• 한국연초학회지
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• 제11권2호
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• pp.203-210
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• 1989

Leucine and isoleucine were reacted with glucose in a propylene glycol solution and volatile compounds produced from these reaction were analysed by gas chromatography and mass spectrometry. A total of 24 compounds were identified in the leucine reaction volatiles and the major components were 2-isopropyl-5-methyl-2-hexenal, methylbutyraldehyde PGA, butyraldehyde PGA, 5-methylfur-fural, isopropylmethylhexenal PGA and 2-acetylpyrrole. From the isoleucing reaction volatiles, 20 compounds were identified and the major components were methylbutyraldehyde PGA, butyraldehyde PGA and 2-acetylpyrrole. The amino acids chosen for this study were considered as giving fruity and cocoa aroma when heated with glucose.

• BMB Reports
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• 제28권6호
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• pp.494-498
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• 1995

Maize mitochondrial tRNAs for isoleucine have been isolated using a putative $tRNA^{Ile}$ gene probe which has been previously isolated and characterized. It contains the 5'-CAT anticodon which would normally recognize the AUG methionine codon. The nucleotide sequence of one of these tRNAs has been partially determined, and contains a modified nucleotide at the first position of the anticodon. This type of posttranscriptional modification event could change the specificity of amino acid acceptance of a tRNA, unlike that deduced from the corresponding gene. An aminoacylation experiment also demonstrated that these purified tRNAs have isoleucine acceptance activity but no methionine-accepting activity.

• 한국식품영양학회지
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• 제9권4호
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• pp.372-378
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• 1996

최소 배지에 여러 아미노산을 첨가하여 배양시킨 Serratia marcescens ATCC 25419 세포 추출물에서 threonine dehydratase의 비활성을 조사한 결과 이소루신은 1~4mM에서 효소의 비활성을 100~140% 정도 증가시킨 반면 15~30mM에서 25~80% 정도 감소시켰다. 루신은 효소의 비활성을 1~120mM에서 60% 이상 감소시켰다. 한편, 발린은 효소의 비활성을 1~4mM에서 20% 정도, 8~10mM에서 10% 정도 감소시켰으나 20mM에서 효소의 비활성을 원래대로 회복시켰다. 각 2mM 농도의 이소루신과 발린 그리고 이소루신과 루신은 효소의 비활성을 각각 75, 50%씩 증가시킨 반면 세 아미노산을 각각 2과 10mM씩 동시 첨가했을 경우에는 각각 25, 58%씩 감소시켰다. 글리옥실산은 효소의 비활성을 75%, 이마다졸, 피루브산, $\alpha$-아미노부티르산 그리고 AMP는 모두 50%씩, 호모세린, $\alpha$-케토글루타르산, $\alpha$-케토부티르산 및 IPTG를 첨가했을 경우는 모두 25%씩 감소시켰다. cAMP는 효소의 비활성을 1~2mM에서 10~40% 정도 감소시킨 반면 10mM에서 80% 증가시켰다. 이러한 결과들로부터 S. marcescens threonine dehydratase는 E. coli K-12 효소와는 다르게 낮은 농도의 이소루신에 의해 효소의 비활성이 증가되고, 높은 농도의 이소루신 (10~30mM)에 의해서는 감소되는 등 이소루신 생합성 과정에서 조절 역할을 하는 것으로 생각된다.

• Natural Product Sciences
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• 제7권2호
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• pp.27-32
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• 2001

In addition to known cucurbitacins, a glucosphingosine type cerebroside and amino acids were isolated from the roots of Trichosanthes kirilowii. The structure of cerebroside was determined as soya-cerebroside I by means of spectroscopic methods. Fifteen amino acids were identified as aspartic acid, glutamic acid, serine, glycine, histidine, citrulline, threonine, alanine, proline, tyrosine, valine, isoleucine, leucine, phenylalanine and tryptophan, among which the major components such as citrulline, phenylalanine, leucine/isoleucine and valine were isolated.

• Mycobiology
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• 제33권1호
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• pp.23-29
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• 2005

The effects of different concentrations of three amino acids as carbon and or nitrogen sources on mycelial dry weights, changes in pH values of synthetic medium, ammonia secretion and extracellular protease activity by three zoosporic fungi, pathogens of fish and shellfish, were studied. As compared with the control, the addition of isoleucine and aspartic acid as nitrogen sources were generally stimulative for mycelial dry weight production whereas phenylalanine was inhibitory irrespective to the tested fungal species. When amino acids served as carbon and nitrogen sources, the mycelial dry weights of the three fungi were increased (mostly non-significantly) relative to untreated control but weights were decreased as the concentrations of the three amino acids raised. The addition of individual amino acids as carbon and nitrogen sources to the medium significantly increased pH values of the medium comparable to the control. The addition of each of the three amino acids as carbon and nitrogen sources to the medium significantly induced ammonia secretion by the three species of zoosporic fungi. Ammonia secretion in synthetic medium amended with amino acids as nitrogen source raised by the three zoosporic fungi relative to untreated control except in case of Achlya racemosa treated with isoleucine. Extracellular protease activity was almost promoted in case of Achlya proliferoides and Saprolegnia furcata cultures treated with isoleucine and aspartic acid individually in presence of glucose and vice versa in case of phenylalanine. However, extracellular protease activity of A. racemosa decreased compared with the control at various concentrations of isoleucine and both phenylalanine and aspartic acid assumed inconsistent effects. Extracellular protease activity of the three zoosporic fungi in the medium devoid of glucose varied depending upon zoosporic fungal species, the tested amino acid and the applied concentrations. The values of protease activity were approximately less two folds than that obtained in presence of glucose.

• Journal of Nutrition and Health
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• 제13권3호
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• pp.150-154
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• 1980

한국에서 생산된 녹두의 성숙 중에 아미노산의 변화를 구명하기 위하여 개화 후 10일, 15일 20 일, 25일과 30일의 5단계로 취하여 분석한 결과를 요약하면 다음과 같다. 1) 초기에 검출된 아미노산은 histidine, arginine, cystine, aspartic acid, threonine(Serine 포함), glutamic acid와 valine이었고 methionine sulfoxide와 methionine sulfone도 나타났다. 2) 15일에는 초기의 것에 glycine, isoleucine, tyrosine, phenylalanine과 methionine의 5종(種)이 더 검출되었으며, methionine sulfoxide와 methionine sulfone의 양이 감소하면서 methionine이 나타났다. 3) 중기에 leucine이 나타났고 성숙하면서 약간의 증가를 보였고 25일 이후에는 methionine sulfoxide와 methionine sulfone이 검출되지 않는 대신 methionine 앙이 증가하였다. 4) 개화 20일 이후의 아미노산은 완숙기까지 계속 존재하였고 증가된 아미노산은 leucine, valine, isoleucine과 methionine이었으며, 그 외 대부분은 감소 또는 그대로 남았다.

• KSBB Journal
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• 제17권6호
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• pp.515-519
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• 2002

발아현미를 생산하기 위하여 현미를 물에 침지, 키토산을 젖산에 용해하여 침지, 키토산을 글루탐산에 용해하여 침지 하였으며, 발아시키지 않은 현미와 아미노산 및 총 단백질 함량을 비교 분석하였다. 키토산을 50 ppm 되게 5 mM glutamic acid에 용해하여 침지액으로 사용한 경우 가장 높은 alanine, serine, lysine, isoleucine, methionine 함량의 증진과 총 유리아미노산 함량의 증진을 보였다. 또한 total soluble protein의 함량은 발아하지 않은 현미에 비하여 발아한 현미가 모두 낮았다. 특히 CG구는 물발아나 CL 발아시 현저히 감소되던 serine의 함량을 오히려 증진시겼다. 모든 발아구에서 aspartic acid 함량은 현저히 감소하였다. 이는 발아 과정에 의해 aspartic acid가 alanine, lysine, isoleucine, methionine 등으로 전환된 것에 기인된 것이라 여겨진다. 이상의 결과를 종합하면 현미발아시 키토산을 글루탐산에 용해하여 침지액으로 사용하면 유용한 아미노산인 alanine, serine 및 필수아미노산인 lysine, isoleucine, methionine 함량을 현저히 증진시킬 수 있어 영양성이 보강된 발아현미를 얻을 수 있을 것으로 기대된다.

• Journal of Microbiology and Biotechnology
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• 제17권10호
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• pp.1682-1687
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• 2007

The differences in the nonvolatile metabolites of pine-mushrooms (Tricholoma matsutake Sing.) according to different parts and heating times were analyzed by applying principal component analysis (PCA) to $^1H$ nuclear magnetic resonance (NMR) spectroscopy data. The $^1H$ NMR spectra and PCA enabled the differences of nonvolatile metabolites among mushroom samples to be clearly observed. The two parts of mushrooms could be easily discriminated based on PC 1, and could be separated according to different heattreated times based on PC 3. The major peaks in the $^1H$ NMR spectra that contributed to differences among mushroom samples were assigned to trehalose, succinic acid, choline, leucine/isoleucine, and alanine. The content of trehalose was higher in the pileus than in the stipe of all mushroom samples, whereas succinic acid, choline, and leucine/isoleucine were the main components in the stipe. Heating resulted in significant losses of alanine and leucine/isoleucine, whereas succinic acid, choline, and trehalose were the most abundant components in mushrooms heat-treated for 3 min and 5 min, respectively.

• BMB Reports
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• 제49권5호
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• pp.282-287
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• 2016

Tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) is a homo-trimeric cytotoxic ligand. Several studies have demonstrated that incorporation of artificial trimerization motifs into the TRAIL protein leads to the enhancement of biological activity. Here, we show that linkage of the isoleucine zipper hexamerization motif to the N-terminus of TRAIL, referred as ILz(6):TRAIL, leads to multimerization of its trimeric form, which has higher cytotoxic activity compared to its native state. Size exclusion chromatography of ILz(6):TRAIL revealed possible existence of various forms such as trimeric, hexameric, and multimeric (possibly containing one-, two-, and multi-units of trimeric TRAIL, respectively). Increased number of multimerized ILz(6):TRAIL units corresponded with enhanced cytotoxic activity. Further, a high degree of ILz(6):TRAIL multimerization triggered rapid signaling events such as activation of caspases, tBid generation, and chromatin condensation. Taken together, these results indicate that multimerization of TRAIL significantly enhances its cytotoxic activity.

• 약학회지
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• 제43권6호
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• pp.743-750
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• 1999

Human and bovine dopamine transporters (DAT) demonstrate discrete functional differences in the dopamine (DA) transport and cocaine binding. The functional analyses on the chimeras of human and bovine DAT have revealed that the region from the $133^{rd}{\;}to{\;}186^{th}$ residue(encompassing the $3^{rd}$ trans-membrane domain (TM) is responsible for the substrate transport and cocaine binding. The present studies have been done to find out the specific amino acid(s) which is essential for the binding of cocaine to DAT by interchanging the amino acids in that region between human and bovine DAT. When isoleucine, the $152^{nd}$ residue of chimera B3 (bovine DAT sequence) was transformed back to valine, the human DAT residue at the identical position, the cocaine binding was remarkably recovered to 98% of the human DAT values. In addition, the cocaine binding of the human DAT was decreased by 57% by substituting isoleucine for valine at position 152. When isoleucine at position 152 of the chimera B3 was converted to the other amino acids to provide an possible molecular basis for the functional role of the $152^{nd}$ residue, only the conversion to alanine among acids tested significantly the cocaine by 34%, but these effect were not as much as those by the conversion to valine. In conclusion, valine at position 152 is a crucial amino acid for the interaction of cocaine to the DAT.