scholarly journals Studies with Isolated Surviving Rat Hearts. Interdependence of Free Amino Acids and Citric-Acid-Cycle Intermediates

1973 ◽  
Vol 38 (1) ◽  
pp. 86-97 ◽  
Author(s):  
E. Jack Davis ◽  
Jon Bremer
Keyword(s):  
Amino Acids ◽  
Citric Acid ◽  
Free Amino Acids ◽  
Free Amino ◽  
Citric Acid Cycle ◽  
Acid Cycle ◽  
Rat Hearts

scholarly journals Green extraction of proteins, umami and other free amino acids from brown macroalgae Ascophyllum nodosum and Fucus vesiculosus

2021 ◽  
Author(s):  
Viruja Ummat ◽  
Marco Garcia-Vaquero ◽  
Mahesha M. Poojary ◽  
Marianne N. Lund ◽  
Colm O’Donnell ◽  
...  
Keyword(s):  
Amino Acids ◽  
Citric Acid ◽  
Free Amino Acids ◽  
Free Amino ◽  
Food Industry ◽  
Ascophyllum Nodosum ◽  
Fucus Vesiculosus ◽  
Green Solvents ◽  
Brown Macroalgae ◽  
Extraction Solvent

AbstractSeaweeds are a valuable potential source of protein, as well as free amino acids (FAAs) with umami flavour which are in high demand by the food industry. The most commonly used flavouring agents in the food industry are chemically synthesised and therefore are subject to concerns regarding their safety and associated consumer resistance. This study focuses on the effects of extraction time (1 and 2 h) and solvents (0.1 M HCl, 1% citric acid and deionised water) on the extraction of protein and FAAs including umami FAAs from Irish brown seaweeds (Ascophyllum nodosum and Fucus vesiculosus). Extraction yields were influenced by both the extraction solvent and time, and also varied according to the seaweed used. Both seaweeds investigated were found to be good sources of protein, FAAs including umami FAAs, demonstrating potential application as flavouring agents in the food industry. Overall, the use of green solvents (deionised water and citric acid) resulted in higher recoveries of compounds compared to HCl. The results of this study will facilitate the use of more sustainable solvents in industry for the extraction of proteins and flavouring agents from seaweed.

Effect of cyclic AMP on catabolite-repressed zoosporangial formation in Phytophthora capsici

1977 ◽  
Vol 55 (7) ◽  
pp. 840-843 ◽  
Author(s):  
M. Yoshikawa ◽  
H. Masago
Keyword(s):  
Amino Acids ◽  
Citric Acid ◽  
Cyclic Amp ◽  
Catabolite Repression ◽  
Citric Acid Cycle ◽  
Phytophthora Capsici ◽  
Antimycin A ◽  
Acid Cycle

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.

STUDIES ON WHEAT PLANTS USING C14 COMPOUNDS: IV. DISTRIBUTION OF C14 IN GLUTAMIC ACID, ASPARTIC ACID, AND THREONINE ARISING FROM ACETATE-1-C14 AND -2-C14

1957 ◽  
Vol 35 (6) ◽  
pp. 365-371 ◽  
Author(s):  
E. Bilinski ◽  
W. B. McConnell
Keyword(s):  
Amino Acids ◽  
Citric Acid ◽  
Glutamic Acid ◽  
Aspartic Acid ◽  
Citric Acid Cycle ◽  
Carbon Skeleton ◽  
Major Pathway ◽  
Acid Cycle ◽  
Carbon 14

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.

13C-NMR spectroscopic evaluation of the citric acid cycle flux in conditions of high aspartate transaminase activity in glucose-perfused rat hearts

Biochimie ◽  
1998 ◽  
Vol 80 (12) ◽  
pp. 1013-1024 ◽  
Author(s):  
Son Tran-Dinh ◽  
Jacqueline A. Hoerter ◽  
Philippe Mateo ◽  
Franck Gyppaz ◽  
Martine Herve
Keyword(s):  
Citric Acid ◽  
13C Nmr ◽  
Citric Acid Cycle ◽  
Aspartate Transaminase ◽  
Transaminase Activity ◽  
Acid Cycle ◽  
Rat Hearts ◽  
Perfused Rat Hearts

scholarly journals Probing the Origin of Acetyl-CoA and Oxaloacetate Entering the Citric Acid Cycle from the13C Labeling of Citrate Released by Perfused Rat Hearts

1997 ◽  
Vol 272 (42) ◽  
pp. 26117-26124 ◽  
Author(s):  
Blandine Comte ◽  
Geneviève Vincent ◽  
Bertrand Bouchard ◽  
Christine Des Rosiers
Keyword(s):  
Citric Acid ◽  
Citric Acid Cycle ◽  
Acetyl Coa ◽  
Acid Cycle ◽  
Rat Hearts ◽  
Perfused Rat Hearts

Propionyl-L-carnitine-mediated improvement in contractile function of rat hearts oxidizing acetoacetate

1995 ◽  
Vol 268 (1) ◽  
pp. H441-H447 ◽  
Author(s):  
R. R. Russell ◽  
J. I. Mommessin ◽  
H. Taegtmeyer
Keyword(s):  
Citric Acid ◽  
Citric Acid Cycle ◽  
Mechanical Performance ◽  
Ketone Bodies ◽  
Contractile Function ◽  
Sustained Improvement ◽  
Acid Cycle ◽  
Rat Hearts ◽  
Beta Hydroxybutyrate ◽  
Contractile Failure

Prior evidence has suggested that propionyl-L-carnitine improves function in ischemic hearts by providing carnitine for dissipation of acyl-CoA derivatives and propionate for enrichment of the citric acid cycle. Because contractile failure in hearts oxidizing ketone bodies is due to sequestration of free coenzyme A, which can be reversed by the addition of anaplerotic substrates that enrich the citric acid cycle, experiments were performed to determine whether the addition of propionyl-L-carnitine (2 mM) can improve performance in working rat hearts utilizing acetoacetate (7.5 mM). Whereas the addition of propionyl-L-carnitine to acetoacetate resulted in a sustained improvement in the work output of the heart, the addition of propionate (2 mM) or L-carnitine (2 mM) alone to acetoacetate had negligible effects on contractile function. Propionyl-L-carnitine increased the uptake of acetoacetate by 130%, whereas beta-hydroxybutyrate release was minimal and unchanged compared with other groups. These observations show that rates of acetoacetate oxidation are increased commensurate with increased contractile function. Tissue metabolite data indicate that the utilization of propionyl-L-carnitine did not lead to accumulation of citric acid cycle intermediates in the span from citrate to 2-oxoglutarate but to an increase in the tissue content of malate. The results show that addition of propionyl-L-carnitine in hearts oxidizing acetoacetate results in improved mechanical performance that is comparable to the mechanical performance of hearts perfused with glucose as the only substrate. This improvement is most likely conferred by anaplerosis, as suggested by enhanced rates of acetoacetate utilization and citric acid flux.

Use of a single 13C NMR resonance of glutamate for measuring oxygen consumption in tissue

1999 ◽  
Vol 277 (6) ◽  
pp. E1111-E1121 ◽  
Author(s):  
F. Mark H. Jeffrey ◽  
Alexander Reshetov ◽  
Charles J. Storey ◽  
Rui A. Carvalho ◽  
A. Dean Sherry ◽  
...  
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Oxygen Consumption ◽  
Citric Acid ◽  
Magnetic Resonance ◽  
Citric Acid Cycle ◽  
Single Measurement ◽  
Acid Cycle ◽  
Nmr Data ◽  
Rat Hearts ◽  
C Nmr

A kinetic model of the citric acid cycle for calculating oxygen consumption from13C nuclear magnetic resonance (NMR) multiplet data has been developed. Measured oxygen consumption (MV˙o 2) was compared with MV˙o 2 predicted by the model with 13C NMR data obtained from rat hearts perfused with glucose and either [2-13C]acetate or [3-13C]pyruvate. The accuracy of MV˙o 2 measured from three subsets of NMR data was compared: glutamate C-4 and C-3 resonance areas; the doublet C4D34 (expressed as a fraction of C-4 area); and C-4 and C-3 areas plus several multiplets of C-2, C-3, and C-4. MV˙o 2 determined by set 2(C4D34 only) gave the same degree of accuracy as set 3(complete data); both were superior to set 1(C-4 and C-3 areas). Analysis of the latter suffers from the correlation between citric acid cycle flux and exchange between α-ketoglutarate and glutamate, resulting in greater error in estimating MV˙o 2. Analysis of C4D34 is less influenced by correlation between parameters, and this single measurement provides the best opportunity for a noninvasive measurement of oxygen consumption.

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