in phloem loading and unloading processes. In addition, Tdy1 RNA accumulates in protophloem cells upon differentiation, suggesting that Tdy1 may function as soon as phloem cells become competent to transport assimilates. Monitoring the movement of a fluorescent, soluble dye showed that tdy1 leaves have retarded phloem loading. However, once the dye entered into the phloem, solute transport appeared equal in wild-type and tdy1 mutant plants, suggesting that tdy1 plants are not defective in phloem unloading. Therefore, even though Tdy1 RNA accumulates in source and sink tissues, we propose that TDY1 functions in carbon partitioning by promoting phloem loading. Possible roles for TDY1 are discussed. PMID:18923021

  9. Stress response of biomolecules (carbohydrate, protein and lipid profiles) in fish Channa punctatus inhabiting river polluted by Thermal Power Plant effluent

    PubMed Central

    Javed, Mehjbeen; Usmani, Nazura

    2014-01-01

    Qualitative and quantitative assessment of heavy metals in the Thermal Power Plant effluent was performed to study the impact of their toxic effects on various biomarkers (carbohydrate, protein and lipid profiles). Heavy metals present in the water were in the order Fe > Cu > Zn > Mn > Ni > Co > Cr. Fe and Ni exceeded and Cr was equal to the USA standards set by UNEPGEMS. Glycogen in liver (p < 0.001) and muscle (p < 0.01) depleted significantly. Insignificant (p < 0.05) decline in blood glucose (−21.0%) and significant (p < 0.05) elevation in both total protein and globulin in serum, liver and muscle was noted. Albumin decreased significantly (p < 0.01) in serum but showed significant (p < 0.05) increase in liver and muscle. Thus A:G ratio fell in serum and rose in liver and muscle. Similarly lipid profile also gets altered where significant elevation in serum total lipid (p < 0.01), total cholesterol (p < 0.01), phospholipid (p < 0.05), triglycerides (p < 0.001), LDL (p < 0.01) was observed but significant (p < 0.05) decline in VLDL was recorded. These biomarkers suggested that fish become hypoglycemic, hyperlipidemic and hypercholesterolemic. Heavy metals also provoked immune response as evident from the rise in globulin. In conclusion the Thermal Power Plant wastewater containing heavy metals induced stress, making fish weak and vulnerable to diseases. PMID:25737659

  10. Interference of N-hydroxysuccinimide with bicinchoninic acid protein assay.

    PubMed

    Vashist, Sandeep Kumar; Dixit, Chandra Kumar

    2011-07-29

    We report here substantial interference from N-hydroxysuccinimide (NHS) in the bicinchoninic acid (BCA) protein assay. NHS is one of the most commonly used crosslinking agents in bioanalytical sciences, which can lead to serious potential errors in the BCA protein assay based protein estimation if it is present in the protein analyte solution. It was identified to be a reducing substance, which interferes with the BCA protein assay by reducing Cu(2+) in the BCA working reagent. The absorbance peak and absorbance signal of NHS were very similar to those of bovine serum albumin (BSA), thereby indicating a similar BCA reaction mechanism for NHS and protein. However, the combined absorbance of NHS and BSA was not additive. The time-response measurements of the BCA protein assay showed consistent single-phase kinetics for NHS and gradually decreasing kinetics for BSA. The error in protein estimation due to the presence of NHS was counteracted effectively by plotting additional BCA standard curve for BSA with a fixed concentration of NHS. The difference between the absorbance values of BSA and BSA with a fixed NHS concentration provided the absorbance contributed by NHS, which was then subtracted from the total absorbance of analyte sample to determine the actual absorbance of protein in the analyte sample. PMID:21762678