• Korean Journal of Microbiology
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• v.29 no.3
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• pp.172-178
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• 1991

Intracellular purine nucleoside phosphorylase (PNP) from Saccharomyces cerevisiae was partially purified using ammonium sulfate fractionation, heat treatment, a DEAE-Sephadex A-50 anion exchange chromatography and a Sephadex G-100 gel filtration chromatography. The enzyme was purified 20 fold with 3% recovery. The stability of enzyme was kept by addition of inosine and dithiothreitol. The pH optimum was found to be from 6.3 to 7.3 PNP was sensitive to 10mM of $Hg^{2+}$ , $Cu^{2+}$ , and was inactivated completely by 2 mM of p-chloromercuribenzoate and 5,5'-dithiobis (2-nitrobenzoate). The enzyme was capable of catalyzing the phosphorolysis of inosine, deoxyinosine, guanosine, deoxyguanosine and adenosine.

• Bulletin of the Korean Chemical Society
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• v.34 no.4
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• pp.1175-1180
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• 2013

A microfabricated electrochemical cell comprising PDMS-based microchannel and in-channel gold microelectrodes was fabricated as a sensitive and a miniature alternative to the conventional electroanalytical systems. A reproducible fabrication procedure enabled patterning of multiple microelectrodes integrated within a PDMS-based fluidic network. The active area of each electrode was $200{\mu}m{\times}200{\mu}m$ with a gap of $200{\mu}m$ between the electrodes which resulted in a higher signal to noise ratio. Also, the PDMS layer served the purpose of shielding the electrical interferences to the measurements. Analytes such as potassium ferrocyanide; amino acid: cysteine and nucleoside: guanosine were characterized using the fabricated cell. The microchip was comparable to bulk electrochemical systems and its applicability was also demonstrated with flow injection based rapid amperometric detection of DNA samples. The device so developed shall find use as a disposable electrochemical cell for rapid and sensitive analysis of electroactive species in various industrial and research applications.

• Proceedings of the Korean Society for Applied Microbiology Conference
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• 1978.04a
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• pp.98.5-99
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• 1978

항생물질과 RNA 분해효소를 동시에 생산하는 방선균의 한 균주를 토양으로부터 분리하여 이 균주가 생산하는 RNA 분해효소의 물리화학적 성질 및 분해산물에 대해 검토하였다. 효소반응의 최적 pH 및 온도는 명명 pH 5.6과 $50^{\circ}C이었다.$ $37^{\circ}C$ 에서 90분간 열처리 시켰을 때, 이 효소의 활성은 비교적 안정하였지마는 $50^{\circ}C$ 에서 90분간 열처리 시켰을 때는 효소활성이 심하게 저하되었다. 이 효소의 활성은 $Ba^{2+}$ 에 의하여 50% 정도의 저해 작용을 나타내었지만 EDTA에 의해서는 저해되지 않았다. 이 효소에 의한 RNA분해로 이 효소가 대사산물로서 guanosine, adenosine과 밝혀지지 않은 두 가지의 핵산관연물질을 생산함을 알 수 있었다. 제2보에서는 ENase의 효소학적 성질을 검토하였으며 이후 항생물질 측면에서 검토할 예정이다.

• Bulletin of the Korean Chemical Society
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• v.33 no.7
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• pp.2419-2422
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• 2012

• Proceedings of the Membrane Society of Korea Conference
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• 2004.05a
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• pp.65-68
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• 2004

Molecular imprinting, which was first proposed by Wulff and Sarhan in 1972 [1], is a facile way to construct molecular recognition sites by applying a simple radical polymerization [2]. Since 1994, the authors have proposed an alternative molecular imprinting method in which polymeric materials are directly converted into molecular recognition materials [3].(omitted)

• Microbiology and Biotechnology Letters
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• v.23 no.3
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• pp.316-321
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• 1995

Some properties of $\beta$-1, 3-glucan synthase system in Saccharamyces cerevisiae were investigated. By extraction with detergent and salt, the membrane preparations could be dissociated into two components, one soluble, the other still membrane bound. Both components, in addition to GTP, were necessary for the activity of $\beta$-1, 3-glucan synthase like other fungi. The protective effect of guanosine nucleotides on the soluble factor pointed to the possibility that this fraction contained a GTP-binding protein. Addition of increasing amounts of soluble factor to a constant amount of insoluble catalytic factor, vice versa, gave rise to a saturation curve. These results, including different types of evidence, indicate that the soluble factor and the catalytic factor form a complex.

• Archives of Pharmacal Research
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• v.8 no.3
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• pp.109-117
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• 1985

The interaction of salicylic acid (S. A.), salicylamide (S,M) with nucleic acid base derivatives such as 9-ethyl adenine (A), 1-cyclohexyl uracil (U), 2', 3'-benzylidine-5' trityl-cytidine (C), gaunosine-2', 3', 5'-isobutylate (G) has been spectroscopically investigated to determine the binding mechanism. NMR and IR spectra were measured in nonpolar solvents. The association constant K of the formation of complex was calculated from the IR spectra. Compounds S. A. and A form a 1:1 or 1:2 cyclic hydrogen-bonded complex depending on the sample concentration. Compounds S. A. and U form a 1:1 or 1:2 hydrogen-bonded complex on the sample concentration. Compounds S. A. and C form a 2:1 hydrogen-bonded complex at low concentration (0.0016M). Compound S. A. binds compound G, but its binding does not completely break the self-association of compound G, Compound S. M. binds compounds A. U. C. G. very weakly.

• Bulletin of the Korean Chemical Society
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• v.6 no.5
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• pp.270-272
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• 1985

The rate constants of the hydrogen-deuterium exchange of 8-CH groups in 5'-rAMP and 5'-GMP were measured by laser Raman spectroscopy. The Arrhenius activation energies calculated from the rate constants measured as a function of temperature were similar for both compounds. However, the effects of pD on exchange rate constants were different for the two compounds. Our kinetic data support the exchange reaction mechanism involving an ylide type intermediate.

• Proceedings of the PSK Conference
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• 2002.10a
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• pp.249.1-249.1
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• 2002

This study was carried out to demonstrate the effects of oral administration of DA-8159. a selective phosphodiesterase 5 inhibitor. on development of pulmonary hypertension induced by monocrotaline (MCT). MCT-treated rats(60mg/kg) were divided into three groups and orally administered vehicle, 1 mg/kg or 5 mg/kgg of DA-8159 twice a day for 3 weeks. Increased right ventricular weights, medial wall thickening in pulmonary arteries. myocardial fibrosis, decrease of plasma cyclic guanosine monophosphate (cGMP) level and body weight gains were shown in MCT group. (omitted)

• Applied Microscopy
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• v.41 no.1
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• pp.1-11
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• 2011

This experiment was performed to evaluate the morphological responses of the gastric epithelial cells of the mouse, inoculated with Ehrlich carcinoma cells in the inguinal area, following administration of 5-fluorouracil, mitomycin C or Acriflavine-Guanosine compound (AG60). In this study, each mouse was inoculated with $1{\times}10^7$ Ehrlich carcinoma cells subcutaneously in the inguinal area. From next day after inoculations, 0.2 mL of saline, 5-fluorouracil (30 mg/kg), mitomycin C ($400{\mu}g/kg$) or AG60 (30 mg/kg) were injected to the animals every other day, respectively. Each animals were sacrificed after 7th injection and tissue were taken from the gastric mucosa. Thereafter, the ultrathin sections were stained with uranyl acetate and lead citrate. In the 5-fluorouracil-, mitomycin C- or AG60-treated mice, myelin figures and multivesicular bodies within the gastric mucous epithelial cells were observed more frequently than those of the normal control. In the 5-fluorouracil-treated mice, membrane structures containing a few mucous granules in the luminal space were observed. Indeed, bulging cytoplasmic process containing mucous granules protruding into the gastric lumen were observed in the mitomycin Ctreated mice. Therefore, this study suggested that AG60 as compared with 5-fluorourail and mitomycin C may effective medicine without damage to the secretion ability of gastric mucous epithelial cells.