• Journal of Microbiology and Biotechnology
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• 제17권6호
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• pp.993-1001
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• 2007

The technique of serological analysis of antigens by recombinant cDNA expression library (SEREX) uses autologous patient sera as a screening probe to isolate tumor-associated antigens for various tumor types. Isolation of tumor-associated antigens that are specifically reactive with patient sera, but not with normal sera, is important to avoid false-positive and autoimmunogenic antigens for the cancer immunotherapy. Here, we describe a selection methodology to isolate patient sera-specific antigens from a yeast surface-expressed cDNA library constructed from 15 patient lung tissues with non-small cell lung cancer (NSCLC). Several rounds of positive selection using patient sera alone as a screening probe isolated clones exhibiting comparable reactivity with both patient and normal sera. However, the combination of negative selection with allogeneic normal sera to remove antigens reactive with normal sera and subsequent positive selection with patient sera efficiently enriched patient sera-specific antigens. Using the selection methodology described here, we isolated 3 known and 5 unknown proteins, which have not been isolated previously, but and potentially associated with NSCLC.

• Bulletin of the Korean Chemical Society
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• 제30권6호
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• pp.1309-1312
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• 2009

Surface potential and growth processes of hexadecanethiol (HDT) self-assembled monolayers (SAMs) on Au(111) surfaces were examined by Kelvin probe method and scanning tunneling microscopy. It was found that surface potential strongly depends on surface structure of HDT SAMs. The surface potential shift for the striped phase of HDT SAMs chemisorbed on Au(111) surface was +0.45 eV, which was nearly the same as that of the flat-lying hexadecane layer physisorbed on Au(111) surface. This result indicates that the interfacial dipole layer induced by adsorption of alkyl chains is a main contributor to the surface potential change. In the densely-packed HDT monolayer, further change of the surface potential was observed, suggesting that the dipole moment of the alkanethiol molecules is an origin of the surface potential change. These results indicate that the work function of a metal electrode can be modified by controlling the molecular orientation of an adsorbed molecule.

• Bulletin of the Korean Chemical Society
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• 제31권12호
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• pp.3623-3631
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• 2010

We prepared several novel molecular transporters built on myo- and scyllo-inositol scaffolds with variations in the number of guanidine residues, linker chain lengths and patterns. Some of these transporters were found to localize in mitochondria, and the mitochondrial affinity seems to be substantially related to the scaffold stereochemistry.

• Nano
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• 제13권10호
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• pp.1850116.1-1850116.14
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• 2018

In this study, we report the mercury ions ($Hg^{2+}$) mediated phosphorus-containing carbon dots (PCDs) as a selective "off-on" fluorescence probe for glutathione (GSH), cysteine (Cys) and homocysteine (Hcys). PCDs obtained by hydrothermal reaction are sensitive to $Hg^{2+}$ ions and its fluorescence can be significantly quenched owing to the electron transfer from the lowest unoccupied molecular orbital (LUMO) of PCDs to $Hg^{2+}$. Interestingly, the weak fluorescence of $Hg^{2+}$-mediated PCDs could be gradually recovered with the addition of GSH, Cys and Hcys. This can be attributed to the formation of $Hg^{2+}-S$ complex due to the super affinity of $Hg^{2+}$-sulfydryl bond. The formation of $Hg^{2+}-S$ complex extremely reduces the oxidation ability of $Hg^{2+}$ that inhibits the electron transfer from LUMO of PCDs to $Hg^{2+}$ and re-opens the native electron transition from LUMO to the highest occupied molecular orbital (HOMO) of PCDs. Thus, the green fluorescence of PCDs is switched on. Furthermore, the present $Hg^{2+}$-mediated PCDs assay exhibits a high selectivity for GSH, Cys and Hcy and has been successfully used to detect the total biothiols content in human urine samples.

• BMB Reports
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• 제37권5호
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• pp.546-551
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• 2004

The increasing pace of development in molecular biology during the last decade has had a direct effect on mass testing and diagnostic applications, including blood screening. We report the model Microarray that has been developed for Hepatitis B virus (HBV) and Hepatitis D virus (HDV) detection. The specific primer pairs of PCR were designed using the Primer Premier 5.00 program according to the conserved regions of HBV and HDV. PCR fragments were purified and cloned into pMD18-T vectors. The recombinant plasmids were extracted from positive clones and the target gene fragments were sequenced. The DNA microarray was prepared by robotically spotting PCR products onto the surface of glass slides. Sequences were aligned, and the results obtained showed that the products of PCR amplification were the required specific gene fragments of HBV, and HDV. Samples were labeled by Restriction Display PCR (RD-PCR). Gene chip hybridizing signals showed that the specificity and sensitivity required for HBV and HDV detection were satisfied. Using PCR amplified products to construct gene chips for the simultaneous clinical diagnosis of HBV and HDV resulted in a quick, simple, and effective method. We conclude that the DNA microarray assay system might be useful as a diagnostic technique in the clinical laboratory. Further applications of RD-PCR for the sample labeling could speed up microarray multi-virus detection.

• 생명과학회지
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• 제11권5호
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• pp.423-431
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• 2001

Agrobacterium에 의한 식물형질전환은 가장 일반적으로 많은 사용되는 식물형질전환 기술이냐 이 과정에서 관여하는 식물 유전자들에 대한 관여하는 식물 유전자들에게 대한 연구는 거의 전무한 상태다. 본 연구는 Agrobacterium의 감염에 저항성을 보이는 새로운 돌연변이들의 분리와 분석 연구에 연속하여 Agrobacterium에 의한 식물형질전환에 관여하는 Arabidopsis RAT3 유전자의 cDNA와 gemonic clone을 plasmid rescue 기술을 이용하여 분리하였다. 염기서열 분석결과, 매우 유사한 2개의 유전자가 (RAT3-1과 RAT3-2)약 600bp 간격을 두고 연속하여 존재함을 밝혔다. 그중 RAT3-1 이 mutagen으로 사용된 T-DNA에 의해 손상을 받아 rat3 돌연변이 형질이 유도되었다. RAT3 유전자의 단백질의 분자량은 15 kDa 정도이며 아미노 밀단에 분비를 위한 signal peptide를 가지며 단백질이 전체적인 매우 친수성인 것으로 미루어 세포막 밖으로 분비될 것으로 생각된다. 이들 유전자의 정확한 생물학적 기능에 대한 연구들이 수행 중이며, 이러한 기초연구는 식물형질전환 기술의 개발에 기여할 것이다.

• 식물조직배양학회지
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• 제24권3호
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• pp.161-165
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• 1997

옥수수의 색소합성을 조절하는 pattern allele의 하나인 R-mb유전자의 구조와 유전적 분석을 수행하였다. R-mb 유전자의 유전분석을 수행한 결과를 검토하여 볼 때 후대로 진행됨에 따라 색소 발현빈도_의 감소경향을 보이고 있었다. 또한 R-mb 유전자가 몇 개의 R subcomplex로 존재하는가를 알기 위해서는 우선 R specific probe인 pR-nj:1를 이용하여 Southern blot hybridization을 실시한 결과 약 3.9kb 및 약 7.75kb영역에서 2개의 band가 관찰되었다. R-mb 유전자를 클로닝하기 위하여 λFIXIIvector를 이용하여 library를 만들고 이로부터 mb-II, III, V, Ⅵ, Ⅶ 등 5개의 clone을 3차의 screen을 거쳐 확보하고 이중 mb-II 및 mb-Ⅵ를 중심으로 제한효소지도를 작성하였으며, 이 유전자의 구조와 기타 R locus관련 유전자들과 비교하였으며, 이러한 두 개의 R 요소가 어떻게 색소발현에 영향을 미치는가에 대에 검토하였다.

• 미생물학회지
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• 제32권4호
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• pp.258-263
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• 1994

보리수나무(Elaeagnus umbellata) 뿌리혹엣 분리한 공생균주인 Frankia 균주 EuIK1 게놈에 대해 K. pneumoniae의 nifH,D를 탐침으로 Southern hybridization을 수행한 결과, 3.2 Kb와 5.5 Kb BamHI 절편과 15 Kb PstI 절편이 강한 혼성화 반응을 보여 이들 절편에 nifH,D 유전자가 존재함을 확인하였다. 동일 탐침을 사용한 colony hybridization을 통해 pWE15 cosmid vector 에 작성되 게놈 library로부터 하나의 nif-클론 (pEuNIF)을 선별하였다. 이 클론을 BamHI으로 절단한 후 동일한 탐침으로 혼성화 반응을 수행한 결과, 3.2 Kb와 5.5 Kb가 강한 혼성화 반응을 보였으며, 이 결과는 게놈 혼성화 반응 결과와 일치하였다. 그러나 Frankia FaC1의 nifH 만을 탐침으로 이용한 결과 3.2Kb BamHI 절편만이 혼성화 반응을 나타내었다. 또한 3.2 Kb의 3‘ 말단과 5.5 Kb의 5’ 말단의 염기서열로부터 추론한 아미노산 서열을 ArI3의 nifD와 비교한 결과 182번부터 240번까지, 241번부터 282번까지의 아미노산 서열과 각각 매우 높은 유사성을 보였다. 이러한 결과로부터 3.2Kb 절편에는 nifH와 일부의 nifD 서열이 존재하고, 이 절편에 연속된 5.5Kb 절편에는 나머지 nifD서열이 존재함을 알 수 있었다.

• 한국양식학회:학술대회논문집
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• 한국양식학회 2003년도 추계학술발표대회 논문요약집
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• pp.132-133
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• 2003

The marine dinoflagellate genus Alexandrium comprise PSP producing A. acatenella, A. angustitabuzatum, A. catenella, A. fundyense, A. minutum, A. ostenfezdii, A. tamiyavanichii and A. tamarense. In monitoring toxic Alexandrium, rapid and exact species identification is one of the significant prerequisite work, however we have suffered confusion of species definition in Alexandrium. To surmount this problem, we chose DNA probing, which has long been used as an alternative for conventional identification methods, primarily relying on morphological approaches using microscope in microbial field. Oligonucleotide DNA probes targeting rRNA or rDNA have been commonly used in diverse studies to detect and enumerate cells concerned as a culture-indetendent powerful tool. Despite of the massive literature on the HAB species containing Alexandrium, application of DNA probing for species identification and detection has been limited to a few documents. DNA probes of toxic A. tamarense, A. catenella and A. tamiyavanichii, and non-toxic A. affine, A. fraterculus, A. insuetum and A. pseudogonyaulax were designed from LSU rDNA D1-D2, and applied to whole cell-FISH. Each DNA probes reacted only the targeted Alexandrium cells with very high species-specificity within Alexandrium. The probes could detect each targeted cells obtained from the natural sea water samples without cross-reactivity. Labeling intensity varied in the growth stage, this showed that the contents of probe-targeted cellular rRNA decreased with reduced growth rate. Double probe TAMID2S1 achieved approximately two times higher fluorescent intensity than that with single probe TAMID2. This double probe did not cross-react with any kinds of microorganisms in the natural sea waters. Therefore we can say that in whole-cell FISH procedure this double DNA probe successfully labeled targeted A. tamiyavanichii without cross-reaction with congeners and diverse natural bio-communities.

• Applied Biological Chemistry
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• 제25권4호
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• pp.224-231
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• 1982

liposome에 결합되어 있는 ${\alpha}-Tocopherol$의 형광을 이용하여 liposome의 상전이온도를 측정할 수 있었다. 이는 ${\alpha}-Tocopherol$의 vitamin E로서의 중요성 이외에 형광성 프로브로서의 새로운 가치의 발견이다. 형광성 프로브로서 그 응용의 확대를 위한 필수적인 기초자료의 수집을 위해, 분자분광학적성질을 조사하였다. 용액중의 ${\alpha}-Tocopherol$은 monomer와 dimer의 두가지 형태로 존재하며, 단파장흡수대$(291{\sim}294nm)$의 monomer는 형광성인데 반하여 dimer는 298nm 부근을 흡수하는 비형광성이고 분자간수소결합에 의하여 형성되었음이 밝혀졌다. liposome에 결합된 ${\alpha}-Tocopherol$은 각종 유기용매 중에서의 ${\alpha}-Tocopherol$과는 판이한 형광성질을 갖고 있었고 chromanolate이온형태의 화학종으로부터 생긴 것으로 해석되었다.