scholarly journals New insights into the role of the branched-chain aminotransferase proteins in the human brain

2015 ◽  
Vol 93 (7) ◽  
pp. 987-998 ◽  
Author(s):  
Jonathon Hull ◽  
Vinood B. Patel ◽  
Susan M. Hutson ◽  
Myra E. Conway
2002 ◽  
Vol 71 (2) ◽  
pp. 863-874 ◽  
Author(s):  
S. M. Hutson ◽  
D. Berkich ◽  
P. Drown ◽  
Baiyang Xu ◽  
Michael Aschner ◽  
...  

2012 ◽  
Vol 123 (6) ◽  
pp. 997-1009 ◽  
Author(s):  
Jonathon Hull ◽  
Maya El Hindy ◽  
Patrick G. Kehoe ◽  
Katy Chalmers ◽  
Seth Love ◽  
...  

2000 ◽  
Vol 66 (2) ◽  
pp. 571-577 ◽  
Author(s):  
Mireille Yvon ◽  
Emilie Chambellon ◽  
Alexander Bolotin ◽  
Florence Roudot-Algaron

ABSTRACT In Lactococcus lactis, which is widely used as a starter in the cheese industry, the first step of aromatic and branched-chain amino acid degradation is a transamination which is catalyzed by two major aminotransferases. We have previously purified and characterized biochemically and genetically the aromatic aminotransferase, AraT. In the present study, we purified and studied the second enzyme, the branched-chain aminotransferase, BcaT. We cloned and sequenced the corresponding gene and used a mutant, along with the luciferase gene as the reporter, to study the role of the enzyme in amino acid metabolism and to reveal the regulation of gene transcription. BcaT catalyzes transamination of the three branched-chain amino acids and methionine and belongs to class IV of the pyridoxal 5′-phosphate-dependent aminotransferases. In contrast to most of the previously described bacterial BcaTs, which are hexameric, this enzyme is homodimeric. It is responsible for 90% of the total isoleucine and valine aminotransferase activity of the cell and for 50 and 40% of the activity towards leucine and methionine, respectively. The original role of BcaT was probably biosynthetic since expression of its gene was repressed by free amino acids and especially by isoleucine. However, in dairy strains, which are auxotrophic for branched-chain amino acids, BcaT functions only as a catabolic enzyme that initiates the conversion of major aroma precursors. Since this enzyme is still active under cheese-ripening conditions, it certainly plays a major role in cheese flavor development.


2008 ◽  
Vol 35 (S 01) ◽  
Author(s):  
C Helmchen ◽  
J Klinkenstein ◽  
T Sander ◽  
J Gliemroth ◽  
B Machner ◽  
...  

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Cai Tan ◽  
Zhihua Zheng ◽  
Xiaogang Wan ◽  
Jiaqing Cao ◽  
Ran Wei ◽  
...  

AbstractThe change in gut microbiota is an important mechanism of the amelioration of type 2 diabetes mellitus (T2DM) after bariatric surgery. Here, we observe that the modified jejunoileal bypass effectively decreases body weight gain, fasting blood glucose, and lipids level in serum; additionally, islet β-cell function, glucose tolerance, and insulin resistance were markedly ameliorated. The hypoglycemic effect and the improvement in islet β-cell function depend on the changes in gut microbiota structure. modified jejunoileal bypass increases the abundance of gut Escherichia coli and Ruminococcus gnavus and the levels of serum glycine, histidine, and glutamine in T2DM rats; and decreases the abundance of Prevotella copri and the levels of serum branched chain amino acids, which are significantly related to the improvement of islet β-cell function in T2DM rats. Our results suggest that amino acid metabolism may contribute to the islet β-cell function in T2DM rats after modified jejunoileal bypass and that improving gut microbiota composition is a potential therapeutic strategy for T2DM.


2021 ◽  
Vol 11 (8) ◽  
pp. 960
Author(s):  
Mina Kheirkhah ◽  
Philipp Baumbach ◽  
Lutz Leistritz ◽  
Otto W. Witte ◽  
Martin Walter ◽  
...  

Studies investigating human brain response to emotional stimuli—particularly high-arousing versus neutral stimuli—have obtained inconsistent results. The present study was the first to combine magnetoencephalography (MEG) with the bootstrapping method to examine the whole brain and identify the cortical regions involved in this differential response. Seventeen healthy participants (11 females, aged 19 to 33 years; mean age, 26.9 years) were presented with high-arousing emotional (pleasant and unpleasant) and neutral pictures, and their brain responses were measured using MEG. When random resampling bootstrapping was performed for each participant, the greatest differences between high-arousing emotional and neutral stimuli during M300 (270–320 ms) were found to occur in the right temporo-parietal region. This finding was observed in response to both pleasant and unpleasant stimuli. The results, which may be more robust than previous studies because of bootstrapping and examination of the whole brain, reinforce the essential role of the right hemisphere in emotion processing.


2011 ◽  
Vol 212 (1) ◽  
pp. 85-94 ◽  
Author(s):  
Megan N Purpera ◽  
Li Shen ◽  
Marzieh Taghavi ◽  
Heike Münzberg ◽  
Roy J Martin ◽  
...  

Elevation of dietary or brain leucine appears to suppress food intake via a mechanism involving mechanistic target of rapamycin, AMPK, and/or branched chain amino acid (BCAA) metabolism. Mice bearing a deletion of mitochondrial branched chain aminotransferase (BCATm), which is expressed in peripheral tissues (muscle) and brain glia, exhibit marked increases in circulating BCAAs. Here, we test whether this increase alters feeding behavior and brain neuropeptide expression. Circulating and brain levels of BCAAs were increased two- to four-fold in BCATm-deficient mice (KO). KO mice weighed less than controls (25.9 vs 20.4 g,P<0.01), but absolute food intake was relatively unchanged. In contrast to wild-type mice, KO mice preferred a low-BCAA diet to a control diet (P<0.05) but exhibited no change in preference for low- vs high-protein (HP) diets. KO mice also exhibited low leptin levels and increased hypothalamicNpyandAgrpmRNA. Normalization of circulating leptin levels had no effect on either food preference or the increasedNpyandAgrpmRNA expression. If BCAAs act as signals of protein status, one would expect reduced food intake, avoidance of dietary protein, and reduction in neuropeptide expression in BCATm-KO mice. Instead, these mice exhibit an increased expression of orexigenic neuropeptides and an avoidance of BCAAs but not HP. These data thus suggest that either BCAAs do not act as physiological signals of protein status or the loss of BCAA metabolism within brain glia impairs the detection of protein balance.


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