Amino acid activity in the Nelson–Somogyi glucose assay

1990 ◽  
Vol 68 (7) ◽  
pp. 1479-1481 ◽  
Author(s):  
Mahesh K. Upadhyaya ◽  
David W. Konesky
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Glutamic Acid ◽  
Key Words ◽  
Reducing Sugars ◽  
Reducing Sugar ◽  
Manganese Ions ◽  
Isoleucine Leucine ◽  
Glucose Assay ◽  
Color Development

The Nelson–Somogyi assay has been widely used to measure reducing sugars in plant research. We found that the L-amino acids cysteine, cystine, serine, tryptophan, and tyrosine (at 0.1 to 1 mM) react in the Nelson–Somogyi glucose assay, yielding high absorbance values. Alanine, arginine, aspartic acid, glutamic acid, glycine, histidine, hydoxyproline, isoleucine, leucine, lysine, methionine, phenylalanine, proline, threonine, and valine showed little or no effect on color development. Manganese ions strongly inhibited color development in the presence of glucose, serine, cystine, and tryptophan. Investigators measuring glucose in biological materials using this assay must consider the activity of amino acids and (or) the effect of manganese ions in the reaction mixture when interpreting their results. Key words: Nelson–Somogyi assay, sugar analysis, glucose assay, reducing sugar assay.

Amino Acid Requirements for the Wheat Stem Sawfly Determined with Glucose-U-C14 after Vacuum-infiltration

1964 ◽  
Vol 96 (8) ◽  
pp. 1133-1137 ◽  
Author(s):  
R. Kasting ◽  
A. J. McGinnis
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Glutamic Acid ◽  
Vacuum Infiltration ◽  
Artificial Diets ◽  
Isoleucine Leucine ◽  
Wheat Stem Sawfly ◽  
Carbon 14 ◽  
Amino Acid Requirements ◽  
Radioactive Substrate

AbstractGlucose-U-C14 was incorporated into immature larvae of the wheat stem sawfly, Cephus cinctus Nort., by vacuum-infiltration. These insects were too small to be conveniently injected and could not be easily fed on artificial diets. About half of them survived the infiltration treatment. C14O2 was produced by the organism showing that the radioactive substrate was metabolized. Of the amino acids isolated from the larvae, proline, alanine, glutamic acid, serine, aspartic acid, and glycine contained relatively large quantities of carbon-14 indicating biosynthesis, and are classed as nutritionally non-essential. In contrast, arginine, isoleucine, leucine, lysine, phenylalanine, threonine, tyrosine, and valine contained little, if any, radioactivity and are classed as nutritionally essential. The concentrations of some of the amino acids in the larval tissues are also presented.

EFFECTS OF DIETARY UREA LEVEL ON AMINO ACID CONCENTRATIONS IN RUMINANT TISSUES

1973 ◽  
Vol 53 (4) ◽  
pp. 717-724 ◽  
Author(s):  
H. A. SALEM ◽  
T. J. DEVLIN ◽  
J. R. INGALLS ◽  
G. D. PHILLIPS
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Glutamic Acid ◽  
Latin Square ◽  
Essential Amino Acids ◽  
Plasma Amino Acid ◽  
Isoleucine Leucine ◽  
Rumen Microorganisms ◽  
Rumen Epithelium ◽  
Amino Acid Concentrations

The effects of a semipurified diet containing 0 (0% urea-N diet), 50 (39% urea-N diet), or 100% (76% urea-N diet) of added dietary nitrogen (N) as urea on the amino acid concentrations in ruminant tissues was investigated. Three rumen-fistulated bull calves averaging 240 kg were used in a latin square design. The calves were fed using a continuous feeder to provide 7 kg of feed daily. Each experimental period of the latin square was 40 days divided into four 10-day intervals. Liver samples were obtained on the 9th day of each 10-day interval and rumen epithelium and rumen microorganisms were obtained on the 10th day of each 10-day interval. Blood samples were collected on the 6th, 8th, and 10th day of each 10-day interval for the determination of plasma amino acid patterns as well as the amino acid concentrations in the tissues. Plasma amino acid patterns indicated that when the 76% urea-N diet was fed the levels of aspartic acid, citrulline, glutamic acid, glycine, and proline were increased. Most of the essential amino acids were decreased on the 76% urea-N diet as compared with the 0% urea-N diet. All amino acids of rumen microorganisms were increased on the 39% urea-N diet with the exception of arginine, lysine, and threonine, which decreased slightly or did not show any change. Most amino acids were lower on the 76% urea-N diet as compared with the 39% or 0% urea-N diets. All essential amino acids measured in the liver were reduced on the 76% urea-N diet. Cystine, glutamic acid, glycine, isoleucine, leucine, lysine, tryptophan, and valine were also reduced on the 39% urea-N diet. In rumen epithelium, there was a reduction of the essential amino acids and an increase of the nonessential amino acids on the 76% urea-N diet.

Free amino acid and amine concentrations in liver: effects of hydrocortisone and fasting

1962 ◽  
Vol 202 (4) ◽  
pp. 695-698 ◽  
Author(s):  
S. A. Kaplan ◽  
C. S. Nagareda Shimizu
Keyword(s):  
Amino Acids ◽  
Protein Synthesis ◽  
Amino Acid ◽  
Glutamic Acid ◽  
Free Amino ◽  
Mouse Liver ◽  
Free Fraction ◽  
Aminobutyric Acid ◽  
Isoleucine Leucine ◽  
Total Pool

Concentrations of the following Ninhydrin-reacting substances (NRS) were determined in the unhydrolyzed protein-free fraction of mouse liver by column chromatography: phosphoethanolamine, taurine, urea, aspartic acid, threonine, serine, glutamine, proline, glutamic acid, glycine, alanine, valine, cystine, methionine, isoleucine, leucine, tyrosine, phenylalanine, ß-alanine, ß-aminoisobutyric acid, α-aminobutyric acid, ornithine, ethanolamine, lysine, histidine, and arginine. The NRS present in highest concentration was taurine. Adrenalectomy, fasting for 24 hr, and cortisol administration had little effect on the sum of NRS or individual amino acids. Administration of cortisol did, however, decrease the concentration of amino acids in fasted adrenalectomized animals but increased their concentration in nonfasted adrenalectomized animals. Since the concentration of amino acids was lowered or raised under circumstances known to increase protein synthesis, it is concluded that increased protein synthesis promoted by cortisol is independent of the total pool of amino acids in liver.

AMINO ACID FORMATION FROM GLUCOSE IN THE ISOLATED ADRENOCORTICAL AND THYROID TISSUE OF THE RABBIT

1963 ◽  
Vol 44 (1) ◽  
pp. 128-132 ◽  
Author(s):  
Hans Hammar ◽  
Bo Hellman ◽  
Stig Larsson
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Glutamic Acid ◽  
Adrenal Cortex ◽  
Aspartic Acid ◽  
Thyroid Tissue ◽  
Acid Formation ◽  
Isoleucine Leucine ◽  
The Individual

ABSTRACT Quantitative paper-radiochromatography was used for measuring the amino acid formation from uniformly labelled 14C-glucose in slices from the isolated adrenal cortex and the thyroid. In both these organs glucose was utilized in the synthesis of the following amino acids: alanine, aspartic acid, glutamic acid, glutamine, arginine, proline, glycine and isoleucine/leucine. Distinct differences were noted in the rate of formation of the individual amino acids; the value for alanine being no less than 5 times higher in the thyroid than in the adrenocortical tissue. While TSH had no effect on the conversion of glucose in the thyroid, there was a tendency for a lower amino acid (glutamine) formation, when the adrenal cortex was incubated with ACTH.

scholarly journals Biosynthesis of ‘essential’ amino acids by scleractinian corals

1997 ◽  
Vol 322 (1) ◽  
pp. 213-221 ◽  
Author(s):  
Lisa M. FITZGERALD ◽  
Alina M. SZMANT
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Glutamic Acid ◽  
Reef Coral ◽  
Acid Synthesis ◽  
Essential Amino Acids ◽  
Acropora Cervicornis ◽  
Isoleucine Leucine ◽  
Amino Acid Synthesis ◽  
Protein Amino Acids

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

The Change Rules of Physiochemical Indexes of Luzhou-Flavor Daqu Based on Continuous Flow Chemical Analyzer

2014 ◽  
Vol 881-883 ◽  
pp. 761-765 ◽  
Author(s):  
Hui Bo Luo ◽  
Da Di Wang ◽  
Yi Wang ◽  
Yong Wang ◽  
Cai Hong Wang
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Free Amino Acid ◽  
Free Amino Acids ◽  
Continuous Flow ◽  
Free Amino ◽  
Reducing Sugars ◽  
Reducing Sugar ◽  
Total Acid ◽  
Chemical Analyzer

The continuous flow chemical analyzer was applied for the determination of the content of total acid, reducing sugars and free amino acids of Luzhou-flavor Daqu in the whole making process including fermentation and storage period. The result showed that the total acid, reducing sugars and free amino acids had a dramatic change in the period of Daqu fermentation and had a higher level with a small fluctuation in the prophase of Daqu storage. In the late phase of Daqu storage, the total acid and reducing sugars decreased considerably and tend to be stable finally, while the free amino acid was still maintained at a high level. The total acid and reducing sugar had a significant positive correlation (the correlation coefficient of total acid and reducing sugar content was 0.946,P<0.01), and both of them had no correlation with the content of free amino acid.

The uptake of amino acids by mouse cells (strain LS) during growth in batch culture and chemostat culture: the influence of cell growth rate

1967 ◽  
Vol 168 (1013) ◽  
pp. 421-438 ◽  
Keyword(s):  
Amino Acids ◽  
Growth Rate ◽  
Amino Acid ◽  
Cell Growth ◽  
Glutamic Acid ◽  
Batch Culture ◽  
Amino Acid Uptake ◽  
Essential Amino Acids ◽  
Growth Yields ◽  
Acid Uptake

The uptake of thirteen essential amino acids by mouse LS cells in suspension culture was determined by bacteriological assay methods. Chemostat continuous-flow cultures were used to determine the effect of different cell growth rates on the quantitative amino acid requirements for growth. The growth yields of the cells ( Y = g cell dry weight produced/g amino acid utilized) were calculated for each of the essential amino acids. A mixture of the non-essential amino acids, serine, alanine and glycine increased the cell yield from the essential amino acids. The growth yields from nearly all the essential amino acids in batch culture were increased when glutamic acid was substituted for the glutamine in the medium. The growth yields from the amino acids in batch culture were much less at the beginning than at the end of the culture. The highest efficiencies of conversion of amino acids to cell material were obtained by chemostat culture. When glutamic acid largely replaced the glutamine in the medium the conversion of amino acid nitrogen to cell nitrogen was 100 % efficient (that is, the theoretical yield was obtained) at the optimum growth rate (cell doubling time, 43 h). The maximum population density a given amino acid mixture will support can be calculated from the data. It is concluded that in several routinely used tissue culture media the cell growth is limited by the amino acid supply. In batch culture glutamine was wasted by (1) its spontaneous decomposition to pyrrolidone carboxylic acid and ammonia, and (2) its enzymic breakdown to glutamic acid and ammonia, but also glutamine was used less efficiently than glutamic acid. Study of the influence of cell growth rate on amino acid uptake rates per unit mass of cells indicated that a marked change in amino acid metabolism occurred at a specific growth rate of 0.4 day -1 (cell doubling time, 43 h). With decrease in specific growth rate below 0.4 day -1 there was a marked stimulation of amino acid uptake rate per cell and essential amino acids were consumed increasingly for functions other than synthesis of cell material.

scholarly journals AMINO ACID COMPOSITION AND ELECTROPHORETIC PROPERTIES OF HYPERTENSIN I

1955 ◽  
Vol 102 (4) ◽  
pp. 435-440 ◽  
Author(s):  
Leonard T. Skeggs ◽  
Walton H. Marsh ◽  
Joseph R. Kahn ◽  
Norman P. Shumway
Keyword(s):  
Amino Acids ◽  
Quantitative Analysis ◽  
Amino Acid ◽  
Ion Exchange ◽  
Amino Acid Composition ◽  
Acid Composition ◽  
Isoelectric Point ◽  
Column Chromatography ◽  
Isoleucine Leucine ◽  
Ion Exchange Column

A preparation of hypertensin I was purified by countercurrent distribution and was shown to migrate as a single component in starch blocks at pH 9.3 and 4.2. It had an isoelectric point of 7.7. Quantitative analysis by ion exchange column chromatography showed eight amino acids in approximately unimolar proportion: aspartic, proline, valine, isoleucine, leucine, tyrosine, phenylalanine, and arginine. There were in addition two moles of histidine.

scholarly journals Amino Acid Composition of Milk from Cow, Sheep and Goat Raised in Ailano and Valle Agricola, Two Localities of ‘Alto Casertano’ (Campania Region)

Foods ◽  
2021 ◽  
Vol 10 (10) ◽  
pp. 2431
Author(s):  
Nicola Landi ◽  
Sara Ragucci ◽  
Antimo Di Maro
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Glutamic Acid ◽  
Protein Content ◽  
Total Protein ◽  
Free Amino ◽  
Raw Milk ◽  
Total Amino Acid ◽  
Total Protein Content ◽  
Campania Region

Cow, sheep and goat raw milk raised in Ailano and Valle Agricola territories (‘Alto Casertano’, Italy) were characterized (raw proteins, free and total amino acids content) to assess milk quality. Raw milk with the highest total protein content is sheep milk followed by goat and cow milk from both localities. Total amino acid content in cow, goat and sheep raw milk is 4.58, 4.81 and 6.62 g per 100 g, respectively, in which the most abundant amino acid is glutamic acid (~20.36 g per 100 g of proteins). Vice versa, the free amino acids content characteristic profiles are different for each species. In particular, the most abundant free amino acid in cow, sheep and goat raw milk is glutamic acid (9.07 mg per 100 g), tyrosine (4.72 mg per 100 g) and glycine (4.54 mg per 100 g), respectively. In addition, goat raw milk is a source of taurine (14.92 mg per 100 g), retrieved in low amount in cow (1.38 mg per 100 g) and sheep (2.10 mg per 100 g) raw milk. Overall, raw milk from ‘Alto Casertano’ show a high total protein content and are a good source of essential amino acids.

scholarly journals Effect of Different Edaphic Crop Conditions on the Free Amino Acid Profile of PH-16 Dry Cacao Beans

Agronomy ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1637
Author(s):  
Quintino Reis de Araujo ◽  
Guilherme Amorim Homem de Abreu Loureiro ◽  
Cid Edson Mendonça Póvoas ◽  
Douglas Steinmacher ◽  
Stephane Sacramento de Almeida ◽  
...  
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Glutamic Acid ◽  
Free Amino Acid ◽  
Free Amino Acids ◽  
Free Amino ◽  
Principal Component ◽  
Amino Acid Profile ◽  
Gamma Aminobutyric Acid ◽  
Significant Difference

Free amino acids in cacao beans are important precursors to the aroma and flavor of chocolate. In this research, we used inferential and explanatory statistical techniques to verify the effect of different edaphic crop conditions on the free amino acid profile of PH-16 dry cacao beans. The decreasing order of free amino acids in PH-16 dry cacao beans is leucine, phenylalanine, glutamic acid, alanine, asparagine, tyrosine, gamma-aminobutyric acid, valine, isoleucine, glutamine, lysine, aspartic acid, serine, tryptophan, threonine, glycine. With the exception of lysine, no other free amino acid showed a significant difference between means of different edaphic conditions under the ANOVA F-test. The hydrophobic free amino acids provided the largest contribution to the explained variance with 58.01% of the first dimension of the principal component analysis. Glutamic acid stands out in the second dimension with 13.09%. Due to the stability of the biochemical profile of free amino acids in this clonal variety, it is recommended that cacao producers consider the genotype as the primary source of variation in the quality of cacao beans and ultimately the chocolate to be produced.

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