Transamination, deamidation, and the utilisation of asparagine amino nitrogen in pea leaves

1985 ◽  
Vol 63 (5) ◽  
pp. 881-884 ◽  
Author(s):  
Trung Chanh Ta ◽  
Kenneth W. Joy
Keyword(s):  
Amino Acids ◽  
Nitrogen Cycle ◽  
Amino Nitrogen ◽  
Amide Group ◽  
Leaf Expansion ◽  
Amino Group ◽  
Direct Transfer ◽  
Presence And Absence ◽  
Similar Decrease

The fate of 15N from the amino group of labelled asparagine was followed in growing pea leaves, in the presence and absence of inhibitors of deamidation (DONV, 5-diazo-4-oxo-L-norvaline) and transamination (AOA, aminooxyacetate). The label was widely incorporated into various amino acids, especially aspartate, glutamate, alanine, and homoserine, as well as glycine and serine. Treatment with AOA considerably decreased the label of all these amino acids except aspartate, consistent with the production of the latter by deamidation of asparagine. This was confirmed by the use of DONV, which decreased aspartate labelling by over 70%; a similar decrease in glutamate labelling suggested that the latter was labelled predominantly by transamination of aspartate. In contrast, DONV had a much smaller effect on the labelling of alanine, homoserine, glycine, and serine, indicating a direct transfer of amino nitrogen from asparagine, rather than transfer from aspartate (or glutamate). The labelling of glycine and serine and the transfer of amino nitrogen to ammonia and glutamine (amide group) were consistent with a flow of asparagine nitrogen into the photorespiratory nitrogen cycle. During leaf expansion there was a decrease in the amount of asparagine metabolised, and a decreasing participation of deamidation as the leaf matured.

The Ion Associates of Methyl-, Ethyl- and Isopropyl Derivatives of Dialkylaminoethyl Dialkylamidofluorophosphate with Bromophenol Blue

1992 ◽  
Vol 57 (1) ◽  
pp. 56-63 ◽  
Author(s):  
Emil Halámek ◽  
Zbyněk Kobliha
Keyword(s):  
Extraction Efficiency ◽  
Ion Pairs ◽  
Amino Nitrogen ◽  
Ion Pair ◽  
Amide Group ◽  
Bromophenol Blue ◽  
Amino Group ◽  
Methyl Ethyl ◽  
Derivatives Of

Nine new Tammelin esters were studied on the basis of the chloroform extracts of their ion associates with bromophenol blue. A study was made of the effect of the alkyl on the amino and amido groups of dialkylaminoethyl dialkylamidofluorophosphate and on the extraction efficiency of the ion pair. An increase in the number of carbon atoms on the amide group leads to the increase in the extraction efficiency of the ion pairs as a consequence of the increasing hydrophobicity. A further contribution to the increase in the extraction efficiency with increasing number of carbon atoms in the alkyls of the amino nitrogen is clearly retarded by the increasing basicity of the amino group. An extraction spectrophotometric determination of the test derivatives of dialkylaminoethyl dialkylamidofluorophosphate was developed and the interferences from precursors in the synthesis were examined.

scholarly journals The fate of amino acids in isolated perfused livers of developing sheep

1979 ◽  
Vol 42 (3) ◽  
pp. 467-476 ◽  
Author(s):  
P. M. J. Savan ◽  
Majorie K. Jeacock ◽  
D. A. L. Shepherd
Keyword(s):  
Amino Acids ◽  
Oxygen Consumption ◽  
N Uptake ◽  
Amino Nitrogen ◽  
Casein Hydrolysate ◽  
Unit Weight ◽  
Substrate Uptake ◽  
Urea Production ◽  
Presence And Absence ◽  
Made In

1. In order to establish whether or not there is a change in the relative rates of anabolism and catabolism of amino acids in the livers of lambs as they mature, a study has been made in isolated perfused livers obtained from foetal, suckling and ruminating lambs. The livers were perfused in a recirculating system and a mixture of amino acids (casein hydrolysate) was infused as substrate in the presence and absence of glucagon.2. The oxygen consumption of the livers per unit weight increased as the lambs matured but the uptake of α-amino nitrogen declined. A comparison of the rates of O2 consumption and substrate uptake indicated that in foetal lambs less than 20% of the amino acids could have been oxidized, whereas in ruminating lambs all the amino acids taken up could have been oxidized.3. In livers obtained from foetal lambs, the rate of urea production per unit weight of liver was approximately double that observed in ruminating lambs. Comparison of the rate of urea production and α-NH2-N uptake indicated that more than 60% of the substrate uptake was used for non-catabolic processes in the foetal lambs, whereas in ruminating animals all the α-NH2-N taken up could be accounted for as urea.4. Gluconeogenesis could not be detected in lambs at any age studied and glucagon had no effect on any of the parameters studied.

scholarly journals BIOCHEMICAL STUDIES ON SHOCK

1944 ◽  
Vol 79 (1) ◽  
pp. 9-22 ◽  
Author(s):  
Frank L. Engel ◽  
Helen C. Harrison ◽  
C. N. H. Long
Keyword(s):  
Blood Pressure ◽  
Amino Acids ◽  
Oxygen Saturation ◽  
Hepatic Artery ◽  
Arterial Oxygen Saturation ◽  
Amino Nitrogen ◽  
Arterial Oxygen ◽  
High Positive Correlation ◽  
Peripheral Tissues ◽  
Arterial Blood

1. In a series of rats subjected to hemorrhage and shock a high negative correlation was found between the portal and peripheral venous oxygen saturations and the arterial blood pressure on the one hand, and the blood amino nitrogen levels on the other, and a high positive correlation between the portal and the peripheral oxygen saturations and between each of these and the blood pressure. 2. In five cats subjected to hemorrhage and shock the rise in plasma amino nitrogen and the fall in peripheral and portal venous oxygen saturations were confirmed. Further it was shown that the hepatic vein oxygen saturation falls early in shock while the arterial oxygen saturation showed no alteration except terminally, when it may fall also. 3. Ligation of the hepatic artery in rats did not affect the liver's ability to deaminate amino acids. Hemorrhage in a series of hepatic artery ligated rats did not produce any greater rise in the blood amino nitrogen than a similar hemorrhage in normal rats. The hepatic artery probably cannot compensate to any degree for the decrease in portal blood flow in shock. 4. An operation was devised whereby the viscera and portal circulation of the rat were eliminated and the liver maintained only on its arterial circulation. The ability of such a liver to metabolize amino acids was found to be less than either the normal or the hepatic artery ligated liver and to have very little reserve. 5. On complete occlusion of the circulation to the rat liver this organ was found to resist anoxia up to 45 minutes. With further anoxia irreversible damage to this organ's ability to handle amino acids occurred. 6. It is concluded that the blood amino nitrogen rise during shock results from an increased breakdown of protein in the peripheral tissues, the products of which accumulate either because they do not circulate through the liver at a sufficiently rapid rate or because with continued anoxia intrinsic damage may occur to the hepatic parenchyma so that it cannot dispose of amino acids.

MATHEMATICAL MODELS FOR THE SYNTHESIS OF PLANT-BASED COMPOSITIONS WITH IMPROVED AMINO ACID COMPOSITION

2021 ◽  
Author(s):  
Irina Gaivoronskaya ◽  
Valenitna Kolpakova
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Mathematical Models ◽  
Functional Properties ◽  
Amino Nitrogen ◽  
Essential Amino Acids ◽  
Major Allergen ◽  
Structural Features ◽  
Covalent Bonds ◽  
Pea Protein

The aim of the work was to optimize the process of obtaining multicomponent protein compositions with high biological value and higher functional properties than the original vegetable protein products. Was realized studies to obtain biocomposites on the base of pea protein-oat protein and pea protein-rice protein. Developed composites were enriched with all limited amino acids. For each of the essential amino acids, the amino acid score was 100% and higher. Protein products used in these compositions are not in major allergen list, which allows to use these compositions in allergen-free products and specialized nutrition. To determine biosynthesis parameters for compositions from pea protein and various protein concentrates with the use of transglutaminase enzyme, was studied effect of concentration and exposition time on the amount of amino nitrogen released during the reaction. Decreasing of amino nitrogen in the medium indicated the occurrence of a protein synthesis reaction with the formation of new covalent bonds. Were determined optimal parameters of reaction: the hydromodule, the exposure time, the concentration of EP of the preparation, were obtained mathematical models. Studies on the functional properties of composites, the physicochemical properties of the proteins that make up their composition, and structural features will make it possible to determine the uses in the manufacture of food products based on their ability to bind fat, water, form foam, gels, and etc.

Special transport and neurological significance of two amino acids in a configuration conventionally designated as D.

1994 ◽  
Vol 196 (1) ◽  
pp. 297-305 ◽  
Author(s):  
H N Christensen ◽  
A A Greene ◽  
D K Kakuda ◽  
C L MacLeod
Keyword(s):  
Amino Acids ◽  
Receptor Site ◽  
Amino Group ◽  
Carboxylate Group ◽  
Gamma Aminobutyric Acid ◽  
Imino Group ◽  
Group A ◽  
The Central Nervous System ◽  
Lower Homolog ◽  
Alpha Amino Acid

We point out an ability of certain amino acids to be recognized at a biological receptor site as though their amino group bore, instead of an alpha relationship to a carboxylate group, a beta, gamma or delta relationship to the same or a second carboxylate group. For aspartate, the unbalanced position of its amino group between a pair of carboxylates allows its occasional biorecognition as a beta-rather than as an alpha-amino acid, whereas for proline and its homologs, their cyclic arrangement may allow the imino group, without its being replicated, to be sensed analogously as falling at either of two distances from the single carboxylate group. The greater separation might allow proline to be seen as biologically analogous to gamma-aminobutyric acid. This more remote positioning of the imino group would allow the D-form of both amino acids to present its amino group in the orientation characteristic of the natural L-form. The dual modes of recognition should accordingly be signalled by what appears to be low stereospecificity, actually due to a distinction in the enantiorecognition of the two isomers. Competing recognition for transport between their respective D- and L-forms, although it does not prove that phenomenon, has been shown for proline and, significantly, even more strongly for its lower homolog, 2-azetidine carboxylate. Such indications have so far revealed themselves rather inconspicuously for the central nervous system binding of proline, reviewed here as a possible feature of a role suspected for proline in neurotransmission.

The influence of diet on the nitrogenous components passing to the duodenum and through the lower ileum of sheep

1966 ◽  
Vol 166 (1002) ◽  
pp. 63-79 ◽  
Keyword(s):  
Amino Acids ◽  
Glutamic Acid ◽  
Nitrogen Content ◽  
Aspartic Acid ◽  
Total Nitrogen ◽  
Amino Nitrogen ◽  
Terminal Part ◽  
High Nitrogen ◽  
Low Nitrogen ◽  
Lower Ileum

Analyses of the alimentary contents flowing to the duodenum of sheep during 24 h show that when the sheep are consuming a low-nitrogen diet more total nitrogen and amino nitrogen pass to the duodenum than are eaten daily in the food whereas when the sheep are eating high nitrogen diets, less total nitrogen and less amino nitrogen pass to the duodenum. The disparity between the total nitrogen and amino nitrogen content of the diets largely disappeared by the time the alimentary contents reached the terminal part of the ileum. From 64 to 68% of the nitrogen entering the duodenum and 54 to 64% of the nitrogen in the ileal contents was in the form of amino nitrogen. Proportionately more of the amino nitrogen was in solution in the ileal contents than in the duodenal contents. Losses of amino acids in the stomach when a high-nitrogen diet was consumed were especially large for glutamic acid, aspartic acid, proline, arginine and leucine. They were least for cystine and threonine. Gains of amino acids in the stomach when low nitrogen diets were consumed were all substantial except for proline, where a loss was found when hay and flaked maize were given. When these changes are considered as proportions of the quantities eaten then trends are similar for all acids. Changes in the molar proportions of the amino acids present in hydrolysates of the duodenal and ileal contents are discussed together with the significance of these changes in relation to the nutrition of the sheep.

ChemInform Abstract: 3,5-Dinitro-1-(4-nitrophenyl)-4-pyridone as a Novel Protecting Reagent for the Amino Group in L-Amino Acids. Part 2.

1983 ◽  
Vol 14 (25) ◽  
Author(s):  
E. MATSUMURA ◽  
H. OKA ◽  
N. KAMAKURA ◽  
Y. HEIKE ◽  
M. ARIGA ◽  
...  
Keyword(s):  
Amino Acids ◽  
Amino Group

Quantitative Method for Estimating Fecal Amino Acids

1975 ◽  
Vol 21 (10) ◽  
pp. 1437-1440 ◽  
Author(s):  
Christopher W I Owens ◽  
Walfredo Padovan
Keyword(s):  
Amino Acids ◽  
Ion Exchange ◽  
Column Chromatography ◽  
Quantitative Method ◽  
Normal Values ◽  
Amino Nitrogen ◽  
Exchange Column ◽  
Ion Exchange Column ◽  
Fresh Stool

Abstract We describe a method for quantitatively estimating 24 ninhydrin-reacting substances, including the commoner amino acids, in fecal dialysate prepared from ingested dialysis bags retrieved from fresh stool. It is accurate to 2 µmol of α-amino nitrogen per liter of fecal dialysate, and for most substances recovery of added standards is 100%. It involves dilution, ultrafiltration, and automated ion-exchange column chromatography of the dialysate. Some normal values are provided.

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