• 분석과학
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• 제7권1호
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• pp.41-52
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• 1994

아미노산 중 alanine, threonine, isoleucine, leucine, aspartic acid, methionine, glutamic acid, tyrosine을 대상으로 열처리, 산처리, UV 광선 조사, 효소(trypsin)의 영향을 살펴보고 6N-HCl, $105^{\circ}C$로 가열했을 때 이성화하는 정도를 측정하였다. 또한 Mass Spectrometer를 이용할 때 각 아미노산의 fragment되는 과정을 조사하여 GC에서 서로 겹칠 때 분석하는 법을 개발하였다. HPLC에서 cyclodextrin bonded phase를 이용해서 dansyl amino acid의 분리를 시도하였다.

• Food Science and Biotechnology
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• 제16권3호
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• pp.343-348
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• 2007

Starch contents play important roles in determining the fruit quality. Stawberry accumulates starch in the early stages and then mobilized into soluble sugars during fruit ripening. To date the molecular studies on the ADP-glucose pyrophosphorylase (AGPase), a key enzyme of starch biosynthesis, were not reported. cDNAs encoding small (FagpS) and large (FagpL1 and FaspL2) AGPase subunits were isolated from strawberry (Fragaria ${\times}$ ananassa Duch. cv. Niyobou). Both FagpS and FagpL1 cDNAs have open reading frames deriving 55-58 kDa polypeptides, where FagpL2 contains a partial fragment. Sequence analyses showed that FagpS has a glutamate-threonine-cysteine-leucine (ETCL) instead of a glutamine-threonine-cysteine-leucine (QTCL) motif found in all the dicot plants except for Citrus. In fruits, FagpS and FagpL1 were expressed in all stages with a little change in the amounts of transcripts. In the case of FagpL2, we were not able to detect any signal from all stages of fruit development and all tissues except for very a weak signal from the leaf. The results indicate that FagpL1 and FagpL2 show ubiquitous and leaf-specific expression patterns, respectively. The studies suggest that the starch contents in strawberry might be controlled by the expression of AGPase gene at both the transcriptional and post-transcriptional levels during fruit development.

• Journal of Nutrition and Health
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• 제28권10호
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• pp.976-985
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• 1995

Changes in free amino acid concentrations is blood and various tissues were evaluated in cats adapted to the low-protein diet(20% protein, LPD) or the high-protein diet(60% protein, HPD) for 5 weeks. Cumulative body weigth gain for the 5 week period was 463$\pm$43g, and -128$\pm$40g for cats fed HPD and LPD, respectively. Feeding HPD significantly increased the size of liver and kidney. Cats adapted to HPD for 5 weeks have significantly elevated plasma concrntrations of essential amino acids (branched-chain amino acides, threonine, trytophan, phenylalanine and methoionine), whereas plasma levels of non-essential amino acids(alanine, asparagine, glycine, glutamine and serine) were significantly reduced in animals adapted to HPD(p<0.01, or p<0.001) compared to the values for the cats fed LPD. Changes in free amino acid concentratioks in whole blood induced by the variations in dietary level of protein closely reflect the pattern seen in plasma. Amino acids such as branched-chain amino acids, proline and threonine were most difficult to maintain homeostasis and consistantly elevated in lever, kidney, skeletal muscle and brain, as well as in blood of cats adapted to HPD(p<0.01 or p<0.001). All of the free amino acids in jejunum, excluding taurine and ornithine, were significantly elevated in animals adapted to HPD, most probably due to the rapid absorption of large amount of amino acids across the epithelium of small intestine.

• 한국자기공명학회논문지
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• 제19권2호
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• pp.88-94
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• 2015

Bub1 is one of the spindle checkpoint proteins and plays a role in recruitment of the related proteins to kinetochore. Here, we studied the structural characteristic of the evolutionarily conserved 160 amino acid region in the N-terminus (hBub1 CD1), using Circular Dichroism (CD) and NMR. Our CD results showed that hBub1 CD1 is a highly helical protein and its structure was affected by pH: as pH was elevated to basic pH, the helical propensity increased. This could be related to the surface charge of the hBub1 CD1. However, the structural change did not largely depend on the salt concentration, though the thermal stability a little increased. The previous NMR analysis revealed that the hBub1 CD1 adopts eight helices, which is consistent with the CD result. Our result would be helpful for evaluating the molecular mechanism of the hBub1 CD1 and protein-protein interactions.

• BMB Reports
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• 제32권5호
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• pp.468-473
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• 1999

Nuclear Factor 1 (NF1) proteins are a family of transcriptional factors consisting of four different types: NF1-A, -B, -C, and -X. Some NF1 transcription factors contain a heptasequence motif, SPTSPSY, which is found as a repeat sequence in the carboxy terminal domain (CTD) of the largest subunit of RNA polymerase II. A similar heptasequence, SPTSPTY, is contained in rat liver NF1-A at a position between residues 469 and 475. In order to investigate the roles of the individual amino acids of the heptasequence of rat liver NF1-A in transcriptional activation, we systematically substituted single and multiple amino acid residues with alanine residue(s) and evaluated the transcriptional activities of the mutated NF1-A. Substitution of a single amino acid reduced transcriptional activity by 10 to 30%, except for the proline residue at position 473, whose substitution with alanine did not affect transcriptional activity. However, changes of all four serine and threonine residues to alanine or of the tyrosine residue along with the serine residue at position 469 to alanine reduced the activity to almost background levels. Our results indicate that multiple serine and threonine residues, rather than a single residue, may be involved in the modulation of the transcriptional activities of the factor. Involvement of the tyrosine residue is also implicated.

• 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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• 제36권1호
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• pp.75-80
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• 2004

본 연구에서는 맛성분과 관능검사자료를 중회귀 분석하여 보리간장 맛을 평가하였다. 단순상관에서는 proline, alanine, methionine, lysine, histidine, lavulinic acid, ${\alpha}$-ketogutaric acid 및 citric acid와 관능검사 점수사이의 상관계수가 유의성이 높은 것으로 나타났으며, threonine, serine, cystein, phenylalanine, succinic acid, arabinose, xylose 및 sucrose 둥의 성분은 관능검사 점수에 거의 상관이 없는 것으로 나타났다. 하지만 단순상관분석으로는 보리간장 맛의 품질을 측정하는 것이 불가능하였다. 중회귀 분석을 실시한 결과 결정계수가 0.93 이상을 나타내어 맛성분 함량과 중회귀식을 이용하여 보리간장 맛의 93%를 추정하는 것이 가능하였다.

• Environmental Analysis Health and Toxicology
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• 제22권2호통권57호
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• pp.165-170
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• 2007

Elevation of homocysteine levels is a risk factor for cardiovascular diseases and liver diseases. It has been reported that both streptozotocin-induced type I diabetic rats and obese type II diabetic rats have plasma total homocysteine lower than each control rats. We determined the effects of lean type II diabetes on homocysteine levels using type 2 diabetic Goto-Kakizaki rats. The concentrations of serum glucose were increased to ${\sim}two-fold$ of control levels and the total cholesterol levels were also increased in GK rats. Hepatic aspartate, histidine, threonine, alanine and methionine levels were significantly increased in GK rats. Plasma aspartate and glutamate levels were elevated, but threonine and arginine levels were decreased in GK rats. Plasma total homocysteine levels were not changed in GK rats, but hepatic total homocysteine levels were increased to ${\sim}three-fold$ of control levels. These results suggest that hepatic metabolism of sulfur-amino acid may be altered in diabetic condition.

• Journal of Nutrition and Health
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• 제10권4호
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• pp.97-103
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• 1977

Changes of free amino acids as taste compounds during the fermentation of oyster were analyzed by amino acid autoanalyzer. In fresh oyster, taurine, glutamic acid and alanine were abundant amino acids and the amounts of taurine (731mg%, on moisture and salt free base), glutamic acid (365mg%) and alanine (345.4mg% ) were 63.8% of the total free amino acids. Cystine, isoleucine, phenylalanine, leucine and histidine were detected as less abundant free amino acids and the amount of those amino. acids ranged from 5. 5mg% (cystine) to 32.9mg% (histidine). The free amino acids analyzed in this experiment were not changed in composition hut changed in amounts during 124 days of fermentation. Aspartic acid and leucine were continually increased during 124 days of fermentation. Lysine, histidine, threonine, serine, glutamic acid, tyrosine and phenyalanine were increased unlit 68 days of fermentation and than decreased gradually. The increase of arginine, glycine, valine and isoleucine were fluctuated. Taurine were dramatically decreased during the 124 days of fermentation. It is believed that glutamic acid, alanine, lecuine, serine, Iysine and threonine play an important role as taste compounds in fermented oyster because those amino acids were most abundant in fermented oyster.

• Animal cells and systems
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• 제11권2호
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• pp.205-213
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• 2007

Nek6 belongs to NIMA1 (never in mitosis, gene A) related kinase, which was originally identified in Aspergillus nidulans as a serine/threonine kinase critical for cell cycle progression. We noticed that the putative SUMOylation site is localized on the $K^{252}$ residue in $^{251}FKsD^{254}$ of Nek6, based on the consensus sequence ${\Phi}KxE$; where ${\Phi}$ represents L, I, V or F and x is any amino acid. We observed that the Nek6 SUMO mutant (K252R) has decreased protein kinase activity, nuclear speckle localization and protein stability, compared with that of the Nek6 wild type. However, the Nek6 SUMO mutant increased the cell survival rate of COS-1 cells as determined by FACS analysis. Therefore, our data suggest that SUMOylation on the $K^{252}$ residue of Nek6 is required for its normal functions, such as proper nuclear localization, kinase activity and protein stability, to control cell cycle.