• Bulletin of the Korean Chemical Society
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• 제34권4호
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• pp.1145-1152
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• 2013

The rate constant of alkaline fading of methyl green ($ME^{2+}$) was measured in the presence of non ionic (TX-100), cationic (DTAB) and anionic (SDS) surfactants. $ME^{2+}$ hydrolyses and fades in neutral water and in this work we search the effects of surfactants on its fading rate. The rate of reaction showed remarkable dependence on the electrical charge of the used surfactants. It was observed that the reaction rate constant decreased in the presence of DTAB and SDS and increased in the presence of TX-100. Binding constants of $ME^{2+}$ to TX-100, DTAB and SDS and the related thermodynamic parameters were obtained by classical (or stoichiometric) model. The results show that binding of $ME^{2+}$ to TX-100 and DTAB are two-region and that of SDS is three-region. Also, the binding constants of $ME^{2+}$ to surfactant molecules in DTAB/TX-100 and SDS/TX-100 mixed solutions and their stoichiometric ratios were obtained.

• 약학회지
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• 제32권5호
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• pp.334-339
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• 1988

AraC-5'-methylthioacetate (araC-MTA, 1) and araC-5'-butylthioacetate (araC-BTA, 2) were prepared and their physical and chemical properties and in vivo antitumor activities were examined. Both compounds were found to have higher partiton coefficients (n-hexanol/water) than their parent araC and to be hydrolyzed to araC within an hour in mouse plasma and ascitic fluid solutions. In in vivo antitumor activity test they showed similar potency to araC, which were assumed due to too quick hydrolyses of them to parent in the body fluid.

• 생명과학회지
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• 제12권1호
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• pp.26-31
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• 2002

촉매화된 acetylcholine esterase가수분해의 기질로 사용될 choline ester를 두 가지 방법으로 합성하였다. 먼저, ethylene sulfide를 출발물질로 하여 2-chloroethyl thiohex-anoate, 2-chloroethyl thioheptanoate, 2-chloroethyl thiooc-tanoate를 각각 합성하였고 여기에 trimethyl amine을 첨가하여 hexanonyl thiocholine, octanonyl thiocholine을 합성하였다. 두 번째 방법으로 ethylene sulfide에 dimethyl amine을 첨가시켜 acid anhydride로 acylation 시킨 후 methyl iodide를 첨가하여 heptanoyl thiocholine, decanoyl thiocholine을 합성하였다. 합성된 hexanonyl thiocholine을 기질로 하여 butyrylcholine esterase와의 반응을 연구 하고자 한다. 또한 본 연구에서는 한국 과학 기술원 도핑컨트롤 센터와 연계하여 acetylcholine esterase와 기질인 acyl-thiocholine과의 입체적으로 둘러싸인 acyl-binding site를 분자 조형하고자 노력 중에 있다.

• Bulletin of the Korean Chemical Society
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• 제11권1호
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• pp.65-69
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• 1990

The nucleophilic substitution reactions of naphthalene-1,5-disulfonyl chloride and 4-fluorosulfonylbenzenesulfonyl chloride with p-substituted anilines and methyl substituted pyridines in methanol-acetonitrile mixtures and hydrolyses of those disulfonyl halides have been studied by means of conductometric and polarographic methods. A large difference in the selective parameter, ${\rho}_N$ between mono-sulfonyl chloride and disulfonyl halide can be taken as an evidence that the second $SO_2Cl$ grolup of naphthalene-1,5-disulfonyl chloride also takes part in the reaction in contrast to sulfonyl fluoride in 4-fluorosulfonylbenzenesulfonyl chloride, which only acts as a substituent in the nucleophilic substitution reaction.

• 한국식품과학회지
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• 제20권3호
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• pp.338-343
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• 1988

분획(分劃)된 대두(大豆) 7S 및 11S 단백질(蛋白質)의 단백질분해효소(蛋白質分解酵素)(trypsin, alcalase 및 pronase)에 대한 반응성(反應性)을 동력학변수(動力學變數)인 Km 과 Vmax 및 가수분해도(加水分解度)(DH)를 측정(測定)하여 검토(檢討)하였으며 가수분해물의 전기영동분석(電氣泳動分析)을 실시하였다. 효소(酵素)의 대두단백질(大豆蛋白質)에 대한 친화력(親化力)은 대체로 가열처리(加熱處理)된 단백질(蛋白質)은 기질농도(基質濃度) 1.5(w/w) 이하(以下)에서 가수분해(加水分解)에 대하여 기질조해작용(基質阻害作用)을 보였다. 1시간(時間) 가수분해(加水分解)에 따라 alcalase에 의하여 가장 큰 가수분해도(加水分解度)가 얻어졌으며 7S 단백질(蛋白質)에 대하여 60% 및 11S 단백질(蛋白質)에 대하여 80%였다. Trypsin 은 가열처리(加熱處理)되지 않은 단백질(蛋白質)에는 11S 단백질(蛋白質)의 acidic subunit 이외에는 거의 작용(作用)하지 못했으며 alcalase는 특이적으로 2S 단백질(蛋白質)에 변화(變化)를 가져오는 것으로 전기영동분석(電氣泳動分析)에서 나타났다.

• 한국식품영양과학회지
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• 제26권3호
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• pp.422-429
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• 1997

For the complete and accurate amino acid determination of protein and food samples, 3 different hydrolysis procedures have been conducted in parallel for each sample, which include the alkaline hydrolysis for tryptophan determination, performic acid oxidation prior to the acid hydrolysis for the determination of cysteine and cystine, and the 6N HCl hydrolysis for the determination of the rest of amino acids. In the present study, amino acid concentrations obtained from the modified single hydrolysis procedure were compared with the values from the conventional hydrolysis procedures in casein and nine food and composite dish samples. In most of the samples tested, the modified single hydrolysis procedure gave significantly higher values of cysteins and cystein compared to the performic acid oxidation method, but resulted in a considerable destruction of tryptophan in food and composited dish samples. There was no consistent difference in the rest of amino acid concentrations between the two hydrolysis systems. Therefore, for complete amino acid determination of various foods and composite dishes, the single hydrolysis method may replace the 6N HCl hydrolysis and performic acid oxidation methods, and thereby reduces 3 hydrolyses to 2 steps with much higher recoveries of the sulfur containing amino acids.

• 한국균학회지
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• 제19권4호
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• pp.253-257
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• 1991

담자균효모와 관련분류를 균주의 균체당조성(菌體糖組成)을 수식없이 원래 상태로 분석할 수 있는 HPLC법을 사용하여 분석하였다. Leucosporidium lari-marini는 균체당 xylose를 함유하고 있으나 Leucosporidium antarcticum, Leucosporidium scottii, Leucosporidium fellii, Rhodosporidium fluviale는 균체당 xylose를 함유하지 않았다. Leucosporidium scottii에서 종래 xylose 함유가 보고된 균주에서 xylose를 확인할 수 없었다 . 균체당 조성에 기초한 수리분석결과와 다른 성질을 함께 고려하면 L.antarcticum과 L. antarcticum과 L. lari-marini는 Cystofilobasidium속이나 Mrakia속에 이적되어야 함이 시사되었다.

• Journal of Microbiology and Biotechnology
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• 제14권2호
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• pp.344-349
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• 2004

A gene encoding inulin-degrading enzyme of Bacillus sp. snu-7 with ORF of 1536 nucleotides was cloned. And it was overexpressed as His-tagged protein in E. coli BL21(DE3) pLysS using pRSET B vector containing mature enzyme sequence. Maximum enzyme production was achieved by IPTG (0.1 mM) induction at $OD_{600}$ 1.2 and $30^{\circ}C$ followed by 6 h incubation. The expressed protein purified through immobilized metal affinity chromatography showed molecular mass of 60 kDa on SDS-PAGE. Results of thin-layer chromatography using inulin as a substrate showed the enzyme to be an exotype inulinase capable of producing only monomeric fructose as a product. $K_m$ and $k_{cat}$, for the hydrolyses of inulin and sucrose were $2.28\pm0.08$ mM and 358.05$\pm$20.38 $min^{-l}$, and 22.02$\pm$0.41 mM and 4619.11$\pm$215.12 $$min^{-1}, respectively. Optimal activity of the exoinulinase occurred at pH 7.0 and $50^{\circ}C$.

• 한국자원식물학회:학술대회논문집
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• 한국자원식물학회 2018년도 춘계학술발표회
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• pp.81-81
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• 2018

The present study was investigated on in vitro anti-obesity effect of 4-hydroxybenzyl alcohol from Cudrania tricuspidata. We isolated various compounds from Cudrania tricuspidata. Among these compounds, anti-obesity effects of 4-hydroxybenzyl alcohol was examined by lipase activity assay, cyclic adenosine monophosphate (cAMP)-specific phosphodiesterase type IV (PDE4) activity assay, and citrate synthase activity assay. 4-hydroxybenzyl alcohol and Cudrania tricuspidata extracts inhibited the enzymatic activities of lipase, PDE4, and citrate synthase. Lipase is known to mediate the hydrolysis of triacylglycerol in adipose tissue and cholesterol esters in other tissue or cells. Also, PDE4 hydrolyses cAMP, a crucial secondary messenger for in metabolic pathways including glucose and lipid metabolism, lipolysis, and thermogenic function. 4-hydroxybenzyl alcohol and Cudrania tricuspidata extracts induced the inhibitory effect against each enzymatic activity on several specific substrates as observed by detection at 405 or 412 nm. These findings might be attributable to the inhibition of adipogenesis, and partial prevention of obesity. In conclusion, these results show that 4-hydroxybenzyl alcohol and Cudrania tricuspidata may be a critical candidate as a natural anti-obesity source.

• Archives of Pharmacal Research
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• 제25권1호
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• pp.80-85
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• 2002

The incubation of porcine renal proximal tubules (PTs) resulted in the release of the Glycosylphosphatidylinositol (GPI)-anchored renal dipeptidase (RDPase, EC 3. 4. 13. 19) from the membrane after a lag period of approximately 6 hours. This spontaneous release of RDPase from the membrane was inhibited by antibiotics. When the incubation supernatant was added back to fresh PTs, both the antibiotic inhibition of RDPase release and the lag period disappeared. The released RDPase reacted with an anti-cross reacting determinant antibody indicating the presence of the Ins (1, 2-cyc)P. These results suggest that bacteria in the PTs, when incubated, grow find Secrete a phosphatidylinmsitol-specific phospholipase C (PIPLC). This enzyme then hydrolyses the GPI-anchored RDPase and is transferable. RDPase was purified following its release from the membrane by this simple and inexpensive method which may also be applied to other GPI-anchored proteins.