STUDIES ON WHEAT PLANTS USING C14 COMPOUNDS: III. THE UTILIZATION OF ACETATE FOR AMINO ACID BIOSYNTHESIS

1957 ◽  
Vol 35 (6) ◽  
pp. 357-363 ◽  
Author(s):  
E. Bilinski ◽  
W. B. McConnell
Keyword(s):  
Amino Acids ◽  
Specific Activity ◽  
Aromatic Amino Acids ◽  
Carboxyl Group ◽  
Acid Biosynthesis ◽  
Methyl Group ◽  
Medium Activity ◽  
Branched Chain ◽  
Direct Incorporation ◽  
Carboxyl Carbon

Sixteen amino acids were isolated from the gluten of wheat plants, the stems of which had been injected with acetate-1-C14 or -2-C14. With both tracers the C14 labelled amino acids varied markedly from each other in specific activity. Glutamic acid, proline, and arginine were most active, followed by the four-carbon amino acids aspartic acid and threonine, while the short-chain amino acids glycine, alanine, serine, and methionine possessed medium activity. Branched-chain and aromatic amino acids, and the two basic amino acids lysine and histidine were weakly labelled, but showed marked differences from each other not only in specific activity but in the relative amounts of carboxyl and methyl groups of acetate incorporated. Acetate-2-C14 generally gave amino acids of highest activity, but acetate-1-C14 was most effective for labelling glycine, histidine, and serine. Partial degradation by ninhydrin decarboxylation clearly showed that the carboxyl group of acetate tended, in general, to appear to a greater extent in the carboxyl group of amino acids than did the methyl group. Direct incorporation of the carboxyl carbon of acetate in C1 of leucine was observed.

STUDIES ON WHEAT PLANTS USING C14 COMPOUNDS: III. THE UTILIZATION OF ACETATE FOR AMINO ACID BIOSYNTHESIS

1957 ◽  
Vol 35 (1) ◽  
pp. 357-363 ◽  
Author(s):  
E. Bilinski ◽  
W. B. McConnell
Keyword(s):  
Amino Acids ◽  
Specific Activity ◽  
Aromatic Amino Acids ◽  
Carboxyl Group ◽  
Acid Biosynthesis ◽  
Methyl Group ◽  
Medium Activity ◽  
Branched Chain ◽  
Direct Incorporation ◽  
Carboxyl Carbon

Sixteen amino acids were isolated from the gluten of wheat plants, the stems of which had been injected with acetate-1-C14 or -2-C14. With both tracers the C14 labelled amino acids varied markedly from each other in specific activity. Glutamic acid, proline, and arginine were most active, followed by the four-carbon amino acids aspartic acid and threonine, while the short-chain amino acids glycine, alanine, serine, and methionine possessed medium activity. Branched-chain and aromatic amino acids, and the two basic amino acids lysine and histidine were weakly labelled, but showed marked differences from each other not only in specific activity but in the relative amounts of carboxyl and methyl groups of acetate incorporated. Acetate-2-C14 generally gave amino acids of highest activity, but acetate-1-C14 was most effective for labelling glycine, histidine, and serine. Partial degradation by ninhydrin decarboxylation clearly showed that the carboxyl group of acetate tended, in general, to appear to a greater extent in the carboxyl group of amino acids than did the methyl group. Direct incorporation of the carboxyl carbon of acetate in C1 of leucine was observed.

scholarly journals Xylo-Oligosaccharides in Prevention of Hepatic Steatosis and Adipose Tissue Inflammation: Associating Taxonomic and Metabolomic Patterns in Fecal Microbiomes with Biclustering

2021 ◽  
Vol 18 (8) ◽  
pp. 4049
Author(s):  
Jukka Hintikka ◽  
Sanna Lensu ◽  
Elina Mäkinen ◽  
Sira Karvinen ◽  
Marjaana Honkanen ◽  
...  
Keyword(s):  
Amino Acids ◽  
Adipose Tissue ◽  
Hepatic Steatosis ◽  
Insulin Signaling ◽  
Aromatic Amino Acids ◽  
Adipose Tissue Inflammation ◽  
Tissue Inflammation ◽  
Beneficial Effects ◽  
Male Wistar Rats ◽  
Branched Chain

We have shown that prebiotic xylo-oligosaccharides (XOS) increased beneficial gut microbiota (GM) and prevented high fat diet-induced hepatic steatosis, but the mechanisms associated with these effects are not clear. We studied whether XOS affects adipose tissue inflammation and insulin signaling, and whether the GM and fecal metabolome explain associated patterns. XOS was supplemented or not with high (HFD) or low (LFD) fat diet for 12 weeks in male Wistar rats (n = 10/group). Previously analyzed GM and fecal metabolites were biclustered to reduce data dimensionality and identify interpretable groups of co-occurring genera and metabolites. Based on our findings, biclustering provides a useful algorithmic method for capturing such joint signatures. On the HFD, XOS-supplemented rats showed lower number of adipose tissue crown-like structures, increased phosphorylation of AKT in liver and adipose tissue as well as lower expression of hepatic miRNAs. XOS-supplemented rats had more fecal glycine and less hypoxanthine, isovalerate, branched chain amino acids and aromatic amino acids. Several bacterial genera were associated with the metabolic signatures. In conclusion, the beneficial effects of XOS on hepatic steatosis involved decreased adipose tissue inflammation and likely improved insulin signaling, which were further associated with fecal metabolites and GM.

scholarly journals Low Energy Diet-induced and Bariatric Surgery-induced Weight Loss Decreases Branched-chain and Aromatic Amino Acids in Plasma and Tissue (P21-078-19)

2019 ◽  
Vol 3 (Supplement_1) ◽  
Author(s):  
Zhanxuan Wu ◽  
Karl Fraser ◽  
Marlena Kruger ◽  
Garth Cooper ◽  
Anne-Thea McGill ◽  
...  
Keyword(s):  
Bariatric Surgery ◽  
Amino Acids ◽  
Weight Loss ◽  
Aromatic Amino Acids ◽  
Fold Change ◽  
Low Energy ◽  
Post Surgery ◽  
T1 And T2 ◽  
Branched Chain ◽  
Low Energy Diet

Abstract Objectives Plasma levels of branched-chain amino acids (BCAA) and aromatic amino acids (AAA) phenylalanine (phe) and tyrosine (tyr) have been associated with obesity, insulin resistance and risk of type 2 diabetes. This study aimed to investigate the response of circulating plasma and tissue levels of BCAA and AAA to weight loss, and to correlate the level of these metabolites in plasma and tissue in obese women. Methods 28 obese (mean BMI 46.2 kg/m2) women underwent low energy diet (LED)-induced weight loss (−9.2 ± 4.2 kg) followed by bariatric surgery-induced weight loss (−23.6 ± 2.5 kg). Plasma at baseline (t0), post-LED/pre-surgery (t1) and 6-month post-surgery (t2) as well as biopsies of subcutaneous abdomen adipose tissue (SAfat), superficial thigh adipose tissue (Tfat) and vastus lateralis thigh muscle (Tmuscle) at both t1 and t2 were collected, and profiled using mass spectrometry-based metabolomics approach. Paired t-tests were applied to assess between-timepoint differences, and Pearson correlation used to calculate correlation coefficient of metabolite levels between plasma and tissue. Results Plasma BCAA and AAA were all significantly reduced post-LED at t1 (fold-change of 0.76–0.85 for val, leu, ile, tyr and phe, P < 0.05) and 6-month post-surgery at t2 (fold-change of 0.74–0.85 for val, leu, ile, tyr and phe, P < 0.05) as compared to baseline t0; but not significant between t1 and t2, although trends of decrease were observed. Among the 3 tissue biopsies, only SAfat showed significantly decreased levels of tyr, leu and ile at t2 compared to t1 (fold-change for tyr 0.63, leu 0.66, ile 0.68, P < 0.05). In addition, plasma levels of val and ile were correlated with Tfat levels at both t1 and t2 (r2 = 0.47–0.57), and that of val, ile and leu were correlated with Tmuscle at t1 only (r2 = 0.64–0.67). Conclusions Circulating levels of BCAA and AAA were decreased by weight loss interventions. The decrease following an LED program was sustained after bariatric surgery without further significant decrease. Bariatric surgery also decreased BCAA levels in SAfat; moreover, our data suggested that plasma BCAA levels correlated well with peripheral tissue Tfat and Tmuscle. Funding Sources The New Zealand National Science Challenge High-Value Nutrition program.

In Vitro adsorption Spectrum of Plasma Amino Acids by Coated Charcoal Hemoperfusion

1983 ◽  
Vol 6 (5) ◽  
pp. 267-270 ◽  
Author(s):  
Z.Q. Shi ◽  
T.M.S. Chang
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Hepatic Coma ◽  
Aromatic Amino Acids ◽  
Molar Ratio ◽  
Adsorption Experiment ◽  
Preferential Adsorption ◽  
Branched Chain ◽  
Charcoal Hemoperfusion

In order to clarify wether coated charcoal hemoperfusion is capable of normalizing amino acid disturbances in hepatic coma, in vitro adsorption and in vitro hemoperfusion studies were carried out. We have found that collodion-coated activated charcoal beads preferentially removed much more aromatic acids (AAA) than branched chain amino acids (BCAA). In the in vitro adsorption experiment with 50 μM amino acid standards aqueous solution, 99% of AAAs were removed by charcoal while only 50 to 81% of BCAAs were removed. As the concentration of amino acids in solution was doubled from μM to 100 μM, BCAA removal was halved while about 90% of AAA was still being removed. In vitro hemoperfusion with heparinized blood from hepatic failure rats, the clearance and the removal of AAAs were significantly greater than those of BCAAs. Consequently, the molar ratio of BCAA over AAA was markedly improved from the initial 1.09 to 3.87 after 60 min of hemoperfusion. Thus, we have demonstrated the preferential adsorption of aromatic amino acids by collodion-coated charcoal beads. The correction of BCAA/AAA molar ratio is also demonstrated.

scholarly journals Effects Of Menstrual Cycle On Branched-chain And Aromatic Amino Acids During Endurance Exercise In Female Athletes

2019 ◽  
Vol 51 (Supplement) ◽  
pp. 547
Author(s):  
Mikako Sakamaki-Sunaga ◽  
Kayoko Kamemoto ◽  
Mizuki Yamada ◽  
Tomoka Matsuda ◽  
Hazuki Ogata
Keyword(s):  
Amino Acids ◽  
Menstrual Cycle ◽  
Endurance Exercise ◽  
Female Athletes ◽  
Aromatic Amino Acids ◽  
Branched Chain

scholarly journals CodY-Regulated Aminotransferases AraT and BcaT Play a Major Role in the Growth of Lactococcus lactis in Milk by Regulating the Intracellular Pool of Amino Acids

2003 ◽  
Vol 69 (6) ◽  
pp. 3061-3068 ◽  
Author(s):  
Emilie Chambellon ◽  
Mireille Yvon
Keyword(s):  
Amino Acids ◽  
Growth Inhibition ◽  
Lactococcus Lactis ◽  
Double Mutant ◽  
Wild Type Strain ◽  
Aromatic Amino Acids ◽  
Nitrogen Sources ◽  
Nutritional Factors ◽  
Keto Acids ◽  
Branched Chain

ABSTRACT Aminotransferases, which catalyze the last step of biosynthesis of most amino acids and the first step of their catabolism, may be involved in the growth of Lactococcus lactis in milk. Previously, we isolated two aminotransferases from L. lactis, AraT and BcaT, which are responsible for the transamination of aromatic amino acids, branched-chain amino acids, and methionine. In this study, we demonstrated that double inactivation of AraT and BcaT strongly reduced the growth of L. lactis in milk. Supplementation of milk with amino acids and keto acids that are substrates of both aminotransferases did not improve the growth of the double mutant. On the contrary, supplementation of milk with isoleucine or a dipeptide containing isoleucine almost totally inhibited the growth of the double mutant, while it did not affect or only slightly affected the growth of the wild-type strain. These results suggest that AraT and BcaT play a major role in the growth of L. lactis in milk by degrading the intracellular excess isoleucine, which is responsible for the growth inhibition. The growth inhibition by isoleucine is likely to be due to CodY repression of the proteolytic system, which is necessary for maximal growth of L. lactis in milk, since the growth of the CodY mutant was not affected by addition of isoleucine to milk. Moreover, we demonstrated that AraT and BcaT are part of the CodY regulon and therefore are regulated by nutritional factors, such as the carbohydrate and nitrogen sources.

Branched-chain and aromatic amino acids and cardiometabolic risk in Black African and Asian Indian populations

Metabolomics ◽  
2020 ◽  
Vol 16 (10) ◽  
Author(s):  
Lungile Khambule ◽  
Tracy Snyman ◽  
Shane A. Norris ◽  
Nigel J. Crowther ◽  
Jaya A. George
Keyword(s):  
Amino Acids ◽  
Asian Indian ◽  
Cardiometabolic Risk ◽  
Aromatic Amino Acids ◽  
Black African ◽  
Indian Populations ◽  
Branched Chain

BCAA intake affects protein metabolism in muscle after but not during exercise in humans

2001 ◽  
Vol 281 (2) ◽  
pp. E365-E374 ◽  
Author(s):  
Eva Blomstrand ◽  
Bengt Saltin
Keyword(s):  
Amino Acids ◽  
Recovery Period ◽  
Aromatic Amino Acids ◽  
Branched Chain Amino Acids ◽  
Cycle Exercise ◽  
Placebo Condition ◽  
Muscle Concentration ◽  
Branched Chain ◽  
Sparing Effect ◽  
Exercise In Humans

Branched-chain amino acids (BCAA) or a placebo was given to seven subjects during 1 h of ergometer cycle exercise and a 2-h recovery period. Intake of BCAA did not influence the rate of exchange of the aromatic amino acids, tyrosine and phenylalanine, in the legs during exercise or the increase in their concentration in muscle. The increase was ∼30% in both conditions. On the other hand, in the recovery period after exercise, a faster decrease in the muscle concentration of aromatic amino acids was found in the BCAA experiment (46% compared with 25% in the placebo condition). There was also a tendency to a smaller release (an average of 32%) of these amino acids from the legs during the 2-h recovery. The results suggest that BCAA have a protein-sparing effect during the recovery after exercise, either that protein synthesis has been stimulated and/or protein degradation has decreased, but the data during exercise are too variable to make any conclusions about the effects during exercise. The effect in the recovery period does not seem to be mediated by insulin.

Amino Acid Metabolism in Plants. III. Purification and Some Properties of a Multispecific Aminotransferase Isolated from Bushbean Seedlings (Phaseolus vulgaris L.)

1972 ◽  
Vol 50 (7) ◽  
pp. 813-829 ◽  
Author(s):  
J. C. Forest ◽  
F. Wightman
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Aspartic Acid ◽  
Aspartate Aminotransferase ◽  
Soluble Protein ◽  
Specific Activity ◽  
Aromatic Amino Acids ◽  
Total Activity ◽  
Aminotransferase Activity ◽  
Aromatic Aminotransferase

The development of aromatic aminotransferase activity was examined in cotyledons, roots, and shoots of bushbean seedlings growing under light or dark conditions for the first 2 weeks after germination. All three aromatic amino acid – α-ketoglutarate aminotransferase activities were found to have similar patterns of development in comparable organs grown under the two environmental conditions, and the changes in levels of activity appeared unrelated to variations in the endogenous amounts of free aromatic amino acids in the organs of these seedlings. The highest total activity for all three transamination reactions was found in the shoots of light-grown seedlings after 14 days, whereas the aminotransferases showing highest specific activity were found in roots of both kinds of seedlings after 8 days of growth. The intracellular distribution of the three aromatic aminotransferase activities and of aspartate aminotransferase activity was investigated by differential centrifugation of root homogenates. Only a total of 10% of these two activities was found in the two particulate fractions; the soluble protein in the final supernatant fraction accounted for almost 90% of the total aromatic and aspartate aminotransferase activities.The aromatic aminotransferase in the soluble protein fraction from seedling roots was purified about 600-fold by pH precipitation, ammonium sulfate fractionation, and Sephadex chromatography, and the recovery obtained was 30–35% based on total activity. It was observed that the specific activity for aspartate–α-ketoglutarate aminotransferase increased proportionally to the increase in aromatic aminotransferase activities during the different steps of purification. Gel electrophoresis of the purified fraction revealed only one protein band which corresponded to the product-specific stained band for the three aromatic aminotransferase activities assayed on other gels. The molecular weight of the purified aminotransferase was found to be about 128 000 daltons and its Stokes radius was calculated to be 43 ± 3 Å. The pH optima for the three aromatic aminotransferase activities and for aspartate aminotransferase activity were all found to be 8.5. The purified enzyme showed no specific requirement for pyridoxal phosphate and an examination of its amino acid substrate specificity revealed that it was able to catalyze transamination of L-aspartic acid, L-phenylalanine, L-tyrosine, and L-tryptophan when α-ketoglutarate was provided as amino group acceptor. The enzyme was also found to catalyze transamination of L-glutamic acid when oxaloacetate was used as amino group acceptor, but neither pyruvate nor glyoxylate were utilized as amino acceptors for transamination of any of the amino acids examined. The enzyme was found to catalyze transamination of aspartic acid with much greater velocity than its rate of reaction with any of the three aromatic amino acids, and the inclusion of aspartic acid in a reaction medium at equimolar concentration with any one of the three aromatic amino acids resulted in strong inhibition of the aromatic aminotransferase activity of the enzyme. All the evidence indicates that the soluble protein fraction purified from bushbean roots contained only one aminotransferase which was able to catalyze the transamination of five L-amino acids. The demonstration of the substrate multispeciftcity of this pure enzyme represents the first evidence for a multispecific aminotransferase in plants.

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