• 한국미생물·생명공학회지
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• 제19권5호
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• pp.477-486
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• 1991

Aspergillus niger가 생산하는 $\alpha$-galactosidase의 효소학적 성질을 조사하기 위하여 시험균주를 밀기울 배양한 후 생성된 $\alpha$-galactosidase를 염석, 이온교환 크로마토그래피 및 겔 여과 등의 방법으로 정제한 후 정제효소의 효소학적 성질을 검토하였다. Asp. niger를 밀기울 배지에서 $30^{\circ}C$, 4일 배양했을 때 효소활성이 가장 높았으며 $\alpha$-galactosidase는 황산암모늄 염석, DEAE-cellulose 및 DEAE-Sephadex A-50 이온교환 크로마토그래피, sephadex G-150 겔 여과 등에 의하여 23.7배까지 정제되었으며 비활성이 1,229U/mg.protein, 수율 14이었고 HPLC와 PAGE에 의해 순도가 확인되었다.

• 약학회지
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• 제53권3호
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• pp.114-118
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• 2009

Bioemulsifiers are those chemicals which are produced from microorganisms but which have both hydrophilic and hydrophobic groups. $\alpha$-Glucosidase inhibitor ($\alpha$-GI) produced from Bacillus lentimorbus B-6 (B-6) showed bioemulsifying activity. But $\beta$-glucosidase inhibitor produced from B-6 didn't show emulsifying activity. $\alpha$-GI was purified from supernatant of B-6 grown in minimal culture medium containing glucose and sodium glutamate by Sephadex G-100 column chromatography and isolated from $\beta$-GI by dialysis against water. Toluene was determined as the best substrate for emulsifying activity of $\alpha$-GI. $\alpha$-GI showed thermostability at $100^{\circ}C$ for 15 min, high salt tolerance up to 32% NaCl and wide range of pH-stability at pH $4\sim10$. Emulsifying character of $\alpha$-GI can be useful for the liposome formation for the treatment of diabetes mellitus.

• Bulletin of the Korean Chemical Society
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• 제27권7호
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• pp.1001-1004
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• 2006

The m-calpain activity hydrolyzing a fluorogenic substrate of N-Succinyl-Leu-Leu-Val-Tyr-7-amino-4-methylcourmarin (LLVY-AMC) was significantly stimulated by more than two-fold in the presence of 5$\mu$M $\alpha$synuclein at $15{^{\circ}C}$. The stimulation was also confirmed with azocasein. The stimulation of the peptide hydrolyzing activity required structural intactness of $\alpha$-synuclein since the C-terminally or N-terminally modified proteins such as $\beta$-synuclein, $\alpha$-syn1-97, and $\alpha$-syn61-140 did not increase the proteolytic activity. Instead, however, the N-terminally truncated $\alpha$-syn61-140 was shown to drastically suppress the calpain activity. Since the N-terminal truncation was known to be the primary cleaving event of calpain-mediated proteolysis of $\alpha$-synuclein and the $\alpha$-syn61-140 has been demonstrated to be resistant against the calpain digestion, it has been proposed that the intracellular calpain activity could be regulated in a reciprocal manner by $\alpha$-synuclein and its proteolyzed C-terminal fragment. Based on the results, a possible physiological function of $\alpha$-synuclein has been suggested as a calpain regulator which contains both stimulatory and inhibitory activities.

• 대한화장품학회지
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• 제25권3호
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• pp.87-99
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• 1999

천연 물질로 지용성인 뉴질랜드산 차나무 정유(Manuka oil), 그 구성 성분인 $\alpha$-pinene, Oxy’less clear, 수용성인 자몽 종자 추출물(Citrex) 및 그 구성성분인 R-limonene의 항균력 을 측정 평가하여 항균력을 보다 향상시키고 광범위하게 사용할 수 있는 방부제의 처방을 제안하였다. 항균력 측정에는 disk diffusion법이 사용되었으며, 균주로는 그람 음성균인 Escherichia coli와 그람 양성균인 Staphylococcus aureus을 사용하였다. Manuka oil과 $\alpha$-pinene은 항균력이 10${\mu}\ell$/paper disk일 때에는 큰 차이가 없었으나 2${\mu}\ell$/paper disk이하의 소량의 시료에서는 Manuka oil이 $\alpha$-pinene에 비해 월등하게 우수하였다. Citrex가 R-limonene보다 두 균주에 대하여 항균력이 모든 농도에서 우수한 성능을 보였다 Oxy’less clear은 두 균주에 대하여 모든 농도에서 파라벤류 propyl para hydroxybenzoate(PPHB)나 R-limonene보다는 항균효과가 우수하며 $\alpha$-pinene과는 비슷하게 나타났고, Manuka oil과 Citrex보다 약간 낮게 나타났다. 이상을 종합해 본 결과 Manuka oil과 Citrex가 다른 물질들에 비해 항균력이 가장 우수한 것으로 나타났다. 항균력이 우수한 지용성 물질 Manuka oil과 확산도가 큰 수용성 물질 Citrex를 적절히 혼합하여 항균력을 향상시키고 광범위하게 사용할 수 있는 이상적인 혼합비(Manuka oil : Citrex)를 구하였는데 Escherichia coli에 대해서는 75 : 25이었고 Staphylococcusureus에 대해서는 25 : 75 이었다.

• Journal of Pharmaceutical Investigation
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• 제21권3호
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• pp.143-147
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• 1991

${\alpha}-amylase$ was immobilized on the surface of polyethylene glycol(M.W. 2000) grafted polyurethane film using diisocyanate in an attemp to develop enzyme immobilized polymeric materials. The surface morphology of the modified polyurethane film was examined by SEM. Effects of pH and temperature on the activity of the immobilized ${\alpha}-amylase$ were investigated. The optimal pH range of the activity was $7.0{\sim}7.5.$ The immobilized ${\alpha}-amylase$ demonstrated high thermal stability and maintained consistent activity during long-term storage.

• 한국자원식물학회지
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• 제22권1호
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• pp.71-77
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• 2009

제주도에 자생하는 피자식물 289종 454점을 대상으로 항산화활성과 ${\alpha}$-amylase 저해활성을 검색하였다. DPPH radical에 대한 전자공여능으로 측정한 항산화활성은 붉나무의 오배자, 굴피나무의 열매, 참죽나무의 줄기 메탄올 조추출물에서 높은 활성을 보였다. 특히, 붉나무의 오배자의 항산화활성은 94.2${\pm}$0.8%로 본 실험에 동일 농도의 대조구로 사용된 BHA(61.7${\pm}$0.6%)와 ascorbic acid(53.6${\pm}$0.7%) 보다도 활성이 높았다. 그리고 붉나무, 굴피나무, 참죽나무 이외의 나머지 52점의 식물들도 차나무 잎의 활성보다 높았다. ${\alpha}$-Amylase 저해활성은 곰의말채의 줄기와 잎, 조록나무의 잎과 소지, 정금나무의 잎 등 9종 11점에서 80% 이상의 높은 활성을 보였다. 앞으로 식품 소재 또는 생약으로의 개발 가능성을 모색하기 위해서 활성성분의 분리 및 동정 그리고 이들 물질을 이용한 임상실험 등 보다 심도있는 연구가 요구된다.

• Journal of Radiation Protection and Research
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• 제11권2호
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• pp.130-138
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• 1986

CA 80-15 및 LR 115-1 cellulose nitrate 비적검출기를 사용하여 지표공기중의 ${\alpha}$방사능을 측정 해석하였는바 이 검출기의 검출효율은 $0.1{\mu}Ci$의 $^{241}Am\;{\alpha}$선을 사용하여 결정하였다. 지표에서 방출되는 라돈과 그 자핵종들에 의한 ${\alpha}$방사능을 검출하기 위하여 두가지의 라돈컵을 사용하였으며 이들을 각각 지름이 15cm, 깊이가 45cm인 이웃한 두개의 땅구덩이를 만들어 그 안에 설치하여 일정기간 ${\alpha}$방사능에 노출하였다. 두 라돈컵중 하나는 구덩이 지표면에 거꾸로 밀착시켜 밀폐공간이 되게 하고 다른 하나는 바닥에서 일정한 거리를 띄우고 컵 윗면에 구멍을 뚫어 공기의 소통이 가능하도록 하여 그 검출결과를 비교 검토하였다. ${\alpha}$입자에 피폭된 비적검출기는 부식처리한 후 현미경으로 판독하고 통계분석 하였으며 그 결과를 지표공기 단위부피당 ${\alpha}$방사능농도로 환산 평가하였다.

• Mycobiology
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• 제39권4호
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• pp.278-282
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• 2011

The objective of this study was to find useful fungi with ${\alpha}$-amylase activity from the Korean traditional nuruk for the quality of traditional Korean alcoholic beverage. In this study, 165 samples of traditional nuruk were collected from 170 regions throughout Korea and the fungi were isolated to a total of 384 strains. In order to investigate the effect of microflora on nuruk, ${\alpha}$-amylase activity, saccharogenic power (SP), starch hydrolysis activity and acid producing activity were evaluated. Ten strains were selected by ${\alpha}$-amylase activity, which ranged from 458.47 to 1,202.75 U/g. The size of the discolored zone for the starch hydrolysis activity of each fungus ranged from 0.3 to 2 cm. The SP of the 10 strains ranged from 228.8 to 433.4 SP. Of the 10 stains, three were identified as Aspergillus oryzae, two as Aspergillus flavus, two as Lichtheimia sp., one as Rhizopus oryzae and two as other strains. The total aflatoxins present in the nuruks were examined using enzyme-linked immunosorbent assay. The 10 nuruks had less than 1.11 ppb of aflatoxins.

• 생명과학회지
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• 제8권4호
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• pp.387-394
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• 1998

A thermophilic bacterium (strain DG0303) producing a thermostable $\alpha$-glucosidase was isolated from manure and identified as Bacillus sp. Strain DG0303 produced high level of $\alpha$-glucosidase compared with other thermophilic Bacillus strains. The cellular protein patterns were also compared with other Bacillus strains by sodium dodecyl sulfatepolyacrylamide gel electrophoresis(SDS-PAGE). On the basis of 16S rDNA analysis the Bacillus sp. DG0303 was found to be a member of Bacillus rDNA group 5. The optimum temperature for growth was 65$\circ$C and no growth was obtained at 40$\circ$C or 75$\circ$C. The optimum pH for growth was 5.5 to 8.5. $\alpha$-glucosidase activity was produced during growth and most activity was detected in the culture supernatant. The $\alpha$-glucosidase production was constitutive in the absence of carbohydrates. High level of enzyme activity was detected when the culture was grown on medium containing starch. Addition of glucose resulted in the repression of the $\alpha$-glucosidase production. The optimum pH and tempoerature for enzyme activity were pH 5.0 and 65$\circ$C, respectively. When analyzed by zymogram, the culture supernatant showed a single $\alpha$-glucosidase band with a molecular weight of approximately 60,000.

• Journal of Applied Biological Chemistry
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• 제43권3호
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• pp.141-146
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• 2000

Glycosidase activities were tested from the grape berries, Vitis labruscana B. Takasumi. Among various glycosidases, $\alpha$-D-galactosidase was found to be the most active in the flesh and other glycosidases were considerably active in the order of the following: $\alpha$-D-mannosidase>$\alpha$-D-glucosidase>$\beta$-D-glucosidase>$\beta$-D-galactosidase. In the seeds, $\alpha$-D-glucosidase activity was the highest and other glycosidases such as $\alpha$-D-galactosidase, $\beta$-D-glucosidase, and $\beta$-D-galactosidase were still significantly active. The $\alpha$-D-galactosidase in the grape flesh was purified over 83-folds through salting-out with $(NH_4)_2SO_4$ and a series of chromatographies employing Sephadex G-50, Octyl-Sepharose, Q-Sepha- rose, and Biogel P-100. The enzyme was a monomer of 45 kDs as determined through SDS-PAGE and Sephacryl S-200 chromatography. The purified enzyme showed a preference of $\alpha$-D-galactose to $\beta$-D-galactose as a substrate about 5.4 times. Sulfhydryl specific reagents such as N-ethylmaleimide and iodoacetamide significantly inhibited the enzyme activity to the extents of 48 and 52% of its initial activity, respectively. The optimumpH range of $\alpha$-D-galactosidase was around 6.5-7.0. The enzyme activity increased by 46% in the presence of 1mM $Fe^{2+}$.