scholarly journals Carbohydrate content of insoluble elastins prepared from adult bovine and calf ligamentum nuchae and tropoelastin isolated from copper-deficient procine aorta

1971 ◽  
Vol 121 (2) ◽  
pp. 197-202 ◽  
Author(s):  
M. E. Grant ◽  
F. S. Steven ◽  
D. S. Jackson ◽  
L. B. Sandberg

1. Insoluble elastin has been prepared by several different methods from adult bovine and calf ligamentum nuchae. Highly purified tropoelastin has been prepared from copper-deficient porcine aorta. 2. Amino acid analyses indicated that all preparations, except that obtained from calf ligamentum nuchae by using an EDTA extraction followed by collagenase digestion (preparation E6), were typical of pure elastin having high concentrations of hydrophobic and low concentrations of hydrophilic amino acids. Preparation E6 was found to contain approx. 40% collagen. 3. The determination and composition of the carbohydrates associated with these preparations is reported. With the exception of preparation E6, the insoluble elastins contained only trace amounts of neutral sugars (0.13–0.35%, w/w) and amino sugars (0.01–0.06%, w/w). The porcine tropoelastin contained virtually no carbohydrate. 4. The results suggest that carbohydrate analyses can yield valuable information about the purity of elastin preparations.

1957 ◽  
Vol 3 (5) ◽  
pp. 721-728 ◽  
Author(s):  
F. Reusser ◽  
J. F. T. Spencer ◽  
H. R. Sallans

The cells of 19 species of bacteria, actinomyces, and yeasts were analyzed for protein and essential amino acids. A rapid quantitative method for amino acid determination using one-dimensional paper chromatography was developed. The cellular protein from all species contained relatively high concentrations of lysine, somewhat lower concentrations of tryptophan and threonine, and very low concentrations of methionine. All of the 10 essential amino acids were found in each species tested, although individual differences in the relative and absolute amounts were observed.


1987 ◽  
Vol 17 (1) ◽  
pp. 27-30 ◽  
Author(s):  
Y. T. Kim ◽  
C. Glerum ◽  
J. Stoddart ◽  
S. J. Colombo

Greenhouse-grown black spruce and jack pine container seedlings were fertilized weekly with a 20–8–20 fertilizer at four concentrations during the fall. Seedlings were sampled when 23 weeks old towards the end of the greenhouse cultural period to determine the effect of fertilization on the free amino acid concentrations. All amino acids, except tryptophan, showed significant increases in concentration with higher levels of fertilizer; the concentration of tryptophan decreased with increasing fertilizer concentration. Amino acids with the highest concentrations in black spruce were arginine, glutamic acid, and proline, while in jack pine, besides these three, aspartic acid and glutamine were also found in high concentrations. Black spruce had significantly higher amino acid concentrations than jack pine. The concentrations of certain free amino acids may be more sensitive indicators of seedling nitrogen status than total foliar nitrogen.


1984 ◽  
Vol 30 (9) ◽  
pp. 1105-1111 ◽  
Author(s):  
A. Hurst ◽  
Esther Ofori ◽  
A. A. El-Banna ◽  
J. Harwig

Staphylococcus aureus MF31 can grow at 46 °C, 2 °C above its normal maximum temperature of growth if 1 M NaCl is added to the medium. In the present work we show that monosodium glutamate, proline, threonine, aspartic acid, and betaine (in order of decreasing effectiveness) also enabled cells to grow at 46 °C. Cells grown at 46 °C in he presence of salt (protected or P cells) accumulated glutamate more rapidly than cells grown at 37 °C without salt (normal or N cells) and contained an increased amino acid pool. The principal constituents of this pool were dicarboxylic amino acids and proline. Turbidimetric evidence suggests that NaCl caused plasmolysis in S. aureus. The P cells, although grown in 1 M NaCl, had about the same Cl− and K+ content as the N cells grown without added NaCl. P cells had increased heat resistance but high concentrations of CaCl2 in the heating menstruum reduced their D55 value from a maximum of 214 min to < 30 s. We suggest that growth at 46 °C in 1 M NaCl can be explained, in part at least, by the increased amino acid pool internal to the cell and the external osmotic support given by Cl− anions excluded by the cell.


1970 ◽  
Vol 23 (5) ◽  
pp. 1143 ◽  
Author(s):  
CJ Brady ◽  
PBH O'connell ◽  
J Smydzuk ◽  
NL Wade

The permeability of pulp tissue of banana fruits and aseptically prepared transverse slices of bananas increases before the respiratory climacteric begins. The permeability change may be measured as leakage of amino acids from pulp tissue, and is not dependent on the soluble carbohydrate content of pulp cells. During the climacteric, amino acid leakage into water increases further.


1932 ◽  
Vol 32 (4) ◽  
pp. 535-543 ◽  
Author(s):  
H. L. A. Tarr

1. Spore formation in eight typical members of the genusBacillushas been studied.2. Three of these strains, including one species ofB. anthracis, have been found to be practically asporogenous under the experimental conditions. In general the following statements hold good for the sporogenous races studied.3. Spore formation is almost, or entirely, inhibited by cultivation on media rich in amino acids, such as tryptic digests of casein or meat. Similar inhibition results following cultivation on a medium containing reasonably high concentrations of a mixture of amino acids and asparagine.4. When such media are suitably diluted with standard inorganic salt solutions the percentage of spores formed is greatly increased, and frequently at least 99 per cent. of spores are formed if the dilution is sufficiently high.5. When simple nitrogenous compounds such as amino acids are added to a dilute casein digest medium in which sporulation is almost complete, a definite decrease in the percentage of spores present is observed. Asparagine, which is probably readily assimilated, apparently completely hinders spore formation in most cases. Other amino acids do not exert so pronounced an effect, and ammonium phosphate does not appreciably inhibit the formation of spores.6. The fact that the addition of glycine suppresses growth markedly when it is added to a dilute casein digest medium, but does not appreciably hinder sporulation, suggests that the formation of spores is not due to any toxic effect of added compounds, or compounds already present in the medium.7. Sporulation is almost complete in a “synthetic” medium in which low concentrations of ammonium phosphate and sucrose represent the sources of nitrogen and carbon, respectively. However, frequent transfers in such a medium may inhibit spore formation partially or entirely in certain instances. This effect probably depends upon the enhanced ability of the culture in question to utilise sucrose as a source of carbon when cultivated constantly in its presence.8. It is concluded, from the above data, that endospore formation in aerobic bacilli bears an inverse relationship to the amount of available nutrient material present in the culture medium.I am indebted to Prof. Sir F. G. Hopkins and Miss M. Stephenson for their constant encouragement during the progress of this work. My thanks are due to Mr Pirie of this Department who kindly furnished me with several of the amino acids employed, and to Dr Miles of the Department of Pathology for his kindness in supplying me with certain of the cultures.


1961 ◽  
Vol 200 (5) ◽  
pp. 1063-1068 ◽  
Author(s):  
John A. Jacquez

The initial velocity of uptake of l-tryptophan by Ehrlich ascites cells can be explained as the sum of two processes: diffusion and an active transport that shows a saturation effect. Azaserine, l-2,4 diaminobutyric acid, l-histidine, and l-leucine, at low concentrations, increase the initial velocity of uptake of l-tryptophan but compete with l-tryptophan at high concentrations. Preliminary loading of the cells with glycine decreases the initial tryptophan flux: preliminary loading of the ascites cells with azaserine or tryptophan markedly increases the initial flux of uptake of the other amino acid.


1977 ◽  
Vol 161 (1) ◽  
pp. 37-47 ◽  
Author(s):  
A M Wu ◽  
W Pigman

The nine-banded armadillo (Dasypus novemcinctus mexicanus Peters) was chosen for this study so that a comparison could be made of the salivary mucus glycoproteins of an ancient mammalian species with those derived from previously studied, more highly evolved species. Two mucus glycoproteins, armadillo submandibular glycoprotein A and armadillo submandibular glycoprotein B, were prepared from the armadillo submandibular gland by a modification of the method of Tettamanti & Pigman (1968) (Arch. Biochem. Biophys. 124, 41-50). The composition of glycoprotein A is the simplest one among the known mucus glycoproteins. Six amino acids constitute 98.5 mol/100mol of the protein of glycoprotein A and 82 mol/100 mol of that of glycoprotein B. These are serine and threonine (which make up 40-50% of the molar amino acid composition), glutamic acid, glycine alanine and valine. Proline is absent from glycoprotein A and comprises only 2.3% of glycoprotein B. For both glycoproteins, the protein content, as determined by the method of Lowry, Rosebrough, Farr & Randall (1951) (J. Biol. Chem 193, 265-275), with bovine serum albumin as standard, was nearly 60% higher than when determined by the sum of the amino acids. The ratios of total mol of amino acid/total mol of carbohydrate are 1:0.63 for glycoprotein A and 1:0.68 for glycoprotein B, N-Acetylneuraminic acid and N-acetylgalactosamine, in a molar ratio of about 0.35:1.00, are the principal carbohydrates present in both glycoproteins. Neutral sugars seem to be absent from glycoprotein A, but galactose and fucose are present in glycoprotein B. The carbohydrate side chains in glycoprotein A are composed of about two-thirds monosaccharide and one-third disaccharide residues, whereas those of glycoprotein B are more complex. For both glycoproteins, essentially all of the N-acetylgalactosamine was attached O-glycosidically to the hydroxyamino acid residues of the protein core. The linkage of N-acetylneuraminic acid glycoprotein A was extremely sensitive to dilute acid and neuraminidase. Glycoprotein B has chemical properties similar to those of glycoprotein A. However, whereas glycoprotein A was susceptible to both Clostridium perfringens and Vibrio cholerae neuraminidases, only the latter enzyme had an effect on glycoprotein B at pH 4.75. Both glycoproteins were homogeneous by cellulose acetate electrophoresis and ultracentrifugal analyses. The apparent mol.wts. of glycoprotein A and glycoprotein B were 7.8 X 10(4) and 3.1 X 10(4) respectively.


1990 ◽  
Vol 259 (5) ◽  
pp. E614-E625 ◽  
Author(s):  
P. Fafournoux ◽  
C. Remesy ◽  
C. Demigne

The aim of the present work was to evaluate in vivo the role of the transport step in hepatic amino acid metabolism. To vary hepatic utilization of amino acids, rats were adapted to diets containing various concentrations of casein (5, 15, and 60%). In rats fed 5 or 15% casein diets, Gln and Glu were released by the liver, and there was a significant uptake of Ala. Hepatic fluxes of amino acids increased considerably after adaptation to high-casein diet (up to 1.55 mumol.min-1.g liver-1 for Ala), because of the rise in afferent concentrations as well as enhanced uptake percentage (peaking at 60–75% for most glucogenic amino acids). Adaptation to a high-protein diet led to induction of not only system A but also of most of the other transport systems (Gly, anionic, T, y+, and to a lesser extent system N); only systems ASC and L were unchanged. The study of amino acid repartition between liver and plasma with different diets indicates that transport could modulate utilization of Ala, Ser, Thr, Gly, Gln, and Asp. For Arg and Asn, present in very low concentrations in liver under any condition, the transport step should be the major locus of control of their metabolism. For amino acids chiefly transported by nonconcentrative systems, such as aromatic amino acids, cellular metabolism could also be limited by the transport process. In conclusion, during adaptation to a high-protein diet, there is apparently a coordinated adaptation of amino acid transport and of their intracellular metabolism. For some amino acids, induction of catabolic enzymes seems greater than that of transport, so that the transport step may play an important role in control of metabolic fluxes. For example, concentration of amino acids such as Thr may be markedly depressed in rats adapted to a high-protein diet.


1993 ◽  
Vol 264 (6) ◽  
pp. R1071-R1076 ◽  
Author(s):  
T. Ugawa ◽  
K. Kurihara

The effects of salts on the canine taste responses to amino acids were examined by recording the activity of the chorda tympani nerve. 1) The tonic responses to most amino acids examined were significantly enhanced by the presence of various salts. 2) The degree of the enhancement varied with the species of amino acid and salt. The responses to most amino acids were enhanced by sodium, potassium, and calcium salts, but not enhanced by magnesium salts. The response to methionine, for example, was enhanced by NaCl, but not by Na phosphate of equimolar Na+. 3) The responses to glycine and alanine were suppressed by high concentrations of NaCl. 4) The presence of salts (NaCl and CaCl2) enhanced the responses to amino acids without affecting the thresholds for the amino acids, suggesting that the presence of the salts did not change the affinity of amino acids to the receptor sites. 5) The enhancing effects of salts on the responses to amino acids could not be explained in terms of permeability of cation and anion of salts. It was speculated that the binding of cation and anion of salts on the receptor membranes induces exposure of the receptor sites for amino acids available for binding of amino acids.


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