STUDIES ON THE METABOLISM OF VALERATE-1-C14 BY UREDOSPORES OF WHEAT STEM RUST

1961 ◽  
Vol 39 (10) ◽  
pp. 1559-1566 ◽  
Author(s):  
H. Reisener ◽  
W. B. McConnell ◽  
G. A. Ledingham
Keyword(s):  
Glutamic Acid ◽  
Soluble Fraction ◽  
Tricarboxylic Acid Cycle ◽  
Tricarboxylic Acid ◽  
Water Soluble ◽  
Aminobutyric Acid ◽  
Puccinia Graminis ◽  
Wheat Stem Rust ◽  
Carbon 14 ◽  
Cellular Components

When uredospores of Puccinia graminis var. tritici race 15B were shaken in a medium containing M/30 phosphate buffer, pH 6.2, and valerate-1-C14, 97% of the radioactivity was removed from the solution in a period of 3 hours. Fifty-five per cent of the carbon-14 was released as carbon dioxide, and 42% was incorporated into the spores. Carbon-14 was found in many cellular components but the water-soluble fraction accounted for 48% of the tracer in the spores. About two thirds of the water-soluble carbon-14 was in a fraction containing amino acids, amides, and peptides, with glutamic acid, glutamine, and γ-aminobutyric acid being highly radioactive. Carbon-5 of glutamic acid and carbon-1 of γ-aminobutyric acid were particularly radioactive. In addition carbon-1 of glutamic acid was appreciably radioactive. The results are consistent with the view that γ-aminobutyric acid was formed by decarboxylation of glutamic acid and that glutamic acid became labelled as a result of β-oxidation of the valerate-1-C14 to yield acetate-1-C14 which in turn was metabolized by the tricarboxylic acid cycle.

THE METABOLISM OF ACETATE BY WHEAT STEM RUST UREDOSPORES

1964 ◽  
Vol 42 (6) ◽  
pp. 883-888 ◽  
Author(s):  
S. Suryanarayanan ◽  
W. B. McConnell
Keyword(s):  
Carbon Dioxide ◽  
Glutamic Acid ◽  
Tricarboxylic Acid Cycle ◽  
Tricarboxylic Acid ◽  
Water Soluble ◽  
Puccinia Graminis ◽  
Acid Fraction ◽  
Wheat Stem Rust ◽  
Acid Cycle ◽  
Carbon 14

When uredospores of Puccinia graminis var. tritici (race 15B) were incubated at pH 6.2 in phosphate buffer containing either acetate-1-C14or -2-C14, about 12% of the radioactivity was removed from the solution in a period of 3 hours. Respired carbon dioxide contained about 45% and 22% of the carbon-14 taken up as acetate-1-C14and acetate-2-C14, respectively. Incorporation of carbon-14 into spore components was considerably higher with acetate-2-C14than with acetate-1-C14. With either tracer most of the radioactivity in water-soluble spore materials was accounted for in amino acids and neutral substances. Glutamic acid was particularly radioactive and accounted for about 40% of the radioactivity in the amino acid fraction. Incorporation of carbon-14 into the glutamic acid skeleton was consistent with the view that both the tricarboxylic acid cycle and the glyoxalate cycle were functioning.

THE METABOLISM OF VALERATE-2-C14 BY UREDOSPORES OF WHEAT STEM RUST

1963 ◽  
Vol 41 (1) ◽  
pp. 1-7 ◽  
Author(s):  
H. Reisener ◽  
A. J. Finlayson ◽  
W. B. McConnell
Keyword(s):  
Carbon Dioxide ◽  
Glutamic Acid ◽  
Specific Activity ◽  
Tricarboxylic Acid Cycle ◽  
High Specific Activity ◽  
Water Soluble ◽  
Buffer Solution ◽  
Wheat Stem Rust ◽  
Carbon 14 ◽  
Water Soluble Extract

When uredospores of Puccinia graminis var. tritici race 15B were shaken in a medium containing M/30 phosphate buffer, pH 6.2, and valerate-2-C14, about 88% of the radioactivity was removed from the buffer solution in a period of 3 hours. About 40% of the carbon-14 taken from the buffer was found in a water-soluble extract of the spores and about 15% was respired as carbon dioxide. The result is compared with an earlier report that carbon 1 of valerate is more extensively released as carbon dioxide and less extensively incorporated into spore components. Glutamic acid, glutamine, γ-aminobutyric acid, and alanine of high specific activity were isolated. It was estimated from partial degradation that more than one-half of the carbon-14 of glutamic acid occurred in position 4 and that carbon 5 was very weakly labelled. Citric acid was also of high specific activity and was labelled predominantly in the internal carbons.It is concluded that respiring rust spores utilize externally supplied valerate by β-oxidation, which releases carbons 1 and 2 in a form which is metabolized as acetate by the tricarboxylic acid cycle.

THE METABOLISM OF PELARGONATE-1-C14 BY WHEAT STEM RUST UREDOSPORES

1965 ◽  
Vol 43 (1) ◽  
pp. 91-96 ◽  
Author(s):  
S. Suryanarayanan ◽  
W. B. McConnell
Keyword(s):  
Amino Acids ◽  
Glutamic Acid ◽  
Glyoxylate Cycle ◽  
Water Extract ◽  
Aminobutyric Acid ◽  
Pelargonic Acid ◽  
Puccinia Graminis ◽  
Wheat Stem Rust ◽  
Carbon 14 ◽  
The Glyoxylate Cycle

Uredospores of Puccinia graminis var. tritici were incubated in phosphate buffer (pH 6.2) containing pelargonic acid-1-C14. After 3 hours 97.5% of the tracer was assimilated. Fifty-five percent of this was released as C14O2 and 36.2% was incorporated into the spores. About one-half of the carbon-14 in the spores was soluble in ethanol and water, whereas nearly a third was ether extractable. The amino acid and carbohydrate fractions contained about equal amounts of carbon-14 and together accounted for two-thirds of the radioactivity in the ethanol–water extract. The organic acids were also radioactive. Glutamic acid, γ-aminobutyric acid, aspartic acid, and alanine were the most highly labelled amino acids. Fifty-three percent of the radioactivity in glutamic acid was found in carbon 1 and 46% in carbon 5. This distribution suggests β-oxidation of pelargonic acid to acetyl CoA and extensive utilization of the latter by means of the glyoxylate cycle.

THE METABOLISM OF VALERATE-2-C14 BY UREDOSPORES OF WHEAT STEM RUST

1963 ◽  
Vol 41 (1) ◽  
pp. 1-7 ◽  
Author(s):  
H. Reisener ◽  
A. J. Finlayson ◽  
W. B. McConnell
Keyword(s):  
Carbon Dioxide ◽  
Glutamic Acid ◽  
Specific Activity ◽  
Tricarboxylic Acid Cycle ◽  
High Specific Activity ◽  
Water Soluble ◽  
Buffer Solution ◽  
Wheat Stem Rust ◽  
Carbon 14 ◽  
Water Soluble Extract

When uredospores of Puccinia graminis var. tritici race 15B were shaken in a medium containing M/30 phosphate buffer, pH 6.2, and valerate-2-C14, about 88% of the radioactivity was removed from the buffer solution in a period of 3 hours. About 40% of the carbon-14 taken from the buffer was found in a water-soluble extract of the spores and about 15% was respired as carbon dioxide. The result is compared with an earlier report that carbon 1 of valerate is more extensively released as carbon dioxide and less extensively incorporated into spore components. Glutamic acid, glutamine, γ-aminobutyric acid, and alanine of high specific activity were isolated. It was estimated from partial degradation that more than one-half of the carbon-14 of glutamic acid occurred in position 4 and that carbon 5 was very weakly labelled. Citric acid was also of high specific activity and was labelled predominantly in the internal carbons.It is concluded that respiring rust spores utilize externally supplied valerate by β-oxidation, which releases carbons 1 and 2 in a form which is metabolized as acetate by the tricarboxylic acid cycle.

STUDIES ON WHEAT PLANTS USING C14 COMPOUNDS: V. GERMINATION STUDIES WITH LABELLED WHEAT SEEDS

1957 ◽  
Vol 35 (1) ◽  
pp. 1259-1266 ◽  
Author(s):  
W. B. McConnell
Keyword(s):  
Carbon Dioxide ◽  
Amino Acid ◽  
Glutamic Acid ◽  
Active Compound ◽  
Specific Activity ◽  
Tricarboxylic Acid Cycle ◽  
Tricarboxylic Acid ◽  
Acid Cycle ◽  
Carbon 14 ◽  
Wheat Seeds

Radioactive wheat seeds, obtained by injecting acetate-C14 into the stems of the parent plants, were germinated in the absence of light and nutrient and the fate of the carbon-14 was observed. Carbon respired as carbon dioxide had a higher specific activity than any of the major seed components except protein. Variations were found in the patterns by which material was transferred from the kernel to new tissue as reflected in a comparison of the activity of various components. Glutamic acid was the most active compound isolated either from the original seeds or from the new tissues. This observation, together with similarities noted in the intramolecular distribution of carbon-14 in glutamic acid of new tissue and seed residues, indicated that glutamic acid was reutilized for the biosynthesis of seedling protein. Changes in the labelling of glutamic acid during transfer to new tissue are qualitatively in accord with the idea that at least some of the amino acid is used after re-entry into the tricarboxylic acid cycle.

STUDIES ON WHEAT PLANTS USING C14 COMPOUNDS: V. GERMINATION STUDIES WITH LABELLED WHEAT SEEDS

1957 ◽  
Vol 35 (12) ◽  
pp. 1259-1266 ◽  
Author(s):  
W. B. McConnell
Keyword(s):  
Carbon Dioxide ◽  
Amino Acid ◽  
Glutamic Acid ◽  
Active Compound ◽  
Specific Activity ◽  
Tricarboxylic Acid Cycle ◽  
Tricarboxylic Acid ◽  
Acid Cycle ◽  
Carbon 14 ◽  
Wheat Seeds

Radioactive wheat seeds, obtained by injecting acetate-C14 into the stems of the parent plants, were germinated in the absence of light and nutrient and the fate of the carbon-14 was observed. Carbon respired as carbon dioxide had a higher specific activity than any of the major seed components except protein. Variations were found in the patterns by which material was transferred from the kernel to new tissue as reflected in a comparison of the activity of various components. Glutamic acid was the most active compound isolated either from the original seeds or from the new tissues. This observation, together with similarities noted in the intramolecular distribution of carbon-14 in glutamic acid of new tissue and seed residues, indicated that glutamic acid was reutilized for the biosynthesis of seedling protein. Changes in the labelling of glutamic acid during transfer to new tissue are qualitatively in accord with the idea that at least some of the amino acid is used after re-entry into the tricarboxylic acid cycle.

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 METABOLISM OF PUTRESCINE (1,4-DIAMINOBUTANE) BY MYCOBACTERIA ISOLATED FROM FISH: II. STUDIES WITH ARSENITE-INHIBITED CELLS AND CELL-FREE EXTRACTS

1967 ◽  
Vol 13 (5) ◽  
pp. 521-531 ◽  
Author(s):  
T. P. T. Evelyn
Keyword(s):  
Succinic Acid ◽  
Tricarboxylic Acid Cycle ◽  
Significant Proportion ◽  
Tricarboxylic Acid ◽  
The Other ◽  
Aminobutyric Acid ◽  
Succinic Semialdehyde ◽  
Amino Group ◽  
Intact Cells ◽  
Acid Cycle

Three mycobacterial strains isolated from fish degraded putrescine by a pathway in which γ-aminobutyraldehyde (Δ′-pyrroline), γ-aminobutyric acid, succinic semialdehyde, and succinic acid were intermediates. These results agree substantially with those of other workers using different microorganisms. Intact cells utilized γ-aminobutyric acid in a transaminase reaction with endogenously supplied α-ketoglutarate to produce succinic semialdehyde and glutamate. Studies with arsenite-poisoned cells showed that a significant proportion of putrescine was metabolized via pyruvate and alanine. When putrescine-1,4-14C was substrate, HCl extracts of cells contained radioactive aspartate and glutamate in addition to alanine. The further metabolism of succinate therefore proceeded in two directions: one yielding oxalacetate and α-ketoglutarate by way of the tricarboxylic acid cycle, and the other branching off the cycle to yield pyruvate. Studies with cell-free extracts suggested that putrescine nitrogen was assimilated via glutamate, which served as the amino-group donor to yield alanine and aspartate.

THE METABOLISM OF PROPIONATE BY WHEAT STEM RUST UREDOSPORES

1963 ◽  
Vol 41 (3) ◽  
pp. 737-743 ◽  
Author(s):  
H. Reisener ◽  
A. J. Finlayson ◽  
W. B. McConnell ◽  
G. A. Ledingham
Keyword(s):  
Carbon Dioxide ◽  
Amino Acids ◽  
Glutamic Acid ◽  
Stem Rust ◽  
Water Extract ◽  
Hot Water ◽  
Insoluble Residue ◽  
Soluble Carbohydrates ◽  
Wheat Stem Rust ◽  
Carbon 14

When uredospores of wheat stem rust were shaken for 3 hours with phosphate buffer (pH 6.2) containing propionate-1-C14, -2-C14, or -3-C14, about 55% of the carbon-14 was removed from the solution. With propionate-1-C14, most of the carbon-14 taken up was released as carbon dioxide-C14, whereas about 20% and 31% of propionate carbon 2 and carbon 3, respectively, was incorporated into the spores. The specific activity of a fraction consisting of the free amino acids of a hot-alcohol and hot-water extract of the spores increased markedly with increase in the position number of propionate in which the carbon-14 was located. A similar relation was observed for other fractions such as soluble carbohydrates, ether-soluble material, organic acids, and insoluble residue from spores. The most active amino acids isolated were glutamic acid, γ-aminobutyric acid, and alanine. Partial degradations showed that with propionate-2-C14 the carboxyl groups of glutamic acid were especially radioactive, whereas with propionate-3-C14 the internal carbons were most radioactive.It is concluded that propionate metabolism in the rust spores involved conversion of carbon 1 to carbon dioxide, and utilization of carbons 2 and 3 as acetate with carbon 2 behaving as the carboxyl carbon.

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