scholarly journals The Incorporation of 14C from Sodium Acetate-2-14C into the Amino Acids of the Soil-Inhabiting Nematode, caenorhabditis briggsae

1960 ◽  
Vol 37 (3) ◽  
pp. 435-443
Author(s):  
W. L. NICHOLAS ◽  
ELLSWORTH C. DOUGHERTY ◽  
EDER LINDSAY HANSEN ◽  
OSMUND HOLM-HANSEN ◽  
VIVIAN MOSES
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Chick Embryo ◽  
Sodium Acetate ◽  
Liver Extract ◽  
Protein Hydrolysate ◽  
Cysteic Acid ◽  
Caenorhabditis Briggsae ◽  
Adequate Diet ◽  
Chick Embryo Extract

1. The nematode, Caenorhabditis briggsae was cultured axenicaily in a mixture of chick embryo extract, autoclaved liver extract and sodium acetate-2-14C. A protein hydrolysate was prepared from the worms and the eggs which were collected from the cultures. 2. Chromatography and radioautography were carried out in a study of the amino acid composition of the hydrolysate. The following amino acids were found labelled: aspartic acid, glutamic acid, alanine, proline, glycine, serine. Cystein and cystine were oxidized to cysteic acid which was also labelled. The following amino acids were not labelled: arginine, histidine, lysine, methionine, threonine, tyrosine, valine and the combined spot representing phenylalanine, leucine and isoleucine. Tryptophane would have been destroyed by our method of hydrolysis. 3. Since the labelled amino acids are synthesized by the worm, it is suggested, tentatively, that they are not required in an otherwise adequate diet. So far as the unlabelled amino acids are concerned, it is suggested, on the basis of the results of certain culture experiments (published separately) that, with the probable exception of tyrosine, they are essential in the diet of C. briggsae.

scholarly journals Amino acid production in isolated rat liver mitochondria

1973 ◽  
Vol 134 (2) ◽  
pp. 431-436 ◽  
Author(s):  
W. Ferdinand ◽  
W. Bartley ◽  
V. Broomhead
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Amino Acid Composition ◽  
Acid Composition ◽  
Lipid Hydroperoxide ◽  
Liver Mitochondria ◽  
Cysteic Acid ◽  
Rat Liver Mitochondria ◽  
Isolated Mitochondria ◽  
Selective Retention

Amino acid analyses of mitochondrial membranes are compared with the amino acid composition of whole mitochondria (Alberti, 1964) and found to be very similar except in the cystine content. The composition of the endogenous amino acids found in freshly prepared mitochondria has been established and shown to differ considerably from the amino acid composition of membranes or whole mitochondria. The amino acids produced during anaerobic incubation of mitochondria at pH7.4, on the other hand, resemble the membrane in composition, supporting the view that neutral proteinase activity is responsible for their appearance. Aerobic incubation produces a similar pattern of amino acids except that amino acids such as proline, serine, asparagine, glutamic acid and glutamine, which can be metabolically utilized under aerobic conditions, are present to a smaller extent. The presence of large relative concentrations of endogenous taurine, cysteic acid and oxidized glutathione and the accumulation of taurine during incubation is found. The selective retention of taurine and cysteic acid within the mitochondria is established. It is proposed that the first step in the degeneration of isolated mitochondria results from lipid hydroperoxide accumulation caused by the lack of glutathione reductase in isolated mitochondria.

Liver extract and its free amino acids equally stimulate gastric acid secretion

1980 ◽  
Vol 239 (6) ◽  
pp. G493-G496 ◽  
Author(s):  
E. J. Feldman ◽  
M. I. Grossman
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Acid Secretion ◽  
Gastric Acid Secretion ◽  
Free Amino Acid ◽  
Free Amino Acids ◽  
Free Amino ◽  
Liver Extract ◽  
Amino Acid Mixture ◽  
Acid Mixture

Using intragastric titration in dogs with gastric fistulas, dose-response studies were carried out with liver extract and with a mixture of amino acids that matched the free amino acids found in liver extract. All solutions were adjusted to pH 7.0 and osmolality to 290 mosmol x kg-1. Doses are expressed as the sum of the concentrations of all free amino acids. At each dose studied (free amino acid concentration: 2.8, 5.6, 11, 23, and 45 mM), acid secretion in response to the free amino acid mixture was not significantly different from that of liver extract. The peak response to both liver extract and the free amino acid mixture occurred with the 23-mM dose and represented about 60% of the maximal response to histamine. The serum concentrations of gastrin after liver extract and the amino acid mixture were not significantly different. It is concluded that in dogs with gastric fistula, gastric acid secretion and release of gastrin were not significantly different in response to liver extract and to a mixture of amino acids that simulated the free amino acid content of liver extract.

Effect of a Leucine Analogue on Incorporation of Glycine into the Proteins of Explanted Chick Embryos

Development ◽  
1958 ◽  
Vol 6 (2) ◽  
pp. 262-269
Author(s):  
Phyllis W. Schultz ◽  
Heinz Herrmann
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Chick Embryo ◽  
Total Protein ◽  
Nutrient Medium ◽  
Chick Embryos ◽  
Agar Gel ◽  
Egg Extract ◽  
Amino Acid Analogues

Amino acid analogues have been observed to give rise to abnormal forms of development of chick and amphibian embryos (Herrmann, 1953; Rothfels, 1954; Waddington & Sirlin, 1954; Feldman & Waddington, 1955; Herrmann, Rothfels-Konigsberg, & Curry, 1955). Assuming that these disturbances may be due to interference with the utilization of amino acids for protein formation, we have attempted an analysis of this effect by comparison of the protein contents and of the uptake of glycine into the proteins of chick embryo explants in the presence and absence of amino acid analogues. The results of such experiments are reported in this paper. The chick embryos used for explanation, the explantation technique, and the determination of total protein glycine and of tracer glycine were essentially the same as described previously (Herrmann & Schultz, 1958). The embryos were explanted at the 11–13 somite stage on to the surface of an agar gel containing egg extract as nutrient medium following the procedure given by Spratt (1947) as modified by Rothfels (1954).

Selective Chemical Deuteration of Aromatic Amino Acids: A Retrospective

1997 ◽  
Author(s):  
K.S. Matthews ◽  
R. Matthews
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Aromatic Amino Acid ◽  
Protein Hydrolysate ◽  
Aromatic Amino Acids ◽  
Cellular Protein ◽  
Target Protein ◽  
Chemical Methods ◽  
Lactose Repressor ◽  
Selective Deuteration

In 1970 when we began post-doctoral work in the laboratory of Professor Oleg Jardetzky, selective deuteration of proteins to limit the number of protons present in the system for subsequent analysis was a newly developed and effective technique for NMR exploration of protein structure (Crespi et al., 1968; Markley et al., 1968). This approach allowed more facile assignment of specific resonances and generated the potential to follow the spectroscopic behavior of protons for a specific amino acid sidechain over a broad range of conditions. The primary method for labeling at that time involved growth of microorganisms (generally bacteria or algae) in D2O, followed by isolation of the deuteratedamino acids from a cellular protein hydrolysate. The amino acids isolated were, therefore, completely deuterated. Selective deuteration of a target protein was achieved by growing the producing organism on a mixture of completely deuterated and selected protonated amino acids under conditions that minimized metabolic interconversion of the amino acids. In one-dimensional spectra, aromatic amino acid resonances occur well downfield of the aliphatic resonances, and this region can therefore be examined somewhat independently by utilizing a single protonated aromatic amino acid to simplify the spectrum of the protein. However, the multiple spectral lines generated by aromatic amino acids can be complex and overlapping, precluding unequivocal interpretation. To address this complication, chemical methods were developed to both completely and selectively deuterate side chains of the aromatic amino acids, thereby avoiding the costly necessity of growing large volumes of microorganisms in D2O and subsequent tedious isolation procedures. In addition, selective deuteration of the amino acids simplified the resonance patterns and thereby facilitated assignment and interpretation of spectra. The methods employed were based on exchange phenomena reported in the literature and generated large quantities of material for use in growth of microorganisms for subsequent isolation of selectively labeled protein (Matthews et al., 1977a). The target protein for incorporation of the selectively deuterated aromatic amino acids generated by these chemical methods was the lactose repressor protein from Escherichia coli, and greatly simplified spectra of this 150,000 D protein were produced by this approach.

Short-interval absorption and metabolism of some amino acids in Trypanosoma gambiense

Parasitology ◽  
1972 ◽  
Vol 64 (3) ◽  
pp. 379-387 ◽  
Author(s):  
L. H. Chappell ◽  
G. C. Southworth ◽  
C. P. Read
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Short Interval ◽  
Cysteic Acid ◽  
Transaminase Activity ◽  
Glutamate Pyruvate Transaminase ◽  
Glutamate Pyruvate ◽  
High Level ◽  
Rate Limiting ◽  
Trypanosoma Gambiense

During 2 min incubations of Trypanosoma gambiense (bloodstream form) with [U-14C]glucose (1 mM) over 60% of absorbed label was detected in free alanine. In the presence of 12·5 mM unlabelled alanine, the amount of alanine synthesized from glucose was reduced by less than 10%. These data support previous observations on the high level of transaminase activity in African human trypanosomes.Alanine, aspartate and glutamate were metabolized to various other free amino acids whereas a significant amount of label derived from [14C]arginine could not be accounted for by amino acid assay.The sulphur containing amino acids, cysteic acid and taurine, were apparently synthesized from alanine, glutamate and arginine. The significance of these syntheses is poorly understood.Following incubations of trypanosomes for 2 min in exogenous amino acids the internal free pool became imbalanced due to accumulation and metabolism of the substrate amino acid.Evidence obtained indicated that the level of free endogenous glutamate may be rate limiting for the glutamate-pyruvate transaminase system.

scholarly journals Amino acid uptake in isolated chick embryo heart cells. Effect of insulin

1969 ◽  
Vol 114 (1) ◽  
pp. 97-105 ◽  
Author(s):  
G. G. Guidotti ◽  
Britta Lüneburg ◽  
A. F. Borghetti
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Chick Embryo ◽  
Isolated Heart ◽  
Cardiac Cells ◽  
Cell Permeability ◽  
Heart Cells ◽  
Acid Uptake ◽  
Aminoisobutyric Acid ◽  
Isolated Heart Cells

1. The preparation of cell suspensions by treatment of chick embryo hearts with collagenase at various stages of development is described. 2. Measurements of oxygen consumption, incorporation of labelled leucine into protein and accumulation of labelled α-aminoisobutyric acid against a concentration gradient indicated a long-lasting viability of the isolated heart cells in vitro; a satisfactory preservation of subcellular structures, including plasma membrane, was assessed by electron-microscopic examination. 3. The rate of α-aminoisobutyric acid accumulation by cardiac cells isolated from hearts at different stages of embryological development decreased with aging; insulin stimulated the intracellular accumulation of this amino acid analogue. 4. Insulin increased the uptake by isolated heart cells of several 14C-labelled naturally occurring amino acids; however, the fraction of amino acid taken up by the cells that was recovered free intracellularly, and therefore the concentration ratio (between intracellular water and medium), was enhanced by the hormone only with glycine, proline, serine, threonine, histidine and methionine. When isolated heart cells were incubated in the presence of a mixture of labelled amino acids, the addition of insulin increased the disappearance of radioactivity from the medium. 5. The general pattern of amino acid transport (in the absence and in the presence of insulin) in isolated cardiac cells was similar to that found in intact hearts, suggesting that the biological preparation described in this paper might be useful for studies of cell permeability and insulin action.

scholarly journals Homology between a histidine-rich protein from Plasmodium lophurae and a protein associated with the knob-like protrusions on membranes of erythrocytes infected with Plasmodium falciparum.

1980 ◽  
Vol 151 (6) ◽  
pp. 1534-1538 ◽  
Author(s):  
A Kilejian
Keyword(s):  
Amino Acids ◽  
Plasmodium Falciparum ◽  
Amino Acid ◽  
Amino Acid Composition ◽  
Acid Composition ◽  
Immunoelectron Microscopy ◽  
Protein Hydrolysate ◽  
Cross Reactivity ◽  
Plasmodium Lophurae

The incorporation of several radioactive amino acids into the knob protein of Plasmodium falciparum was compared. Histidine showed better incorporation than proline. A protein hydrolysate, which had all major amino acids except histidine and methionine, showed relatively poor incorporation as compared with proline, and no labeling could be detected with methionine or leucine. These results strongly suggest that the amino acid composition of the knob protein has the same peculiarities as that of a histidine-rich protein characterized from P. lophurae. Immunoelectron microscopy suggested possible immunological cross-reactivity between these two proteins.

scholarly journals RELATIONSHIP BETWEEN BITTERNESS OF BREWER’S YEAST HYDROLYSATE AND HYDROPHOBIC AMINO ACID CONTENT

2018 ◽  
Vol 54 (2C) ◽  
pp. 458
Author(s):  
Nguyen Thi Thanh Ngoc
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Acid Content ◽  
Bitter Taste ◽  
Protein Hydrolysate ◽  
Amino Acid Content ◽  
Brewer’S Yeast ◽  
Hydrophobic Amino Acid ◽  
Brewer's Yeast ◽  
Wide Range

Brewer’s yeast spent, obtained after the main fermentation stage, is a rich- in-protein source(protein content accounts for 48 - 50 % dry matter). In order to use efficiently this source, it washydrolysed by different methods. Protein hydrolysate products are normally mixtures of peptidesand amino acids. Protein hydrolysates have a wide range of applications in food. It can be usedas emulsifying agents in a number of applications such as salad dressings, spreads, ice cream,coffee whitener, cracker, and meat products like sausages. However, bitterness in hydrolysates isone of the major undesirable aspects for various applications in food processing. In this study,we used enzymatic mixture alcalase and flavourzyme, yeast treatment methods to hydrolysebrewer’s yeast. The hydrolysate and fractions of protein hydrolysate obtained after filtration with10 kDa and 3 kDa filters were used for determination of bitterness and hydrophobic amino acidscontent. The bitter taste of hydrolysate was determined by sensory method (using quininestandard) and amino acid content was analysed by HPLC method. The result showed the closerelationship between bitter taste and hydrophobic amino acid content. The bitter taste of proteinhydrolysate was reduced as the hydrophobic amino acid content decreased. When the bitter taste(equivalent to quinine concentration) decreased from 16.25 μmol/l to 3.59 μmol/l, the totalcontent of hydrophobic amino acids in protein hydrolysate reduced from 1653 μg/ml to 932μg/ml.

scholarly journals Quantitative Analysis of Amino Acids Using Papre Chromatography

1956 ◽  
Vol 9 (2) ◽  
pp. 281 ◽  
Author(s):  
RH Hackman ◽  
Mahian Lazarus
Keyword(s):  
Amino Acids ◽  
Quantitative Analysis ◽  
Amino Acid ◽  
Protein Hydrolysate ◽  
Simple Method ◽  
One Dimensional ◽  
Straight Line ◽  
Line Relationship

A simple method for the quantitative analysis of amino [teids [n'eHent ill a protein hydrolysate, or in other mixtures of amino aeids, is deserihocl. The amino aeids are separated on one�dimensional paper chromatogmllls, fOUl" solvent syst;mns being used to resolvo 17 amino acids. The chromatogrums are treatm! with a suitable reagent; to detect the spots corresponding to each amino acid . .!Daeh chromatogram, {,ftcr being made somi�t,mllsparent with dimeth:vlphthalato, is scanned nutomnticnlly, with a densitometer, and the intensity of the light transmitted by the coloured spots is recorded on light-sensitive paper. A straight line relationship was found to hold, [or all amino acids, boi;wcell conccnh'ntioll and log per cent. transmission, Tho most useful range of amino aoid OOllcolltmtion was 2 5 mlYI although tho mothod is usable in tho rango 1-"10 mlVl. 'l'he method includes a nnmber of nOW tOclllli(juOS and tho HYOeage cooflicient of variation for a sillglo readillg for an an1ino n.eid is 5-7 pOl' COllt.

Renal secretion of amino acids in ophidian reptiles

1986 ◽  
Vol 250 (4) ◽  
pp. R712-R720 ◽  
Author(s):  
S. Benyajati ◽  
W. H. Dantzler
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Tubular Secretion ◽  
Cysteic Acid ◽  
Thamnophis Sirtalis ◽  
Renal Secretion ◽  
Renal Tubular Secretion ◽  
Beta Alanine ◽  
Renal Tubular ◽  
Filtered Load

Net renal tubular secretion of endogenous beta-amino acids (taurine, beta-alanine, beta-aminoisobutyric acid) and their endogenous analogue (L-cysteic acid) was revealed in the olive sea snake, Aipysurus laevis, and in the garter snake, Thamnophis sirtalis, by renal clearance methods. The net secretory rates ranged from 16 to 795 nmol X kg-1 X h-1, with taurine being secreted at the highest rates. These rates of secretion are comparable to those observed in marine fish, the only other group of vertebrates exhibiting renal tubular secretion of L-amino acids under physiological conditions. However, only some snakes (8-58%) demonstrated net tubular secretion; the others (0-58%) showed net tubular reabsorption of these amino acids. Net tubular secretion was consistently observed whenever the filtered load of the amino acid was low, and net reabsorption was apparent whenever the filtered load was high; the two variables being significantly correlated. An analysis of the net amino acid transport rates, both secretory and reabsorptive, as a function of the filtered load suggests that in snakes the beta-amino acids are reabsorbed and secreted at discrete tubular sites, with the secretory sites located beyond the major reabsorptive sites. Taurine, beta-alanine, and L-cysteic acid appear to share a common transport system in the snake renal tubule cells.

Sign in / Sign up

Export Citation Format

Share Document