Studies on wheat plants using 14C-labelled compounds. XXII. Incorporation into wheat protein

1969 ◽  
Vol 47 (1) ◽  
pp. 19-23 ◽  
Author(s):  
W. B. McConnell
Keyword(s):  
Glutamic Acid ◽  
Specific Activity ◽  
Tricarboxylic Acid Cycle ◽  
Tricarboxylic Acid ◽  
Radioactive Tracers ◽  
Wheat Protein ◽  
Acid Cycle ◽  
Late Stages ◽  
Kernel Protein

Thatcher wheat plants were labelled with 14C by injecting radioactive tracers into the top internode of the stem during late stages of plant growth. The distribution of 14C in fully mature plants was examined, emphasis being placed on the labelling of kernel-protein amino acids.Glutamine was only slightly more effective than glutamic acid for labelling glutamic acid isolated from the gluten hydrolysate, indicating that glutamic acid and glutamine are extensively interconverted in the wheat plants. Proline and glutamic acid also are readily interconverted, proline-14C yielding protein in which the glutamic acid has a higher specific activity than does the proline. By contrast, arginine-5-14C did not yield highly labelled glutamic acid.14C from glyoxylate-1-14C was widely distributed among kernel components but it produced glycine and serine with carboxyl carbons of exceptionally high specific activity.Succinate-1,4-14C, succinate-2,3-14C, and aspartic acid-14C all labelled glutamic acid of kernel protein more extensively than the other amino acids of the protein. The role of the tricarboxylic acid cycle in utilizing these tracers is discussed.

METABOLISM OF C14 AMINO ACIDS AND AMIDES IN DETACHED LEAVES

1956 ◽  
Vol 34 (4) ◽  
pp. 423-433 ◽  
Author(s):  
C. D. Nelson ◽  
G. Krotkov
Keyword(s):  
Amino Acids ◽  
Double Bond ◽  
Glutamic Acid ◽  
Broad Bean ◽  
Specific Activity ◽  
Tricarboxylic Acid Cycle ◽  
Tricarboxylic Acid ◽  
Activity Data ◽  
Acid Cycle ◽  
Bean Leaves

Detached broad bean leaves were placed with their petioles in 0.01 M ammonium nitrate and allowed to carry on photosynthesis in C14O2 for various periods from 12 to 125 min. The radioactivities of the various amino acids formed from C14O2 were determined. In addition, these amino acids were degraded by decarboxylation with ninhydrin. From the specific activity data it was concluded that the amino acid closest to the site of carbon dioxide fixation in photosynthesis was alanine, followed by aspartic and glutamic acids, with the amides farthest removed. From the intramolecular distribution of label it was concluded that asparagine and glutamine were formed from their corresponding amino acids. The labelling in aspartic and glutamic acids was not consistent with the view that these two amino acids are formed from their corresponding α-keto acids produced by operation of the conventional tricarboxylic acid cycle. A C2 plus C2 condensation is postulated for the formation of aspartic acid. A shift in the double bond in the aconitase reaction of the tricarboxylic acid cycle would account for the observed labelling in glutamic acid. When acetate-1-C14 was fed to detached broad bean leaves in the light or dark, the distribution of label in glutamic acid supported the suggestion that there is such a. shift in the double bond in the aconitase reaction. Sodium arsenite, infiltrated into tobacco leaves, inhibited the biosynthesis of asparagine but not that of glutamine.

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 THE RÔLE OF THE TRICARBOXYLIC ACID CYCLE IN ACETATE OXIDATION IN ESCHERICHIA COLI

1956 ◽  
Vol 222 (1) ◽  
pp. 307-319
Author(s):  
Charles Gilvarg ◽  
Bernard D. Davis
Keyword(s):  
Escherichia Coli ◽  
Tricarboxylic Acid Cycle ◽  
Tricarboxylic Acid ◽  
Acetate Oxidation ◽  
Acid Cycle

scholarly journals On the role of the tricarboxylic acid cycle in plant productivity

2018 ◽  
Vol 60 (12) ◽  
pp. 1199-1216 ◽  
Author(s):  
Youjun Zhang ◽  
Alisdair R. Fernie
Keyword(s):  
Tricarboxylic Acid Cycle ◽  
Plant Productivity ◽  
Tricarboxylic Acid ◽  
Acid Cycle

AN ANOMALOUS TRICARBOXYLIC ACID CYCLE IN ACETOBACTER MELANOGENUM

1960 ◽  
Vol 38 (3) ◽  
pp. 193-203 ◽  
Author(s):  
D. H. Bone ◽  
R. M. Hochster
Keyword(s):  
Specific Activity ◽  
Tricarboxylic Acid Cycle ◽  
Tricarboxylic Acid ◽  
Acid Cycle ◽  
Oxidase System ◽  
Isocitric Dehydrogenase ◽  
Highly Active ◽  
Carbon Compounds ◽  
Condensing Enzyme

Extracts of gluconate-grown Acetobacter melanogenum contain condensing enzyme and DPN-isocitric dehydrogenase of low specific activity. No evidence could be found for the presence of phosphotransacetylase, aconitase, or TPN-isocitric dehydrogenase. Since the organism or its extracts cannot synthesize the necessary four carbon compounds from pyruvate and from acetate, it is concluded that the tricarboxylic acid cycle does not function in extracts of this organism in the usually accepted manner.The pyruvic oxidase system was found to be highly active, acetaldehyde being the chief intermediate and acetate the end product. The mechanism for the slow incorporation of acetate into other cell constituents is, at present, unknown.

Sporulation ofGibberella ZeaeIV. Role of the Tricarboxylic-Acid Cycle in Macroconidium Production

Mycologia ◽  
1979 ◽  
Vol 71 (4) ◽  
pp. 688-698 ◽  
Author(s):  
Bor-Fuei Huang ◽  
R. F. Dawson ◽  
R. A. Cappellini
Keyword(s):  
Tricarboxylic Acid Cycle ◽  
Tricarboxylic Acid ◽  
Acid Cycle

scholarly journals Role of Phosphoenolpyruvate in the NADP-Isocitrate Dehydrogenase and Isocitrate Lyase Reaction in Escherichia coli

2006 ◽  
Vol 189 (3) ◽  
pp. 1176-1178 ◽  
Author(s):  
Tadashi Ogawa ◽  
Keiko Murakami ◽  
Hirotada Mori ◽  
Nobuyoshi Ishii ◽  
Masaru Tomita ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Isocitrate Dehydrogenase ◽  
Isocitrate Lyase ◽  
Tricarboxylic Acid Cycle ◽  
Tricarboxylic Acid ◽  
Glyoxylate Shunt ◽  
Acid Cycle ◽  
Uncompetitive Inhibition

ABSTRACT Phosphoenolpyruvate inhibited Escherichia coli NADP-isocitrate dehydrogenase allosterically (Ki of 0.31 mM) and isocitrate lyase uncompetitively (Ki ′ of 0.893 mM). Phosphoenolpyruvate enhances the uncompetitive inhibition of isocitrate lyase by increasing isocitrate, which protects isocitrate dehydrogenase from the inhibition, and contributes to the control through the tricarboxylic acid cycle and glyoxylate shunt.

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