Kegg Pathway: Carbohydrate Metabolism

Plant Mol Biol. 2009 Nov 19;
Chao WS, Serpe MD

Underground adventitious buds of leafy spurge (Euphorbia esula) undergo three well-defined phases of dormancy, para-, endo-, and ecodormancy. In this study, relationships among genes involved in Carbohydrate Metabolism and bud dormancy were examined after paradormancy release (growth induction) by decapitation and in response to seasonal signals. Real-time PCR was used to determine the expression levels of Carbohydrate Metabolism genes at different phases of bud dormancy. Among differentially-regulated genes, expression of a specific Euphorbia esula beta-amylase gene (Ee-BAM1) increased 100-fold after growth induction and 16,000-fold from July (paradormancy) to December (ecodormancy). Sequence data analysis indicated that two genes, Ee-BAM1 and Ee-BAM2, could encode this beta-amylase. However, real-time PCR using gene-specific primer pairs only amplified Ee-BAM1, indicating that Ee-BAM2 is either specific to other organs or not abundant. The deduced amino acid sequences of these two genes are very similar at the N-terminal but differ at the C-terminal. Both contain a nearly identical, predicted 48-amino acid plastid transit peptide. Immunoblot analyses identified a 29 kD (mature Ee-BAM1 after cleavage of the transit peptide) and a 35 kD (unprocessed EeBAM1) protein. Both 35 and 29 kD proteins were constitutively expressed in growth-induced and seasonal samples. Immunolocalization indicated that Ee-BAM1 is in the cytosol of cells at the shoot tip of the bud. Ee-BAM1 also surrounds the amyloplasts in mature cells toward the base of the bud. These observations suggests that Ee-BAM1 may have dual functions; serving as reserve protein in the cytosol and as a degrading enzyme at the surface of amyloplasts.

J Strength Cond Res. 2009 Nov 17;
Martínez-Lagunas V, Ding Z, Bernard JR, Wang B, Ivy JL

Martínez-Lagunas, V, Ding, Z, Bernard, JR, Wang, B, and Ivy, JL. Added protein maintains efficacy of a low-Carbohydrate sports drink. J Strength Cond Res 24(x): 000-000, 2009-The purpose of the present study was to investigate the aerobic capacity characteristics of an isocaloric Carbohydrate (CHO) plus protein (PRO) drink and a low-calorie CHO plus PRO drink against a traditional 6% CHO sports beverage. Twelve male and female trained cyclists exercised on 4 separate occasions at intensities that varied between 55 and 75% &OV0312;o2max for 2.5 hours and then at 80% &OV0312;o2max until fatigued. Supplements (255.4 +/- 9.1 mL) were provided every 20 minutes and consisted of a 4.5% Carbohydrate plus 1.15% protein complex (CHO/PRO H), a 3% Carbohydrate plus 0.75% protein complex (CHO/PRO L), a 6% Carbohydrate supplement (CHO), or a placebo (PLA). Time to fatigue at 80% &OV0312;o2max was significantly longer (p < 0.05) during the CHO (26.9 +/- 6.1 minutes, mean +/- SE), the CHO/PRO H (30.5 +/- 5.9 minutes), and the CHO/PRO L (28.9 +/- 6.5 minutes) trials compared with the PLA trial (14.7 +/- 3.4 minutes), with no significant differences among the CHO, CHO/PRO H, and CHO/PRO L treatments. In general, blood glucose, plasma insulin, and Carbohydrate oxidation were elevated above PLA during the CHO, CHO/PRO H, and CHO/PRO L trials, whereas plasma free fatty acids, rating of perceived exertion, and fat oxidation values were lower during the CHO, CHO/PRO H, and CHO/PRO L trials compared with the PLA trial. Only minor differences in blood parameters occurred among the CHO, CHO/PRO H, and CHO/PRO L treatments. In summary, partially substituting PRO for CHO in a sports drink did not enhance aerobic capacity, but substitution was able to occur without loss of efficacy. Thus, adding PRO to a low-calorie CHO sports drink may be an effective strategy to enhance aerobic capacity while limiting Carbohydrate and caloric consumption.

Pharm Res. 2006 May; 23(5): 1038-42
Kimura T, Shibukawa A, Matsuzaki K

PURPOSE: The purpose of this study was to investigate the role of biantennary branching glycans of alpha1-acid glycoprotein (AGP) and its genetic variants in the enantioselective binding of oxybutynin (OXY). METHOD: Human native AGP was separated using imminodiacetate-copper (II) affinity chromatography into two fractions, the A variant and a mixture of the F1 and S variants (F1-S). These fractionated AGPs were further separated by concanavalin A affinity chromatography into two fractions, with and without biantenarry glycans. An on-line high-performance liquid chromatography (HPLC) system consisting of a high-performance frontal analysis column, an extraction column, and an analytical HPLC column was developed to determine the binding affinities of OXY enantiomers for respective AGP species. RESULTS: The total binding affinity as well as the enantiomeric selectivity of OXY in the F1-S mixed variant was significantly higher than that for the A variant, indicating that the chiral recognition ability of native AGP for the OXY enantiomers highly depends on the F1-S mixed variant. Furthermore, not only the genetic variants but also bianntenary glycans of AGP affect the binding affinity of OXY and are also responsible for the enantioselectivity. CONCLUSIONS: Both genetic variants and glycan structures significantly contribute to the enantioselectivity and the binding affinity of OXY.

Curr Microbiol. 2009 Nov 17;
Tang P, Hseu YC, Chou HH, Huang KY, Chen SC

Cyanide has been proved to be degraded by Klebsiella oxytoca. In order to examine the physiological responses of cyanide degradation by this bacterium, two-dimensional (2-DE) electrophoresis approach and MALDI-TOF-MS allow us to identify 106 proteins spots that were significantly altered in the presence of 1 mM cyanide in relative to that in 1 mM ammonia when K. oxytoca grown at the late-log phase. Among them, 27 proteins were successfully identified. These proteins were involved in Carbohydrate Metabolism, nucleotide Metabolism, amino acid Metabolism, nitrogen Metabolism, stress responses, oxidation-reduction reactions, transporters, and miscellaneous function. Some proteins related with regulation of nitrogen assimilation pathways (glutamine synthetase), oxidative stress repairing (catalase), and protection (neutral trehalase and glycosyltransferase) could improve the effectiveness of cyanide biodegradation. Although the nitrogenase was suggested to participate in cyanide degradation in our previous study, this enzyme induction was not observed as expected. These findings could provide new insights into the inducible mechanisms underlying the capacity of K. oxytoca to tolerate cyanide stress.

FEBS J. 2009 Nov 17;
Nakai H, Baumann MJ, Petersen BO, Westphal Y, Schols H, Dilokpimol A, Hachem MA, Lahtinen SJ, Duus JO, Svensson B

A gene cluster involved in maltodextrin transport and Metabolism was identified in the genome of Lactobacillus acidophilus NCFM, which encoded a maltodextrin-binding protein, three maltodextrin ATP-binding cassette transporters and five glycosidases, all under the control of a transcriptional regulator of the LacI-GalR family. Enzymatic properties are described for recombinant maltose phosphorylase (MalP) of glycoside hydrolase family 65 (GH65), which is encoded by malP (GenBank: AAV43670.1) of this gene cluster and produced in Escherichia coli. MalP catalyses phosphorolysis of maltose with inversion of the anomeric configuration releasing beta-glucose 1-phosphate (beta-Glc 1-P) and glucose. The broad specificity of the aglycone binding site was demonstrated by products formed in reverse phosphorolysis using various Carbohydrate acceptor substrates and beta-Glc 1-P as the donor. MalP showed strong preference for monosaccharide acceptors with equatorial 3-OH and 4-OH, such as glucose and mannose, and also reacted with 2-deoxy glucosamine and 2-deoxy N-acetyl glucosamine. By contrast, none of the tested di- and trisaccharides served as acceptors. Disaccharide yields obtained from 50 mmbeta-Glc 1-P and 50 mm glucose, glucosamine, N-acetyl glucosamine, mannose, xylose or l-fucose were 99, 80, 53, 93, 81 and 13%, respectively. Product structures were determined by NMR and ESI-MS to be alpha-Glcp-(1-->4)-Glcp (maltose), alpha-Glcp-(1-->4)-GlcNp (maltosamine), alpha-Glcp-(1-->4)-GlcNAcp (N-acetyl maltosamine), alpha-Glcp-(1-->4)-Manp, alpha-Glcp-(1-->4)-Xylp and alpha-Glcp-(1-->4)- l-Fucp, the three latter being novel compounds. Modelling using L. brevis GH65 as the template and superimposition of acarbose from a complex with Thermoanaerobacterium thermosaccharolyticum GH15 glucoamylase suggested that loop 3 of MalP involved in substrate recognition blocked the binding of candidate acceptors larger than monosaccharides.

BMC Syst Biol. 2009 Nov 16; 3(1): 108
Pin C, Rolfe MD, Munoz-Cuevas M, Hinton JC, Peck MW, Walton NJ, Baranyi J

ABSTRACT: BACKGROUND: The aging process of bacteria in stationary phase is halted if cells are subcultured and enter lag phase and it is then followed by cellular division. Network science has been applied to analyse the transcriptional response, during lag phase, of bacterial cells starved previously in stationary phase for 1 day (young cells) and 16 days (old cells). RESULTS: A genome scale network was constructed for E. coli K-12 by connecting genes with operons, transcription and sigma factors, metabolic pathways and cell functional categories. Most of the transcriptional changes were detected immediately upon entering lag phase and were maintained throughout this period. The lag period was longer for older cells and the analysis of the transcriptome revealed different intracellular activity in young and old cells. The number of genes differentially expressed was smaller in old cells (186) than in young cells (467). Relatively, few genes (62) were up- or down-regulated in both cultures. Transcription of genes related to osmotolerance, acid resistance, oxidative stress and adaptation to other stresses was down-regulated in both young and old cells. Regarding Carbohydrate Metabolism, genes related to the citrate cycle were up-regulated in young cells while old cells up-regulated the Entner Doudoroff and gluconate pathways and down-regulated the pentose phosphate pathway. In both old and young cells, anaerobic respiration and fermentation pathways were down-regulated, but only young cells up-regulated aerobic respiration while there was no evidence of aerobic respiration in old cells. Numerous genes related to DNA maintenance and replication, translation, ribosomal biosynthesis and RNA processing as well as biosynthesis of the cell envelope and flagellum and several components of the chemotaxis signal transduction complex were up-regulated only in young cells. The genes for several transport proteins for iron compounds were up-regulated in both young and old cells. Numerous genes encoding transporters for Carbohydrates and organic alcohols and acids were down-regulated in old cells only. CONCLUSION: Network analysis revealed very different transcriptional activities during the lag period in old and young cells. Rejuvenation seems to take place during exponential growth by replicative dilution of old cellular components.

BMC Genomics. 2009 Nov 15; 10(1): 524
Arita A, Zhou X, Ellen TP, Liu X, Bai J, Rooney JP, Kurtz A, Klein CB, Dai W, Begley TJ, Costa M

ABSTRACT: BACKGROUND: The understanding of the biological function, regulation, and cellular interactions of the yeast genome and proteome, along with the high conservation in gene function found between yeast genes and their human homologues, has allowed for Saccharomyces cerevisiae to be used as a model organism to deduce biological processes in human cells. Here, we have completed a systematic screen of the entire set of 4,733 haploid S. cerevisiae gene deletion strains (the entire set of nonessential genes for this organism) to identify gene products that modulate cellular toxicity to nickel sulfate (NiSO4). RESULTS: We have identified 149 genes whose gene deletion causes sensitivity to NiSO4 and 119 genes whose gene deletion confers resistance. Pathways analysis with proteins whose absence renders cells sensitive and resistant to nickel identified a wide range of cellular processes engaged in the toxicity of S. cerevisiae to NiSO4. Functional categories overrepresented with proteins whose absence renders cells sensitive to NiSO4 include homeostasis of protons, cation transport, transport ATPases, endocytosis, siderophore-iron transport, homeostasis of metal ions, and the diphthamide biosynthesis pathway. Functional categories overrepresented with proteins whose absence renders cells resistant to nickel include functioning and transport of the vacuole and lysosome, protein targeting, sorting, and translocation, intra-Golgi transport, regulation of C-compound and Carbohydrate Metabolism, transcriptional repression, and chromosome segregation/division. Interactome analysis mapped seven nickel toxicity modulating and ten nickel-resistance networks. Additionally, we studied the degree of sensitivity or resistance of the 111 nickel-sensitive and 72 -resistant strains whose gene deletion product has a similar protein in human cells. CONCLUSIONS: We have undertaken a whole genome approach in order to further understand the mechanism(s) regulating the cell's toxicity to nickel compounds. We have used computational methods to integrate the data and generate global models of the yeast's cellular response to NiSO4. The results of our study shed light on molecular pathways associated with the cellular response of eukaryotic cells to nickel compounds and provide potential implications for further understanding the toxic effects of nickel compounds to human cells.

Biochemistry (Mosc). 2009 Nov; 74(11): 1260-5
Tsvetkov IL, Konichev AS

Sorbitol content was determined in the digestive gland of freshwater snail (Viviparus viviparus L.) in different seasons and in a short-term experiment on the water temperature decrease and on intoxication with cadmium chloride. In the model experiments, changes in activities of enzymes involved in sorbitol Metabolism (acid phosphatases, sorbitol dehydrogenase, and aldose reductase) were also studied. Sorbitol was accumulated by the snail in response to the temperature decrease (as a cryoprotectant) and under conditions of acute intoxication (as a probable metabolic regulator or a nonspecific protective factor). However, the mechanisms of this accumulation are different: on cold adaptation sorbitol is produced as a result of reduction of glucose under the influence of aldose reductase, and on intoxication sorbitol is mainly produced from fructose under the influence of sorbitol dehydrogenase. Pathways of the sorbitol accumulation and its re-involvement into Metabolism are not always the same, and this might be a mechanism for regulation of Carbohydrate Metabolism (at the initial stage of glycolysis) on adaptation to unfavorable factors of the environment.

Appl Microbiol Biotechnol. 2009 Nov 14;
Tisch D, Schmoll M

Light represents a major carrier of information in nature. The molecular machineries translating its electromagnetic energy (photons) into the chemical language of cells transmit vital signals for adjustment of virtually every living organism to its habitat. Fungi react to illumination in various ways, and we found that they initiate considerable adaptations in their metabolic pathways upon growth in light or after perception of a light pulse. Alterations in response to light have predominantly been observed in carotenoid Metabolism, polysaccharide and Carbohydrate Metabolism, fatty acid Metabolism, nucleotide and nucleoside Metabolism, and in regulation of production of secondary metabolites. Transcription of genes is initiated within minutes, abundance and activity of metabolic enzymes are adjusted, and subsequently, levels of metabolites are altered to cope with the harmful effects of light or to prepare for reproduction, which is dependent on light in many cases. This review aims to give an overview on metabolic pathways impacted by light and to illustrate the physiological significance of light for fungi. We provide a basis for assessment whether a given metabolic pathway might be subject to regulation by light and how these properties can be exploited for improvement of biotechnological processes.

PLoS One. 2009; 4(11): e7832
van Lunteren E, Moyer M

BACKGROUND: Respiratory muscle contractile performance is impaired by diabetes, mechanisms of which included altered Carbohydrate and lipid Metabolism, oxidative stress and changes in membrane electrophysiology. The present study examined to what extent these cellular perturbations involve changes in gene expression. METHODOLOGY/PRINCIPAL FINDINGS: Diaphragm muscle from streptozotocin-diabetic rats was analyzed with Affymetrix gene expression arrays. Diaphragm from diabetic rats had 105 genes with at least +/-2-fold significantly changed expression (55 increased, 50 decreased), and these were assigned to gene ontology groups based on over-representation analysis using DAVID software. There was increased expression of genes involved in palmitoyl-CoA hydrolase activity (a component of lipid Metabolism) (P = 0.037, n = 2 genes, fold change 4.2 to 27.5) and reduced expression of genes related to Carbohydrate Metabolism (P = 0.000061, n = 8 genes, fold change -2.0 to -8.5). Other gene ontology groups among upregulated genes were protein ubiquitination (P = 0.0053, n = 4, fold change 2.2 to 3.4), oxidoreductase activity (P = 0.024, n = 8, fold change 2.1 to 6.0), and morphogenesis (P = 0.012, n = 10, fold change 2.1 to 4.3). Other downregulated gene groups were extracellular region (including extracellular matrix and collagen) (P = 0.00032, n = 13, fold change -2.2 to -3.7) and organogenesis (P = 0.032, n = 7, fold change -2.1 to -3.7). Real-time PCR confirmed the directionality of changes in gene expression for 30 of 31 genes tested. CONCLUSIONS/SIGNIFICANCE: These data indicate that in diaphragm muscle type 1 diabetes increases expression of genes involved in lipid energetics, oxidative stress and protein ubiquitination, decreases expression of genes involved in Carbohydrate Metabolism, and has little effect on expression of ion channel genes. Reciprocal changes in expression of genes involved in Carbohydrate and lipid Metabolism may change the availability of energetic substrates and thereby directly modulate fatigue resistance, an important issue for a muscle like the diaphragm which needs to contract without rest for the entire lifetime of the organism.

Med Sci Sports Exerc. 2009 Dec; 41(12): 2158-2164
Cermak NM, Solheim AS, Gardner MS, Tarnopolsky MA, Gibala MJ

INTRODUCTION:: Ingesting protein (PRO) with CHO during prolonged exercise is purported to improve performance compared with CHO alone by altering the regulation of skeletal muscle energy provision. However, no study has directly investigated this issue. We tested the hypothesis that compared with CHO alone, coingestion of PRO would alter markers of metabolic control, including the magnitude of glycogen use and the net expansion of the tricarboxylic acid cycle intermediate pool, which has been linked to the capacity for oxidative energy delivery. METHODS:: Eight trained men (mean +/- SE: age = 29 +/- 2 yr; V O2peak = 55 +/- 2 mL.kg.min) cycled at 69% +/- 1% V O2peak for 90 min on two occasions, and biopsy samples (vastus lateralis) were obtained before and after exercise. In a randomized, double-blind manner, subjects ingested one of two drinks during exercise that contained either 6% CHO or 6% CHO + 2% PRO (CHO + PRO) at a rate of 1 L.h to deliver 60 g.h CHO +/- 20 g.h PRO. RESULTS:: CHO + PRO ingestion increased the plasma concentration of branched chain (561 +/- 46 vs 301 +/- 32 mumol.L) and essential amino acids (1071 +/- 98 vs 670 +/- 71 mumol.L) after exercise versus CHO (both P values