• BMB Reports
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• 제32권2호
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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.

• BMB Reports
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• 제31권3호
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• pp.287-295
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• 1998

Acetolactate synthase (ALS) is the first common enzyme in the biosynthesis of L-Ieucine, L-isoleucine, and L-valine. The sulfonylurea-resistant ALS gene from Nicotiana tabacum was cloned into the bacterial expression vector pGEX-2T. The resulting recombinant plasmid pGEX-ALS3 was used to transform Escherichia coli strain XL1-Blue, and the mutant tobacco ALS (mALS) was expressed in the bacteria as a protein fused with glutathione S-transferase (GST). The fusion product GST-mALS was purified in a single step on a glutathione-Sepharose column. ALS activities of 0.9-2.5 ${\mu}mol/min/mg$ protein were observed in the GST-mALS, and the Km values for pyruvate, FAD, and TPP were 10.8-24.1, $(1.9-8.9){\times}10^{-3}$, and 0.14-0.38 mM, respectively. The purified GST-mALS was resistant to both the sulfonylurea and the triazolopyrimidine herbicides, and lost its sensitivity to end products, L-valine and L-leucine. For comparision, the tobacco wild-type recombinant ALS fused with GST, GST-wALS, was also characterized with respect to its pyruvate and cofactor bindings. These results suggest that the purified mutant recombinant tobacco ALS was functionally active, that the mutations resulting in herbicide resistance has affected pyruvate and cofactor bindings," and that the two classes of herbicides interact at a common site on the plant ALS.

• 한국식품영양과학회지
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• 제14권3호
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• pp.301-304
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• 1985

녹차의 맛을 내는데 주요 성분인 유리아미노산과 유리당을 HPLC로 분석한 결과를 요약하면 다음과 같다. 1. 16종의 유리아미노산이 검출되었다. 즉, aspartic acid, threonine, serine, glutamic acid, proline, glycine, alanine, valine, methionine, isoleucine, leucine, tyrosine, phenylalanine, histidine, lysine, arginine이 그것이었다. 2. 증제차가 볶음차보다 유리아미노산의 함량이 많았고, 녹차중에는 특히 threonine과 aspartic acid, lysine의 함량이 많았다. 3. Fructose, glucose, sucrose, raffinose등 4종의 유리당이 검출되었다. 4. 유리당은 가열시간 증가에 따라 각 성분의 함량이 현저히 감소하였다.

• Journal of Nutrition and Health
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• 제4권1호
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• pp.63-67
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• 1971

(1) 쌀에 있어서 보다 녹두(綠豆)에 있어서 전질소량(全窒素量), 가용성질소양(可溶性窒素量), 단백태질소양(蛋白態窒素量) 및 Alcohal 가용성(可溶性) 질소양(窒素量)이 더욱 많았다. (2) 쌀혼합녹두(混合綠豆)를 지진 경우가 지지기 전(前)보다 전질소양(全窒素量)과 단백태질소양(蛋白態窒素量)이 더 많았고 가용성질소(可溶性窒素), Alcohol 가용성(可溶性) 질소(窒素)에서는 별 차이(差異)가 없었으나 Alcohol 가용성질소(可溶性窒素)에서는 약간의 감소(減少)를 보였다. (3) 녹두(綠豆)를 지짐으로 해서 Valine, ${\gamma}-aminobutyrate$, Glutamine, Arginine, Methionine, Unknown 1,2 가 소실(消失)되었고 Proline, Lysine, Homoserine, Tyrosine은 검출(檢出)되었다. (4) 쌀혼합녹두(混合綠豆)리 지진 경우 지짐으로 해서${\gamma}-aminobutyrate$, Lysine, Histidine, Tyrosine, Cysteine 이 소실(消失)되었고 Phenylalanine, Leucine, ${\beta}-alanine$이 검출(檢出)되었다.

• 분석과학
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• 제7권2호
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• pp.165-171
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• 1994

화학 발암제인 dimetylnitrosamine(DMN)을 Hamster에 구강투여하였을 때 간의 아미노산 조성에 미치는 영향을 규명하기 위하여 reversed phase liquid chromatography법으로 아미노산을 정량하였다. DMN을 투여한 실험군의 간에서의 아미노산의 농도는 대조군에 비해 aspartic acid, glycine, glutamine, histidine, proline, tyrosine, leucine 등은 약 2배, valine, tryptophan은 약 3배, phenylalanine은 약 10배 증가하였고, threonine은 23%로 감소하였으며, serine, alanine, arginine, methionine, isoleucine, lysine은 큰 변화가 없었다.

• 한국식품과학회지
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• 제18권6호
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• pp.492-496
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• 1986

환원탈지유배지에서 자란 Lactobacillus helveticus YM-1의 cell-free filtrate로부터 Streptococcus thermophilus CH-1의 생육촉진을 확인한 결과 이 물질은 분자량이 5,000정도의 peptide로 나타난다. 이 peptide 중에는 aspartic acid, Iysine, proline, leucine, valine, alanine, glutamic acid등의 amino산이 비교적 풍부하였으며, 그중에서 glutamic acid 함량이 가장 높았다. 또 이 Peptide가 생육 촉진효과 나타내는데 가장 중요한 역할을 담당하는 것은 glutamic acid와 Phenylalanine으로 판단되었다.

• 한국식품영양과학회지
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• 제21권3호
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• pp.296-301
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• 1992

고들빼기 잎으로부터 플라보노이드인 luteolin, luteolin 7-0-glucoside 및 apigenin 7-0-glucuronide를 분리하고 그들의 구조를 기기적인 분석방법에 의하여 동정하였으며 또한 유리 아미노산과 관련 화합물들의 조성과 상대함량을 표준품과 동일조건하에서 아미노산 자동분석기로 비교 검토하였다. 가장 함량이 많은 유리 아미노산들은 glutamic acid, aspartic acid, serine, proline, valine 그리고 arginine이었다.

• 한국식품영양과학회지
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• 제21권3호
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• pp.286-290
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• 1992

부추 잎으로부터 purine nucleoside인 adenosine을 분리하고 그 구조를 기기적인 분석방법에 의하여 동정하였으며 또한 유리 아미노산 관련 화합물들의 조성과 상대함량을 표준품과 동일 조건하에서 아미노산 자동 분석 기기로 비교 검토하였다. 가장 함량이 많은 유리 아미노산들은 ala-nine, glutamic acid, aspartic acid 그리고 valine이었다.

• 대한가정학회지
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• 제23권4호
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• pp.55-60
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• 1985

This study was carried out to compare the change of free amino acid content in the radish Kimchi added with anchovy pickle sauce with that added with 15% NaCl solution during 30 days fermentation. RESULTS : 1. During the fermentation, the pH of both sample A and B showed the highest values of 7.3 and 7.1, respectively, and then both decreased continually to the lowest value of 4.2 at the 30th day. 2.The salinity in the juice of sample A was higher than that of sample B in all the steps during fermentation, accompanied with a slight decrease of the salinity in both cases with time elapsed. 3. The free amino-type nitrogen content of sample A was nearly duplicated in the final step than in the initial one,while that of sample B showed no significant changes in all the processing period. 4. The free amino acids detected in the both samples were aspartic acid, threonine, serine, proline, glutamic acid, glycine, alanine, tyrosine, cysteine, valine, methinonine, isoleucine, leucine, phenylalanine, $\gamma-aminobutyrix acid(\ulcorner), ornithine, lysine, histidine and arginine. 5. The amounts of proline, arginine were the highest in all free amino acids during fermentation, and tasty components of radish Kimchi seemed to relate to glutamic acid, alanine, isoleucine, leucine, phenylalanine, more deliciousness of Kimchi A and B seemed to derive from amino acids of anchovy pickle sauce added to Kimci A, such as alanine, valine, phenylalanine, lysine.

• BMB Reports
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• 제30권4호
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• pp.274-279
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• 1997

Acetolactate synthase (ALS) catalyzes the first common step in the biosynthesis of branchedchain amino acids, valine, leucine, and isoleucine. ALS is the target site for several structually diverse classes of herbicides including sulfonylureas, imidazolinones. and triazolopyrimidines. We have purified ALS from etiolated barley shoots to homogeneity. The five major purification steps are ammonium sulfate fractionation, DEAE anion exchange, hydroxylapatite, Bio-Gel A gel filtration, and low pressure Mono-Q chrornatoqraphy. Approximately 170-fold purification was achieved and the yield was 0.45% of initial activity in the crude extract. Both SDS-PAGE and Western blot analysis showed a single polypeptide of ALS with an apparent molecular mass of 64 kDa. The result of nondenaturing gel electrophoresis with activity staining indicated that the molecular mass of its native form is approximately 225 to 250 kDa. The values of $K_m$ for pyruvate. pl. and optimum pH of ALS were determined to be 2.0 mM, 5.2. and 7.0. respectively Feedback inhibition studies showed that ALS is more susceptible to leucine than valine. And $IC_{50}$ value of Cadre, a class of irnidazolinones, is about $1.5\mu{M}$ for ALS.