• Journal of Microbiology and Biotechnology
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• 제10권2호
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• pp.244-250
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• 2000

An ${\alpha}-glucosidase$ gene (aglA) from thermophilic Bacillus sp. DG0303 was cloned, sequenced, and expressed in Escherichia coli. The aglA was localized to the 2.1-kb PvuI-XmnI region within the 5.9-kb DNA insert of the gybrid plasmid pAG1. The gene consisted of an open reading frame of 1,686 bp with an unusual GTG initiation codon and TGA termination codon. The amino acid sequence deduced from the nucleotide sequence predicted a protein of 562 amino acid residues with a M, of 66,551 dalton. A comparative amino acid sequence analysis revealed that DG0303 ${\alpha}-glucosidase$ is related to bacillary oligo-1, 6-glucosidases. The Bacillus sp. DG0303 ${\alpha}-glucosidase$ showed a high sequence identity (36-59%) to the B. flavocaldarius, B. cereus, and B. thermoglucosidasius oligo-1, 6-glucosidases. The number of prolines in theses four ${\alpha}-glucosidases. was observed to increase with increasing thermostability of these enzymes. The cloned ${\alpha}-glucosidase was purified from E. coli $DH5{\alpha}$ bearing pAG1 and characterized. The recombinant enzyme was identical with the native enzyme in its optimum pH and in its molecular mass, estimated by sodium dodecy1 sulfate-polyacrylamide gel electrophoresis. The temperature optimum of the cloned ${\alpha}-glucosidase$ was lower than that of the native enzyme.

• 한국식품영양학회지
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• 제11권6호
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• pp.640-646
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• 1998

For the production of nonprotein $\alpha$-glucosidase inhibitor from the Streptomyces sp. NS15 strain, effects of initial optimum pH, nitrogen sources, carbon sources, cationic metal ions, agitation speed and aeration rate were investigated. Initial optimum pH of medium was 7.0. The most effective nitrogen and carbon sources were soybean meal 2.0%(w/v) and glucose 1.6%(w/v), respectively. The cationic metal ins had no stimulating effect on inhibitory activity of $\alpha$-glucosidase except Fe2+. Agitation speed and aeration rate were effective at 400rpm and 1vvm, respectively. In the jar-fermenter cultivation for 4 days under optimal culture conditions, the culture broth showed the inhibitory acitivity of 3,200units/ml, which is 25 times higher than that of basic medium (CYM) for porcine intestinal $\alpha$-glucosidase. The inhibitory activity of $\alpha$-glucosidase reached about 3,200units/ml after 4 days of cultivation and decreased gradually for a further two days.

• Journal of Microbiology and Biotechnology
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• 제8권3호
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• pp.270-276
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• 1998

Extracellular ${\alpha}$-glucosidase was purified to homogeneity from moderately thermophilic Bacillus sp. DG0303. The thermostable ${\alpha}$-glucosidase was purified by ammonium sulfate fractionation, ion-exchange chromatography, preparative polyacrylamide gel electrophoresis (PAGE), and electroelution. The molecular weight of the enzyme was estimated to be 60 kDa by SDS-PAGE. The optimum temperature for the action of the enzyme was at $60^{\circ}C$. It had a half-life of 35 min at $60^{\circ}C$. The enzyme was stable at the pH range of 4.5~7.0 and had an optimum pH at 5.0. The enzyme preparation did not require any metal ion for activity. The thermostable ${\alpha}$-glucosidase hydrolyzed the ${\alpha}$-1,6-linkages in isomaltose, isomaltotriose, and panose, and had little or no activity with maltooligosaccharides and other polysaccharides. The $K_m$ (mM) for p-nitrophenyl-${\alpha}$-D-glucopyranoside (pNPG), panose, isomaltose, and isomaltotriose were 4.6, 4.7, 40.8, and 3.7 and the $V_{max}$(${\mu}mol{\cdot}min^-1$$mg^-1$) for those substrates were 5629, 1669, 3410, and 1827, respectively. The N-terminal amino acid sequence of the enzyme was MERVWWKKAV. Based on its substrate specificity and catalytic properties, the enzyme has been assigned to be an oligo-1,6-glucosidase.

• 약학회지
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• 제54권5호
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• pp.398-402
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• 2010

[ ${\alpha}$ ]Glucosidase inhibitor is a target in the treatment of type II diabetes through the mainly inhibition of glucose levels after meals. In this study, we purified steppogenin and oxyresveratrol from the stem of Morus alba L. and examined their inhibitory activity against yeast ${\alpha}$-glucosidase. Steppogenin and oxyresveratrol were inhibited yeast ${\alpha}$-glucosidase in a dose dependent manner. The $IC_{50}$ activities (50% inhibition) were 34.4 and 9.3 ${\mu}M$, respectively. The kinetic inhibition of steppogenin showed noncompetitive inhibition ($K_m:1.1{\times}10^{-3}M$; $K_i:1{\times}10^{-5}M$), meanwhile oxyresveratrol showed competitive inhibition ($K_m:4.3{\times}10^{-3}M$; $K_i:3.4{\times}10^{-6}M$) against yeast ${\alpha}$-glucosidase. These results indicate that steppogenin and oxyresveratrol are noncompetitive and competitive inhibitors, respectively, against yeast ${\alpha}$-glucosidase.

• Journal of Microbiology and Biotechnology
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• 제12권6호
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• pp.895-900
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• 2002

A soil microorganism producing ${\alpha}$- and ${\beta}$-glucosidase inhibitors was identified as Bacillus lentimorbus, based on the fatty acid and morphological analyses, along with biochemical and physiological tests. The ${\alpha}$-glucosidase inhibitor was highly produced by this strain in a culture medium containing $0.25\%$ of sodium glutamate and $0.5\%$ of glucose, pH 8.0 at $30^{\circ}C$ for 2 days. The ${\alpha}$-glucosidase inhibitor from culture filtrate of his strain was identified as water soluble, organic solvent nonextractable, and heat stable. In addition to ${\alpha}$-glucosidase inhibitor, this strain also produced ${\beta}$-glucosidase inhibitor in he same culture medium and this inhibitor showed an antifugal activity against Botrytis cinerea. While the production of ${\alpha}$- glucosidase inhibitor was decreased by a glucose concentration higher than $1\%$, the production of ${\beta}$-glucosidase inhibitor was lot Influenced by a glucose concentration higher than $20\%$. The ${\alpha}$-glucosidase inhibitor from culture filtrate of this strain was separated from the ${\beta}$-glucosidase inhibitor through Sephadex G-100 column chromatography.

• BMB Reports
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• 제34권4호
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• pp.347-354
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• 2001

$\alpha$-Glucosidase of an extreme thermophile, Thermus caldophilus GK24 (TcaAG), was purified 80-fold from cells to a homogeneous state and characterized. The enzyme exhibited optimum activity at pH 6.5 and $90^{\circ}C$, and was stable from pH 6.0 to 85 and up to $90^{\circ}C$. The enzyme had a half-life of 85 minutes at $90^{\circ}C$. An analysis of the substrate specificity showed that the enzyme hydrolyzed the non-reducing terminal unit of $\alpha$-1,6-glucosidic linkages of isomaltosaccharides and panose, $\alpha$-1,3-glycosidic bond of nigerose and turanose, and $\alpha$-1,2-glycosidic bond of sucrose. The gene encoding the TcaAG was cloned, sequenced, and sequenced in E. coli. The nucleotide sequence of the gene encoded a 530 amino acid polypeptide and had a G+C content of 68.4% with a strong bias for G or C in the third position of the codons (93.6%). A sequence analysis revealed that TcaAG belonged to the $\alpha$-amylase family. We suggest that this monomeric, thermostable, and broad-acting $\alpha$-glucosidase is a departure from previously exhibited specificities. It is, therefore, a novel $\alpha$-glucosidase.

• 한국자원식물학회지
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• 제26권4호
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• pp.411-416
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• 2013

본 연구는 자생 양치식물 9종의 성엽과 근경을 재료로 ${\alpha}$-glucosidase 억제활성을 분석하여 천연 ${\alpha}$-glucosidase 저해제로서 개발 가능한 식물 소재를 선발하기 위하여 수행하였다. 수확된 성엽과 근경은 수세 후 동결건조 하였으며, 건조시료를 분쇄하여 100% 메탄올 용매로 30분 동안 초음파 추출을 하였고, 추출 후 감압여과 하여 ${\alpha}$-glucosidase 억제활성을 측정하였다. 양성 대조구로는 acarbose를 사용하였다. 추출물 $50{\mu}L$에 0.7 unit ${\alpha}$-glucosidase 효소액 $100{\mu}L$를 넣고 혼합하여 $37^{\circ}C$에서 10분간 반응시킨 후, 1.5 mM ${\rho}$-NPG 기질용액을 $50{\mu}L$ 넣고 $37^{\circ}C$에서 20분간 반응시켰다. 1 M $Na_2CO_3$ 1 mL로 반응을 정지시키고 405 nm에서 흡광도를 측정하였다. 회귀분석을 이용하여 0.7 unit ${\alpha}$-glucosidase 용액의 활성을 50%를 억제하는데 필요한 시료의 농도($IC_{50}$ 값)를 구하였다. 양치식물 9종의 ${\alpha}$-glucosidase 억제활성은 성엽($IC_{50}=14.00{\sim}913.33{\mu}g{\cdot}mL^{-1}$)과 근경 추출물($IC_{50}=12.93{\sim}205.84{\mu}g{\cdot}mL^{-1}$)에서 공히 acarbose($IC_{50}=1413.70{\mu}g{\cdot}mL^{-1}$)에 비해 높았다. 양치식물의 추출물은 acarbose에 비해 성엽은 1.55~100.98배, 근경은 6.87~109.33배 높은 것으로 나타났다. 특히 성엽에서는 석위의 억제활성이, 근경에서는 꿩고비의 ${\alpha}$-glucosidase 억제활성이 가장 높았다. ${\alpha}$-Glucosidase 활성의 50%를 억제하기 위한 성엽과 근경의 필요 생체량은 공히 꿩고비(각 0.35, 0.27 mg)에서 가장 적은 것으로 나타났다. 성엽의 경우는 석위의 $IC_{50}$ 값이 가장 높았으나 가용성 고형분의 함량이 꿩고비에 비해 2.4배 낮아, 오히려 꿩고비의 경제성이 더 높은 것을 알 수 있었다. 본 연구의 결과 꿩고비는 적은 생체량으로도 높은 ${\alpha}$-glucosidase 억제활성을 나타내기 때문에 경제적인 천연 ${\alpha}$-glucosidase 저해제 소재로써 개발 가치가 매우 높은 것을 알 수 있었다.

• Natural Product Sciences
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• 제10권5호
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• pp.223-227
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• 2004

This study was carried out to investigate inhibitory effect of extracts from the root of Paeonia lactiflora on postprandial hyperglycemia. Organic solvent (hexane, ethyl acetate, butanol, aqueous) extracts from the crude drug were fractionated by high performance liquid chromatography. These fractions were examined to evaluate ${\alpha}-glucosidase$ (EC 3. 2. 1. 20) inhibition by microplate colorimetric assay. Among the fractions examined, the ethyl acetate fraction from the roots of Paeonia lactiflora showed potent inhibitory effects on ${\alpha}-glucosidase$. Therefore, further fractionation of the fraction was carried out to isolate the active principles. Finally, we isolated and Purified 1,2,3,4,6-penta-O-galloyl-beta-D-glucose (PGG) as a active principle by activity-guided fractionation. These results suggest that the extract from the root of Paeonia lactiflora can be used as a new nutraceutial for inhibition on postprandial hyperglycemia and PGG might be a candidate for developing an ${\alpha}-glucosidase$ inhibitor.

• 한국식품저장유통학회지
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• 제24권6호
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• pp.879-884
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• 2017

몽골산 I. bungei를 80% 메탄올로 침지 추출하여 얻어진 추출물에 대해 n-hexane, EtOAc 및 n-BuOH의 유기용매를 활용하여 순차 분획을 실시하였고, 얻어진 결과물에 대하여 총 페놀함량, DPPH, $ABTS^+$ 라디칼 소거능 및 ${\alpha}$-glucosidase 저해활성을 평가하였다. DPPH 라디칼 소거활성은 페놀성 화합물의 함량이 높은 EtOAc 가용 분획물에서 $IC_{50}$ 값이 $148.7{\pm}1.6{\mu}g/mL$으로 우수한 DPPH 라디칼 소거 활성을 확인하였고, $ABTS^+$ 라디칼 소거활성 역시 I. bungei의 EtOAc 가용 분획물에서 $IC_{50}$ 값이 $27.8{\pm}0.9{\mu}g/mL$의 매우 우수한 라디칼 소거활성을 확인하였고, 다량 존재하는 페놀성 화합물과 라디칼 소거활성의 관련성을 나타내었다. 또한 ${\alpha}$-glucosidase 저해활성을 평가한 결과 EtOAc 가용 분획물에서 $IC_{50}$값은 $4.6{\pm}0.1{\mu}g/mL$의 강력한 저해활성을 나타내었으며, 이는 양성 대조군인 acarbose의 $IC_{50}$ 값인 $473.2{\pm}5.5{\mu}g/mL$과 비교했을 때 매우 우수한 활성을 나타내었으며, 다양한 화합물이 함유된 상태의 추출물 시료를 단일물질로 정제할 경우 더욱 우수한 활성의 화합물이 존재할 가능성을 기대하게 한다. 향후 이들 추출물의 활성물질 동정을 통한 활성 기작에 대한 연구가 필요하며, 본 연구결과로 보다 우수한 라디칼 소거활성 및 ${\alpha}$-glucosidase 저해활성을 가지는 새로운 천연 기능성 소재 발굴을 위한 기초자료로 활용 가능할 것으로 사료된다.

• International Journal of Industrial Entomology and Biomaterials
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• 제34권2호
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• pp.38-44
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• 2017

Mulberry leaves containing 1-deoxynojirimycin (DNJ) have been recognized as a potentially important source for prevent or treat hyperglycemia. However, DNJ content of natural mulberry leaf are as low as 0.1%. Thus, the most effective method for increasing ${\alpha}$-glucosidase inhibitory activity with the DNJ high-production is needed. In this study, we investigated the influence of ${\alpha}$-glucosidase inhibitory activity according to different pH values (6-9) and inoculation amounts (0.1-0.5%) when Bacillus subtilis cultured on mulberry leaf powder media. We confirmed that ${\alpha}$-glucosidase inhibitory activity was difference according to culture conditions of different pH values, inoculation amounts, and fermentation times. The results of mulberry leaf fermentation according to pH values and inoculation amounts were shown that the optimal conditions for ${\alpha}$-glucosidase inhibitory activity were defined as pH 7 and 9, inoculation amount 0.4%, and incubation until 2 to 4 days. These results can be provided a basic data for the optimal culture conditions increasing ${\alpha}$-glucosidase inhibitory activity from mulberry leaf fermentation.