• Biomolecules & Therapeutics
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• 제6권3호
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• pp.242-246
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• 1998

The inhibitory activities of Amberlite active fraction, which was obtained from methanol soluble fraction of freeze dried slikworm urine, on the rat intestinal glycosidase-catalyzed enzymatic reaction were examined in in viro and in vivo experiments. Amberlite active fraction showed significant inhibitory effects on the hydrolysis of o-glycosidic bond, especially $\alpha$-1,4 bond. On the other hand, the inhibition on the hydrolysis of $\beta$-glycosidic bond was very weak. Oral administration of Amberlite active fraction resulted in a dose-dependent decrease in the blood glucose after an oral maltose load, and postprandial hyperglycemia in carbohydrate-loaded mice was suppressed by Amberlite active fraction at 60 mgHg in decreasing order of maltose, starch, sucrose and lactose. 60 mg/kg of Amberlite active fraction lowered the blood glucose level markedly after 18, 35, and 60 min after an oral maltose load and the antihyperglycemic activity was maintained upto 90 min. In alloxan-induced hyperglycemic mice, Amberlite active fraction at a dose of 100 mg/kg also significantly lowered blood glucose after an oral maltose load, and its efficacy was almost equivalent to that of acarbowe.

• Journal of Applied Biological Chemistry
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• 제43권3호
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• pp.131-135
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• 2000

Human polymorphonuclear neutrophils undergo diaphoresis after a selectin-mediated rolling on the endothelial cells of the blood vessel wall. Extravasation is believed to be an integrin-mediated process. Galectin-1 is a small dimeric beta-galactoside-binding protein synthesized by the endotherial cells and present in the perivascular connective tissue. In this study we suggest the possible role of galectin-1 in extravasation of the activated neutrophils. MAL lectin binding study showed, that f-MetLeuPhe-activated neutrophils decrease surface sialylation and increase galectin-1 binding via exposure of new galectin-1 binding sites. Desialylated HL-60 cells also show the same decrease in MAL binding and increase in galectin-1 binding, an increase which was not observed in the presence of lactose. Galectin-1 blotting analysis detected two possible major ligands (approximately 120 and 160 kDa) of galectin-1 from the desialylated HL-60 cell lysates.

• Asian-Australasian Journal of Animal Sciences
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• 제25권5호
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• pp.659-664
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• 2012

The present experiment aimed to evaluate the effect of HMBi on the production performance and metabolism in dairy cows. Thirty multiparous Holstein dairy cows under similar conditions were randomly assigned to three dietary treatments; i) Control, a basal diet; ii) T1, a basal diet plus HMBi (0 g prepartum and 18 g postpartum); and iii) T2, a basal diet plus HMBi (10 g prepartum and 18 g postpartum). Treatments were initiated 21 d before expected calving and continued through 91 d postpartum. HMBi was top-dressed onto the total mixed ration of each cow. Treatments did not affect dry matter intake, plasma urea nitrogen, peak milk yield, days to peak milk yield, nonesterified fatty acid, glutamate pyruvate transaminase, glutamic oxalaetic transaminase, milk fat content, milk protein content, milk lactose content, and milk solid non-fat content. The milk composition yields were increased by the HMBi-supplemented treatment. The T1 and T2 treatments increased the yields of 4% fat-corrected milk yield, milk fat, milk protein, and milk lactose compared with the control. Although there was no difference in the milk composition of the control and T2-treated cows, the T2-treated cows exhibited higher milk fat yield (increased by 74 g/d), lower milk urea nitrogen (reduced by 3.41%), and plasma ${\beta}$-hydroxy butyrate than the control cows. The results indicate that HMBi supplementation to diet has beneficial effects, and that there is no difference between supplementation at prepartum and starting only at parturition.

• 한국식품영양학회지
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• 제10권3호
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• pp.344-349
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• 1997

Bacillus sp. DSNC 101은 탄소원으로 2.0% oat spelts xylan, 질소원으로 2.0% yeast extract, 그리고 인산염으로 0.4% K2HPO4를 함유한 pH 8.0의 xylanase 생산 배지에서 4$0^{\circ}C$에서 3일간 배양하였을 때 305.0 unit/ml의 xylanase 활성도를 나타내었다. 본 균주는 xylan, 가용성 전분, 볏짚 분말, Avicel, maltose, 그리고 lactose를 유일한 탄소원으로 사용하였을 때 xylanase를 생산하였으나 glucose, xylose, 그리고 arabinose를 사용하였을 때는 xylanase를 생산하지 않았다. 여러 가지 기질들에 대한 배양 상징액의 분해 활성을 조사한 바, xylan 분해 활성 외에 Avicel, carboxymethyl cellulose, 그리고 전분 및 PNPX에 대한 분해 활성은 나타내지 않았다. Xylanase 합성은 glucose에 의해서는 억제되었으나 xylose에 의해서는 억제되지 않았다. 배양 상징액을 이용한 xylan 분해 산물은 xylobiose를 포함한 소당류들이었으며 xylose는 거의 생성되지 않았다.

• 한국균학회지
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• 제13권2호
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• pp.83-87
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• 1985

A. phoenicis는 고온에서도 높은 lactose hydrolysis에 대한 효소 반응 활성을 가지고 있으나, 이 균주에 의한 progesterone의 전환 반응은 반응 온도에 매우 민감한 것으로 나타났다. 균체 내외부의 반응액 조성을 sonication 방법을 이용하여 조사함 결과 반응 초기에 균체의 내부에는 외부에 비하여 $11{\alpha}-hydroxyprogesterone$이 더 높은 농도로 존재하였으나 반응이 진행됨에 따라 균체 내부의 $11{\alpha}-hydroxyprogesterone$이 다른 생성물로 전환되어 오히려 더 낮은 농도의 $11{\alpha}-hydroxyprogesterone$이 존재하였다. A. phoenicis mycelium은 유기용매가 존재하는 반응액내에서도 새로운 액체 배지가 연속적으로 공급될 경우 물질대사를 계속 진행시킬 수 있으며, mycelium의 성장을 저해하지 않는 방법으로 고정된 cell을 이용하여 고정층 반응기에서 연속적으로 A. phoenicis-hydroxyprogesterone을 생산할 수 있다고 판단된다.

• Journal of Microbiology and Biotechnology
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• 제31권4호
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• pp.550-558
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• 2021

Lactobacillus kefiranofaciens contains two types of β-galactosidase, LacLM and LacZ, belonging to different glycoside hydrolase families. The difference in function between them has been unclear so far for practical application. In this study, LacLM and LacZ from L. kefiranofaciens ATCC51647 were cloned into constitutive lactobacillal expression vector pMG36e, respectively. Furtherly, pMG36n-lacs was constructed from pMG36e-lacs by replacing erythromycin with nisin as selective marker for food-grade expressing systems in Lactobacillus plantarum WCFS1, designated recombinant LacLM and LacZ respectively. The results from hydrolysis of o-nitrophenyl-β-galactopyranoside (ONPG) showed that the β-galactosidases activity of the recombinant LacLM and LacZ was 1460% and 670% higher than that of the original L. kefiranofaciens. Moreover, the lactose hydrolytic activity of recombinant LacLM was higher than that of LacZ in milk. Nevertheless, compare to LacZ, in 25% lactose solution the galacto-oligosaccharides (GOS) production of recombinant LacLM was lower. Therefore, two β-galactopyranosides could play different roles in carbohydrate metabolism of L. kefiranofaciens. In addition, the maximal growth rate of two recombinant strains were evaluated with different temperature level and nisin concentration in fermentation assay for practical purpose. The results displayed that 37℃ and 20-40 U/ml nisin were the optimal fermentation conditions for the growth of recombinant β-galactosidase strains. Altogether the food-grade Expression system of recombinant β-galactosidase was feasible for applications in the food and dairy industry.

• Journal of Microbiology and Biotechnology
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• 제27권3호
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• pp.598-609
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• 2017

Pediococcus pentosaceus ID-7 was isolated from kimchi, a Korean fermented food, and it showed high activity for lactose hydrolysis. The ${\beta}$-galactosidase of P. pentosaceus ID-7 belongs to the GH2 group, which is composed of two distinct proteins. The heterodimeric LacLM type of ${\beta}$-galactosidase found in P. pentosaceus ID-7 consists of two genes partially overlapped, lacL and lacM encoding LacL (72.2 kDa) and LacM (35.4 kDa). In this study, Escherichia coli MM294 was used for the production of LacL, LacM, and LacLM. These three types of recombinant proteins were expressed, purified, and characterized. The specific activities of LacLM and LacL were 339 and 31 U/mg, respectively. However, activity was not detected with LacM alone. The optimal pH of LacLM and LacL was pH 7.5 and pH 7.0, and the optimal temperature of LacLM and LacL was $40^{\circ}C$ and $50^{\circ}C$, respectively. The optimal temperature changes indicate that LacLM is able to achieve higher activity at a relatively lower temperature. LacLM was strongly activated by $Mg^{2+}$, $Mn^{2+}$, and $Zn^{2+}$, which was not true for LacL. Consistent with this, EDTA strongly inactivated LacLM and LacL, but the presence of reducing agents did not dramatically alter the activity. Taken together, multiple alignment of amino acid sequences and phylogenetic analysis results of LacL and LacM of P. pentosaceus ID-7 suggest the evolution of LacL into LacLM and that the use of divalent metal ions results in higher activity.

• Asian-Australasian Journal of Animal Sciences
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• 제27권6호
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• pp.886-897
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• 2014

The aim of the present study was to get a total physical and chemical characterization and comparison of the principal components in Bangladeshi buffalo (B), Holstein cross (HX), Indigenous cattle (IC) and Red Chittagong Cattle (RCC) milk. Protein and casein (CN) composition and type, casein micellar size (CMS), naturally occurring peptides, free amino acids, fat, milk fat globule size (MFGS), fatty acid composition, carbohydrates, total and individual minerals were analyzed. These components are related to technological and nutritional properties of milk. Consequently, they are important for the dairy industry and in the animal feeding and breeding strategies. Considerable variation in most of the principal components of milk were observed among the animals. The milk of RCC and IC contained higher protein, CN, ${\beta}$-CN, whey protein, lactose, total mineral and P. They were more or less similar in most of the all other components. The B milk was found higher in CN number, in the content of ${\alpha}_{s2}-$, ${\kappa}$-CN and ${\beta}$-lactalbumin, free amino acids, unsaturated fatty acids, Ca and Ca:P. The B milk was also lower in ${\beta}$-lactoglobulin content and had the largest CMS and MFGS. Proportion of CN to whey protein was lower in HX milk and this milk was found higher in ${\beta}$-lactoglobulin and naturally occuring peptides. Considering the results obtained including the ratio of ${\alpha}_{s1}-$, ${\alpha}_{s2}-$, ${\beta}$- and ${\kappa}$-CN, B and RCC milk showed best data both from nutritional and technological aspects.

• Applied Biological Chemistry
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• 제39권5호
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• pp.333-337
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• 1996

갈락토올리고당의 연속 생산을 위하여 Bacillus sp. A4442가 생산하는 갈락토스 전이활성이 높은 $\beta-galactosidase$를 균체제거 후 농축, 탈염하여 $Diaion^{TM}$ HPA 75(styrene-divinylbenzene resin)에 고정화하였다. 고정화 수율 및 고정화 효소의 활성을 높이기 위하여 효소 고정화에 영향을 주는 변수들을 최적화하였다. 고정화 시간은 실온에서 3시간, Tris 완충액의 농도는 30mM, pH는 8이 적당하였다. 단백질부하가 증가할수록 효소는 다른 단백질과 경쟁적이며 가역적으로 담체에 결합하였으며, 최적부하는 약 25 mg Protein/g resin 이었다. 가교제로서 glutaraldehyde 0.5%를 사용하였을 때 효소의 열 안정성 및 운전 안정성이 현저히 증가하였다. 이러한 실험조건하에서 고정화를 실시하였을 때 고정화 수율은 40% 이상이었으며 그 활성이 약 200 U/g resin인 고정화 효소를 얻을 수 있었다. Packed-bed reactor에서 유당을 갈락토올리고당으로 연속적으로 전환 가능하였고, 이때 고정화 효소 1 g으로 갈락토올리고당 약 300 g을 생산할 수 있었다.

• 한국응용과학기술학회지
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• 제33권2호
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• pp.286-292
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• 2016

화장품용 방부제로 사용하고 있는 1, 2-hexanediol (HD)에 높은 농도의 lactose (300 g/l)를 넣고, 재조합 대장균 ${\beta}$-galactosidase (${\beta}$-gal)를 이용하여 galactose 한 분자를 결합시키는 transgalactosylation 반응을 시켜서, 1, 2-hexanediol galactoside (HD-gal)을 합성하였다. 그리고, 합성된 HD-gal 분자를 확인하기 위하여, HD-gal에 대한 NMR ($^1H$- and $^{13}C$-) 스펙트럼 분석과 mass 스펙트럼 분석을 실시하였다. HD-gal의 $^1H$ NMR 스펙트럼에서 HD에 갈락토실화가 되었음을 보여주는 다양한 피크를 확인하였다. $^1H$ NMR 스펙트럼의 다운필드인 ${\delta}_H$ 4.44 ppm과 ${\delta}_H$ 3.96~3.58 ppm에서 나타나는 다양한 피크들은 HD에 갈락토실화가 되었다는 것을 잘 암시하고 있으며, 또한 $^1H$ NMR 스펙트럼의 업필드에서 나타나는 ${\delta}_H$ 1.60~1.35 ppm과 0.92 ppm의 피크는 HD의 $CH_2$와 $CH_3$ 작용기로부터 나타나는 피크로써 HD가 본 물질에 존재한다는 것을 나타내고 있다. $^{13}C$ NMR 스펙트럼에서는 HD-gal의 알파-아노머와 베타-아노머의 구조에서 기인하는 총 21의 카본피크가 나타났고, 각 아노머마다 12개의 카본이 존재하는데 이중 ${\delta}_C$ 68.6, 60.9 and 13.2 ppm에 보이는 3개의 카본은 겹쳐서 나타나 총 24개의 피크 중 21개가 나타났다. 또한, 질량스펙트럼 분석에서는 protonated HD-gal인 281.1601 (m/z)의 peak를 확인할 수 있었다. 이를 종합하면, NMR ($^1H$- and $^{13}C$-) 스펙트럼 분석 결과와 질량분석 결과들은 우리가 기대했던 HD-gal의 구조와 매우 잘 일치하고 있다는 것을 알 수 있었다. 앞으로 추가적으로, 세균에 대한 minimum inhibitory concentrations (MICs) 조사와 human skin cell에 대한 독성연구를 추가적으로 진행할 예정이며, 이러한 결과를 근거로 항균력을 유지하면서 피부세포에 대한 독성이 감소된 화장품용 방부제의 연구/개발이 계속되기를 기대하고 있다.