• Applied Biological Chemistry
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• 제32권2호
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• pp.132-136
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• 1989

인삼의 에칠아세테이트 가용성 중성분획에서 지질 성분을 분리 정제하여 이화학적 성질 및 분광학적 특성을 조사한 결과 acyl group의 약 70%가 palmitic acid로, 당은 1분자의 ${\beta}-D-glucose$로 구성되어 있는 glycosyldiglyceride였다. 이 물질은 인삼에서는 처음으로 분리 정제되었다.

• Bulletin of the Korean Chemical Society
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• 제33권7호
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• pp.2411-2414
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• 2012

• KSBB Journal
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• 제26권2호
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• pp.93-99
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• 2011

Glycosylation is a key mechanism in determining diversity of natural products, and influencing their bioactivities. This approach requires a core set of glycosyltransferase that synthesizes the diverse sugar structures observed in nature. Recently, the researchers have begun to alter the sugar moiety and glycosylation patterns of natural products both in vivo E. coli system and in vitro for their glycodiversification. This review highlights new glycosylation tools using microbialproduced deoxysugar and a flexible glycosyltransferase on natural plant-flavonoids to generate novel glycoforms with useful biological activity.

• Molecules and Cells
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• 제19권1호
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• pp.137-142
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• 2005

We showed recently that ginsenosides inhibit the activity of various types of ion channel. Here we have investigated the role of the carbohydrate component of ginsenoside $Rg_3$ in the inhibition of $Na^+$ channels. The channels were expressed in Xenopus oocytes by injecting cRNAs encoding rat brain Nav1.2 ${\alpha}$ and ${\beta}1$ subunits, and analyzed by the two-electrode voltage clamp technique. Treatment with $Rg_3$ reversibly inhibited the inward $Na^+$ peak current ($I_{Na}$) with an $IC_{50}$ of $32.2{\pm}4.5{\mu}M$, and the inhibition was voltage-dependent. To examine the role of the sugar moiety, we prepared a straight chain form of the second glucose and a conjugate of this glucose with 3-(4-hydroxyphenyl) propionic acid hydrazide (HPPH). Neither derivative inhibited $I_{Na}$. Treatment with the carbohydrate portion of ginsenoside $Rg_3$, sophorose [${\beta}-D-glucopyranosyl$ ($1{\rightarrow}2$)-${\beta}-glucopyranoside$], or the aglycone (protopanaxadiol), on their own or in combination had no effect on $I_{Na}$. These observations indicate that the carbohydrate portion of ginsenoside $Rg_3$ plays an important role in its effect on the $Na^+$ channel.

• Journal of Microbiology and Biotechnology
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• 제18권8호
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• pp.1386-1392
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• 2008

A gene (sll0158) putatively encoding a glycogen branching enzyme (GBE, E.C. 2.4.1.18) was cloned from Synechocystis sp. PCC6803, and the recombinant protein expressed and characterized. The PCR-amplified putative GBE gene was ligated into a pET-21a plasmid vector harboring a T7 promoter, and the recombinant DNA transformed into a host cell, E. coli BL21(DE3). The IPTG-induced enzymes were then extracted and purified using Ni-NTA affinity chromatography. The putative GBE gene was found to be composed of 2,310 nucleotides and encoded 770 amino acids, corresponding to approx. 90.7 kDa, as confirmed by SDS-PAGE and MALDI-TOF-MS analyses. The optimal conditions for GBE activity were investigated by measuring the absorbance change in iodine affinity, and shown to be pH 8.0 and $30^{\circ}C$ in a 50 mM glycine-NaOH buffer. The action pattern of the GBE on amylose, an $\alpha$-(1,4)-linked linear glucan, was analyzed using high-performance anion-exchange chromatography (HPAEC) after isoamylolysis. As a result, the GBE displayed $\alpha$-glucosyl transferring activity by cleaving the $\alpha$-(1,4)-linkages and transferring the cleaved maltoglycosyl moiety to form new $\alpha$-(1,6)-branch linkages. A time-course study of the GBE reaction was carried out with biosynthetic amylose (BSAM; $M_p{\cong}$8,000), and the changes in the branch-chain length distribution were evaluated. When increasing the reaction time up to 48 h, the weight- and number-average DP ($DP_w$ and $DP_n$) decreased from 19.6 to 8.7 and from 17.6 to 7.8, respectively. The molecular size ($M_p$, peak $M_w{\cong}2.45-2.75{\times}10^5$) of the GBE-reacted product from BSAM reached the size of amylose (AM) in botanical starch, yet the product was highly soluble and stable in water, unlike AM molecules. Thus, GBE-generated products can provide new food and non-food applications, owing to their unique physical properties.

• 유기물자원화
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• 제17권4호
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• pp.48-58
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• 2009

Glycosyl hydrolase(GH, EC 3.2.1.-)는 둘 또는 그 이상의 탄수화물 및 탄수화물과 비탄수화물 부분사이의 글리코시딕 결합(glycosidic bond)을 가수분해하는 효소이다. GH에 대한 새로운 분류법은 효소들의 아미노산 서열의 유사성과 구조적인 특징에 기초를 두고 있다. 본 논문에서는 CAZy 데이터베이스를 통하여 총 115종에 이르는 GHF 유전자 중에서 지렁이로부터 12종의 GHF 유전자를 동정하였다. 이 중 산업적 응용가능성이 높은 5종의 유전자(GHF2, 5, 17, 18, 20)를 선택하여 다른 동물종에서 보고된 유전자와 비교분석하였다. 그 결과 지렁이 GHF 유전자들은 동종의 다른 유전자들과 높은 아미노산서열 상동성을 나타냈으며 활성부위 등의 주요 아미노산 잔기가 잘 보존되어 있었다. 이들 유전자들은 해충방제제, 식품가공업, 의학적 치료제 및 유기성폐기물 처리 등에 활용할 수 있을 것으로 사료된다.

• 한국식품영양과학회지
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• 제28권2호
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• pp.285-291
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• 1999

To confirm the food quality of Urechis unicinctus which have been favored as a special raw seafood in southern area in Korea, the chemical composition of Urechis unicinctus and those glycoprotein were studied. Freeze dried Urechis unicinctus was composed of more than 70% of crude protein and 15% of total carbohydrate. The amino acids such as glycine(18.69%), glutamic acid(12.50%) and aspartic acid(9.37%) were noted as major components of total amino acids. The predominant free amino acids were alanine(32.98%), glycine(27.50%), asparagine(19.65%) and taurine(8.29%), and the sum of them were more than 88% to total free amino acids, so they may cause unique taste of Urechis unicinctus with sweetness. As the basis of sugar composition analysis, 56.35% of glucose and 30.49% of N acetylglucosamine were contained respectively, and they might also play an important role in a sweet taste. The leading carbohydrate moiety of glycoprotein from Urechis unicinctus was identified as glucose and N acetylglucosamine similarly to raw muscle, and they occupied more than 50% of total sugar content. Fucose(18.32%) and D glucuronic acid(12.31%) also detected in higher levels com pared to raw muscle. The total amino acid profile of glycoprotein showed a similar trend to raw muscle protein but glycine was detected a significantly lower than that in raw muscle. The glycoprotein from Urechis unicinctus was composed of 4 kinds of subunits, i.e. 25kDa, 20kDa, 18kDa and 12.5kDa of molecular weights through the SDS polyacrylamide gel electrophoresis. On the basis of the IR spectrum of absorptions appeared in 1,240cm-1 and 850cm-1, the glycoprotein had sulfate groups.

• Preventive Nutrition and Food Science
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• 제1권2호
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• pp.186-189
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• 1996

Neohesperidin dihydrochalcone(NHDC) is an intense sweetener with lingering aftertaste, which limits NHDC to use as a sweetener in food products. This study was conducted to examine the changes of teste quality of NHDC when using $\beta$-cyclodextrin($\beta$-CD) as a taste modifier. A series of $\beta$-CD(0.01%, 0.03%, 0.1%, 0.176%) was added to NHDC solution (100ppm) and the taste quality was evaluated by magnitude estimation. It was found that $\beta$-CD produced a significant effect in the reduction of aftertaste of NHDC(p<0.01) and sweetness as well.(p<0.001). Linear regression(log mean magnitude estimate versus $\beta$-CD concentration) analysis showed that the intensity of sweetness(n=-0.31) decreased more rapidly than that of aftertaste(m=-0.17). This result suggests the possibility that $\beta$-CD may form inclusion complex with NHDC, so that the hydrophobic portion is encapsulated in the cavity of $\beta$-CD and the carbohydrate moiety is oriented to the outside of the cavity. Or it may be that $\beta$-CD competes with the NHDC molecule for binding to the taste receptor, resulting in reduced perceived intensity.

• 생명과학회지
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• 제14권1호
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• pp.51-56
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• 2004

장수상황버섯(Phellinus baumii)의 균사체 성장 및 세포외 다당체(exopolysaccharides) 생산을 위한 액체배양의 최적 배지 및 배양조건에 관한 실험을 수행한 결과, 최적배양 온도와 초기 pH는 각각 3$0^{\circ}C$와 5.0으로 결정되었다. 탄소원의 경우, cellobiose와 maltose가 균사체 성장에는 양호하였으나 저조한 세포외 다당체 생산을 보였으며, 반면에 fructose 와 mannitol 은 상대적으로 높은 수율의 세포외 다당체 생산과 균사체 성장 또한 양호하였다. 최적 질소원으로는 yeast extract가 균사체 성장뿐만 아니라 세포외 다당체 생산에 효과적인 것으로 결정되었다. 최적 배지의 조성은 fructose 20 g/L, yeast extract 20 g/L 및 $CaCl_2$ 0.55 g/L이었으며, 최적 배양조건 하에서 5-L 교반 발효조를 운전한 결과, 최대 균사체 성장(17.43 g/L)과 최대 세포외 다당체 생산(3.6 g/L)을 얻을 수 있었다. 회수된 세포외 다당체는 glycoprotein이었으며 그 조성은 amino acid분석 결과 주로 arginine (14.1%)과 glycin (12.0%)이었으며, cabohydrate의 경우는 mannose (48.7%)와 arabinose (38.4%)이 주성분이었다.

• 한국균학회지
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• 제27권4호통권91호
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• pp.293-298
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• 1999

복령 균핵을 여러단계로 추출하여 얻은 다당류들의 면역 증강활성을 생쥐 비장세포에서 혼합임파구 반응으로 측정하였다. 이들 중 탄산나트륨 추출물의 활성이 가장 높았고 이를 DEAE-셀롤로오스와 Sephadex G-50 크로마토그래피로 면역활성증강물질을 정제하여 PCSC22를 얻었다. PCSC22는 탄수화물과 단백질이 약 78:22의 비율로 이루어진 단백다당체이었으며 GP-HPLC로 측정된 평균분자량은 약 8 kDa이었다. PCSC22 분획은 단당들의 구성성분들 중 mannose(92%)가 가장 많고 galactose(6.2%)와 약간의 arabinose(1.3%)도 함유하고 있는 heteromannan 이었다. 단백질 부분은 총 15종의 아미노산으로 구성되어 있었고 그 중 aspartic acid, serine, valine 등의 합이 약 47%로 주요 성분이었다. PCSC22는 B 임파구의 항체형성능력과 macrophage의 일산화질소 분비능력을 함께 증강시켰다.