scholarly journals Metabolic Pathway Confirmation and Discovery Through 13C-labeling of Proteinogenic Amino Acids

10.3791/3583 ◽  
2012 ◽  
Author(s):  
Le You ◽  
Lawrence Page ◽  
Xueyang Feng ◽  
Bert Berla ◽  
Himadri B. Pakrasi ◽  
...  
Keyword(s):  
Amino Acids ◽  
Metabolic Pathway

Fatty acid recycling in adipocytes: a role for glyceroneogenesis and phosphoenolpyruvate carboxykinase

2003 ◽  
Vol 31 (6) ◽  
pp. 1125-1129 ◽  
Author(s):  
C. Forest ◽  
J. Tordjman ◽  
M. Glorian ◽  
E. Duplus ◽  
G. Chauvet ◽  
...  
Keyword(s):  
Type 2 Diabetes ◽  
Amino Acids ◽  
Adipose Tissue ◽  
Fatty Acid ◽  
White Adipose Tissue ◽  
Metabolic Pathway ◽  
Phosphoenolpyruvate Carboxykinase ◽  
Important Pathway ◽  
Low Activity

FA (fatty acid) recycling in adipose tissue appears to be an important pathway for regulating FA release into the blood during fasting. Re-esterification requires G3P (glycerol 3-phosphate), which cannot be synthesized from glucose because glycolysis is much reduced under such circumstances. In addition, G3P can scarcely originate from glycerol since glycerol kinase has a very low activity in white adipose tissue. It was shown about 35 years ago that a metabolic pathway named glyceroneogenesis, which allows G3P synthesis from non-carbohydrate precursors like pyruvate, lactate or amino acids, is activated during fasting. The major enzyme in this pathway was shown to be PEPCK-C [cytosolic phosphoenolpyruvate carboxykinase (GTP); EC 4.1.1.32]. The present review analyses the mechanisms by which a series of hormones and nutrients affect PEPCK-C gene transcription and glyceroneogenesis and describes evidence for dysregulation of this pathway in type 2 diabetes.

scholarly journals An appeal to magic? The discovery of a non-enzymatic metabolism and its role in the origins of life

2018 ◽  
Vol 475 (16) ◽  
pp. 2577-2592 ◽  
Author(s):  
Markus Ralser
Keyword(s):  
Amino Acids ◽  
Metabolic Pathway ◽  
Metal Cation ◽  
Hydrogen Cyanide ◽  
Metabolic Pathways ◽  
Co2 Fixation ◽  
Enzymatic Reaction ◽  
Krebs Cycle ◽  
Pentose Phosphate ◽  
Long Time

Until recently, prebiotic precursors to metabolic pathways were not known. In parallel, chemistry achieved the synthesis of amino acids and nucleotides only in reaction sequences that do not resemble metabolic pathways, and by using condition step changes, incompatible with enzyme evolution. As a consequence, it was frequently assumed that the topological organisation of the metabolic pathway has formed in a Darwinian process. The situation changed with the discovery of a non-enzymatic glycolysis and pentose phosphate pathway. The suite of metabolism-like reactions is promoted by a metal cation, (Fe(II)), abundant in Archean sediment, and requires no condition step changes. Knowledge about metabolism-like reaction topologies has accumulated since, and supports non-enzymatic origins of gluconeogenesis, the S-adenosylmethionine pathway, the Krebs cycle, as well as CO2 fixation. It now feels that it is only a question of time until essential parts of metabolism can be replicated non-enzymatically. Here, I review the ‘accidents’ that led to the discovery of the non-enzymatic glycolysis, and on the example of a chemical network based on hydrogen cyanide, I provide reasoning why metabolism-like non-enzymatic reaction topologies may have been missed for a long time. Finally, I discuss that, on the basis of non-enzymatic metabolism-like networks, one can elaborate stepwise scenarios for the origin of metabolic pathways, a situation that increasingly renders the origins of metabolism a tangible problem.

Production of 2-aminobutyrate by Megasphaera elsdenii

1994 ◽  
Vol 40 (5) ◽  
pp. 393-396 ◽  
Author(s):  
A. F. Furtado ◽  
T. A. McAllister ◽  
K. -J. Cheng ◽  
L. P. Milligan
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Metabolic Pathway ◽  
Branched Chain Amino Acids ◽  
Potential Sources ◽  
Amino Acid Degradation ◽  
Megasphaera Elsdenii ◽  
Alanine Synthesis ◽  
Casamino Acids ◽  
Branched Chain

Production of the amino acid 2-aminobutyrate was studied in four strains of Megasphaera elsdenii grown on a lactate-based growth medium containing Bacto-casamino acids and yeast extract. Supplementation with threonine increased the production of 2-aminobutyrate in three of the four strains, but no substantial increase in production was noted with serine, methionine, or aspartate, all of which are potential sources for the precursor of 2-aminobutyrate, 2-oxobutyrate. L-Cycloserine, an inhibitor of alanine transaminases, decreased both alanine and 2-aminobutyrate production, suggesting that 2-aminobutyrate synthesis may share the same metabolic pathway as alanine synthesis or that 2-oxobutyrate can act as a substrate for alanine transaminases. Decreases in the production of 2-aminobutyrate were associated with a reduction in the catabolism of branched-chain amino acids in two of the four strains.Key words: Megasphaera, amino acid, degradation, 2-aminobutyrate, rumen.

scholarly journals Integration of Transcriptomics and Metabolomics for Pepper (Capsicum annuum L.) in Response to Heat Stress

2019 ◽  
Vol 20 (20) ◽  
pp. 5042 ◽  
Author(s):  
Jing Wang ◽  
Junheng Lv ◽  
Zhoubin Liu ◽  
Yuhua Liu ◽  
Jingshuang Song ◽  
...  
Keyword(s):  
Amino Acids ◽  
Heat Stress ◽  
Abiotic Stress ◽  
Heat Resistance ◽  
Metabolic Pathway ◽  
Expression Patterns ◽  
Critical Role ◽  
Heat Tolerant ◽  
Metabolome Data ◽  
Accumulation Ability

Heat stress (HS), caused by extremely high temperatures, is one of the most severe forms of abiotic stress in pepper. In the present study, we studied the transcriptome and metabolome of a heat-tolerant cultivar (17CL30) and a heat-sensitive cultivar (05S180) under HS. Briefly, we identified 5754 and 5756 differentially expressed genes (DEGs) in 17CL30 and 05S180, respectively. Moreover, we also identified 94 and 108 differentially accumulated metabolites (DAMs) in 17CL30 and 05S180, respectively. Interestingly, there were many common HS-responsive genes (approximately 30%) in both pepper cultivars, despite the expression patterns of these HS-responsive genes being different in both cultivars. Notably, the expression changes of the most common HS-responsive genes were typically much more significant in 17CL30, which might explain why 17CL30 was more heat tolerant. Similar results were also obtained from metabolome data, especially amino acids, organic acids, flavonoids, and sugars. The changes in numerous genes and metabolites emphasized the complex response mechanisms involved in HS in pepper. Collectively, our study suggested that the glutathione metabolic pathway played a critical role in pepper response to HS and the higher accumulation ability of related genes and metabolites might be one of the primary reasons contributing to the heat resistance.

scholarly journals Genetic predisposition to impaired metabolism of the branched chain amino acids, dietary intakes, and risk of type 2 diabetes

2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Weiqi Wang ◽  
Zengjiao Liu ◽  
Lin Liu ◽  
Tianshu Han ◽  
Xue Yang ◽  
...  
Keyword(s):  
Type 2 Diabetes ◽  
Amino Acids ◽  
Genetic Predisposition ◽  
Metabolic Pathway ◽  
Regression Models ◽  
Branched Chain Amino Acids ◽  
Diabetes Incidence ◽  
Dietary Intakes ◽  
Branched Chain

Abstract Background and objectives Circulating branched chain amino acids (BCAAs) increase the risk of type 2 diabetes (T2D). The genetic variants in the BCAA metabolic pathway influence the individual metabolic ability of BCAAs and may affect circulating BCAA levels together with dietary intakes. So, we investigated whether genetic predisposition to impaired BCAA metabolism interacts with dietary BCAA intakes on the risk of type 2 diabetes and related parameters. Methods We estimated dietary BCAA intakes among 434 incident T2D cases and 434 age-matched controls from The Harbin Cohort Study on Diet, Nutrition and Chronic Non-Communicable Diseases. The genetic risk score (GRS) was calculated on the basis of 5 variants having been identified in the BCAA metabolic pathway. Multivariate logistic regression models and general linear regression models were used to assess the interaction between dietary BCAAs and GRS on T2D risk and HbA1c. Results Dietary BCAAs significantly interact with metabolism related GRS on T2D risk and HbA1c (p for interaction = 0.038 and 0.015, respectively). A high intake of dietary BCAAs was positively associated with diabetes incidence only among high GRS (OR 2.40, 95% CI 1.39, 4.12, P for trend = 0.002). Dietary BCAAs were associated with 0.14% elevated HbA1c (p = 0.003) and this effect increased to 0.21% in high GRS (p = 0.003). Furthermore, GRS were associated with 9.19 μmol/L higher plasma BCAA levels (p = 0.006, P for interaction = 0.015) only among the highest BCAA intake individuals. Conclusions Our study suggests that genetic predisposition to BCAA metabolism disorder modifies the effect of dietary BCAA intakes on T2D risk as well as HbA1c and that higher BCAA intakes exert an unfavorable effect on type 2 diabetes risk and HbA1c only among those with high genetic susceptibility.

scholarly journals Analysis of the Lactobacillus Metabolic Pathway

2010 ◽  
Vol 76 (21) ◽  
pp. 7299-7301 ◽  
Author(s):  
Masahiro Kuratsu ◽  
Yoshimitsu Hamano ◽  
Tohru Dairi
Keyword(s):  
Amino Acids ◽  
Folic Acid ◽  
Metabolic Pathway ◽  
Alternative Pathway ◽  
Lactobacillus Fermentum ◽  
Acid Biosynthesis

ABSTRACT We performed analyses of the phenotypic and genotypic relationships focusing on biosyntheses of amino acids, purine/pyrimidines, and cofactors in three Lactobacillus strains. We found that Lactobacillus fermentum IFO 3956 perhaps synthesized para-aminobenzoate (PABA), an intermediate of folic acid biosynthesis, by an alternative pathway.

Metabolic Engineering of Bacteria for Food Ingredients

2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Abdul M ◽  
◽  
Areej A ◽  
Hasnat A ◽  
Ghazanfar S ◽  
...  
Keyword(s):  
Amino Acids ◽  
Lactic Acid ◽  
Metabolic Engineering ◽  
Lactic Acid Bacteria ◽  
Organic Acids ◽  
Metabolic Pathway ◽  
Alanine Racemase ◽  
Food Ingredients ◽  
Different Strains ◽  
Good Food

Bacteria produces metabolites and their metabolic pathway can be manipulated to produce good food ingredients. These ingredients includes different amino acids, vitamins, carbohydrates, organic acids aroma compounds and bacteriocins. Different genes in different strains of bacteria are identified and harnessed to attain food ingredients and results of manipulation were satisfying. The metabolic pathway of lactic acid bacteria is manipulated to produce amino acids such as L-alanine was produced by silencing the gene that encodes alanine racemase. Moreover, low calorie sugars such as mannitol and tagatose were produced. Lac-lactis is engineered by silencing lacC and lacD genes for the production of tagatose.

Relation of exposure to amino acids involved in sarcosine metabolic pathway on behavior of non-tumor and malignant prostatic cell lines

The Prostate ◽  
2016 ◽  
Vol 76 (7) ◽  
pp. 679-690 ◽  
Author(s):  
Zbynek Heger ◽  
Jaromir Gumulec ◽  
Natalia Cernei ◽  
Hana Polanska ◽  
Martina Raudenska ◽  
...  
Keyword(s):  
Amino Acids ◽  
Cell Lines ◽  
Metabolic Pathway ◽  
Prostatic Cell

scholarly journals The selenophosphate synthetase, selD, is important for Clostridioides difficile physiology

2021 ◽  
Author(s):  
Kathleen McAllister ◽  
Andrea Martinez Aguirre ◽  
Joseph A. Sorg
Keyword(s):  
Amino Acids ◽  
Metabolic Pathway ◽  
Metabolic Process ◽  
Carbon And Nitrogen ◽  
Clostridioides Difficile ◽  
Selenophosphate Synthetase ◽  
Antibiotic Associated Diarrhea ◽  
Initial Characterization ◽  
Significant Burden

The endospore-forming pathogen, Clostridioides difficile, is the leading cause of antibiotic-associated diarrhea and is a significant burden on the community and healthcare. C. difficile, like all forms of life, incorporates selenium into proteins through a selenocysteine synthesis pathway. The known selenoproteins in C. difficile are involved in a metabolic process that uses amino acids as the sole carbon and nitrogen source (Stickland metabolism). The Stickland metabolic pathway requires the use of two selenium-containing reductases. In this study, we built upon our initial characterization of the CRISPR-Cas9-generated selD mutant by creating a CRISPR-Cas9-mediated restoration of the selD gene at the native locus. Here, we use these CRISPR-generated strains to analyze the importance of selenium-containing proteins on C. difficile physiology. SelD is the first enzyme in the pathway for selenoprotein synthesis and we found that multiple aspects of C. difficile physiology were affected (e.g., growth, sporulation, and outgrowth of a vegetative cell post-spore germination). Using RNAseq, we identified multiple candidate genes which likely aid the cell in overcoming the global loss of selenoproteins to grow in medium which is favorable for using Stickland metabolism. Our results suggest that the absence of selenophosphate (i.e., selenoprotein synthesis) leads to alterations to C. difficile physiology so that NAD+ can be regenerated by other pathways.

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