scholarly journals Bicyclo[6.1.0]nonyne and tetrazine amino acids for Diels–Alder reactions

RSC Advances ◽  
2017 ◽  
Vol 7 (70) ◽  
pp. 44470-44473 ◽  
Author(s):  
Xu Li ◽  
Zhengkun Liu ◽  
Shouliang Dong
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
De Novo ◽  
Diels Alder ◽  
Chiral Analysis ◽  
Marfey’S Reagent ◽  
Marfey's Reagent ◽  
General Method

Here we report a general method for the de novo synthesis of a bicyclo[6.1.0]nonyne group containing an amino acid, and used Marfey's reagent for chiral analysis.

scholarly journals Action of growth hormone in vitro on the net uptake and incorporation into protein of amino acids in muscle from intact rabbits given protein-deficient diets

1976 ◽  
Vol 35 (1) ◽  
pp. 1-10 ◽  
Author(s):  
M. R. Turner ◽  
P. J. Reeds ◽  
K. A. Munday
Keyword(s):  
Amino Acids ◽  
Growth Hormone ◽  
Protein Synthesis ◽  
Amino Acid ◽  
De Novo ◽  
Amino Acid Uptake ◽  
Acid Uptake ◽  
Amino Acid Incorporation ◽  
Acid Incorporation

1. Net amino acid uptake, and incorporation into protein have been measured in vitro in the presence and absence of porcine growth hormone (GH) in muscle from intact rabbits fed for 5 d on low-protein (LP), protein-free (PF) or control diets.2. In muscle from control and LP animals GH had no effect on the net amino acid uptake but stimulated amino acid incorporation into protein, although this response was less in LP animals than in control animals.3. In muscle from PF animals, GH stimulated both amino acid incorporation into protein and the net amino acid uptake, a type of response which also occurs in hypophysectomized animals. The magnitude of the effect of GH on the incorporation of amino acids into protein was reduced in muscle from PF animals.4. The effect of GH on the net amino acid uptake in PF animals was completely blocked by cycloheximide; the uptake effect of GH in these animals was dependent therefore on de novo protein synthesis.5. It is proposed that in the adult the role of growth hormone in protein metabolism is to sustain cellular protein synthesis when there is a decrease in the level of substrate amino acids, similar to that which occurs during a short-term fast or when the dietary protein intake is inadequate.

scholarly journals De Novo Synthesis of Amino Acids by the Ruminal Bacteria Prevotella bryantii B14,Selenomonas ruminantium HD4, and Streptococcus bovis ES1

1998 ◽  
Vol 64 (8) ◽  
pp. 2836-2843 ◽  
Author(s):  
Cengiz Atasoglu ◽  
Carmen Valdés ◽  
Nicola D. Walker ◽  
C. James Newbold ◽  
R. John Wallace
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
De Novo ◽  
Dependent Manner ◽  
Streptococcus Bovis ◽  
De Novo Synthesis ◽  
Ruminal Bacteria ◽  
Total N ◽  
Selenomonas Ruminantium ◽  
Prevotella Bryantii

ABSTRACT The influence of peptides and amino acids on ammonia assimilation and de novo synthesis of amino acids by three predominant noncellulolytic species of ruminal bacteria, Prevotella bryantii B14, Selenomonas ruminantiumHD4, and Streptococcus bovis ES1, was determined by growing these bacteria in media containing 15NH4Cl and various additions of pancreatic hydrolysates of casein (peptides) or amino acids. The proportion of cell N and amino acids formed de novo decreased as the concentration of peptides increased. At high concentrations of peptides (10 and 30 g/liter), the incorporation of ammonia accounted for less than 0.16 of bacterial amino acid N and less than 0.30 of total N. At 1 g/liter, which is more similar to peptide concentrations found in the rumen, 0.68, 0.87, and 0.46 of bacterial amino acid N and 0.83, 0.89, and 0.64 of total N were derived from ammonia by P. bryantii, S. ruminantium, andS. bovis, respectively. Concentration-dependent responses were also obtained with amino acids. No individual amino acid was exhausted in any incubation medium. For cultures of P. bryantii, peptides were incorporated and stimulated growth more effectively than amino acids, while cultures of the other species showed no preference for peptides or amino acids. Apparent growth yields increased by between 8 and 57%, depending on the species, when 1 g of peptides or amino acids per liter was added to the medium. Proline synthesis was greatly decreased when peptides or amino acids were added to the medium, while glutamate and aspartate were enriched to a greater extent than other amino acids under all conditions. Thus, the proportion of bacterial protein formed de novo in noncellulolytic ruminal bacteria varies according to species and the form and identity of the amino acid and in a concentration-dependent manner.

scholarly journals The effect of molybdenum on the conversion of sulphate to sulphide and microbial-protein-sulphur in the rumen of sheep

1976 ◽  
Vol 35 (1) ◽  
pp. 11-23 ◽  
Author(s):  
J. M. Gawthorne ◽  
C. J. Nader
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
De Novo ◽  
Rumen Fluid ◽  
Amino Acid Content ◽  
Sodium Molybdate ◽  
Protein S ◽  
Sodium Sulphate ◽  
Microbial Protein ◽  
Sulphide Production

1. [35S]sulphate was used to measure the apparent turnover of sulphate, sulphide and microbial-protein-S in the rumen contents of four sheep that were intraruminally infused with 10 g sodium sulphate/d alone, or together with 126 mg sodium molybdate (50 mg molybdenum/d).2. Infusion of molybdate increased the concentration of sulphate in rumen fluid from 2.2 to 7.2 μg S/ml and decreased the rate of reduction of sulphate to sulphide by 50%. Although the rate of sulphide production was slower, the concentration of sulphide in rumen contents was increased. A dual role for molybdate in the metabolism of sulphide in the rumen is suggested to explain these changes.3. In animals that were not infused with molybdate, only one-third of the S (3.0 g/d) that passed through the sulphate pool in rumen fluid was converted to sulphide, decreasing to one-sixth when molybdate was infused.4. The turnover of S amino acids in microbial protein was not significantly affected by molybdate. Only 52–57% of the S amino acid content of microbial protein was synthesized de novo by way of the sulphide pool.

scholarly journals Mechanism of De Novo Branched-Chain Amino Acid Synthesis as an Alternative Electron Sink in Hypoxic Aspergillus nidulans Cells

2010 ◽  
Vol 76 (5) ◽  
pp. 1507-1515 ◽  
Author(s):  
Motoyuki Shimizu ◽  
Tatsuya Fujii ◽  
Shunsuke Masuo ◽  
Naoki Takaya
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Aspergillus Nidulans ◽  
De Novo ◽  
Acid Synthesis ◽  
Branched Chain Amino Acids ◽  
Amino Acid Synthesis ◽  
Lactate Dehydrogenase Activity ◽  
Branched Chain Amino Acid ◽  
Branched Chain

ABSTRACT Although branched-chain amino acids are synthesized as building blocks of proteins, we found that the fungus Aspergillus nidulans excretes them into the culture medium under hypoxia. The transcription of predicted genes for synthesizing branched-chain amino acids was upregulated by hypoxia. A knockout strain of the gene encoding the large subunit of acetohydroxy acid synthase (AHAS), which catalyzes the initial reaction of the synthesis, required branched-chain amino acids for growth and excreted very little of them. Pyruvate, a substrate for AHAS, increased the amount of hypoxic excretion in the wild-type strain. These results indicated that the fungus responds to hypoxia by synthesizing branched-chain amino acids via a de novo mechanism. We also found that the small subunit of AHAS regulated hypoxic branched-chain amino acid production as well as cellular AHAS activity. The AHAS knockout resulted in higher ratios of NADH/NAD+ and NADPH/NADP+ under hypoxia, indicating that the branched-chain amino acid synthesis contributed to NAD+ and NADP+ regeneration. The production of branched-chain amino acids and the hypoxic induction of involved genes were partly repressed in the presence of glucose, where cells produced ethanol and lactate and increased levels of lactate dehydrogenase activity. These indicated that hypoxic branched-chain amino acid synthesis is a unique alternative mechanism that functions in the absence of glucose-to-ethanol/lactate fermentation and oxygen respiration.

scholarly journals More benign random peptides in E. coli are enriched for similar amino acids as young animal but not plant genes

2020 ◽  
Author(s):  
Luke Kosinski ◽  
Nathan Raul Aviles ◽  
Kevin Gomez ◽  
Joanna Masel
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Amino Acid Composition ◽  
Acid Composition ◽  
De Novo ◽  
Young Animal ◽  
Structural Disorder ◽  
E Coli ◽  
Random Peptide ◽  
Almost All

Proteins are the workhorses of the cell, yet they carry great potential for harm via misfolding and aggregation. Despite the dangers, proteins are sometimes born de novo from non-coding DNA. Proteins are more likely to be born from non-coding regions that produce peptides that do little to no harm when translated than from regions that produce harmful peptides. To investigate which newborn proteins are most likely to "first, do no harm", we estimate fitnesses from an experiment that competed Escherichia coli lineages that each expressed a unique random peptide. A variety of peptide metrics significantly predict lineage fitness, but almost all this predictive power stems from simple amino acid composition. Amino acids that are smaller and that promote intrinsic structural disorder have more benign fitness effects. Our amino acid composition-based predictions also have validity for an independent dataset using small random N-terminal tags. The same amino acids that predict high fitness in E. coli are enriched in young Pfams in animals, but not in plants. To modify Jacques Monod's famous quote, what makes peptides benign in E.coli also makes them benign in elephants, but not in eucalyptus.

Transmembrane transport and intracellular kinetics of amino acids in human skeletal muscle

1995 ◽  
Vol 268 (1) ◽  
pp. E75-E84 ◽  
Author(s):  
G. Biolo ◽  
R. Y. Fleming ◽  
S. P. Maggi ◽  
R. R. Wolfe
Keyword(s):  
Skeletal Muscle ◽  
Amino Acids ◽  
Protein Synthesis ◽  
Amino Acid ◽  
Human Skeletal Muscle ◽  
De Novo ◽  
Transmembrane Transport ◽  
Acid Transport ◽  
De Novo Synthesis ◽  
Intracellular Amino Acid

We have used stable isotopic tracers of amino acids to measure in vivo transmembrane transport of phenylalanine, leucine, lysine, alanine, and glutamine as well as the rates of intracellular amino acid appearance from proteolysis, de novo synthesis, and disappearance to protein synthesis in human skeletal muscle. Calculations were based on data obtained by the arteriovenous catheterization of the femoral vessels and muscle biopsy. We found that the fractional contribution of transport from the bloodstream to the total intracellular amino acid appearance depends on the individual amino acid, varying between 0.63 +/- 0.02 for phenylalanine and 0.22 +/- 0.02 for alanine. Rates of alanine and glutamine de novo synthesis were approximately eight and five times their rate of appearance from protein breakdown, respectively. The model-derived rate of protein synthesis was highly correlated with the same value calculated by means of the tracer incorporation technique. Furthermore, amino acid transport rates were in the range expected from literature values. Consequently, we conclude that our new model provides a valid means of quantifying the important aspects of protein synthesis, breakdown, and amino acid transport in human subjects.

scholarly journals Quantifying dietary macronutrient sources of carbon for bone collagen biosynthesis using natural abundance stable carbon isotope analysis

2006 ◽  
Vol 95 (6) ◽  
pp. 1055-1062 ◽  
Author(s):  
Susan Jim ◽  
Vicky Jones ◽  
Stanley H. Ambrose ◽  
Richard P. Evershed
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
De Novo ◽  
Stable Carbon Isotope ◽  
Isotopic Fractionation ◽  
Essential Amino Acids ◽  
Natural Abundance ◽  
Bone Collagen ◽  
Collagen Biosynthesis ◽  
Indispensable Amino Acids

The diets of laboratory rats were isotopically and nutritionally manipulated using purifiedC3 and/or C4 macronutrients to investigate the routing of dietary carbonto bone collagen biosynthesis. Diets were formulated with purified proteins, carbohydrates andlipids of defined composition and natural abundance stable isotope ratios. Bulk protein and constituent amino acid δ13C values determined for whole diet and bone collagen provided the basis for assessing isotopic fractionation and estimating the degree of routing versus synthesis de novo of essential, non-essential and conditionally indispensable amino acids. Essential and conditionally indispensable amino acids were shown to be routed from diet to collagen with little isotopic fractionation whereas non-essential amino acids differed by up to 20‰. Mathematical modelling of the relationships between macronutrient and tissue δ13C values provided qualitative and quantitative insights into the metabolic and energetic controls on bone collagen biosynthesis. Essential amino acids comprise 21·7% of the carbon in collagen, defining the minimum amount of dietary carbon routing. Estimates of 42 and 28% routing were shown for the non-essential amino acids, glycine and aspartate, respectively. In total, the routing of non-essential and conditionally indispensable amino acids was estimated to equal 29·6% of the carbon in collagen. When the contribution of carbon from the essential amino acids is also considered, we arrive at an overall minimum estimate of 51·3% routing of dietary amino acid carbon into bone collagen.

Steps in amino-acid incorporation into mammary tissue

1958 ◽  
Vol 149 (936) ◽  
pp. 392-400 ◽  
Keyword(s):  
Amino Acids ◽  
Protein Synthesis ◽  
Mammary Gland ◽  
Amino Acid ◽  
De Novo ◽  
Protein Biosynthesis ◽  
Mammary Tissue ◽  
Mammary Cells ◽  
Intact Cells ◽  
Ideal System

The mammary gland in full lactation had for long been recognized as an ideal system for the study of the biosynthesis of protein. The discoveries during the last 5 years of the incorporation of labelled amino acids into the microsomes of cell homogenates and of other reactions of amino acids which might be on the pathway to protein synthesis, encouraged us to study the fate of amino acids in various systems prepared from mammary cells. De novo protein synthesis had not yet been proved in any system which contained no intact cells. So far no net increase in any defined protein fraction during incubations has been found or indeed looked for in our experiments. Naturally one hopes that such studies of the fate of labelled amino acids in cell-free preparations will reveal the detail of enzymic reactions which will prove to be part of the mechanisms of protein biosynthesis. Three types of reactions of amino acids in cell-free preparations from homogenates of many tissues have been studied most extensively. (1) The acyl activation of amino acids to form amino acid-acid adenylates in the presence of ATP and ‘activating enzymes’. (2) The formation of compounds of cell sap-ribonucleic acid ( SRN A ) with amino acids in the presence of ATP and ‘activating enzymes’. (3) The incorporation of amino acids into intracellular particles either from free amino acid or by transfer from amino-acid- SRN A compounds in the presence of ATP , guanosine triphosphate ( GTP ) and ‘activating enzymes’. In this paper we are giving a survey of the results of studies on these three types of reactions in systems prepared from mammary tissue and we are relating these to results obtained with other systems elsewhere. Some comparative studies of the incorporation of labelled amino acids into protein fractions of intact mammary cells (minced tissue) are also presented. All the original results given here were obtained from experiments with guinea-pig mammary gland preparations from animals 2 to 6 days after parturition. Experimental detail will be reported elsewhere.

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