THE BIOSYNTHESIS OF SOME AMINO ACIDS IN PENICILLIUM DIGITATUM

1958 ◽  
Vol 4 (6) ◽  
pp. 627-632 ◽  
Author(s):  
Donald J. Reed ◽  
Vernon H. Cheldelin ◽  
Chih H. Wang

The pathways of biosynthesis of alanine, serine, glycine, aspartic acid, and glutamic acid in Penicillium digitntum have been studied by means of tracer techniques, using glucose-2-C14 and glucose-6-C11 as carbon sources. Alanine appears to be derived directly from pyruvate formed in the glycolytic degradation of glucose. Serine is synthesized from glycine, which is in turn derived mainly from a C2 fragment that originates in the C2–C3 cleavage of pentose, a product of phosphogluconate decarboxylation. The biosynthesis of aspartic acid in this organism may involve several pathways. Glutamic acid appears to be synthesized from glucose intermediates via the conventional reactions of the TCA cycle.

1971 ◽  
Vol 17 (5) ◽  
pp. 683-688 ◽  
Author(s):  
Thomas T. Lillich ◽  
Gerald H. Elkan

The biosynthesis of aspartic acid and the incorporation of its carbon skeleton into glutamic acid and alanine was investigated in Rhizobium japonicum. It was found that oxalacetic acid (OAA) occupies a key position in the metabolism of this amino acid and the dissemination of its carbon skeleton into other amino acids. Aspartic acid is formed by two pathways involving the amination of OAA. In one pathway, OAA is synthesized by the tricarboxylic acid (TCA) cycle and in the other by the carboxylation of either pyruvate or phosphoenolpyruvate. The carbon skeleton of aspartic acid can be incorporated into alanine either by deamination to OAA followed by decarboxylation to pyruvate and reamination or directly by decarboxylation of the number four carbon. There are at least two pathways by which aspartic acid carbon is incorporated into glutamic acid. One path involves the synthesis of α-ketoglutarate from OAA via the TCA cycle, the other is a condensation yielding either β-methylaspartate or α-ketoglutarate, which is then converted to glutamate.


1966 ◽  
Vol 12 (6) ◽  
pp. 1175-1185 ◽  
Author(s):  
I. J. McDonald ◽  
Alice K. Chambers

Micrococcus sp. ATCC No. 407 (M. freudenreichii) produced relatively large amounts of extracellular proteinase in synthetic medium containing methionine, thiamine, biotin, NH4Cl, NaHCO3, NaCl, MgSO4, and FeSO4, with aspartic acid, asparagine, glutamic acid, or glutamine as the carbon source. The organism produced relatively small amounts of proteinase with succinate, malate, fumarate, maltose, maltotriose, or maltotetraose as the carbon source. In synthetic medium containing maltose, any one of several amino acids stimulated growth and proteinase production. The results indicated that the organism is a partial constitutive strain with respect to proteinase production and suggested that proteinase formation is controlled by a form of end-product induction. In the presence of inducer, carbon sources such as succinate or maltose caused suppression of proteinase formation, suggesting control by metabolic repression as well. Because extracellular proteinase formation is induced by amino acids and suppressed by carbon sources such as succinate or maltose, and because the organism can utilize amino acids as carbon sources for growth, it. is suggested that the function of extracellular proteinase in this organism is to ensure a supply of carbon for growth rather than a supply of amino acids for protein synthesis.


Metabolites ◽  
2018 ◽  
Vol 8 (4) ◽  
pp. 66 ◽  
Author(s):  
Manu Shree ◽  
Shyam K. Masakapalli

The goal of this study is to map the metabolic pathways of poorly understood bacterial phytopathogen, Xanthomonas oryzae (Xoo) BXO43 fed with plant mimicking media XOM2 containing glutamate, methionine and either 40% [13C5] xylose or 40% [13C6] glucose. The metabolic networks mapped using the KEGG mapper and the mass isotopomer fragments of proteinogenic amino acids derived from GC-MS provided insights into the activities of Xoo central metabolic pathways. The average 13C in histidine, aspartate and other amino acids confirmed the activities of PPP, the TCA cycle and amino acid biosynthetic routes, respectively. The similar labelling patterns of amino acids (His, Ala, Ser, Val and Gly) from glucose and xylose feeding experiments suggests that PPP would be the main metabolic route in Xoo. Owing to the lack of annotated gene phosphoglucoisomerase in BXO43, the 13C incorporation in alanine could not be attributed to the competing pathways and hence warrants additional positional labelling experiments. The negligible presence of 13C incorporation in methionine brings into question its potential role in metabolism and pathogenicity. The extent of the average 13C labelling in several amino acids highlighted the contribution of pre-existing pools that need to be accounted for in 13C-flux analysis studies. This study provided the first qualitative insights into central carbon metabolic pathway activities in Xoo.


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.


2013 ◽  
Vol 14 (1) ◽  
pp. 105
Author(s):  
T. Georgieva ◽  
P. Zorovski

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.


1960 ◽  
Vol 38 (11) ◽  
pp. 1229-1234 ◽  
Author(s):  
R. Kasting ◽  
A. J. McGinnis

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.


1967 ◽  
Vol 105 (1) ◽  
pp. 299-310 ◽  
Author(s):  
H. J. Somerville ◽  
J. L. Peel

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.


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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