scholarly journals Theoretical Inversion of Amino Acids (Alanine and Aspartic Acid) by Semi-Empirical Methods

Author(s):  
Musa E. Mohamed

The inversion reaction coordinate of free amino acids (alanine, aspartic acid) have been computationally calculated by semi-empirical methods AM1. A transition state for free alanine and aspartic acid were obtained as a three membered ring in which the α-C-H and α-C-CH3 are slightly elongated, 1.2 and 2.17 Å respectively in the alanine transition state. The activation energy of alanine is 77.52 kcal/mol in the gas phase and 76.66 kcal/mol in aqueous phase, and for aspartic acid is 54.87 kcal/mol in the gas phase and 50.86 kcal/mol in aqueous phase.

1966 ◽  
Vol 101 (3) ◽  
pp. 591-597 ◽  
Author(s):  
R M O'Neal ◽  
R E Koeppe ◽  
E I Williams

1. Free glutamic acid, aspartic acid, glutamic acid from glutamine and, in some instances, the glutamic acid from glutathione and the aspartic acid from N-acetyl-aspartic acid were isolated from the brains of sheep and assayed for radioactivity after intravenous injection of [2-(14)C]glucose, [1-(14)C]acetate, [1-(14)C]butyrate or [2-(14)C]propionate. These brain components were also isolated and analysed from rats that had been given [2-(14)C]propionate. The results indicate that, as in rat brain, glucose is by far the best precursor of the free amino acids of sheep brain. 2. Degradation of the glutamate of brain yielded labelling patterns consistent with the proposal that the major route of pyruvate metabolism in brain is via acetyl-CoA, and that the short-chain fatty acids enter the brain without prior metabolism by other tissue and are metabolized in brain via the tricarboxylic acid cycle. 3. When labelled glucose was used as a precursor, glutamate always had a higher specific activity than glutamine; when labelled fatty acids were used, the reverse was true. These findings add support and complexity to the concept of the metabolic; compartmentation' of the free amino acids of brain. 4. The results from experiments with labelled propionate strongly suggest that brain metabolizes propionate via succinate and that this metabolic route may be a limited but important source of dicarboxylic acids in the brain.


1979 ◽  
Vol 6 (2) ◽  
pp. 88-92 ◽  
Author(s):  
Allan R. Hovis ◽  
Clyde T. Young ◽  
Cedric W. Kuhn

Abstract Peanut (Arachis hypogaea L.) cultivars (Starr and Florunner) and four peanut introductions (PI 261945, 261946, 261973, and 261980) were each separately inoculated with a mild strain (M2) and with the necrosis strain (N) of peanut mottle virus. The effects of these viral strains on the chemical composition of peanut seed were evaluated. The chemical characteristics varied with the type of viral infection. The greatest effect was on fatty acids and the least on the total amino acids. In general, peanuts infected with the necrosis strain showed: (1) a decrease in the percentages of stearic and oleic acids, while linoleic, arachidic, behenic, and lignoceric acids increased, (2) increases in the levels of the free amino acids glycine, alanine, isoleucine, histidine, lysine, and arginine, and (3) the total amino acids exhibited a slight decrease in aspartic acid and a slight increase in methionine. Peanuts infected with the mild strain generallly showed: (1) a slight increase in linoleic acid, (2) little effect on the free amino acids, and (3) a small increase in tyrosine and a slight decrease in serine and aspartic acid for the total amino acids. No treatment effect was noted on protein content.


Author(s):  
Musa E. Mohamed ◽  
Abdelhafeez M.A. Mohammed

Vibrational studies of amino acids experimentally and theoretically have been performed. The Semi-empirical methods optimization by PM6 and RM1 on the l- and d-amino acids (alanine, phenylalanine, aspartic and glutamic acid), showed no difference in energy between l-and d-isomers. The vibrational frequencies were calculated by semi-emprical methods (PM6 and RM1) and Ab Initio methods (B3LYP/6-31+G(d) and were scaled down by factors of 0.925 (RM1), 1.09 (PM6) and 0.89 (B3LYP/6-31+G(d)). The calculated and experimental vibrational frequencies have shown good general agreement.


1996 ◽  
Vol 44 (1) ◽  
pp. 43-48 ◽  
Author(s):  
S.C. Agrawal ◽  
U.K. Sharma

Westiellopsis prolifica Janet and Chaetophora attenuata Hazen cultures released sugars (glucose, fructose, and sucrose), organic acids (oxaloacetic acid and oxalic acid), amino acids, and protein. W. prolifica cultures released the amino acids glycine, serine, cystine, glutamic acid, aspartic acid, and α-alanine, while C. attenuata cultures released glycine, serine, aspartic acid, and α-alanine. W. prolifica and C. attenuata cultures of all ages released more extracellular protein than total free amino acids. Cultures of C. attenuata released more protein than cultures of the same age of W. prolifica. The filtrates from old cultures of W. prolifica and C. attenuata decreased the total chlorophyll content of all algae tested, totally suppressed conjugation in Spirogyra decimino and zoospore formation in C. attenuata, and drastically decreased spore germination in W. prolifica, thus producing stressful conditions affecting the growth and reproduction of these and other algae.


1975 ◽  
Vol 21 (3) ◽  
pp. 414-417 ◽  
Author(s):  
Yasuyuki Doi ◽  
Akikatsu Kataura

Abstract Free amino acids in the tonsils of 20 individuals were measured column chromatographically. Those always found in readily detectable amounts included O-phosphoserine, taurine, O-phosphoethanolamine, aspartic acid, hydroxyproline, threonine, serine, glutamic acid, proline, glycine, alanine, α-amino-n-butyric acid, valine, cystine, methionine, isoleucine, leucine, tyrosine, phenylalanine, ornithine, γ-amino-butyric acid, lysine, histidine, and arginine. Results were compared for three clinical pathological groups and for four age groups. Some abnormal values may result from the pathological conditions.


1978 ◽  
Vol 234 (4) ◽  
pp. F325-F331 ◽  
Author(s):  
T. N. Pullman ◽  
F. A. Carone ◽  
S. Oparil ◽  
S. Nakamura

[14C]angiotensin II ([14C]AII) was microinjected alone or with excess L-isoleucine (IIe) or L-aspartic acid (Asp) into renal tubules of anesthetized rats. Urinary excretion of 14C-labeled material was measured, and the intact peptide and its metabolites were identified and quantified. When isoleucine was administered with [14C]AII, urinary recovery of the 14C-labeled material increased directly with distance of infusion site from glomerulus, and most of the radioactivity in urine was [14C]Ile. The data suggest that isoleucine interfered with reabsorption of [14C]Ile derived from hydrolysis of [14C]AII and less so with the hydrolysis itself. When aspartic acid was administered with [14C]AII into the proximal 5/6 of the proximal convolution, total urinary recovery of the 14C-labeled material was unchanged, but percentage of recovery as [14C]AII increased; with infusion into the distal 1/6 of the proximal convolution, total urinary recovery of the 14C labele increased. The data suggest that aspartic acid interfered with the enzymatic hydrolysis of [14C]AII and reabsorption of isoleucine. In distal tubules the 14C label was almost completely recovered as intact [14C]AII in all protocols. The results show that free amino acids influence proximal tubular handling of small linear peptides in rats.


1959 ◽  
Vol 37 (6) ◽  
pp. 957-964 ◽  
Author(s):  
J. E. J. Habowsky ◽  
R. W. Shuel

The protein constituents of the larval diets of queen and worker honeybees were separated by continuous paper electrophoresis. The electrophoretic patterns of royal jelly of any age and the early worker diet were similar and comprised five ninhydrin-reactive bands or fractions. Fraction 1 (nearest the cathode) contained lysine as a free amino acid. Fractions 3 and 4 appeared to be complex polypeptides. Alanine, asparagine, aspartic acid, glutamic acid, glycine, histidine, isoleucine and/or leucine, lysine, phenylalanine, threonine, tyrosine, valine, and an unidentified substance were found in chromatograms of the acid hydrolyzate of fraction 3; the hydrolyzate of fraction 4 contained the same amino acids except for threonine. Fractions 2 and 5 were not characterized. Electrophoresis of the diet of worker larvae older than 3 days showed a pronounced fading of all bands, attributable to the dilution of the solids by the addition of honey which occurs at this time. There appeared to be no qualitative differences between the protein fractions of royal jelly and worker diet which would account for the differentiation of female honeybees into queens and workers. The decrease with age in the percentage of protein in the worker diet may be significant.


2018 ◽  
Vol 16 (1) ◽  
pp. 833-841 ◽  
Author(s):  
Magdalena Dziągwa-Becker ◽  
Ryszard Weber ◽  
Olga Zajączkowska ◽  
Wiesław Oleszek

AbstractThe purpose of this study was to establish the free amino acids profile of Viola tricolor collected from different habitats in Poland. Viola tricolor (heartsease) is a very popular plant found worldwide, classified both as weed and medicinal plant. Based on a validated method, the following nineteen free amino acids were analyzed using liquid chromatography-electrospray ionization coupled to a triple quadrupole mass spectrometer (LC-ESI-MS/MS):alanine, glycine, leucine, valine, isoleucine, proline, phenylalanine, tryptophan, tyrosine, serine, threonine, methionine, asparagine, glutamine, lysine, arginine, histidine, aspartic acid, glutamic acid. The total free amino acids (TAA) ranged from 9938.0 to 11393.8 mg/kg of fresh weight. The variability of the investigated amino acids with respect to different habitat conditions was statistically assessed using the method of discriminant and cluster analysis. Alanine, valine, glutamine and aspartic acid were the most abundant free amino acids present in both localizations. The ratio of total essential amino acids (EAA) to TAA was 0.27 and 0.11 in Zagródki and Wrocław, respectively. Discriminant analysis has demonstrated that the investigated habitats significantly differentiated the free amino acids content of Viola tricolor. Only methionine showed a similar concentration in both Viola tricolor populations.


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