• Journal of Applied Biological Chemistry
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• 제55권3호
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• pp.173-178
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• 2012

충치 형성 과정에 중요한 불용성 글루칸의 합성과 관련된 sucrose-glucan glucosyltransferase (Gtf)를 Streptococcus mutans Ingbritt 의 배양액에서 염석과, Sephadex G-150, CM-Sephadex, DEAE-Sephadex column을 통과시켜 정제하였다. 회수율 6.3%였으며, 정제율 13배였다. sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE)에서 이 효소의 분자량은 66 kDa이며, 최적 pH와 온도는 각각 6.0과 $40^{\circ}C$이였다. 이 효소는 0.1 mM $Hg^{2+}$, $Cu^{2+}$, $Al^{3+}$에 의하여 22-59% 저해되었다. 이 효소는 2 mM 자이리톨에 의하여 40% 저해 받았으며, 0.05% 수용성 키토산, 글리콜 키토산, 글리콜 키틴에 의하여 35-45% 저해되었다. 키틴 유도체가 Gtf 활성을 억제한다는 보고는 본 연구가 최초이며, 이는 키틴 유도체를 구강청결제의 소재로 활용할 수 있음을 제시한다.

• Journal of Microbiology and Biotechnology
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• 제19권3호
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• pp.257-264
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• 2009

A $\beta$-agarase gene, agaB34, was functionally cloned from the genomic DNA of a marine bacterium, Agarivorans albus YKW-34. The open reading frame of agaB34 consisted of 1,362 bp encoding 453 amino acids. The deduced amino acid sequence, consisting of a typical N-terminal signal peptide followed by a catalytic domain of glycoside hydrolase family 16 (GH-16) and a carbohydrate-binding module (CBM), showed 37-86% identity to those of agarases belonging to family GH-16. The recombinant enzyme (rAgaB34) with a molecular mass of 49 kDa was produced extracellularly using Escherichia coli $DH5{\alpha}$ as a host. The purified rAgaB34 was a $\beta$-agarase yielding neoagarotetraose (NA4) as the main product. It acted on neoagarohexaose to produce NA4 and neoagarobiose, but it could not further degrade NA4. The maximal activity of rAgaB34 was observed at $30^{\circ}C$ and pH 7.0. It was stable over pH 5.0-9.0 and at temperatures up to $50^{\circ}C$. Its specific activity and $k_{cat}/K_m$ value for agarose were 242 U/mg and $1.7{\times}10^6/sM$, respectively. The activity of rAgaB34 was not affected by metal ions commonly existing in seawater. It was resistant to chelating reagents (EDTA, EGTA), reducing reagents (DTT, $\beta$-mercaptoethanol), and denaturing reagents (SDS and urea). The E. coli cell harboring the pUC18-derived agarase expression vector was able to efficiently excrete agarase into the culture medium. Hence, this expression system might be used to express secretory proteins.

• Journal of Microbiology and Biotechnology
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• 제22권1호
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• pp.58-68
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• 2012

An investigation was conducted on the enhancement of production and purification of an oxidant and SDS-stable alkaline protease (BHAP) secreted by an alkalophilic Bacillus horikoshii, which was screened from the body fluid of a unique Korean polychaeta (Periserrula leucophryna) living in the tidal mud flats of Kwangwha Island in the Korean West Sea. A prominent effect on BHAP production was obtained by adding 2% maltose, 1% sodium citrate, 0.8% NaCl, and 0.6% sodium carbonate to the culturing medium. The optimal medium for BHAP production contained (g/l) SBM, 15; casein, 10; $K_2HPO_4$, 2; $KH_2PO_4$, 2; maltose, 20; sodium citrate, 10; $MgSO_4$, 0.06; NaCl, 8; and $Na_2CO_3$, 6. A protease yield of approximately 56,000 U/ml was achieved using the optimized medium, which is an increase of approximately 5.5-fold compared with the previous optimization (10,050 U/ml). The BHAP was homogenously purified 34-fold with an overall recovery of 34% and a specific activity of 223,090 U/mg protein using adsorption with Diaion HPA75, hydrophobic interaction chromatography (HIC) on Phenyl-Sepharose, and ion-exchange chromatography on a DEAE- and CM-Sepharose column. The purified BHAP was determined a homogeneous by SDS-PAGE, with an apparent molecular mass of 28 kDa, and it showed extreme stability towards organic solvents, SDS, and oxidizing agents. The $K_m$ and $k_{cat}$ values were 78.7 ${\mu}M$ and $217.4s^{-1}$ for N-succinyl-Ala-Ala-Pro-Phe-pNA at $37^{\circ}C$ and pH 9, respectively. The inhibition profile exhibited by PMSF suggested that the protease from B. horikoshii belongs to the family of serine proteases. The BHAP, which showed high stability against SDS and $H_2O_2$, has significance for industrial application, such as additives in detergent and feed industries.

• 생약학회지
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• 제40권4호
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• pp.408-414
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• 2009

This study was performed to investigate the anti-hyperglycemia effects of the Triticum aestivum wheat sprout (TAWS) water extracts in the diabetic mice. Diabetic experimental model was established by intraperitoneal injection of streptozotocin into male Balb/c mice. Mice were divided into five groups: normal (CON), diabetic control (DM), and three experimental groups (DM-100, diabetes with TAWS extracts 100mg/kg; DM-50, diabetes with TAWS extracts 50 mg/kg; DM-25, diabetes with TAWS extracts 25 mg/kg). TAWS extracts were administered orally in diabetic mice. Body weight, food intake, and blood glucose levels were recorded for 12 days and blood insulin levels were measured at the day 12. Oral administration of TAWS extracts reduced slightly food intake and induced a little body weight gain in DM-100 groups. The blood level of glucose was decreased in the dose-dependent manner; 55% in the DM-100 group and 39.7% in the DM-50 group. The blood level of insulin also was improved 10 folds in the DM-100 group and 3.6 folds in the DM-50 group compared to the DM group. The contents of total phenolic compounds and total flavonoids in 1 g dry mass of TAWS extracts were 6.6 mg of tannic acid equivalents and 1.0 mg of 8-hydroquinolline equivalents, respectively. In addition, the antioxidant and DPPH radical scavenging activity of TAWS extracts were 1.2 mM and 1.8 mM ascorbic acid equivalents, respectively. These results suggest that TAWS water extracts could contribute to attenuate clinical symptoms of diabetes mellitus.

• 대한원격탐사학회지
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• 제21권1호
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• pp.73-81
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• 2005

We construct improved geocentric digital elevation model (DEM), estimate tidal dynamics and ice stream velocity over Sulzberger Ice Shelf, West Antarctica employing differential interferograms from 12 ERS tandem mission Synthetic Aperture Radar (SAR) images acquired in austral fall of 1996. Ice, Cloud, and land Elevation Satellite (ICESat) laser altimetry profiles acquired in the same season as the SAR scenes in 2004 are used as ground control points (GCPs) for Interferometric SAR (InSAR) DEM generation. 20 additional ICESat profiles acquired in 2003-2004 are then used to assess the accuracy of the DEM. The vertical accuracy of the OEM is estimated by comparing elevations with laser altimetry data from ICESat. The mean height difference between all ICESat data and DEM is -0.57m with a standard deviation of 5.88m. We demonstrate that ICESat elevations can be successfully used as GCPs to improve the accuracy of an InSAR derived DEM. In addition, the magnitude and the direction of tidal changes estimated from interferogram are compared with those predicted tidal differences from four ocean tide models. Tidal deformation measured in InSAR is -16.7cm and it agrees well within 3cm with predicted ones from tide models. Lastly, ice surface velocity is estimated by combining speckle matching technique and InSAR line-of-sight measurement. This study shows that the maximum speed and mean speed are 509 m/yr and 131 m/yr, respectively. Our results can be useful for the mass balance study in this area and sea level change.

• 한국식품과학회지
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• 제35권2호
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• pp.297-301
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• 2003

동맥경화증과 같은 심혈관 질환을 야기시키는 주요 위험요인인 혈중 콜레스테롤의 수준을 낮추기 위하여 콜레스테롤 생합성 과정의 속도조절단계 효소의 하나인 squalene synthase의 활성을 저해하는 물질을 분리 정제하여, 물질의 이화학적 특성과 생물학적 특성을 검토하였다. Squalene synthase 저해물질은 acetone extraction, ethyl acetate extraction, silica gel column chromatography, sephadex LH-20 column chromatography, 결정화 등을 이용하여 분리 정제하여 YUF-01을 얻었다. 기기분석을 통하여 구조분석을 행한 결과 YUF-01은 분자량 368, 분자식 $C_{20}H_{21}O_6$으로 분석되었으며 243과 421 nm 에서 UV-VIS 흡광을 나타내었고 $^{13}C$ NMR spectrum과 $^1H$ NMR spectrum을 검토하였을 때 aromatic ketone 구조인 curcuminoid 계통의 curcumin과 일치하였다. Squalene synthase에 대한 curcumin의 $IC_{50}$ 값은 $100{\mu}M$이었으며, non-competitive inhibitor로 작용하였다.

• Fisheries and Aquatic Sciences
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• 제9권4호
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• pp.153-159
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• 2006

The ark shell (or 'blood clam') Scapharca broughtonii is a filter-feeding bivalve that has red blood and inhabits waters approximately 10m in depth off the southern coast of South Korea. This study was part of a larger research project investigating the causes of death and restoration of shellfish resources, which are important aquaculture products in South Korea. We examined physiological responses related to survival, respiration, excretion, and amino acid changes as a result of changes in salinity. The 9-day median lethal salinity ($LS_{50}$) was 16.5 psu with confidence limits of 14.9-18.1 psu. At $25^{\circ}C$, the oxygen consumption and ammonia-nitrogen excretion rates were increased with decreases in salinity. Although the osmolality of individuals was acclimated within 2 h at 26.4 psu and 12 h at 19.8 psu, it took more than 5 days at a salinity of 13.2 psu, whereas no individuals acclimated and all died at a salinity of 6.6 psu. Of the amino acids present in the blood, taurine and alanine increased in response to decreased salinity. Tissues of the gill and the mid-gut gland were affected by decreasing salinity. These data will provide important fundamental information for examining the causes of mass mortality of shellfish in the summer.

• 한국작물학회지
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• 제45권3호
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• pp.151-157
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• 2000

옥수수수염에 함유되어 있는 maysin 및 유사 flavonoid 물질의 분리 및 정제법을 확립하여 신품종 육성의 기초적인 자료를 제공하고자 본 시험을 수행하였으며 얻어진 결과를 요약하면 다음과 같다. 1. Preparative $C_{18}$ 컬럼에서 10% MeOH에 용출된 물질은 neochlorogenic acid, chlorogenic acid 및 4-caffeoylquinic acid였으며 30% MeOH로 용출된 물질은 rhamnosyl isoorientin이었고 maysin은 50%의 MeOH에서 용출되었다. 2. Silicic acid 컬럼으로 maysin 조추출물의 1차 정제시 100% ethyl acetate 500$m\ell$로 컬럼에 흡착되어 있는 maysin을 용출시켰으며, 이때 수거된 maysin의 순도는 75% 이상에 해당하였고, $C_{18}$ 컬럼($\frac{1}{2}$$\times$43")으로 maysin의 2차 정제시 maysin의 순도는 95% 이상에 달하였다. 3. FAB-MS에 의한 maysin의 분자량은 577M＋H m/z이고, fragmentation으로 보아 431M＋H m/z은 rhamnose에 해당하였고, $^1$H 및 $^{13}$C NMR에 의한 spectrum을 확인한 결과 분리한 물질이 maysin임을 확인할 수 있었다. 있었다.

• 한국식품위생안전성학회지
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• 제34권5호
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• pp.413-420
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• 2019

본 연구에서는 chlorogenic acid 이성질체 9종과 arbutin을 분석하기 위하여, 전처리 과정과 UHPLC-MS/MS 동시분석 조건을 확립하였다. UHPLC-MS/MS에서 C18 column을 사용하여 15분 동안 분석할 수 있는 용매 조성을 만들고, 10가지 물질에 대한 정량, 정성 이온을 선택하여 negative 모드에서 분석하는 동시분석법을 확립하였고 과일류를 대상으로 추출, 진탕추출, 초음파 추출, 원심분리, 농축 등의 과정을 거치는 전처리법을 개발하였다. 기기분석과 전처리법에 대한 유효성은 특이성, 직선성, 정확성, 정밀성 그리고 검출한계 및 정량한계 등을 통하여 확인하였다. 회수율은 48.1-120.3%, intraday precision(RSD)는 0.4-7.9%, interday precision (RSD)는 0.0-7.2%로 확인되었다. 따라서, 본 연구에서 확립한 동시분석방법은 과일류 중 chlorogenic acid와 arbutin을 효과적으로 분석하는데 유용할 것으로 사료된다.

• 천문학회보
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• 제40권2호
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• pp.30.3-31
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• 2015

We present a kinematic analysis of 172 likely member galaxies of the Ursa Major Cluster. In order to understand the dynamical state of the cluster, we investigate the correlation of the cluster morphology with rotation, the velocity dispersion profile, and the rotation amplitude parallel to the global rotation direction. Both the minor axis and the rotation are very well-aligned with the global rotation axis in the outer region at half radius (> 0.5 $R_{max}$), but not in the inner region. The cluster exhibits low velocity dispersion and rotation amplitude profiles in the inner region, but higher in the outer. Both profiles exhibit outwardly increasing trends, suggesting an inside-out transfer of angular momentum of dark matter via violent relaxation, as revealed by a recent off-axis major-merging simulation. From Dressler-Schectman plots in the plane of galactic positions, and velocity versus position angle of galaxy, we are able to divide the Ursa Major Cluster into two substructures: Ursa Major South (UMS) and Ursa Major North (UMN). We derive a mass of $3.2{\times}10^{14}M_{\odot}$ for the cluster through the two-body analysis by the timing argument with the distance information (37 for UMN and 36 for UMS) and the spin parameter of ${\lambda}=0.049$. The two substructures appear to have passed each other 4.4 Gyr ago and are moving away to the maximum separation.