Studies of the pathway of HCN formation from glycine in a psychrophilic basidiomycete

1977 ◽  
Vol 55 (15) ◽  
pp. 2065-2069 ◽  
Author(s):  
E. W. B. Ward ◽  
A. N. Starratt ◽  
J. R. Robinson
Keyword(s):  
Amino Acids ◽  
Aspartic Acid ◽  
Glyoxylic Acid

Eleven [14C]-labeled amino acids were tested for their ability to serve as precursors of HCN in cultures of a psychrophilic basidiomycete. Only glycine and, to a much lesser degree, L-serine and L-aspartic acid were effective. By using [2-14C, 15N]glycine, it was demonstrated that the C–N bond remains intact during the conversion to HCN. No evidence was obtained for the participation of N-hydroxyglycine or glyoxylic acid oxime as intermediates in the pathway of HCN formation.

OBSERVATIONS ON THE ENZYMATIC DEGRADATION AND CONVERSION OF CERTAIN L- AND D-AMINO ACIDS BY AN EFFECTIVE STRAIN OF RHIZOBIUM MELILOTI

1955 ◽  
Vol 1 (9) ◽  
pp. 743-748 ◽  
Author(s):  
D. C. Jordan
Keyword(s):  
Amino Acids ◽  
Glutamic Acid ◽  
Aspartic Acid ◽  
Rhizobium Meliloti ◽  
Effective Strain ◽  
Glyoxylic Acid ◽  
Amino Group ◽  
Intact Cells ◽  
Ammonia Recovery ◽  
Probable Occurrence

Washed intact cells of an effective strain of Rhizobium meliloti oxidatively deaminated glycine and the L- and D-isomers of a number of amino acids. The interpretation of the data concerning ammonia recovery was complicated, however, by the probable occurrence of transamination and assimilation. Glyoxylic acid, produced by removal of the glycine amino group, was isolated as the corresponding dinitrophenylhydrazone. No anaerobic decarboxylation of glutamic acid or histidine was observed. Cell-free extracts synthesized glutamic acid from α-ketoglutaric acid when glycine, L-histidine, D-aspartic acid, or D-valine acted as amino-group donors. In addition, acetone-dried cells formed alanine from D-aspartic acid and pyruvate. Alanine racemase activity was detected in cell-free extracts and acetone-dried cells, but racemization of aspartic or glutamic acids did not occur. L-glutamic acid, formed by cell-free extracts in mixtures containing D-aspartic and α-ketoglutaric acids, may have been produced by a series of three coupled reactions involving racemization and L-and D-amino acid transamination.

TRANSFORMATION DE L'ACIDE γ-HYDROXYGLUTAMIQUE EN ALANINE ET EN ACIDE GLYOXYLIQUE

1961 ◽  
Vol 39 (10) ◽  
pp. 1595-1603 ◽  
Author(s):  
L. P. Bouthillier ◽  
Y. Binette ◽  
G. Pouliot
Keyword(s):  
Amino Acids ◽  
Comparative Study ◽  
Glutamic Acid ◽  
Aspartic Acid ◽  
Glyoxylic Acid ◽  
Racemic Mixture ◽  
Animal Tissues ◽  
Direct Formation ◽  
Liver Homogenates

A method is described for the synthesis of γ-hydroxyglutamic-5-C14 acid (racemic mixture). Doses of this substance were administered intraperitoneally to rats and among the amino acids isolated from the tissue proteins, glycine showed the highest radioactivity. This finding is compatible with the postulated theory that γ-hydroxyglutamic acid may be cleaved with the formation of alanine and glyoxylic acid, the latter being normally converted into glycine by amination in the animal tissues. Following the incubation of γ-hydroxyglutamic-5-C14 acid and also γ-hydroxyglutamic-2-C14 acid in the presence of rat liver homogenates, evidence was obtained, by the carrier technique, for the direct formation of radioactive glyoxylic acid and alanine; no trace of glutamic acid or aspartic acid could be detected in the incubation media. As a result of a comparative study of the breakdown in vitro of the racemates of γ-hydroxyglutamic-5-C14 acid, it was found that the isomers of erythro-DL-γ-hydroxyglutamic acid are utilized to a much greater extent than the isomers of threo-DL-γ-hydroxyglutamic acid.

Enzymatic Synthesis of 15N-L-aspartic Acid Using Recombinant Aspartase from Escherichia Coli K12

2008 ◽  
Vol 59 (11) ◽  
Author(s):  
Iulia Lupan ◽  
Sergiu Chira ◽  
Maria Chiriac ◽  
Nicolae Palibroda ◽  
Octavian Popescu
Keyword(s):  
Amino Acids ◽  
Aspartic Acid ◽  
Enzymatic Synthesis ◽  
Large Scale ◽  
Recombinant Dna ◽  
Industrial Enzymes ◽  
Recombinant Dna Technology ◽  
Bacterial Fermentation ◽  
Natural Protein ◽  
Novel Method

Amino acids are obtained by bacterial fermentation, extraction from natural protein or enzymatic synthesis from specific substrates. With the introduction of recombinant DNA technology, it has become possible to apply more rational approaches to enzymatic synthesis of amino acids. Aspartase (L-aspartate ammonia-lyase) catalyzes the reversible deamination of L-aspartic acid to yield fumaric acid and ammonia. It is one of the most important industrial enzymes used to produce L-aspartic acid on a large scale. Here we described a novel method for [15N] L-aspartic synthesis from fumarate and ammonia (15NH4Cl) using a recombinant aspartase.

Post-proline endopeptidase, further characterization of the enzyme from pig kidneys

1984 ◽  
Vol 49 (8) ◽  
pp. 1846-1853 ◽  
Author(s):  
Karel Hauzer ◽  
Tomislav Barth ◽  
Linda Servítová ◽  
Karel Jošt
Keyword(s):  
Amino Acids ◽  
Aspartic Acid ◽  
Ion Exchange Chromatography ◽  
Exchange Chromatography ◽  
Relative Molecular Mass ◽  
Enzyme Molecule ◽  
Thiol Compounds ◽  
Modified Method ◽  
N Terminus

A post-proline endopeptidase (EC 3.4.21.26) was isolated from pig kidneys using a modified method described earlier. The enzyme was further purified by ion exchange chromatography on DEAE-Sephacel. The final product contained about 95% of post-proline endopeptidase. The enzyme molecule consisted of one peptide chain with a relative molecular mass of 65 600 to 70 000, containing a large proportion of acidic and alifatic amino acids (glutamic acid, aspartic acid and leucine) and the N-terminus was formed by aspartic acid or asparagine. In order to prevent losses of enzyme activity, thiol compounds has to be added.

The potential mechanism of atmospheric new particle formation involving amino acids with multiple functional groups

2021 ◽  
Author(s):  
Jiarong Liu ◽  
Ling Liu ◽  
Hui Rong ◽  
Xiuhui Zhang
Keyword(s):  
Amino Acids ◽  
Aspartic Acid ◽  
Functional Groups ◽  
Atmospheric Aerosols ◽  
Potential Role ◽  
Particle Formation ◽  
Potential Mechanism ◽  
New Particle Formation

Amino acids are recognized as significant components of atmospheric aerosols. However, its potential role in the atmospheric new particle formation (NPF) is poorly understood, especially aspartic acid (ASP), one of...

The Xylem Sap of Maize Roots: Its Collection, Composition and Formation

1988 ◽  
Vol 15 (4) ◽  
pp. 557 ◽  
Author(s):  
MJ Canny ◽  
ME Mccully
Keyword(s):  
Amino Acids ◽  
Organic Acids ◽  
Organic Acid ◽  
Aspartic Acid ◽  
Xylem Sap ◽  
Great Variability ◽  
Reduced Pressure ◽  
Transpiration Stream ◽  
Maize Roots ◽  
Total Amino Acids

Three methods of sampling xylem sap of maize roots were compared: sap bleeding from the stem cut just above the ground; sap bleeding from the cut tops of roots still undisturbed in the ground; and sap aspirated from excavated roots under reduced pressure. The bleeding saps were often unobtainable. When their composition was measured with time from cutting, the concentrations of the major solutes approximately doubled in 2 h. Aspirated sap was chosen as the most reliable sample of root xylem contents. Solute concentrations of the saps showed great variability between individual roots for all solutes, but on average the concentrations found (in �mol g-1 sap) were: total amino acids, 1.8; nitrate, 1.8; sugars (mainly sucrose), 5.4; total organic acids, 18.3. Individual amino acids also varied greatly between roots. Glutamine, aspartic acid and serine were generally most abundant. The principal organic acid found was malic, approximately 8 �mol g-1. From these analyses the ratios of carbon in the fractions (sugars : amino acids : organic acids) = (44 : 6 : 50). 14Carbon pulse fed to a leaf appeared in the root sap within 30 min, rose to a peak at 4-6 h, and declined slowly over a week. During all this time the neutral, cation and anion fractions were sensibly constant in the proportions 86 : 10 : 4. The 14C therefore did not move towards the equilibrium of 12C-compounds in the sap. It is argued that the results do not support a hypothesis of formation of amino carbon from recent assimilate and reduced nitrate in the roots and an export of this to the shoot in the transpiration stream.

scholarly journals Transforming growth factor alpha: mutation of aspartic acid 47 and leucine 48 results in different biological activities.

1988 ◽  
Vol 8 (3) ◽  
pp. 1247-1252 ◽  
Author(s):  
E Lazar ◽  
S Watanabe ◽  
S Dalton ◽  
M B Sporn
Keyword(s):  
Amino Acids ◽  
Biological Activity ◽  
Amino Acid ◽  
Growth Factor ◽  
Aspartic Acid ◽  
Transforming Growth Factor ◽  
Biologically Active ◽  
Single Amino Acid ◽  
Transforming Growth Factor Alpha ◽  
Factor Alpha

To study the relationship between the primary structure of transforming growth factor alpha (TGF-alpha) and some of its functional properties (competition with epidermal growth factor (EGF) for binding to the EGF receptor and induction of anchorage-independent growth), we introduced single amino acid mutations into the sequence for the fully processed, 50-amino-acid human TGF-alpha. The wild-type and mutant proteins were expressed in a vector by using a yeast alpha mating pheromone promoter. Mutations of two amino acids that are conserved in the family of the EGF-like peptides and are located in the carboxy-terminal part of TGF-alpha resulted in different biological effects. When aspartic acid 47 was mutated to alanine or asparagine, biological activity was retained; in contrast, substitutions of this residue with serine or glutamic acid generated mutants with reduced binding and colony-forming capacities. When leucine 48 was mutated to alanine, a complete loss of binding and colony-forming abilities resulted; mutation of leucine 48 to isoleucine or methionine resulted in very low activities. Our data suggest that these two adjacent conserved amino acids in positions 47 and 48 play different roles in defining the structure and/or biological activity of TGF-alpha and that the carboxy terminus of TGF-alpha is involved in interactions with cellular TGF-alpha receptors. The side chain of leucine 48 appears to be crucial either indirectly in determining the biologically active conformation of TGF-alpha or directly in the molecular recognition of TGF-alpha by its receptor.

Synthesis and characterization of poly(aspartic acid) derivatives conjugated with various amino acids

2010 ◽  
Vol 18 (5) ◽  
pp. 881-890 ◽  
Author(s):  
Ji-Heung Kim ◽  
Chang Mo Son ◽  
Young Sil Jeon ◽  
Woo-Seok Choe
Keyword(s):  
Amino Acids ◽  
Aspartic Acid ◽  
Synthesis And Characterization

scholarly journals Utilization in vivo of glucose and volatile fatty acids by sheep brain for the synthesis of acidic amino acids

1966 ◽  
Vol 101 (3) ◽  
pp. 591-597 ◽  
Author(s):  
R M O'Neal ◽  
R E Koeppe ◽  
E I Williams
Keyword(s):  
Amino Acids ◽  
Fatty Acids ◽  
Glutamic Acid ◽  
Aspartic Acid ◽  
Free Amino Acids ◽  
Free Amino ◽  
Specific Activity ◽  
Tricarboxylic Acid Cycle ◽  
Sheep Brain ◽  
The Brain

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.

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