scholarly journals GABA plays a key role in plant acclimation to a combination of high light and heat stress

2021 ◽  
Author(s):  
Damián Balfagón ◽  
Aurelio Gómez-Cadenas ◽  
José L. Rambla ◽  
Antonio Granell ◽  
Carlos de Ollas ◽  
...  
Keyword(s):  
Amino Acids ◽  
Heat Stress ◽  
Amino Acid ◽  
Abiotic Stresses ◽  
Elevated Temperatures ◽  
Metabolic Response ◽  
High Light ◽  
Aminobutyric Acid ◽  
Proteinogenic Amino Acid ◽  
Plant Acclimation

ABSTRACTPlants are frequently subjected to different combinations of abiotic stresses, such as high light intensity and elevated temperatures. These environmental conditions pose an important threat to agriculture production, affecting photosynthesis and decreasing yield. Metabolic responses of plants, such as alterations in carbohydrates and amino acid fluxes, play a key role in the successful acclimation of plants to different abiotic stresses, directing resources towards stress responses and suppressing growth. Here we show that the primary metabolic response of Arabidopsis thaliana plants to high light or heat stress is different than that of plants subjected to a combination of high light and heat stress. We further demonstrate that a combination of high light and heat stress results in a unique metabolic response that includes increased accumulation of sugars and amino acids, coupled with decreased levels of metabolites participating in the tricarboxylic acid (TCA) cycle. Among the amino acids exclusively accumulated during a combination of high light and heat stress, we identified the non-proteinogenic amino acid γ-aminobutyric acid (GABA). Analysis of different mutants deficient in GABA biosynthesis, in particular two independent alleles of glutamate decarboxylase 3 (gad3), reveal that GABA plays a key role in the acclimation of plants to a combination of high light and heat stress. Taken together, our findings identify a new role for GABA in regulating plant responses to stress combination.One sentence summaryThe non-proteinogenic amino acid γ-aminobutyric acid (GABA) is required for plant acclimation to a combination of high light and heat stress in Arabidopsis.

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.

scholarly journals Quantification By Gas Chromatography of the Content of Amino Acids Present in Sausages Fortified with Quinoa Vegetable Protein

2021 ◽  
Author(s):  
A. Zavala ◽  
M. González ◽  
P. Pino
Keyword(s):  
Amino Acids ◽  
Gas Chromatography ◽  
Amino Acid ◽  
Vegetable Protein ◽  
Amino Acid Profile ◽  
Aminobutyric Acid ◽  
Precolumn Derivatization ◽  
Proportional Relationship ◽  
Quinoa Flour

The objective of this research was to determine the quality of the protein present in sausages fortified with quinoa as a substitute for animal protein, through the identification and quantification of amino acids, using gas chromatography and precolumn derivatization. The amino acid composition found in the analyzed products was predominantly composed of: Threonine (THR) with a concentration of 1046.32µmol / L, aminobutyric acid (ABA) with a concentration of 9685.68 µmol / L and glutamic acid (GLU) with a concentration of 1178.71 µmol / L. These values were found in the treatment with the highest percentage of quinoa flour, establishing a directly proportional relationship between the concentrations of these amino acids and the percentage of quinoa. Gas chromatography was an adequate technique for determining the amino acid profile due to its speed and sensitivity. Keywords: amino acids, sausages, quinoa, derivatization, gas chromatography. RESUMEN La presente investigación tiene por objetivo determinar la calidad de la proteína presente en embutidos fortificados con quinua como sustituyente de la proteína animal, a través de la identificación y cuantificación de aminoácidos mediante la aplicación de cromatografía de gases y la derivatización precolumna. La composición de aminoácidos encontrada en los productos analizados destaca la presencia mayoritaria de: Treonina (THR) con una concentración de 1046,32 µmol/L, ácido aminobutírico (ABA) con una concentración de 9685,68 µmol/L  y ácido glutámico (GLU) con una concentración de 1178,71 µmol/L, todos estos valores se presentaron en el tratamiento con mayor porcentaje de harina de quinua estableciéndose una relación directamente proporcional entre las concentraciones de estos aminoácidos y el porcentaje de adición de quinua en los tratamientos estudiados. Se puede concluir que la cromatografía de gases empleada resultó una técnica adecuada para la determinación del perfil aminoacídico por la rapidez y sensibilidad presentada sobre las muestras estudiadas.  Palabras claves: aminoácidos, embutidos, quinua, derivatización, cromatografía de gases.  

Radiation Damage to Polypeptides and Proteins in the Solid State: Changes in Amino Acid Composition *

1981 ◽  
Vol 36 (3-4) ◽  
pp. 310-318 ◽  
Author(s):  
J. Seredynski ◽  
T. Söylemez ◽  
W. Baumeister
Keyword(s):  
Amino Acids ◽  
Electron Microscope ◽  
Amino Acid ◽  
Solid State ◽  
Trypsin Inhibitor ◽  
Concanavalin A ◽  
Thin Layers ◽  
Aminobutyric Acid ◽  
Sensitivity Pattern ◽  
State Changes

Thin layers of synthetic homopolypeptides (poly-α-Ala, -Arg, -Asn, -Asp, -Glu, -His, -Lys and -Tyr) and proteins (myoglobin, concanavalin A, trypsin-inhibitor) were irradiated under solid state conditions in an electron microscope with 100 keV electrons. Radiolytic changes were investigated by amino acid analysis. The results are discussed in terms of the relative radiosensitivities of the constituent amino acids, and possible topochemical effects on the sensitivity pattern emerging. An attempt is also made to trace at least some of the predominant pathways of amino acid transformation, namely the production of alanine and a-aminobutyric acid

Variations in the concentrations of free amino acids in the plasma of the dairy cow at parturition

1972 ◽  
Vol 39 (3) ◽  
pp. 355-364 ◽  
Author(s):  
R. Verbeke ◽  
E. Roets ◽  
G. Peeters
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Free Amino ◽  
Milk Protein ◽  
Sampling Period ◽  
Aminobutyric Acid ◽  
Amino Acid Utilization ◽  
Amino Acid Levels ◽  
The Mean ◽  
Peak Value

SummaryThe plasma levels of individual amino acids were studied in 6 dairy cows from 4 days before to 3 days after calving. During this sampling period, the concentrations of 13 amino acids showed significant changes. The levels of several amino acids were depressed markedly in the sample collected immediately before calving. Following parturition, the concentration of most amino acids gradually returned to values obtained 3 days before calving. The glutamine and alanine contents of the plasma rose to a peak value 1 day after calving and subsequently decreased. The mean concentrations of glycine and α-aminobutyric acid did not change before parturition but rose significantly thereafter. These observations are discussed in terms of amino-acid utilization for milk protein synthesis and gluconeogenesis at the onset of lactation. The changes in plasma amino acid levels appear to be synchronized with those reported for prolactin and progesterone in the 24 h before parturition. This may indicate an important influence of both hormones on the lactogenic process in the cow. The highly significant correlations obtained between the concentrations of 14 individual amino acids are discussed.

scholarly journals Peri-operative amino acid administration and the metabolic response to surgery

2002 ◽  
Vol 61 (3) ◽  
pp. 337-343 ◽  
Author(s):  
Eva Selldén
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
General Anaesthesia ◽  
Heat Generation ◽  
Metabolic Response ◽  
Cellular Mechanisms ◽  
Amino Acid Infusion ◽  
Awake State ◽  
Energy Consuming ◽  
Thermic Effect

General anaesthesia causes hypothermia due to decreased metabolic rate and impaired thermoregulation. Many warming devices are in use to prevent heat loss, but little attention has been paid to stimulating the body's own heat generation. All nutrients raise energy expenditure, and the highest thermic effect is ascribed to amino acids and proteins, 30–40% in the awake state. Amino acids infused during general anaesthesia exert a thermic effect that is enhanced compared with that in the awake state. At awakening from anaesthesia, post-operative hypothermia may be prevented without shivering. The tissues involved and the mechanisms by which nutrients stimulate heat production are still not completely understood. However, these findings support the existence of an inhibitory action normally exerted by central thermosensors, in order to maintain oxidative metabolism within certain limits, to prevent hyperthermia. During anaesthesia central thermosensors are silenced and, hence, amino acid thermogenesis is exaggerated. The amino acid-induced heat generation during anaesthesia predominantly occurs in extra-splanchnic tissues, most probably in skeletal muscle. It may reflect an increased protein turnover, as both protein breakdown and synthesis are energy-consuming processes known to generate heat. Possibly, amino acid infusion provides substrates, otherwise mobilized from the body's own tissues, needed for wound healing and immunological function. However, other cellular mechanisms may also contribute to this non-shivering thermogenesis.

Incorporation of carbon atoms from glucose into free amino acids in brain under normal and altered conditions

1970 ◽  
Vol 48 (3) ◽  
pp. 228-235 ◽  
Author(s):  
Y. Yoshino ◽  
K. A. C. Elliott
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Aspartic Acid ◽  
Free Amino Acids ◽  
Free Amino ◽  
Acid Level ◽  
Specific Activity ◽  
Specific Radioactivity ◽  
Aminobutyric Acid ◽  
Aminooxyacetic Acid

The time course of entry of radioactive carbon from intravenously administered [U-14C]-glucose into free amino acids in the brains of rats has been studied using an automatic amino acid analyzer coupled through a flow cell with a scintillation counter. Radioactivity appeared rapidly in alanine, aspartic acid, glutamic acid, glutamine, and γ-aminobutyric acid as previously shown, and in an unknown ninhydrin-positive substance present in very small amount. Urea, serine, and glycine became slightly radioactive. Four hours after giving the radioactive glucose, the specific activity in all soluble substances was low. In pentobarbital anesthesia, specific radioactivity was increased in alanine and decreased in γ-aminobutyric acid, aspartic and glutamic acids, and glutamine. A high proportion of radioactivity remained in glucose. Under hypoxia, alanine increased in amount but decreased in specific activity, and the specific activities of the other strongly labelled amino acids decreased. The proportion of the total radioactivity found in glucose and lactate increased. During picrotoxin and pentylenetetrazol convulsions, changes occurred which were similar to those under hypoxia. After aminooxyacetic acid administration, the well-known great increase in γ-aminobutyric acid level was found to be accompanied by a decrease in glutamate and also in aspartic acid and alanine, indicating inhibition of the three transaminases concerned. The previously observed brief rapid postmortem increase in the amount of γ-aminobutyric acid was confirmed; alanine also increased briefly but no other amino acid did so. The increased γ-aminobutyric acid had the same specific radioactivity as the original but the extra alanine was less radioactive than the original. When the γ-aminobutyric acid level had been increased by administration of aminooxyacetic acid, the rapid postmortem increase did not occur.

scholarly journals Amino acid transporter (AAT) gene family in foxtail millet (Setaria italica L.): widespread family expansion, functional differentiation, roles in quality formation and response to abiotic stresses

BMC Genomics ◽  
2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Yang Yang ◽  
Yongmao Chai ◽  
Jiayi Liu ◽  
Jie Zheng ◽  
Zhangchen Zhao ◽  
...  
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Gene Family ◽  
Abiotic Stresses ◽  
Foxtail Millet ◽  
Functional Differentiation ◽  
Setaria Italica ◽  
Evolutionary Features ◽  
Sequence Characteristics ◽  
Quality Formation

Abstract Background Amino acid transporters (AATs) plays an essential roles in growth and development of plants, including amino acids long-range transport, seed germination, quality formation, responsiveness to pathogenic bacteria and abiotic stress by modulating the transmembrane transfer of amino acids. In this study, we performed a genome-wide screening to analyze the AAT genes in foxtail millet (Setaria italica L.), especially those associated with quality formation and abiotic stresses response. Results A total number of 94 AAT genes were identified and divided into 12 subfamilies by their sequence characteristics and phylogenetic relationship. A large number (58/94, 62%) of AAT genes in foxtail millet were expanded via gene duplication, involving 13 tandem and 12 segmental duplication events. Tandemly duplicated genes had a significant impact on their functional differentiation via sequence variation, structural variation and expression variation. Further comparison in multiple species showed that in addition to paralogous genes, the expression variations of the orthologous AAT genes also contributed to their functional differentiation. The transcriptomic comparison of two millet cultivars verified the direct contribution of the AAT genes such as SiAAP1, SiAAP8, and SiAUX2 in the formation of grain quality. In addition, the qRT-PCR analysis suggested that several AAT genes continuously responded to diverse abiotic stresses, such as SiATLb1, SiANT1. Finally, combined with the previous studies and analysis on sequence characteristics and expression patterns of AAT genes, the possible functions of the foxtail millet AAT genes were predicted. Conclusion This study for the first time reported the evolutionary features, functional differentiation, roles in the quality formation and response to abiotic stresses of foxtail millet AAT gene family, thus providing a framework for further functional analysis of SiAAT genes, and also contributing to the applications of AAT genes in improving the quality and resistance to abiotic stresses of foxtail millet, and other cereal crops.

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.

scholarly journals Oxygen reactivity with pyridoxal 5′-phosphate enzymes: biochemical implications and functional relevance

Amino Acids ◽  
2020 ◽  
Vol 52 (8) ◽  
pp. 1089-1105 ◽  
Author(s):  
Giovanni Bisello ◽  
Carmen Longo ◽  
Giada Rossignoli ◽  
Robert S. Phillips ◽  
Mariarita Bertoldi
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Human Health ◽  
Carbonyl Compounds ◽  
Aminobutyric Acid ◽  
Reaction Pathways ◽  
Oxidative Reactions ◽  
Reaction Specificity ◽  
Functional Relevance ◽  
Oxygen Reactivity

Abstract The versatility of reactions catalyzed by pyridoxal 5′-phosphate (PLP) enzymes is largely due to the chemistry of their extraordinary catalyst. PLP is necessary for many reactions involving amino acids. Reaction specificity is controlled by the orientation of the external aldimine intermediate that is formed upon addition of the amino acidic substrate to the coenzyme. The breakage of a specific bond of the external aldimine gives rise to a carbanionic intermediate. From this point, the different reaction pathways diverge leading to multiple activities: transamination, decarboxylation, racemization, elimination, and synthesis. A significant novelty appeared approximately 30 years ago when it was reported that some PLP-dependent decarboxylases are able to consume molecular oxygen transforming an amino acid into a carbonyl compound. These side paracatalytic reactions could be particularly relevant for human health, also considering that some of these enzymes are responsible for the synthesis of important neurotransmitters such as γ-aminobutyric acid, dopamine, and serotonin, whose dysregulation under oxidative conditions could have important implications in neurodegenerative states. However, the reactivity of PLP enzymes with dioxygen is not confined to mammals/animals. In fact, some plant PLP decarboxylases have been reported to catalyze oxidative reactions producing carbonyl compounds. Moreover, other recent reports revealed the existence of new oxidase activities catalyzed by new PLP enzymes, MppP, RohP, Ind4, CcbF, PvdN, Cap15, and CuaB. These PLP enzymes belong to the bacterial and fungal kingdoms and are present in organisms synthesizing bioactive compounds. These new PLP activities are not paracatalytic and could only scratch the surface on a wider and unexpected catalytic capability of PLP enzymes.

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