• 한국미생물·생명공학회지
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• 제18권3호
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• pp.309-316
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• 1990

Bacillus circulans F-2의 생산하는 NaCl 의존성 amylase(NaCl-dependent amylase) 유전자를 함유하는 1795bp의 DNA 염기배열을 결정하였다. 본 유전자의 ORF는 총염기수 1005bp(335 아미노산)로 구성되며, 분자량 38,006의 amylase의 분자량 약 35,000과 일치하였다. 본 유전자의 상류영역(upstream region)에는 고초균(Bacillus subtiis)의 전형적인 전사발현영역(transcriptional region)과 상보적인 DNA역역이 존재하였다. 성숙단백질의 N-말단측 아미노산 배열은 Ala-Ser-Lys-Val-Gly이며, 분비에 필요한 20개의 signal 아미노산 배열을 갖는 전형적인 분비 단백질임이 확인 되었다. 한편 다른 amylase들과 비교결과, smylase 활성발현과 밀접히 관련되 있는 4개 부위의 상보성영역(homologous region)을 가지고 있었다.

• Journal of Ginseng Research
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• 제24권3호
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• pp.153-156
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• 2000

In order to improve the qualities of red ginseng extract and decrease precipitate formation in ginseng drink, red ginseng extract were hydrolyzed with ${\alpha}$-Amylase and characteristics of the hydrolyzed ginseng extract were investigated. 1.08% of isomaltose were produced and glucose content was increased from 2.83% to 11.03% in the hydrolyzed red ginseng extract. Total ginsenoside content of the hydrolyzed ginseng extract were decreased from 1,661 mg/100g extract to 1,389 mg/100g extract. The hydrolyzed ginseng extract enhanced the growth of Lactobacillus casei, Lactobacillus rhamnosus and Lactobacillus helveticus. Bitterness and astringency of the hydrolyzed ginseng extract were lower than those of the ginseng extract Precipitate formations in ginseng drink prepared with the hydrolyzed ginseng extract were significantly reduced in the storage conditions of 40$^{\circ}C$ for 4 weeks compared to those of control.

• 한국작물학회지
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• 제44권4호
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• pp.391-395
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• 1999

Barnyardgrass had relatively higher growth vigor at the earlier growth stage than inbred rice did, showing the 2 fold higher $\alpha$-amylase activity during the periods of germination and large leaf area Expansion with high net photosynthetic rate at the earlier autotrophic stage, but it performed weak growth at the late growth stage. However, the hlybrid rice Shanyou 63 had significantly higher $\alpha$-amylase activity and net photosynthetic rate than that of barnyardgrass, exhibiting heterosis for two physiologica1 traits during the germination (6~12 days) and autotrophic phase, respectively. Accordingly, hybrid rice, Shanyou 63, exhibited heterotic effect at the early growing stage when were presented with barnyardgrass. Shanyou 63 exhibited stronger tillering ability, faster leaf area expansion and higher net photosynthetic rate than those of barnyardgrass.

• 한국작물학회지
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• 제44권3호
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• pp.273-276
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• 1999

Some metabolites and embryo growth of primed tobacco (Nicotiana tabacum L. cv. ‘KFI09’) seeds were observed during priming. The seeds were primed at 15 and $25^{\circ}C$ for 1, 2, 3, 5, 10 and 15 days in a -0.8 MPa polyethylene glycol 6000 (PEG) solution. The time to 50% seed germination (T$_{50}$) was greatly reduced when the seeds were primed at $25^{\circ}C$ when compared with 15$^{\circ}C$. The $\alpha$-amylase activity and sugars and amino acid contents in the seeds primed at $25^{\circ}C$ greatly increased, while $\alpha$-amylase activity was similar, and sugar and amino acid contents increased slightly in the seeds primed at 15$^{\circ}C$. When the seeds were primed at $25^{\circ}C$, growth of the embryo which was enclosed by endosperm was detected, while the endosperm became thinner as the priming duration was extended.d.

• Journal of Microbiology and Biotechnology
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• 제4권1호
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• pp.7-12
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• 1994

A yeast strain secreting glucoamylase was transformed with an expression vector (pMS12) containing the promoter of yeast alcohol dehydrogenase I gene ADC1, mouse salivary $\alpha$-amylase cDNA, and a segment of yeast $21\mu m$ plasmid. The transformed strain could produce ethanol from starch (4%, w/v) through a direct one-step process with the conversion efficiency of 93.2%, during 5 days of fermentation, while the original, untransformed strain exhibited a conversion efficiency of 38.1% under the same condition. When the regulatory site of the ADC1 promoter region was removed, the production of ethanol increased to 29~37% in the presence of exogenous 3%(v/v) ethanol in the fermentation medium.

• 한국환경보건학회지
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• 제29권4호
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• pp.48-54
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• 2003

This study investigated retrogradation properties of Jeungpyun substituted for cereals with dietary fibers of 60% of brown rice, and barley. Quality changes during storage periods of the functional Jeungpyun, were studied using $\alpha$-amylase iodine enzyme digestion methods, X-ray diffraction patterns, and differential scanning calorimetry (DSC). The barley substituted samples showed significantly lower retrogrdation rates than those of control when examined by $\alpha$-amylase method. The Relative crystallity by X-ray diffraction patterns had typical A type in all samples with appealing big crystallity around its diffraction angle 23$^{\circ}$degrees as storage periods were increased. The brown rice and barley Jeunpyun made smaller crystallity than that of control, representing slower retrogradation rates. The batter controls had significantly lower ΔH than the other compared samples when measured by DSC, but had significantly higher ΔH after 30 days of storage, implying that the control required more energy for regelatinization after the 30 days of storage.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2005년도 생물공학의 동향(XVII)
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• pp.821-826
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• 2005

Postprandial hyperglycemia plays an important role in the development of type 2 diabetes and complications associated with the disease such micro-and macro-vascular disease. The present study investigated the effect and action mechanism of a ethanolic extract from the Schizandra chinensis(SC-E) on hypeglycemia in vivo and in vitro. In vitro, SE-E demonstrated a potent inhibitory effects on ${\alpha}-amylase$ activity ($IC_{50}$ : 4 ${\mu}g/ml$). Its inhibition on ${\alpha}-amylase$ was determined to be competitive type. Oral administration of SE-E markedly lowered plasma glucose levels in non-fasted streptozotocin induced diabetic rats (45 mg/kg BW). In addition when it was orally administrated to rats with starch (2g/kg BW), SC-E (50 and 100 mg/kg BW) significantly suppressed the increase of blood glucose levels after starch loading . These results suggest that some edible plants merit further evaluation for clinical usefulness as anti-diabetic drugs.

• Applied Biological Chemistry
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• 제31권3호
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• pp.267-273
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• 1988

Transformed, hybrid strains of the yeast Saccharomyces capable of simultaneous secretion of both glucoamylase and ${\alpha}-amylase$ have been produced. These strains can carry out direct, one-step assimilation of starch with conversion efficiency greater than 93% during a 5 day growth period. One of the transformants converts 92.8% of available starch into reducing sugars in only 2 days. Glucoamylase secretion by these strains results from expression of one or more chromosomal STA genes derived from Saccharomyces diastaticus. The strains were transformed by a plasmid(pMS12) containing mouse salivary ${\alpha}-amylase$ cDNA in an expression vector containing yeast alcohol dehydrogenase promoter and a segment of yeast $2{\mu}$ plasmid. The major starch hydrolysis product produced by crude amylases found in culture broths is glucose, indicating that ${\alpha}-amylase$ and glucoamylase act cooperatively.

• BMB Reports
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• 제37권6호
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• pp.642-647
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• 2004

The lysine residues of Bacillus licheniformis $\alpha$-amylase (BLA) were chemically modified using citraconic anhydride or succinic anhydride. Modification caused fundamental changes in the enzymes specificity, as indicated by a dramatic increase in maltosidase and a reduction in amylase activity. These changes in substrate specificity were found to coincide with a change in the cleavage pattern of the substrates and with a conversion of the native endo- form of the enzyme to a modified exo- form. Progressive increases in the productions of $\rho$-nitrophenol or glucose, when para nitrophenyl-maltoheptaoside or soluble starch, respectively, was used as substrate, were observed upon modification. The described changes were affected by the size of incorporated modified reagent: citraconic anhydride was more effective than succinic anhydride. Reasons for the observed changes are discussed and reasons for the effectivenesses of chemical modifications for tailoring enzyme specificities are suggested.

• 한국식품저장유통학회지
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• 제23권1호
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• pp.80-88
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• 2016

천연색소 혼합물의 생리활성을 검증하고자 하고자 천연색소 7종에 대하여 ABTS 라디칼 소거활성과 DPPH 라디칼 소거활성, 콜레스테롤 흡착활성 및 COX-2 저해활성을 측정하였으며, 활성이 우수하였던 시료 3종(아선약, 오배자, 정향)을 선별하였다. 선정된 3종 시료의 혼합물 4종(아선약+오배자, 아선약+정향, 오배자+정향, 아선약+오배자+정향)에 대해서는 콜레스테롤 흡착활성, COX-2 저해활성, ${\alpha}$-glucosidase 및 ${\alpha}$-amylase 저해활성을 측정하였다. 천연색소 시료들은 DPPH 라디칼 소거활성에 비해 ABTS 라디칼 소거활성이 더 우수하였으며, 콜레스테롤 흡착활성은 정향이 유의적으로 높았고, COX-2 저해활성은 아카시아 분말이 유의적으로 낮았으며, 여타 시료간에는 유의적인 활성의 차이가 없었다. ${\alpha}$-Amylase 저해활성은 아선약과 오배자에서 높았으나, 혼합물들에서는 서로간에 유의적인 차이가 없었다. ${\alpha}$-Glucosidase 저해활성은 아선약 분말이 가장 높았고, 아선약이 첨가된 혼합물의 활성이 더 높았다. 이상의 결과를 종합하여 볼 때 천연색소의 생리활성은 혼합물로 조성하여 활용할 때 시너지 효과를 얻을 수 있으나, 조합되는 물질간의 상호작용에 따라 활성의 증감 정도는 상이하므로 이에 대해서는 앞으로 더 많은 연구가 필요할 것으로 생각된다.