• The Korean Journal of Food And Nutrition
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• v.9 no.4
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• pp.372-378
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• 1996

The effects of branched chain amino acids and metabolites in growth media on the biosynthesis of Serratia marcescens threonine dehydratase activity were examined. The enzyme activity was decreased above 60% by leucine among the range from 1 to 20 mM, and the enzyme activity was decreased approximately 20% by a low concentration of valine (1 to 4 mM), but not affected at high concentration (20 mM). However, the enzyme activity was increased approximately 100 to 140% by a low concentration of isoleucine (1 to 4 mM), but decreased approximately 25 to 80% at high concentration (15 to 30 mM). The enzyme activity was decreased by 25 and 58% by the simultaneous addition of all three branched chain amino acids at 2 and 10 mM concentration, respectively, but increased by 75 and 50% by the combination addition of isoleucine plus valine and isoleucine plus leucine at 2 mM, respectively. cAMP was decreased the enzyme activity approximately 10 to 40% by a low concentration (1 to 2 mM), but increased by 80% at high concentration (10 mM). These data suggest that S. marcescens threonine dehydratase should be multivalently repressed by branched chain amino acids, but positively regulated by a low isoleucine concentration and may play a regulatory role in an isoleucine biosynthetic pathway unlike the E. coli K-12 enzyme.

• Journal of Genetic Medicine
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• v.11 no.1
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• pp.22-26
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• 2014

Maple syrup urine disease (MSUD) is a disorder that involves the metabolism of branched chain amino acids, arising from a defect in branched-chain ${\alpha}$-keto acid dehydrogenase complex. Mutations have been identified in the BCKDHA, BCKDHB, or DBT genes, which encode different subunits of the BCKDH complex. Although encephalopathy and progressive neurodegeneration are its major manifestations, the severity of the disease may range from the severe classic type to milder intermediate variants. We report two Korean siblings with the milder intermediate MSUD who were diagnosed with MSUD by a combination of newborn screening tests using tandem mass spectrometry and family genetic screening for MSUD. At diagnosis, the patients' plasma levels were elevated for leucine, isoleucine, valine, and alloisoleucine, and branched-chain ${\alpha}$-keto acids and branched-chain ${\alpha}$-hydroxy acids were detected in their urine. BCKDHA, BCKDHB, and DBT analysis was performed, and two novel mutations were identified in BCKDHB. Our patients were thought to have the milder intermediate variant of MSUD, rather than the classic form. Although MSUD is a typical metabolic disease with poor prognosis, better outcomes can be expected if early diagnosis and prompt management are provided, particularly for milder forms of the disease.

• Asian-Australasian Journal of Animal Sciences
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• v.20 no.2
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• pp.295-306
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• 2007

The growth and health of the fetus and neonate are directly influenced by the nutritional and physiological status of sows. Sows are often under catabolic conditions due to restrict feeding program during pregnancy and low voluntary feed intake during lactation. The current restrict feeding program, which aims at controlling energy intake during gestation, results in an inadequate supply of dietary protein for fetal and mammary gland growth. Low voluntary feed intake during lactation also causes massive maternal tissue mobilization. Provision of amino acids and fatty acids with specific functions may enhance the performance of pregnant and lactating sows by modulating key metabolic pathways. These nutrients include arginine, branched-chain amino acids, glutamine, tryptophan, proline, conjugated linoleic acids, docosahexaenoic acid, and eicosapentaenoic acid, which can enhance conception rates, embryogenesis, blood flow, antioxidant activity, appetite, translation initiation for protein synthesis, immune cell proliferation, and intestinal development. The outcome is to improve sow reproductive performance as well as fetal and neonatal growth and health. Dietary supplementation with functional amino acids and fatty acids holds great promise in optimizing nutrition, health, and production performance of sows and piglets. (Supported by funds from Texas Tech, USDA, NLRI-RDA-Korea, and China NSF).

• Korean Journal of Weed Science
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• v.16 no.2
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• pp.122-131
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• 1996

The inhibition characteristics of chlorsulfuron [CHL, 2-chloro-N-[{ (4-methoxy-6-methyl-1,3,5-triazin-2-yl)amino}carbonyl]benzenesulfonamide] and imazaquin [IMA, 2-{4,5-dihydro-4-methyl-4-(1-methy-lethyl)-5-oxo-1H-imidazol-2-yl}-3-quinolinecarboxylic acid] on acetolactate synthase(ALS) activity of corn plants were investigated. CHL and IMA rapidly inhibited ALS activity of corn plants in vitro. Their $I_{50}$ values for ALS activity were 100nM and $5{\mu}M$, respectively, indicating that CHL had 50 times more inhibitory effect on ALS activity than IMA. The first applied herbicide had a dominant inhibitory effect on ALS activity when the two herbicides were applied sequentially. Branched-chain amino acids, valine(Val), leucine(Leu), and isoleucine(Ile) showed a feedback inhibition on ALS activity ; Val or Leu had a more inhibitory effect on ALS activity than Ile. Branchedchain amino acids and CHL or IMA exhibited an additive effect on inhibiting ALS activity. This suggests that branched-chain amino acids inhibit ALS activity by a different mechanisms) from that of CHL or IMA. Apparent ALS activity, which was measured on the basis of the conversion of pyruvate to acetolactate, was decreased by the addition of 2-ketobutyrate into the ALS reaction mixture in a concentration-dependent manner. In addition, kinetic studies revealed that CHL acts as a noncompetitive inhibitor, while IMA acts as an uncompetitive inhibitor to ALS with respect to pyruvate.

• BMB Reports
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• v.32 no.2
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• pp.210-213
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• 1999

In Serratia marcescens, acetolactate produced by the catabolic acetolactate synthase (ALS) is converted into acetoin, its physiological role of which is to maintain intracellular pH homeostasis. In this study, the expression mode of catabolic ALS by aeration and branched-chain amino acids was examined by the ELISA method. The amount of catabolic ALS decreased approximately 93% under aerobic conditions. We also showed that the expression of catabolic ALS decreased approximately 34 % and 65 % in the presence of 2.5 mM and 10 mM leucine, respectively. The repression of catabolic ALS by leucine has not been reported previously. In contrast to leucine, catabolic ALS levels increased approximately 13% and 38% by treatment with 2.5 mM and 10 mM isoleucine, respectively, while valine alone did not have any significant effect on the synthesis of catabolic ALS. The amount of catabolic ALS was also reduced to approximately 32% and 45% in the presence of 10 mM Leu+Ile and Leu+Ile+Val, respectively. The regulatory mode of the Serratia catabolic ALS suggests that catabolic ALS may also have a role in supplying acetolactate as an intermediate of valine and leucine biosynthesis in addition to the maintenance of internal pH.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.8
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• pp.523-530
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• 2019

This study was performed to develop Sulgidduk prepared with different levels (0, 3, 6, 9 and 12%) of defatted mealworm powder and to evaluate the characteristics of this Sulgidduk. We performed an assessment of color values, mechanical properties, general compositions and branched amino acids of Sulgidduk prepared with different levels of defatted mealworm powder. For the color values, the lightness(L) was decreased with increased amount of defatted mealworm powder, while the redness(a) and yellowness(b) were relatively increased. For the mechanical properties, the hardness and gumminess were significantly increased according to the increased amounts of defatted mealworm powder, but the chewiness, springiness and cohesiveness showed significant differences. For the sensory evaluation, the overall quality of Sulgidduk prepared with 6% defatted mealworm powder (MS-6) was higher as compared with that of the other Sulgidduk samples. For the general composition, the moisture and crude ash contents of MS-6 did not shown differences, while the crude protein was higher than those of the control, and the carbohydrate content of the control was higher than that of the MS-6. The contents of branched amino acids (valine, leucine and isoleucine) of MS-6 were higher than those of the control. Therefore, it was concluded that MS-6 could be a protein rich food as a good source of branched amino acids such valine, leucine and isoleucine.

• Journal of the Korean Society of Food Science and Nutrition
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• v.13 no.4
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• pp.451-458
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• 1984

The effects of branched chain amino acids added to a diet on changes in the body weight with or without liver, moist and dry liver weight, protein, DNA, $^3H-thymidine$ incorporation into DNA, ana mitotic index of regenerating liver were studied in partial hepatectomized rat. Experimental diet was a 14.63% casein diet supplemented with 1.49% L-leucine, 0.90% L-isoleucine and 0.98% L-Valine, and control diet was an 18.0% casein. In both diets, 2.54% nitrogen were included. Rats fed experimental diet were significantly increased body weight with or without liver 7 days, and regenerated weight of dry liver and an index of liver regeneration 5 days after partial hepatectomy. Mitotic index, contents of protein and DNA increased in regenerating liver after partial hepatectomy was higher in experimental diet group. This results suggest that branched chain amino acids have an benefitial effect on whole body as well as liver regeneration after partial hepatectomy in rat.

• The Korean Journal of Pesticide Science
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• v.2 no.3
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• pp.1-20
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• 1998

Chlorsulfuron, one of sulfonylurea herbicides acts through inhibition of acetolactate syuthase (EC 4.1.3.18; ALS, also known as acetohydroxyacid synthase) in the branched-chain amino acid biosynthesis process. After chlorsulfuron-ALS interaction, many physiological and metabolic disruptions occur in plants. However, it is not clear how this chlorsulfuron-ALS interaction affects those physiological and metabolic processes and how this interaction leads subsequently to plant death. Several researchers suggested that the death of chlorsulfuron-treated plants might be due to a shortage of the branched-chain amino acids, an accumulation of toxic metabolites, and/or a depletion of photoassimilates. It remains as a mystery presently, however, if such changes result in the plant death. In this review, we discussed how the chlorsulfuran-ALS interaction leads to physiological and metabolic disruptions in plants.

• Bulletin of the Korean Chemical Society
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• v.33 no.12
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• pp.4074-4078
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• 2012

The first step in the common pathway for the biosynthesis of branched chain amino acids is catalyzed by acetohydroxyacid synthase (AHAS). The AHAS is found in plants, fungi and bacteria. With an aim to identify new anti-tuberculosis drugs that inhibit branched chain amino acid biosynthesis, we screened a chemical library against Mycobacterium tuberculosis AHAS. The screening identified four compounds, AVS 2087, AVS 2093, AVS 2236, and AVS 2387 with $IC_{50}$ values of 0.28, 0.21, 3.88, and $0.25{\mu}M$, respectively. Moreover, these four compounds also showed strong inhibition against reconstituted AHAS with $IC_{50}$ values of 0.37, 0.26, 1.0, and $1.18{\mu}M$, respectively. The basic scaffold of the AVS group consists of 1-pyrimidin-2-yl-1H-[1,2,4]-triazole-3-sulfonamide. The most active compound, AVS 2387, showed the lowest total interaction energy -8.75 Kcal/mol and illustrates its binding mode by hydrogen bonding with $H_{\varepsilon}$ of Gln517 with the distance of $2.24{\AA}$.

• Journal of Microbiology and Biotechnology
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• v.33 no.6
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• pp.724-735
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• 2023

NdgR, a global regulator in soil-dwelling and antibiotic-producing Streptomyces, is known to regulate branched-chain amino acid metabolism by binding to the upstream region of synthetic genes. However, its numerous and complex roles are not yet fully understood. To more fully reveal the function of NdgR, phospholipid fatty acid (PLFA) analysis with gas chromatography-mass spectrometry (GC-MS) was used to assess the effects of an ndgR deletion mutant of Streptomyces coelicolor. The deletion of ndgR was found to decrease the levels of isoleucine- and leucine-related fatty acids but increase those of valine-related fatty acids. Furthermore, the defects in leucine and isoleucine metabolism caused by the deletion impaired the growth of Streptomyces at low temperatures. Supplementation of leucine and isoleucine, however, could complement this defect under cold shock condition. NdgR was thus shown to be involved in the control of branched-chain amino acids and consequently affected the membrane fatty acid composition in Streptomyces. While isoleucine and valine could be synthesized by the same enzymes (IlvB/N, IlvC, IlvD, and IlvE), ndgR deletion did not affect them in the same way. This suggests that NdgR is involved in the upper isoleucine and valine pathways, or that its control over them differs in some respect.