• Macromolecular Research
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• 제16권1호
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• pp.1-5
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• 2008

The enzymatic hydrolysis of chitin has been studied for almost a century, and early work established that at least two enzymes are required, a chitinase that mainly yields the disaccharide N,N'-diacetylchitobiose, or $(GlcNAc)_2$, and a "chitobiase", or ${\beta}$-N-acetylglucosaminidase, which gives the final product G1cNAc. This pathway has not been completely identified but has remained the central concept for the chitin catabolism through the $20^{th}$ century1 including in marine bacteria. However, the chitin catabolic cascade is quite complex, as described in this review. This report describes three biologically functional genes involved in the chitin catabolic cascade of Vibrios in an attempt to better understand the metabolic pathway of chitin.

• 한국동물학회지
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• 제36권1호
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• pp.123-132
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• 1993

곤충의 탈피작용에서 일어나는 키틴 분해대사를 구명하기 위한 목적으로 배추흰나비 (Pieris rupae L.)에서 3종의 서N-acetylglucosaminldase(El, Ell, Elll)를 분리, 정제하였다. Polvacrylamide gel 상에서 이들 효소의 활성은 기질과 triphenvltetrazolium chloride와의 반응 결과 생기는 발색정도로 확인하였다. 각각의 분자량은 76,000, 55,000, 35,000 da, pl 값은 모두 5.8이었으며 후p$\beta$GlcNAc와 각p$\beta$GaINAc에 대해서 다같이 기질특이성을 나타내었다. 또한 El과 Elll는 탈피 시기와 일치하는 전용 말기에 최대 활성을 나타내었으며 Ell는 용화 직후에 최대 활성을 나타내었다.

• Bulletin of the Korean Chemical Society
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• 제34권5호
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• pp.1339-1344
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• 2013

We have synthesized several glycosyl ergosterols and 5,6-dihydroergosterols (DHE) and examined their effects on production of nitric oxide (NO) and iNOS protein expression in LPS-treated RAW264.7 macrophage cells. Our results showed that DHE derivatives inhibited production of NO and iNOS protein expression more strongly than ergosterol derivative. Especially, DHE-Glc exhibited most potent inhibitory activity without cytotoxicity up to the concentration of $100{\mu}M$.

• 약학회지
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• 제13권4호
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• pp.111-120
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• 1969

The determination of $\alpha$-pyrrolidone in ginseng extract by gas liquid chromatography (GLC) was established. $\alpha$-Pyrrolidone in extract was tentatively identified by comparison of the relative retention time of sample peak with those of reference compound and coinjection noted peak enhancement. The .alpha.-pyrrolidone peak elimination was demonstrated by formation of oxime when treated with excess of NH$_{2}$OH ${\cdot}$ HCl and NaOH, allowed to stand at room temperature for 5 minute. The elimination was also observed when samples were treated by the same procedure. The above method was proved to be useful for the determination of $\alpha$-pyrrolidone in ginseng extract and in ginseng extract mixed with 51 plant extracts.

• Archives of Pharmacal Research
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• 제4권2호
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• pp.117-122
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• 1981

The carpophores of a mushroom, Naematoloma fasciculare (Fr.) Karst, were extracted with 0.2 N NaOH and the extract was dialyzed through visking tube. It was found to contain an antitumor activity against sarcoma 180 implanted in mice. The components of this aqueous extract were found to be a polysaccharide and a protein by color reactions including Anthrone and Lowery-Folin tests. The hydrolysis of the polysaccharide with 3% HCL-Me-OH and trimethylsily lation of the hydrolysate yielded five monosaccharides, i. e. glucose, frutose, mannose, galactose and xylose, which were detected and analyzed by GLC. After hydrolysis of the protein with 6N HCl, 15 amino acids, including aspartic acid and glutamic acid, were detected and analyzed by an auto amino acid analyzer.

• Carbon letters
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• 제4권1호
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• pp.10-13
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• 2003

The structural studies of amorphous isotropic carbon prepared from pyrolysis of phenol formaldehyde resin have been carried out using X-ray diffraction. X-ray diffraction from as prepared sample at $1000^{\circ}C$ and a sample treated at $1900^{\circ}C$ revealed that both are amorphous even though there are small differences in short range order. It is found that both are graphite like carbon (GLC) with predominantly $sp^2$ hybridization. Small angle X-ray scattering results show that as prepared sample mainly consists of thin two dimensional platelets of graphitic carbon whereas they grow in thickness to become three dimensional materials of nano dimensions.

• 한국식품과학회지
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• 제30권6호
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• pp.1247-1251
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• 1998

식초의 에탄올과 초산을 동시에 분석하고자 packed column으로 gas chromatographic analysis을 모색하였다. Tenax-GC를 충진물로 사용하여 $2\;m{\times}2\;mm$의 stainless steel column을 제조하고 식초를 여과하여 column에 직접 주입한 결과 내부 표준 물질로 사용한 isopropyl alcohol과 에탄올, 초산이 20분 이내에서 완전히 분리되었으며 정확도가 매우 높은 것으로(P<0.05)나타났다. 19종의 식초를 이용하여 적정방법으로 산도를, packed column GSC로 에탄올과 초산을, HPLC로 초산을, capillary column GLC로 에탄올과 초산을 각각 분석하여 분석치들을 상호 비교하였다.

• BMB Reports
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• 제51권12호
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• pp.609-610
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• 2018

Glycosylation is one form of protein modification and plays a key role in protein stability, function, signaling regulation and even cancer. NleB and SseK are bacterial effector proteins and possess glycosyltransferase activity, even though they have different substrate preferences. NleB/SseKs transfer the GlcNAc sugar to an arginine residue of host proteins, leading to reduced $NF-{\kappa}B-dependent$ responses. By combining X-ray crystallography, NMR, molecular dynamics, enzyme kinetic assays and in vivo experiments, we demonstrated that a conserved HEN (His-Glu-Asn) motif in the active site plays a key role in enzyme catalysis and virulence. The lid-domain regulates the opening and closing of the active site and the HLH domain determines the substrate specificity. Our findings provide evidence for the enzymatic mechanism by which arginine can be glycosylated by SseK/NleB enzymes.

• 대한약학회:학술대회논문집
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• 대한약학회 2003년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2-2
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• pp.197.4-198
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• 2003

As an attempt to search for bioactive natural constituents exerting antinociceptive and antiinflammatory activities, we examined the potency of the extract of R. coreanus fruits by the activity-guided fractionation. The EtOAc- and BuOH fraction and those alkaline hydrolysates showed significant antinociceptive effects as assessed by writhing-, hot plate- and tail flicks tests in mice and rats as well as antiinflammatory effect in rats with carrageenan-induced edema. BuOH extract was subjected to column chromatography to obtain a large amount of niga-ichigoside F$_1$ (1, 23-hydroxytormentic acid 28-O-glc), which was again hydrolyzed in NaOH solution to yield an aglycone 23-hydroxytormentic acid (1a). (omitted)

• 대한유전성대사질환학회지
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• 제5권1호
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• pp.65-75
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• 2005

목적: 뮤코지방증 유형 II와 III은 리소좀 효소인N-acetylglucosaminyl-1-phosphotransferase (UDP-N-acetylglucosamine, GlcNAc-phospho-transferase)의 결손에 의해 초래되며, 상염색체 열성으로 유전되는 질환이다. ${\alpha}/{\beta}/{\gamma}$ subunit로 구성되는 이 효소의 결핍으로 인해 리소좀으로 운반되는 수십 종류의 효소들에 mannose-6-phosphate(M6P)를 부착하는 과정에 장애가 생겨 분해되지 않은 물질이 축적되어 질병이 초래된다. 이 질환에 있어서 산전 진단과 유전 상담을 위해서는 상기 효소의 해당 유전자가 밝혀져 있어야 하나, 현재 이 효소의 ${\gamma}$ subunit를 암호화하는 유전자가 GNPTAG에 해당된다고 밝혀져 있을 뿐 ${\alpha}/{\beta}$ subunit을 암호화하는 GNPTA에 해당하는 유전자는 밝혀져 있지 않고 돌연변이 역시 보고된 적이 없다. 본 연구는 리소좀 효소의 인산화에 관여하는 N-acetylglucosamine-1-phospho-transferase의 결함이 있는 환자의 섬유아세포를 이용하여 리소좀 연관 신규 유전자를 찾아내고, 그 유전자를 대상으로 돌연변이를 규명하고자 하였다. 방법: 이를 위해 5명의 환자와5명의 연령, 성별이 일치하는 정상아의 섬유아세포를 계대 배양하여 이 세포를 이용하여 수행한 subtractive hybridization을 통해 신규 유전자를 탐색하고, 신규 유전자를 대상으로 돌연변이 분석을 수행하였다. 결과: 연구 결과 환자에서 발현이 증가된 유전자 73개와 발현이 감소된 유전자 50개를 밝혀냈다. 분석된 유전자 중에서 MGC4170이환자에서는 발현되지 않으나 정상인에서는 발현됨을 발견하였고, 이 유전자가 아직 밝혀지지 않은 GNPTA로 확인되어 환자를 대상으로 돌연변이 분석을 시행하였다.분석 결과 기존에 돌연변이가 보고되었던 GNPTAG에는 돌연변이가 없었으나, MGC4170에는 7개의 돌연변이가 발견되었다. 본 연구는 GlcNAc-phosphotransferase의 ${\alpha}/{\beta}$ subunit에 해당되는 MGC4170의 최초 돌연변이 보고이다. 결론: 본 연구를 통해 뮤코지방증 II형과 III형에서 발현되는 유전자 군을 파악할 수 있었으며, 동시에 MGC4170 돌연변이를 규명함으로써 이 질환의 병리 기전 연구와 산전 진단에 기여하고자 한다.