An extracellular proteolytic enzyme from Scopalariopsis brevicaulis. II. Hydrolysis of poly amino acids

1972 ◽  
Vol 18 (7) ◽  
pp. 1165-1167 ◽  
Author(s):  
Kartar Singh ◽  
Claude Vézina
Keyword(s):  
Amino Acids ◽  
Glutamic Acid ◽  
Aspartic Acid ◽  
Proteolytic Enzyme ◽  
Ph Values ◽  
Optimum Ph ◽  
Extracellular Proteolytic Enzyme ◽  
Scopulariopsis Brevicaulis ◽  
Hydrolysis Of

Scopulariopsis brevicaulis protease hydrolyzed poly-L-lysine and poly-L-glutamic acid; optimum pH values for hydrolysis were 10.6 and 4.7 respectively. Final products of poly-L-lysine digestion by the protease were intermediate peptides from tetramer upwards. Pentalysine was not hydrolyzed by the enzyme. The protease had no action on poly-L-aspartic acid, poly-L-alanine, poly-L-glycine, poly-L-valine, or poly-L-leucine.

Uptake of Dipeptides Containing Basic and Acidic Amino Acids by Rat Small Intestine in Vitro

1972 ◽  
Vol 43 (6) ◽  
pp. 823-837 ◽  
Author(s):  
D. Burston ◽  
Jill M. Addison ◽  
D. M. Matthews
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Glutamic Acid ◽  
Aspartic Acid ◽  
Free Amino Acids ◽  
Free Amino ◽  
Tissue Uptake ◽  
Acidic Amino Acids ◽  
Hydrolysis Of

1. The characteristics of transport and hydrolysis of twenty-two dipeptides containing basic and acidic amino acids by rat ileal rings were investigated in vitro. The peptides included combinations of basic and neutral, basic and basic, basic and acidic, acidic and acidic, and acidic and neutral amino acids. 2. All peptides studied were removed intact from the bulk phase of the incubation medium, though, in general, only free amino acids appeared in the tissue. Uptake of one or both constituent amino acids was greater from the peptide than from the equivalent amino acid or amino acid mixture in the case of at least one peptide from each group and in eighteen of the twenty-two peptides studied. In general, there was no relationship between the extent of uptake of amino acids from peptides and the extent of their hydrolysis by the system. The results support the hypothesis that there is more than one mode of uptake of amino acids from peptides. 3. Hydrolysis of γ-glutamyl-l-glutamic acid by intact intestine or intestinal homogenate was slight, and intact peptide was taken up by the tissue. Uptake of free glutamic acid from this peptide was poor. Comparison of γ-glutamyl-l-glutamic acid with three other slowly hydrolysed dipeptides, glycyl-d-valine, sarcosylglycine and glycylsarcosine, suggested that all four were transported into the mucosal cells and hydrolysed intracellularly. The results indicate that the presence of a γ-linkage or a d-amino acid, or methylation of the free amino group as in sarcosylglycine, impair both transport and hydrolysis of peptide, but that attachment of a methyl group to the N of the peptide bond, as in glycylsarcosine, impairs hydrolysis but has no effect on peptide transport. 4. l-Aspartic acid and l-glutamic acid were extensively transaminated by the intestine, whether presented as free amino acids or in peptides. Evidence was obtained suggesting that production of alanine from aspartic acid resulted from direct transamination of aspartic acid with pyruvic acid, rather than from a sequence of two reactions involving aspartate and alanine aminotransferases. 5. The results show that more rapid uptake of amino acids from peptides than from free amino acids is not confined to peptides made up of neutral amino acids, and probably occurs with many small peptides. Uptake of lysine and the dicarboxylic amino acids, which are particularly slowly absorbed from free solution, was much greater from several dipeptides than from the free amino acids. The results suggest the importance of mucosal peptide uptake in protein absorption.

An extracellular proteolytic enzyme from Scopulariopsis brevicaulis. 1. Purification and properties

1971 ◽  
Vol 17 (8) ◽  
pp. 1029-1042 ◽  
Author(s):  
Kartar Singh ◽  
Claude Vézina
Keyword(s):  
Proteolytic Enzyme ◽  
Deae Cellulose ◽  
Alkaline Proteases ◽  
Casein Hydrolysis ◽  
Purification And Properties ◽  
Optimum Ph ◽  
Sh Reagents ◽  
Extracellular Proteolytic Enzyme ◽  
Scopulariopsis Brevicaulis ◽  
Insulin Chains

A proteolytic enzyme present in culture filtrates of Scopulariopsis brevicaulis was purified about 200-fold by (NH4)2SO4 and ethanol fractionations followed by chromatography on DEAE-cellulose, DEAE-Sephadex, and hydroxylapatite. Ultracentrifugation of the purified enzymes showed only one sedimenting component and its molecular weight was estimated to be about 24 000. The protease hydrolyzed casein, urea-denatured hemoglobin, gelatin, fibrinogen, fibrin, insulin chains A and B, but not human serum albumin or ovalbumin. It also coagulated milk. The enzyme had no action on the various peptides tested and showed low esterase activity. Optimum pH for casein hydrolysis was 10.5 to 11; for hemoglobin hydrolysis 7.0–9.5, and for gelatin hydrolysis, 6.0–8.0. The enzyme activity was unaffected by most metal ions, SH-reagents, and some natural trypsin inhibitors. The protease was strongly inhibited by diisopropylfluorophosphate and phenylmethanesulfonyl fluoride. Although similar in some respects to CA-7, the enzyme isolated from Aspergillus oryzae, and other alkaline proteases, the S. brevicaulis protease does not appear to be identical with any one of them.

The value of 21 amino acids as nitrogen sources for Phytophthora cactorum and P. heveae

1971 ◽  
Vol 17 (10) ◽  
pp. 1319-1325 ◽  
Author(s):  
J. A. Leal ◽  
M. E. Gallegly ◽  
V. G. Lilly
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Glutamic Acid ◽  
Aspartic Acid ◽  
Culture Media ◽  
Nitrogen Sources ◽  
Ammonium Nitrogen ◽  
Phytophthora Cactorum ◽  
Ph Values

The value of 21 amino acids as nitrogen sources for Phytophthora cactorum (Leb. and Cohn) Schroet. and P. heveae Thompson has been studied using the dry weights of mycelium, changes in the pH values of the culture media, and the accumulation of ammonium nitrogen in the culture media as the criteria. Two concentrations of each amino acid were used to furnish 106 and 424 mg N/liter. The three parameters mutually supported each other in dividing the amino acids into two groups, poor and good.The following amino acids were poor sources of nitrogen for both species: L-hydroxyproline, L-isoleucine, L-leucine, L-lysine, L-methionine, and L-tryptophan. L-Phenylalanine was a good amino acid for P. cactorum, and a poor amino acid for P. heveae. L-Cysteine and L-valine were good sources of nitrogen for P. heveae, but poor nitrogen sources for P. cactorum. The following amino acids were good sources of nitrogen for both species: L-α-alanine, L-arginine, L-asparagine, L-aspartic acid, L-glutamine, L-glutamic acid, glycine, L-histidine, L-proline, L-serine, L-threonine, and L-tyrosine.

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.

scholarly journals The Content of Non-essential Amino Acids in the Grains of Winter and Spring Varieties of Oats (Avena sativa L.) under the Conditions of Central Southern Bulgaria

2013 ◽  
Vol 14 (1) ◽  
pp. 105
Author(s):  
T. Georgieva ◽  
P. Zorovski
Keyword(s):  
Amino Acids ◽  
Glutamic Acid ◽  
G Protein ◽  
Aspartic Acid ◽  
Avena Sativa ◽  
Essential Amino Acids

The purpose of this survey is to study the content of non-essential amino acids in four winter (Dunav 1, Ruse 8, Resor 1, Line M-K) and five spring (Obraztsov chiflik 4, Mina, HiFi, Novosadski golozarnest and Prista 2) cultivars of oats grown in Central Southern Bulgaria within the period from 2007 to 2009. The tested cultivars have different contents of non-essential amino acids. Dunav 1 has the highest quantity of glicine (5.12 g/100 g protein) of all the winter cultivars, Ruse 8 has the highest quantity of alanine (5.69 g/100 g protein) and Resor 1 – the highest quantity of arginine (6.14 g/100 g protein). Generally speaking, the spring cultivars have a larger quantity of glutamic acid (from 25.86 to 26.07 g/100 g protein) and proline (from 6.15 to 8.21 g/100 g protein) but a smaller quantity of glycine (from 4.68 to 4.99 g/100 g protein) compared to the winter cultivars. The naked cultivar Mina has the highest quantity of cystine (2.14 g/100 g protein), cultivar Prista 2 has the highest quantity of proline (8.21 g/100 g protein) and glutamic acid (26.07 g/100g protein) and HiFi ranks first in terms of aspartic acid (9.05 g/100 g protein), serine (5.02 g/100 g protein) and tyrosine (2.09 g/100 g protein). In the study we have also established certain relations between non-essential amino acids.

USE OF GLUTAMIC ACID-U-C14 TO DETERMINE NUTRITIONALLY ESSENTIAL AMINO ACIDS FOR LARVAE OF THE BLOW FLY, PHORMIA REGINA

1960 ◽  
Vol 38 (11) ◽  
pp. 1229-1234 ◽  
Author(s):  
R. Kasting ◽  
A. J. McGinnis
Keyword(s):  
Amino Acids ◽  
Glutamic Acid ◽  
Aspartic Acid ◽  
Essential Amino Acids ◽  
Phormia Regina ◽  
Blow Fly ◽  
Isoleucine Leucine ◽  
Low Level ◽  
Third Instar Larvae

The production of C14O2 by third-instar larvae of the blow fly, Phormia regina Meig., after it was injected with glutamic acid-U-C14, indicates that this substrate was metabolized under these conditions. However, the nutritionally essential amino acids lysine, phenylalanine, valine, isoleucine, leucine, and threonine, isolated from the injected larvae, contained little radioactivity. A low level of radioactivity in arginine, histidine, and methionine suggests that they were slowly synthesized. The nutritionally non-essential amino acids alanine, serine, aspartic acid, and proline contained large quantities of radioactivity; tyrosine and glycine were exceptions. These results, in agreement with earlier work that used glucose-U-C14, show that radioactivity data are useful for determining certain of the nutritionally essential amino acids.

scholarly journals Tracer studies on the biosynthesis of amino acids from lactate by Peptostreptococcus elsdenii

1967 ◽  
Vol 105 (1) ◽  
pp. 299-310 ◽  
Author(s):  
H. J. Somerville ◽  
J. L. Peel
Keyword(s):  
Amino Acids ◽  
Glutamic Acid ◽  
Aspartic Acid ◽  
Tricarboxylic Acid Cycle ◽  
Carbon Chain ◽  
Tricarboxylic Acid ◽  
Diaminopimelic Acid ◽  
Reaction Sequence ◽  
Tracer Studies ◽  
Cell Fractions

Peptostreptococcus elsdenii, a strict anaerobe from the rumen, was grown on a medium containing yeast extract and [1−14C]- or [2−14C]-lactate. Radioisotope from lactate was found in all cell fractions, but mainly in the protein. The label in the protein fraction was largely confined to a few amino acids: alanine, serine, aspartic acid, glutamic acid and diaminopimelic acid. The alanine, serine, aspartic acid and glutamic acid were separated, purified and degraded to establish the distribution of 14C from lactate within the amino acid molecules. The labelling patterns in alanine and serine suggested their formation from lactate without cleavage of the carbon chain. The pattern in aspartic acid suggested formation by condensation of a C3 unit derived directly from lactate with a C1 unit, probably carbon dioxide. The distribution in glutamic acid was consistent with two possible pathways of formation: (a) by the reactions of the tricarboxylic acid cycle leading from oxaloacetate to 2-oxoglutarate, followed by transamination; (b) by a pathway involving the reaction sequence 2 acetyl-CoA→crotonyl-CoA→glutaconate→glutamate.

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.

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