Effects of tritiated water on the metabolism and germination of jack pine seeds

1971 ◽  
Vol 49 (12) ◽  
pp. 2139-2149 ◽  
Author(s):  
D. J. Durzan ◽  
A. J. Mia ◽  
B. S. P. Wang
Keyword(s):  
Amino Acids ◽  
Glutamic Acid ◽  
Unit Area ◽  
Tritiated Water ◽  
Jack Pine ◽  
Aminobutyric Acid ◽  
Insoluble Protein ◽  
Amide Content ◽  
Insoluble Protein Fraction ◽  
Inhibited Water

Tritium, imbibed as tritiated water, which evoked the germination of jack pine, was recovered from alcohol-soluble and insoluble components of seeds. At 12 h, tritium labeled nonexchangeably a few but not all free amino acids. By 96 h, all amino acids contained tritium but in seeds killed by heat no radioactive amino acids were detected. Radioactivity in glutamic acid, alanine, proline, and γ-aminobutyric acid implicated key roles for α-ketoacids and semialdehydes during germination. Two neutral fractions accounted for over 80% of the tritium in alcohol-soluble compounds.Levels of tritium above 1.0 mCi/ml water per gram dry seed inhibited water intake after 1 h and inactivated the germination of seeds by 96%. The total soluble N and amide content were also significantly reduced as alanine N increased. Specific activities of glutamine and γ-aminobutyric acid but not of all amino acids were proportional to tritium dose. Radioactivity in glutamine was not associated with the amide N supporting the specific labeling by tritium at the α-carbon of glutamic acid. At high levels of tritium radioactivity was concentrated in the insoluble (protein) fraction and was accompanied by brittleness of tissues and subcellular disruption. Tritium although localized mostly in the cytoplasm was more concentrated per unit area throughout chromatin regions of the nucleus than in the cytoplasm.

The incorporation of tritiated water into amino acids in the presence of urea by white spruce seedlings in light and darkness

1973 ◽  
Vol 51 (2) ◽  
pp. 351-358 ◽  
Author(s):  
D. J. Durzan
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Glutamic Acid ◽  
Covalent Binding ◽  
Tritiated Water ◽  
Continuous Light ◽  
White Spruce ◽  
Aminobutyric Acid ◽  
Soluble Nitrogen ◽  
Pyrrolidone Carboxylic Acid

White spruce seedlings containing urease were exposed to 0.16 M urea for 4 h in continuous light. Seedlings accumulated total soluble nitrogen as amides and arginine, and increased their content of bound amino acid nitrogen. In darkness, total soluble nitrogen declined and the increase of total bound amino acids was not as great as in light. In both treatments, the fate of tritiated water was examined by recovery of nonexchangeable tritium from amino acids. As urea was consumed, more tritium was recovered from seedlings in light than in darkness. In both treatments tritium followed the nitrogen of urea and was bound covalently, initially in glutamic acid, and subsequently wherever an α-keto acid was a precursor for the synthesis of the corresponding amino acid, viz. alanine and aspartic acid. In light, tritium was recovered mainly from glutamic acid, followed by glutamine, and to a lesser extent by γ-aminobutyric acid. In darkness, while glutamic acid was prominent initially, more radioactivity was recovered from γ-aminobutyric and glutamic acids compared to glutamine and to the light treatment. Glutamic acid was the main bound amino acid containing covalent tritium.The occurrence of tritium at the α-carbon of glutamic acid was supported by transfer of this tritium after decarboxylation to γ-aminobutyric acid, and by conversion of bound glutamate-3H to radioactive pyrrolidone carboxylic acid during acid hydrolysis of protein.Although urea nitrogen contributed to arginine synthesis in light, no tritium was found in arginine nor its precursors in the ornithine cycle until later, when nearly all amino acids were radioactive. This is consistent with the absence of covalent binding of tritium in ureido precursors leading to arginine biosynthesis, and supports the idea that tritium did not readily follow the carbon of urea into covalent linkage.

Glutamic acid and gamma-aminobutyric acid neurotransmitters in central control of breathing

1991 ◽  
Vol 70 (1) ◽  
pp. 1-7 ◽  
Author(s):  
H. Kazemi ◽  
B. Hoop
Keyword(s):  
Amino Acids ◽  
Glutamic Acid ◽  
Respiratory Control ◽  
Ventral Surface ◽  
Control Of Breathing ◽  
Aminobutyric Acid ◽  
Central Control ◽  
Gamma Aminobutyric Acid ◽  
Tracer Kinetic ◽  
Kinetic Investigations

We review recent cross-disciplinary experimental and theoretical investigations on metabolism of the amino acid neurotransmitters glutamic acid and gamma-aminobutyric acid (GABA) in the brain during hypoxia and hypercapnia and their possible role in central control of breathing. The roles of classical modifiers of central chemical drive to breathing (H+ and cholinergic mechanisms) are summarized. A brief perspective on the current widespread interest in GABA and glutamate in central control is given. The basic biochemistry of these amino acids and their roles in ammonia and bicarbonate metabolism are discussed. This review further addresses recent work on central respiratory effects of inhibitory GABA and excitatory glutamate. Current understanding of the sites and mechanisms of action of these amino acids on or near the ventral surface of the medulla is reviewed. We focus particularly on tracer kinetic investigations of glutamatergic and GABAergic mechanisms in hypoxia and hypercapnia and their possible role in the ventilatory response to hypoxia. We conclude with some speculative remarks on the critical importance of these investigations and suggest specific directions of research in central mechanisms of respiratory control.

THE METABOLISM OF PELARGONATE-1-C14 BY WHEAT STEM RUST UREDOSPORES

1965 ◽  
Vol 43 (1) ◽  
pp. 91-96 ◽  
Author(s):  
S. Suryanarayanan ◽  
W. B. McConnell
Keyword(s):  
Amino Acids ◽  
Glutamic Acid ◽  
Glyoxylate Cycle ◽  
Water Extract ◽  
Aminobutyric Acid ◽  
Pelargonic Acid ◽  
Puccinia Graminis ◽  
Wheat Stem Rust ◽  
Carbon 14 ◽  
The Glyoxylate Cycle

Uredospores of Puccinia graminis var. tritici were incubated in phosphate buffer (pH 6.2) containing pelargonic acid-1-C14. After 3 hours 97.5% of the tracer was assimilated. Fifty-five percent of this was released as C14O2 and 36.2% was incorporated into the spores. About one-half of the carbon-14 in the spores was soluble in ethanol and water, whereas nearly a third was ether extractable. The amino acid and carbohydrate fractions contained about equal amounts of carbon-14 and together accounted for two-thirds of the radioactivity in the ethanol–water extract. The organic acids were also radioactive. Glutamic acid, γ-aminobutyric acid, aspartic acid, and alanine were the most highly labelled amino acids. Fifty-three percent of the radioactivity in glutamic acid was found in carbon 1 and 46% in carbon 5. This distribution suggests β-oxidation of pelargonic acid to acetyl CoA and extensive utilization of the latter by means of the glyoxylate cycle.

The metabolism of L-proline by jack pine seedlings

1971 ◽  
Vol 49 (12) ◽  
pp. 2163-2173 ◽  
Author(s):  
D. J. Durzan ◽  
P. K. Ramaiah
Keyword(s):  
Amino Acids ◽  
Carboxylic Acid ◽  
Glutamic Acid ◽  
Specific Activity ◽  
Jack Pine ◽  
Sharp Drop ◽  
Peroxidase Isoenzyme ◽  
Succinamic Acid ◽  
Pine Seedlings ◽  
Pyrrolidone Carboxylic Acid

The metabolism of L-proline was studied in 6-day-old jack pine seedlings, freshly excised from the nutritive female gametophyte. During the following 24 h, a sharp drop in free amino acids and protein was observed. Although levels of free proline were low, uniformly labeled 14C-L-proline and proline-3, 4-3H served as precursors for the dicarboxylic amino acids and their corresponding amides, glutamine and asparagine, which usually accumulate during germination. The origin of asparagine while unresolved did not involve β-cyanoalanine. Other products of proline metabolism included Δ1-pyrroline-5-carboxylic acid, glutamic acid, and γ-aminobutyric acid. With 14C-proline, radioactivity in alanine and serine resulted presumably from refixation of 14CO2 that was released by the decarboxylation of glutamic acid and other organic acids. The remaining products, e.g. pyrrolidone carboxylic acid, succinamic acid, and succinimide, were more closely related to the fate of glutamine than to proline.Radioactivity in proline and derived amino acids was recovered from soluble proteins separated on polyacrylamide gels. Five fractions revealed a similar diurnal turnover of specific activity. Three of these contained peroxidase isoenzyme activity. The recovery of tritium from peroxidase isoenzymes was related through the metabolism of proline to the intake and metabolism of water as well as to the appearance of enzyme activity in vascular tissues and emerging root and shoot apices.

Modulatory effects of some amino acids and neuropeptides on luminescence in the brittlestar amphipholis squamata

1999 ◽  
Vol 202 (13) ◽  
pp. 1785-1791 ◽  
Author(s):  
N.D. Bremaeker ◽  
F. Baguet ◽  
M.C. Thorndyke ◽  
J. Mallefet
Keyword(s):  
Amino Acids ◽  
Glutamic Acid ◽  
Cholinergic System ◽  
Aminobutyric Acid ◽  
Amphipholis Squamata

Amphipholis squamata is a polychromatic luminescent ophiuroid. The effects of amino acids (γ -aminobutyric acid, GABA, taurine, glycine and glutamate), N-methyl-d-aspartate (NMDA) and the invertebrate neuropeptides Antho-RFamide, FMRFamide and SALMFamides S1 and S2 were tested on acetylcholine-induced luminescence from isolated arms of clear and black specimens of Amphipholis squamata. The results showed that GABA, glycine and Antho-RFamide inhibited ACh-induced luminescence of clear specimens and had no significant effect on black specimens. Glutamic acid had no significant effect on ACh-induced luminescence, but triggered luminescence in the absence of ACh in both types of specimen. Taurine, NMDA and FMRFamide showed no significant effects on either clear or black specimens. S1 potentiated ACh-induced luminescence of clear and black specimens, while S2 had no clear modulatory effect on luminescence. These results suggest that, in addition to the previously described cholinergic system in Amphipholis squamata, there is also a modulatory component to luminescence control. Moreover, we observed a difference in modulation of luminescence between clear and black specimens.

EXUDATE PRODUCED BY GLOMERELLA CINGULATA SPORES IN THE PRESENCE OF COPPER AND DITHIOCARBAMATE IONS

1962 ◽  
Vol 40 (1) ◽  
pp. 25-33 ◽  
Author(s):  
G. D. Thorn ◽  
L. T. Richardson
Keyword(s):  
Amino Acids ◽  
Glutamic Acid ◽  
Response Curve ◽  
Ternary Complex ◽  
Copper Ions ◽  
Aminobutyric Acid ◽  
Glomerella Cingulata ◽  
Egg Albumin ◽  
Reduced Toxicity ◽  
Dosage Response Curve

Small amounts of copper ions induce the release from spores of Glomerella cingulata Spauld. & Schrenk. of increased amounts of amino acids, predominantly glutamic acid, α-alanine, γ-aminobutyric acid, aspartic acid, glycine, leucine(s), and serine. Sodium dimethyldithiocarbamate, and copper in the form of the dimethyldithiocarbamate complex, do not show this effect. Added protein, such as egg albumin or cellulase, or the extracellular protein of spores suspended in water, forms a soluble ternary complex with dithiocarbamate and copper ions. This results in little or no loss of dithiocarbamate from solution and in reduced toxicity in the first mode of the dosage–response curve.

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.

Free amino acid concentrations in needles of Norway spruce and Scots pine trees on different sites in areas with two levels of nitrogen deposition

1990 ◽  
Vol 20 (8) ◽  
pp. 1132-1136 ◽  
Author(s):  
Ann-Britt Edfast ◽  
Torgny Näsholm ◽  
Anders Ericsson
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Glutamic Acid ◽  
Nitrogen Deposition ◽  
Free Amino Acids ◽  
Free Amino ◽  
Aminobutyric Acid ◽  
Site Quality ◽  
Southern Sweden ◽  
Amino Acid Concentrations

The effects of nitrogen deposition and site quality on amino acid concentrations in needles of Piceaabies (L.) Karst. and Pinussylvestris L. trees were studied in two areas that represent different levels of nitrogen deposition: one area in southern Sweden and one area in northern Sweden receive, respectively, approximately 20–30 and 3 kg•ha−1•year−1 of nitrogen. On each area three site quality classes were chosen for each tree species. The site classes were chosen to represent poor, medium, and good sites typical for each area. Free amino acids in the needles were analyzed as 9-fluorenylmethyl formate derivatives by high-performance liquid chromatography. The total nitrogen was determined with a CHN elemental analyzer, and other mineral nutrients were determined with an inductively coupled plasma analyzer. Arginine, glutamic acid, glutamine, γ-aminobutyric acid, and aspartic acid were the quantitatively dominating amino acids in the needles of both species from all sites in both northern and southern Sweden. These amino acids represented 50–80% of the total concentration of free amino acids in the needles. The concentration of arginine in the needles of both spruce and pine increased with decreasing site index and showed high variations between individual trees. For both species, the highest concentrations of arginine were found in the southern area, which had the highest deposition of nitrogen. Concentrations of glutamic acid, glutamine, and γ-aminobutyric acid in the needles of both species showed significant differences between some of the sites on both areas, but these differences showed no general pattern that correlated with the site indexes. In relation to nitrogen, low concentrations of phosphorus and potassium were found in needles from the poorest spruce sites in both areas compared with corresponding values for the good spruce sites. The results are discussed in relation to nitrogen deposition and mineral nutrient imbalance.

Amino Acids in the Cobalt-Induced Epileptogenic and Nonepileptogenic Cat's Cortex

1972 ◽  
Vol 50 (8) ◽  
pp. 740-752 ◽  
Author(s):  
Ikuko Koyama
Keyword(s):  
Amino Acids ◽  
Cerebral Cortex ◽  
Glutamic Acid ◽  
Aspartic Acid ◽  
Aminobutyric Acid ◽  
Cobalt Powder ◽  
Cortical Tissue ◽  
Excitatory Effect ◽  
Epileptic Discharges ◽  
Adult Cats

Epileptogenic cortical foci were produced by the topical application of cobalt powder to the exposed anterior or posterior sigmoid gyrus of adult cats. Within 60–90 min after application, epileptic discharges were observed only in the area adjacent to the cobalt-treated region (focus). Twenty-four hours later, tonic and clonic epileptic convulsions occurred. These seizures disappeared by the 3rd day after treatment. The concentration of amino acids in the cortex was determined during three periods after the application of cobalt: preconvulsive period (acute), 0–360 min; convulsive period (semi-acute), 24–48 h; postconvulsive period (chronic), 30–70 days.In the cortical tissue adjacent to the site of cobalt application, glutamic acid, aspartic acid, and γ-aminobutyric acid were decreased, while there was a marked increase in glycine, threonine, serine, and taurine during the convulsive period. In the preconvulsive period, the amino acids in the superfusates of the cobalt-treated cortex were measured. The rate of release of glutamic acid increased within 90 min after cobalt application together with a corresponding decrease of the rate of release of glutamine and urea. The excitatory effect of the liberated glutamic acid may play an important role in the production of focal epileptic discharges following the application of cobalt powder to the cerebral cortex.

Purification of Antihemophilic Factor (Factor VIII) by Amino Acid Precipitation*

1964 ◽  
Vol 11 (01) ◽  
pp. 064-074 ◽  
Author(s):  
Robert H Wagner ◽  
William D McLester ◽  
Marion Smith ◽  
K. M Brinkhous
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Factor Viii ◽  
Plasma Protein ◽  
Acid Precipitation ◽  
Aminobutyric Acid ◽  
Gamma Aminobutyric Acid ◽  
Specific Procedure ◽  
Beta Alanine ◽  
Antihemophilic Factor

Summary1. The use of several amino acids, glycine, alpha-aminobutyric acid, alanine, beta-alanine, and gamma-aminobutyric acid, as plasma protein precipitants is described.2. A specific procedure is detailed for the preparation of canine antihemophilic factor (AHF, Factor VIII) in which glycine, beta-alanine, and gammaaminobutyric acid serve as the protein precipitants.3. Preliminary results are reported for the precipitation of bovine and human AHF with amino acids.

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