• Journal of Applied Biological Chemistry
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• 제49권4호
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• pp.192-194
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• 2006

• Applied Biological Chemistry
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• 제25권3호
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• pp.182-188
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• 1982

일차아민과 반응하여 형광활성화합물을 형성하는 fluorescamine을 이용하여 어떤 시료중에 포함된 극미량의 trypsin inhibitor의 함량 또는 그 활성도를 측정하는 형광방법을 기술하였다. 세 가지 두류종실 즉 대두, 녹두 및 팥의 상대적 antitryptic activity 측정을 예로들어 본방법의 분석화학 우적수성을 여러 각도에서 검토하였던바, 효소반응속도론적 접근으로 이루어진 본방법은 동일한 접근으로 이루어진 기존의 흡광광도방법과 비교하여 측정감도는 대략 100배이상이였으며 casein과 같은 천연기질을 사용하는 경우에서는 실험과정이 보다 단순하여 빠른 방법으로 판정되었다.

• 분석과학
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• 제8권3호
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• pp.359-364
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• 1995

Urinary dipeptidase와 alanine dehydrogenase의 연쇄반응을 이용한 형광분석법을 개발하였다. 반응계는 기질로서 L-ala-ala, ${\beta}-NAD^+$, L-alanine dehydrogenase와 pH 9의 12.5mM sodium carbonate buffer를 포함하며 urinary dipeptidase를 가함으로써 반응을 시작했다. 생성된 NADH는 여기파장 340nm, 형광파장 460nm에서 측정했다. 기존의 glycyldehydrophenylalanine(Gdp)의 가수분해 방법과 형광분석법을 비교한 결과 0.996의 높은 상관계수를 나타냈으며 10배 이상의 감도 증가를 보였다.

• BMB Reports
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• 제30권4호
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• pp.258-261
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• 1997

A simple quantitative assay method for ribonuclease activity has been developed. This method is based on the decrease of fluorescence intensity emitted by the ethidium bromide bound to RNA due to the degradation of RNA by ribonuclease. The substrate RNA was reacted with ribonuclease A and the fluorescence intensity was measured after the addition of ethidium bromide. The intensity difference was calculated using a blank reaction mixture containing no RNase. Whole cellular RNA substrate produced a significant error and was not suitable for this assay method possibly because of local microheterogeniety caused by high molecular weight rRNA. but satisfying results were obtained with tRNA substrate. The intensity difference increased linearly by raising enzyme concentration up to $2{\times}10^{-4}$ Kunitz Units of ribonuclease A. More refined and reliable results were obtained by use of initial reaction velocities which were calculated from the plots of intensity difference vs time. A linear relationship between initial velocities and enzyme concentrations was observed up to 0.01 Kunitz Units of enzyme.

• 대한약학회:학술대회논문집
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• 대한약학회 2002년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.1
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• pp.109.1-109.1
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• 2002

• 대한약학회:학술대회논문집
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• 대한약학회 2002년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.1
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• pp.105.3-106
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• 2002

• Journal of Microbiology and Biotechnology
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• 제30권5호
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• pp.662-667
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• 2020

Epidermal growth factor receptor (EGFR) mutations are not only genetic markers for diagnosis but also biomarkers of clinical-response against tyrosine kinase inhibitors (TKIs) in non-small cell lung cancer (NSCLC). Among the EGFR mutations, the in-frame deletion mutation in EGFR exon 19 kinase domain (EGFR exon 19-del) is the most frequent mutation, accounting for about 45% of EGFR mutations in NSCLCs. Development of sensitive method for detecting the EGFR mutation is highly required to make a better screening for drug-response in the treatment of NSCLC patients. Here, we developed a fluorometric tandem gene amplification assay for sensitive detection of low-abundance EGFR exon 19-del mutant genomic DNA. The method consists of pre-amplification with PCR, thermal cycling of ligation by Taq ligase, and subsequent rolling circle amplification (RCA). PCR-amplified DNA from genomic DNA samples was used as splint DNA to conjugate both ends of linear padlock DNA, generating circular padlock DNA template for RCA. Long stretches of ssDNA harboring multiple copies of G-quadruplex structure was generated in RCA and detected by thioflavin T (ThT) fluorescence, which is specifically intercalated into the G-quadruplex, emitting strong fluorescence. Sensitivity of tandem gene amplification assay for detection of the EGFR exon 19-del from gDNA was as low as 3.6 pg, and mutant gDNA present in the pooled normal plasma was readily detected as low as 1% fraction. Hence, fluorometric detection of low-abundance EGFR exon 19 deletion mutation using tandem gene amplification may be applicable to clinical diagnosis of NSCLC patients with appropriate TKI treatment.

• BMB Reports
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• 제56권11호
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• pp.606-611
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• 2023

The main protease (Mpro) of SARS-CoV-2 cleaves 11 sites of viral polypeptide chains and generates essential non-structural proteins for viral replication. Mpro is an important drug target against COVID-19. In this study, we developed a real-time fluorometric turn-on assay system to evaluate Mpro proteolytic activity for a substrate peptide between NSP4 and NSP5. It produced reproducible and reliable results suitable for HTS inhibitor assays. Thus far, most inhibitors against Mpro target the active site for substrate binding. Mpro exists as a dimer, which is essential for its activity. We investigated the potential of the Mpro dimer interface to act as a drug target. The dimer interface is formed of domain II and domain III of each protomer, in which N-terminal ten amino acids of the domain I are bound in the middle as a sandwich. The N-terminal part provides approximately 39% of the dimer interface between two protomers. In the real-time fluorometric turn-on assay system, peptides of the N-terminal ten amino acids, N10, can inhibit the Mpro activity. The dimer interface could be a prospective drug target against Mpro. The N-terminal sequence can help develop a potential inhibitor.

• KSBB Journal
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• 제21권6호
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• pp.489-492
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• 2006

분자육종의 목적을 위하여 Agrobacterium을 이용한 Brassica napus 식물의 유전적 형질전환은 폭 넓게 시행되어 왔다. B. napus cv. napus는 유지작물의 하나이면서 이 또한 Agrobacterium을 이용한 형질전환이 가능하다. 본 연구에서는 agroinfiltration방법을 이용시 유채유묘의 형질전환이 낯은 효율로 나타나고 있으며 이는 fluorometric GUS assay에 의하여 판단되었다. 대조적으로 유채유묘에 대하여 sodium hydrosulfite 용액을 agroinfiltration 과정 이전에 처리할 경우 형질전환율이 상당히 증가하는 것을 관찰할 수 있었다. RT-PCR에 의한 GUS유전자발현의 확인을 통하여 유채유도를 이용한 일시발현체계의 개발가능성을 제시하였다.

• 한국임상약학회지
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• 제10권1호
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• pp.38-41
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• 2000

A high-performance liquid chromatographic method with fluorometric detection was evaluated for analysis of ofloxacin in plasma. Biological fluids (plasma, $200\;{\mu}L$) were prepared for assay by protein precipitation with chlorofurm. The detection of ofloxacin and triamterene as an internal standard were performed at 358 nm for excitation and 495 nm for emission. The HPLC separation was carried out on Ultrasphere ODS column (4.6 mm${\times}25\;cm,\;5\;{\mu} m$) with acetonitrile $(45\%)$-phosphoric acid $(1.5\%)\;containing\;0.3\%$ sodium laurylsulfate as the mobile phase. The flow-rate was 1.0 mL/min. The calibration graphs were linear from 3.0 to 80 ng/mL with r=0.998. The minimal detectable concentration in plasma was 1.5 ng/mL. The proposed technique is reproducible, selective, reliable and sensitive.