scholarly journals Biosynthesis of food constituents: Amino acids: 1. The glutamic acid and aspartic acid groups – a review

2011 ◽  
Vol 24 (No. 1) ◽  
pp. 1-10
Author(s):  
J. Velíšek ◽  
K. Cejpek

This review article gives a survey of principal pathways that lead to the biosynthesis of the proteinogenic amino acids of the glutamic acid group (glutamic acid, glutamine, proline, arginine) and aspartic acid group (aspartic acid, asparagine, threonine, methionine, lysine, isoleucine) starting with oxaloacetic acid from the citric acid cycle. There is an extensive use of reaction schemes, sequences, and mechanisms with the enzymes involved and detailed explanations using sound chemical principles and mechanisms.

1957 ◽  
Vol 35 (6) ◽  
pp. 365-371 ◽  
Author(s):  
E. Bilinski ◽  
W. B. McConnell

Glutamic acid, aspartic acid, and threonine isolated from the gluten of wheat plants to which acetate-1-C14 or -2-C14 was administered during growth have been degraded to determine the complete intramolecular distribution of C14. Sixty-three per cent of the activity in glutamic acid arising from acetate-1-C14 was in carbon-5 and 20% in carbon-1; glutamic acid from acetate-2-C14 contained 43% of the activity in carbon-4 and about 18% in each of carbons 2 and 3. Acetate-1-C14 resulted in labelling largely in the terminal carbons of aspartic acid, and acetate-2-C14 preferentially labelled the internal carbons. The results show that the Krebs' citric acid cycle provides a major pathway for the biosynthesis of the dicarboxylic amino acids of wheat gluten.Striking parallelism in the intramolecular distribution of carbon-14 in aspartic acid and threonine demonstrates that these amino acids are closely linked biosynthetically and is in accord with the idea that aspartic acid provides the carbon skeleton for threonine.


1957 ◽  
Vol 35 (1) ◽  
pp. 365-371 ◽  
Author(s):  
E. Bilinski ◽  
W. B. McConnell

Glutamic acid, aspartic acid, and threonine isolated from the gluten of wheat plants to which acetate-1-C14 or -2-C14 was administered during growth have been degraded to determine the complete intramolecular distribution of C14. Sixty-three per cent of the activity in glutamic acid arising from acetate-1-C14 was in carbon-5 and 20% in carbon-1; glutamic acid from acetate-2-C14 contained 43% of the activity in carbon-4 and about 18% in each of carbons 2 and 3. Acetate-1-C14 resulted in labelling largely in the terminal carbons of aspartic acid, and acetate-2-C14 preferentially labelled the internal carbons. The results show that the Krebs' citric acid cycle provides a major pathway for the biosynthesis of the dicarboxylic amino acids of wheat gluten.Striking parallelism in the intramolecular distribution of carbon-14 in aspartic acid and threonine demonstrates that these amino acids are closely linked biosynthetically and is in accord with the idea that aspartic acid provides the carbon skeleton for threonine.


1977 ◽  
Vol 55 (7) ◽  
pp. 840-843 ◽  
Author(s):  
M. Yoshikawa ◽  
H. Masago

Zoosporangial formation in Phytophthora capsici was sensitively inhibited by glucose and other catabolites including sugars, citric acid cycle acids, and amino acids, but was only slightly inhibited by 3-O-methylglucose and 2-deoxyglucose and by other seemingly weak catabolites. The inhibitions were specifically prevented by cyclic AMP among the various related nucleotides evaluated. The reversing effect by cyclic AMP was observed only on zoosporangial formation that was partially repressed by catabolites, but the completely repressed zoosporangial formation could not be reversed by cyclic AMP. Furthermore, cyclic AMP failed in reversing zoosporangial formation that was inhibited by antibiotics such as antimycin A and cycloheximide. The results suggested that the initiation of zoosporangial formation in the fungus is under the control of catabolite repression that is mediated by cyclic AMP.


1966 ◽  
Vol 12 (1) ◽  
pp. 1-4 ◽  
Author(s):  
Edwin C. Gangloff

All of the intermediates of the citric acid cycle are shown to be present in the mycelium of 6-day cultures of P. blakesleeanus grown on glucose and on ammonium sulfate, and fed non-radioactive acetate on the fourth and fifth days and acetate-1-C14 on the fifth day of incubation.The concentration of organic acids and certain amino acids, and their specific activity is reported. The high activity of the latter is thought to indicate the presence of a highly labeled pool of nitrogen compounds persisting from the early anabolic reactions after acetate-1-C14 administration.


1956 ◽  
Vol 34 (2) ◽  
pp. 180-190 ◽  
Author(s):  
W. B. McConnell ◽  
L. K. Ramachandran

The transport of carbon-14 injected into the hollow stems of growing wheat plants in the form of sodium acetate-1-C14 and -2-C14 was studied. The labelling efficiency of the tracer and its distribution among components of the wheat kernels was markedly dependent upon the time of injection. Maximum incorporation of activity occurred with plants which were given the tracer about 80 days after seeding. Sodium acetate-1-C14 was less effective for producing labelled kernels and gave rise to more uniform distribution of carbon-14 among the components, very little carbon-14 being utilized for starch synthesis nearer maturity. A high percentage of the carbon-14 content of the gluten resided in the glutamic acid residues. Glutamic acid-C14 injected into the stems was an efficient source of labelling for the plant. The results are consistent with the view that acetate is utilized by way of the Krebs' citric acid cycle.


2021 ◽  
Vol 22 (2) ◽  
pp. 604
Author(s):  
Dirk Roosterman ◽  
Graeme Stuart Cottrell

In 1937, Sir H. A Krebs first published the Citric Acid Cycle, a unidirectional cycle with carboxylic acids. The original concept of the Citric Acid Cycle from Krebs’ 1953 Nobel Prize lecture illustrates the unidirectional degradation of lactic acid to water, carbon dioxide and hydrogen. Here, we add the heart lactate dehydrogenase•proton-linked monocarboxylate transporter 1 complex, connecting the original Citric Acid Cycle to the flow of energy and material. The heart lactate dehydrogenase•proton-linked monocarboxylate transporter 1 complex catalyses the first reaction of the Citric Acid Cycle, the oxidation of lactate to pyruvate, and thus secures the provision of pyruvic acid. In addition, we modify Krebs’ original concept by feeding the cycle with oxaloacetic acid. Our concept enables the integration of anabolic processes and allows adaption of the organism to recover ATP faster.


1983 ◽  
Vol 3 (4) ◽  
pp. 498-506 ◽  
Author(s):  
Jean Holowach Thurston ◽  
Richard E. Hauhart ◽  
James A. Schiro

The recovery of weanling mice from insulin-induced hypoglycemic stupor–coma after injection of sodium -l(+)-lactate (18 mmol/kg) was as rapid (10 min) as in litter-mates treated with glucose (9 mmol/kg). Stimulated by this dramatic action, we studied the effects of lactate injection on brain carbohydrate and energy metabolism in normal and hypoglycemic mice; blood and liver tissue were also studied. Ten minutes after lactate injection in normal mice, plasma lactate levels increased by 15 mmol/L; plasma glucose levels were unchanged, but the β-hydroxybutyrate concentration fell 59%. In the brains of these animals, glucose levels increased 2.3-fold, and there were significant increases in brain glycogen (10%), glucose-6-phosphate (27%), lactate (68%), pyruvate (37%), citrate (12%), and malate (19%); the increase in α-ketoglutarate (32%) was not significant. Lactate injection reduced the cerebral glucose-use rate 40%. These changes were not due to lactate-induced increases in blood [HCO−3] and pH (examined by injection of 15 mmol/kg sodium bicarbonate). Although lactate injection of hypoglycemic mice doubled levels of glucose in plasma and brain (not significant) and most of the cerebral glycolytic intermediates, values were far below normal (still in the range seen in hypoglycemic animals). By contrast, citrate and α-ketoglutarate levels returned to normal; the large increase in malate was not significant. Reduced glutamate levels increased to normal, and elevated aspartate levels fell below normal. Thus, recovery from hypoglycemic stupor does not necessarily depend on normal levels of plasma and/or brain glucose (or glycolytic intermediates). Near normal levels of the Krebs citric acid cycle intermediates suggest that changes in these metabolites, amino acids, or derived substrates relate to the dramatic recovery of hypoglycemic mice after lactate injection.


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