• Bulletin of the Korean Chemical Society
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• 제29권1호
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• pp.69-75
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• 2008

Tautomerism of pyrimidine base cytosine has been comparatively examined on nanoparticle and roughened plate surfaces of silver, gold, and copper by surface-enhanced Raman scattering (SERS). The SERS spectrum was found to be different depending on the metals and their substrate conditions suggesting the dissimilar population of various tautomers of cytosine on the surfaces. The ab initio calculations were performed at the levels of B3LYP, HF, and MP2 levels of theory with the LanL2DZ basis set to estimate the energetic stability of the tautomers with the metal complexes as well as the gas phase state. The amino group and N3-coordinated tautomer was predicted to be more favorable for bonding to Au, whereas the hydroxyl and N1-coordinated zwitter ionic form is most stable with Ag and Cu as a bidentate form from the DFT calculation. The binding energy with the Ag atom is calculated to be smaller than those with the Au and Cu atoms in line with the temperature-dependent SERS spectra of cytosine.

• 미생물학회지
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• 제26권4호
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• pp.362-367
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• 1988

The strain YL 38-3, which was capable of producing extracellular cytosine deaminase, was isolated and taxonomically examined. The isolated strain was identified to be Bacillus polymyxa YL 38-3. The optimal conditions for the enzyme production from Bacillus polymyxa YL 38-3 were investigated. The enzyme production was reached maximum level in the medium containing 0.5% glucose, 0.2% beef extract, 0.5% NaCl and 0.1% $KH_{2}PO_{4}$ (pH 6.0). And the enzyme showed the highest activity when the strain YL 38-3 was cultivated at $35^{\circ}C$ for 24 gours under the initial pH 6.0. By the additions of peptone the extracellular enzyme production was inhibited, meanwhile the intracellular enzyme production was highly stimulated. It was, therefore, deduced that peptone was related to the secretion mechanism of the enzyme from this bacterial cell.

• Journal of Applied Biological Chemistry
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• 제43권1호
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• pp.12-17
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• 2000

To understand the signal transduction pathway that leads to the activation of the wound-inducible proteinase inhibitor II (pin2) promoter. $F_2$ progenies of wound (-) mutant crossed with wild-type Arabidopsis plants were biochemically and genetically characterized. Wound (-) mutant was derived from transgenic Arabidopsis plants containing bacterial cytosine deaminase gene under the control of pin2 promoter. The cytosine deaminase assays indicated that wound (-) mutant is a dominant inhibitor of wound-inducibility as only 3 of the $20F_2$ progenies showed cytosine deaminase (CDase) activity, To construct a structural map of the wound (-) mutant chromosomal regions, cleaved, amplified polymorphic sequences (CAPS) markers that cover all Chromosomes were used. Chromosomal regions covered by three different CAPS markers could be candidates for further fine mapping of the location of the wound (-) mutation. g4026, RGA1 and ASA1 located at 84.9 on recombinant inbred (RI) map of chromosome I, at 1.75 on RI map of chromosome II, and 18.35 on RI map of chromosome V, respectively.

• 대한치과의사협회지
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• 제21권11호통권174호
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• pp.907-916
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• 1983

• Korean Chemical Engineering Research
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• 제48권1호
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• pp.88-92
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• 2010

DNA 구조를 밝히기 위해 의학, 약학 그리고 생명과학분야 등에서 활발한연구가 이루어지고 있다. 그 중 DNA의 염기쌍은 생명체의 정보 전달에 매우 중요한 역할을 하므로 염기쌍의 집중적인 분석이 필요하다. 그래서 DNA의 염기쌍 중 하나인 구아닌과 시토신을 선택하여 분석 실험을 하였다. 구아닌과 시토신의 분석은 Aspen chromatography 전산모사와 HPLC(High Performance Liquid Chromatography) 실험을 통하여 이루어졌다. Aspen Chromatography(ver. 2006 Aspen Tech. U.S.A)로 시료농도, 이동상 유속 그리고 이론단수를 변화시켜 전산모사하였다. HPLC 실험은 $C_{18}$ HPLC column 칼럼과 이동상 water/methanol/acetic acid 혼합액(90/10/0.1)을 이용하여 시료의 주입 농도와 이동상 속도를 변화시켰고 구아닌과 시토신의 크로마토그램의 분리도와 이론단수를 비교하였다. 실험과 전산모사 크로마토그래피 결과가 비교적 일치하였다.

• 대한의용생체공학회:의공학회지
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• 제36권6호
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• pp.296-301
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• 2015

Explant culture condition of dorsal root ganglion have been used to investigate the pathophysiology of peripheral nerve injury, while applying for the various clinical symptom such as trauma, pressure, and stretch. However, explant culture is usually contaminated by mitotic cells, which may observed as a newly divided cells including fibroblast or glia. The mitotic cells could be able to interrupt and change the cell signaling that make it difficult to avoid detrimental effects during the experiments. To eliminate mitotic cells, anti-mitotic reagents like mixture of uridine and 5-fluorodeoxyuridine or cytosine arabinoside were added to the cultures on the following day, but there is no research that investigate viability of anti-mitotic reagent in dorsal root ganglion explant culture. In this study, we investigate inhibition effect of cytosine arabinoside to mitotic cells in dorsal root ganglion explant culture. Also we visualized and analyzed anti-mitotic effect and toxicity of cytosine arabinoside in various concentration condition. This dorsal root ganglion explant culture condition can be applied to research that effect and mechanism of various stimulation and chemical application which affect peripheral nerve regeneration.

• 생물정신의학
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• 제5권2호
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• pp.219-226
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• 1998

Cytosine arabinoside(AraC) inhibits DNA synthesis and ${\beta}$-DNA polymerase, an enzyme involved in DNA repair. This, a potent antimitotic agent, is clinically used as an anticancer drug with side effect of severe neurotoxicity. Earlier reports suggested that inhibition of neuronal survival by AraC in sympathetic neuron may be due to the inhibition of a 2'-deoxycytidine-dependent process that is independent of DNA synthesis or repair and AraC induced a signal that is triggers a cascade of new mRNA and protein synthesis, leading to apoptotic cell death in cultured cerebellar granule cells. The present study would suggest whether caspase family(ICE/CED-3-like protease) involved in AraC-induced apoptosis pathway of PC12 cells. It was observed that treatment of PC12 cells with AraC led to decrease of viability by MTT assay and morphology changes, which did not suggest that AraC induced apoptosis in PC12 cells. The mRNA of caspase-1/caspase-3 were expressed in PC12 cells constitutively, and AraC did not activate caspase family. These results suggest that caspase-1/caspase-3 may not be required for AraC-induced cell death pathway in PC12 cells.

• 미생물학회지
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• 제26권3호
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• pp.207-214
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• 1988

A cytosine deaminase from the cell-free extract of an isolate was examined after ethyl alcohol reactionation. The enzyme catalyzed the conversion of 5-fluorocytosine to 5-fluorouracil by the possession of specificity to the substrate. The optimum temperature and storage time on the stability of the enzyme were at below $50^{\circ}C$ and near 2 days in tris-HCl buffer. The maximum activity was also presented ar 9.0 in pH and $45^{\circ}C$ in temperature. The pHs and temperatures for the enzyme activity ranged from 8.5-9.5 and from 40-$50^{\circ}C$, respectively. the presence of $Ag^{+}, Hg^{2+}, Zn^{2+}$ in the reaction mixture resulted in the marked inhibition in the activity, but 1mM of $Fe^{3+}, K^{+}$, or $Na^{+}$ increased the enzyme activity. The enzyme preparation was vot affected by inhibitors used except N-ethylmaleimide of 1 and 10mM, and considerably activated by 1mM of pyrophosphate and 10mM of phosphate.

• 한국미생물·생명공학회지
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• 제20권2호
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• pp.150-155
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• 1992

토양 분리 균주로부터 얻은 배양액을 20-80 황산암모늄으로 분획한 후 세포의 cytosine deaminase의 성질을 검토하였다. 이 효소는 cytosine과 5-fluorocytosine(5-FC)에 기질 특이성을 가짐으로서 각각 uracil과 5-fluorouracil(5-FU)로 전환을 촉매하였다. 효소안정성에 대한 온도와 보존기간은 tris-HC1 완충용액에서 검토한 결과 최적온도는 $50^{\circ}C$ 부근이하에서 90 이상의 잔존활성을, 보존시간은 4일정도에서 80 이상의 잔존활성을 유지하였다. 최대 pH 8.0과 $37^{\circ}C$의 온도에서 나타났다. 활성에 적당한 pH는 8.0~8.5였고, 온도는 37~$45^{\circ}C$의 범위였다.

• 미생물학회지
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• 제23권3호
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• pp.177-183
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• 1985

20-80%로 황산암모늄 분획한 효소액을 사용하여 Arthrobacter sp. JH-13균주가 생산하는 세포외 cytosme deaminase의 성질을 검토하였다. 검토한 기질 중, 본 효소는 cytosine과 5- f1uorocytosine을 기질로 이용하였으며, 효소의 활성에 대한 최적 pH는 8.0부근이었고, 최적 온도는 $40^{\circ}C$부근으로 나타났다. 본 효소는 0.2M의 p potassium phosphate 완충액 (pH 8.0) 보다 0.2M의 tris-HCl 완충액 (pH 8. 0) 에서 더욱 안정하였다. 온도에 대한 안정성을 검토한 결과. $50^{\circ}C$ 부근까지는 대체로 안정하였으나, $70^{\circ}C$에서는 완전히 활성을 잃었다. 또한 ImM의 $Fe^{3+},\;K^+\;Na^+$ 이온은 효소의 활성을 증가시켰으나 0.01mM의 $Co^{2+},\;Cu^{2+},\;Ni^{2+},\;Hg^{2+},\;Ag^{2+},\;Zn^{2+},\;Ba^{2+},\;Mg^{2+}$ 이온들은 효소의 활성올 강력하게 저해하였다. O.lmM의 p-mercuribenzoate, trichloroacetic acid, N-ethylmaleim mide등은 효소의 활성을 완전히 저해하였으며. O.lmM의 2-mercaptoethanol은 효소의 활성올 약간 증가시키는 것으로 나타났다.