• Bulletin of the Korean Chemical Society
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• 제33권1호
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• pp.100-104
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• 2012

Thrombin is a serine protease that catalyzes the conversion of soluble fibrinogen to insoluble fibrin, and thus induces physiological and pathological blood coagulation. Therefore, it is important to detect thrombin in blood serum for purposes of diagnosis. To achieve this goal, it has been suggested that a 15-mer aptamer strongly binds with thrombin to form a G-quartet structure of the aptamer. Generally, 5'-end thiol-functionalized aptamer has been used as an anti-thrombin binder. Herein, we evaluate the possibility of utilizing a 3'-SH aptasensor for thrombin detection using SPR spectroscopy, and compare the enhancement of the electrochemical signal of the thrombin-aptamer bound on a porous gold substrate. Although the two aptamers have similar configurations, in SPR analysis, the 3'-SH aptamer was a effective aptasensor as well as 5'-SH aptamer. Results from electrochemical analysis showed that the porous gold substrate acted as a good substrate for an aptasensor and demonstrated 5-fold enhancement of current change, as compared to gold thin film.

• Bulletin of the Korean Chemical Society
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• 제35권6호
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• pp.1867-1870
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• 2014

• BMB Reports
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• 제41권2호
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• pp.126-131
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• 2008

The folding of aptamer immobilized on an Au electrode was successfully detected using label-free electrochemical methods. A thrombin binding DNA aptamer was used as a model system in the presence of various monovalent cations. Impedance spectra showed that the extent to which monovalent cations assist in folding of aptamer is ordered as $K^+$ > $NH_4^+$ > $Na^+$ > $Cs^+$. Our XPS analysis also showed that $K^+$ and $NH_4^+$ caused a conformational change of the aptamer in which it forms a stable complex with these monovalent ions. Impedance results for the interaction between aptamer and thrombin indicated that thrombin interacts more with folded aptamer than with unfolded aptamer. The EQCM technique provided a quantitative analysis of these results. In particular, the present impedance results showed that thrombin participates a folding of aptamer to some extent, and XPS analysis confirmed that thrombin stabilizes and induces the folding of aptamer.

• 전기화학회지
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• 제19권4호
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• pp.134-140
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• 2016

새로운 산화환원 표지자를 이용한 압타머 기반의 전기화학적 트롬빈 검출 바이오 센서를 개발하였다. 1차 지방족 아민(primary aliphatic amine) 으로 개질한 압타머를 전기 전도성 고분자 poly-(5,2':5',2"-terthiophene-3'-carboxylic acid) (polyTTCA) 층 위에 공유결합을 통해 고정하여 센서 표면을 개질하였다. Tetrabromophenolphthalein ethyl ester (KTBPE)를 압타머와 상호 작용시켜 전기화학적인 산화환원 표지자로 사용하였다. 압타머로 개질한 층 위에 KTBPE의 산화반응을 differential pulse voltammetry (DPV)를 사용하여 조사하였으며, 최종 센서의 특성은 voltammetry, QCM, and ESCA 를 사용하여 조사하였다. KTBEF와 압타머 센서와 반응 후, KTBPE의 산화 피크는 감소하였다. 센서의 선형 동적 범위는 10.0 ~ 100.0 nM 이었으며, 이 때 검출 한계는 $1.0{\pm}0.2nM$이었다.

• Bulletin of the Korean Chemical Society
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• 제34권3호
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• pp.721-722
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• 2013

• Bulletin of the Korean Chemical Society
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• 제30권1호
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• pp.77-82
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• 2009

Thrombin activatable fibrinolysis inhibitor (TAFI) also known as plasma procarboxypeptidase B or U is a 60 kD glycoprotein, which is the major modulator of fibrinolysis in plasma. TAFI is a proenzyme, which is activated by proteolytic cleavage to an active carboxypeptidase B-like enzyme (TAFIa, 35.8 kD) by thrombin/thrombomodulin and plasmin. Modulation of fibrinolysis occurs when TAFIa enzymatically removes C-terminal lysine residues of partially degraded fibrin, thereby inhibiting the stimulation of tissue plasminogen activator (t-PA) modulated plasminogen activation. TAFIa undergoes a rapid conformational change at $37{^{\circ}C}$ to an inactive isoform called TAFIai. Potato tuber carboxypetidase inhibitor (PTCI) was shown to specifically bind to TAFIa as well as TAFIai. In this study, a novel immunoassay TAFIa/ai ELISA was used for quantitation of the two TAFI activation isoforms TAFIa and TAFIai. The ELISA utilizes PTCI as the capture agent and a double antibody sandwich technique for the detection. Low levels of TAFIa/ai antigen levels were detected in normal plasma and elevated levels were found in hemophilia A plasmas. TAFIa/ai antigen represents a novel marker to monitor fibrinolysis and TAFIa/ai ELISA may be a valuable assay for studying the role of TAFI in normal hemostasis and in pathological conditions.

• KSBB Journal
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• 제26권4호
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• pp.352-356
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• 2011

The detection of biomarkers is an important issue for disease diagnosis. However, many systems are not suitable to detect the biomarker itself directly. For direct detection of biomarker proteins in human serum, a new affinity-capture method using aptamers combined with the mass spectrometry was suggested. Since signals from protein samples cannot be amplified, modified chromatin immunoprecipitation (ChIP) and subsequent cross-linking with formaldehyde between aptamers and target proteins were used not to lose the captured target proteins, which allowed us to perform a harsh washing step to remove the non-specifically bound proteins. As a model system, a thrombin aptamer was used as a bait and thrombin as a target protein. Using our modified ChIP and affinity-capture method, non-specific binding proteins on the beads decreased significantly, suggesting that our new method is efficient and can be applied to developing diagnosis systems for various biomarkers.

• 생명과학회지
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• 제26권11호
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• pp.1289-1297
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• 2016

구강편평세포암종은 구강 내에서 발생하는 가장 흔한 암의 형태로서, 구강암의 90%이상을 차지한다. 구강암은 국소적인 침윤의 양상을 나타내며 또한 조기진단과 치료가 용이하여 암예방을 위한 유용한 모델로 인정되고 있다. 본 연구에서는 생강 유기용매 분획물의 항산화 활성, 트롬빈억제 및 PMA 또는 thrombin에 의해 유도된 MMP- 2 및 MMP-9활성 억제 효과를 조사하였다. 시료들은 생강 열수 추출물을 헥산(hexane), 클로로포름(chloroform), 에틸 아세테이트(Ethyl acetate), 부탄올(butanol) 및 물($H_2O$)과 같은 용매로 분획화하여 사용하였고, $H_2O$ 분획물의 수득율이 9.79%로 가장 높았다. 항산화 활성은 DPPH assay, 세포 생존율 측정은 MTS assay, 항염증 활성은 마우스 대식세포 Raw 264.7세포에서 NO 생성 그리고 MMP-2 및 MMP-9의 mRNA 발현 및 단백질 활성 억제는 인간구강편평세포암종 YD-10B 세포에서 RT-PCR과 zymography방법을 통해 측정하였다. 본 연구의 결과에 의하면 MMP-2/-9 활성은 PMA에 의해 YD-10B세포에서 증가하였고, thrombin 처리에 의해서는 MMP-9 활성이 유의한 증가를 보였다. YD-10B 세포에서, PMA 또는 thrombin처리 모두에서 hexane 분획물이 MMP-2/-9의 mRNA 발현 및 단백질 활성을 유의하게 억제하였다. 그리고 항산화 활성은 hexane과 $H_2O$ 분획물에서 92.38%와 92.96%로 높게 나타났다. 또한 $H_2O$ 분획물에서 65.86%로 가장 유의하게 트롬빈 억제 활성을 보였다. 그러므로 본 연구에서는 생강 hexane분획물이 구강암의 우수한 암 침윤 및 전이 억제제로서의 개발 가능성을 제시하고 있다.

• 한국균학회지
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• 제40권4호
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• pp.296-298
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• 2012

본 연구는 야생버섯으로부터 혈관계질환 관련 생리활성을 확인하여 혈관계질환을 위한 기능성식품 개발에 재료로 사용하기 위해 야생버섯 33종의 야생버섯 메탄올 추출물을 제조하여 심혈관계 질환 생리활성을 확인하였다. 긴대밤그물버섯(Boletellus elatus)과 벽돌빛뿌리버섯(Heterobasidion insulasis)이 높은 혈전용해 활성과 트롬빈저해효과, 항산화활성을 나타내 혈관계질환 치료나 예방을 위한 기능성식품 개발에 이용 가능할 것으로 기대된다.

• 약학회지
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• 제41권1호
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• pp.74-80
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• 1997

A polygonal antibody against recombinant hirudin was raised for the development of a ELISA in biological fluids. Recombinant hirudin was conjugated to maleimide activated carrie r protein, KLH and injected to a rabbit. The third booster collection of antiserum was used as primary antibody for the ELISA. The titer for the detection antibody was determined. The direct ELISA could determine the concentration of hirudin in the range of ~10ng/ml. Affinity pulified IgG was obtained and conjugated to horseradish peroxidase. Purified IgG and IgG-HRP could be used as capture and detection antibody, respectively. Although sandwich ELISA would not give the satisfactory results. it could apply for the detection of hirudin level in the range of ~20 ${\mu}$g/ml.