• Journal of Microbiology and Biotechnology
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• 제34권2호
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• pp.289-295
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• 2024

We have developed an aptamer that specifically binds to Porphyromonas gingivalis to reduce the cellular damage caused by P. gingivalis infection and applied it as a biosensor. P. gingivalis is one of the major pathogens causing destructive periodontal disease among the periodontal microorganisms constituting complex biofilms. Porphyromonas gingivalis G-protein (PGP) known to play an important role in the transmission of germs was used as a target protein for the screening of aptamer. The aptamer that has binds to the G-protein of P. gingivalis, was screened and developed through the Systemic Evolution of Ligands by Exponential Energy (SELEX) method. Modified-Western blot analysis was performed with the aptamer which consisted of 38 single-stranded DNA to confirm the selectivity. ELONA (enzyme linked oligonucleotide assay) used to confirm that the aptamer was sensitive to PGP even at low concentration of 1 ㎍/ml. For the rapid detection of P. gingivalis, we constructed a surface plasmon resonance biosensor with SPREETA using the PGP aptamer. It was confirmed that PGP could be detected as low concentration as at 0.1 pM, which is the minimum concentration of aptamer sensor within 5 min. Based on these results, we have constructed a SPREETA biosensor based on aptamer that can bind to P. gingivalis G-protein. It can be used as an infection diagnosis system to rapidly diagnose and analyze oral diseases caused by P. gingivalis.

• Macromolecular Research
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• 제17권3호
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• pp.192-196
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• 2009

Recently, the multi-screening of target materials has been made possible by the development of the surface plasmon resonance (SPR) imaging method. To adapt this method to biochemical analysis, the multi-patterning technology of protein microarrays is required. Among the different methods of fabricating protein microarrays, the microfluidic platform was selected due to its various advantages over other techniques. Microfluidic devices were designed and fabricated with polydimethylsiloxane (PDMS) by the replica molding method. These devices were designed to operate using only capillary force, without the need for additional flow control equipment. With these devices, multiple protein-patterned sensor surfaces were made, to support the two-dimensional detection of various protein-protein interactions with SPR. The fabrication technique of protein microarrays can be applied not only to SPR imaging, but also to other biochemical analyses.

• Tuberculosis and Respiratory Diseases
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• 제60권4호
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• pp.412-418
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• 2006

연구배경 : 클라미디아 감염의 진단은 혈청검사로 이루어진다. 현재 표준 방법은 MIF(microimmunofluorescence)이나 이 방법은 주관적이고 시간이 많이 걸리는 단점이 있다. 최근을 SPR(surface plasmon resonance) 센서를 이용한 단백질 칩이 감염의 새로운 진단 방법으로 제시되고 있다. 클라미디아 감염의 진단을 위한 단백질 칩 개발을 위하여 금 칩 표면에 세균을 고정하고 클라미디아 균에 대한 항체와 표면 위 세균과의 반응을 SPR 센서를 이용하여 측정하고자 하였다. 방법 : 표면 항원으로 배양한 Chlamydophila pneumoniae LKK1의 EB를 정제하였다. 양전하를 띤 PDDA (polydiallyldimethylammonium chloride)를 이용하여 전하를 이용한 단백질 칩을 제작하였다. 클라미디아 균을 고정시킨 후에 atomic force microscopy를 이용하여 표면을 관찰하였다. 클라미디아 균에 대한 항체를 투여하고 나서 자체 제작한 SPR 센서를 이용하여 항원 항체 반응을 SPR 파장 변화로 측정하였다. 결과 : 양전하를 띤 PDDA 표면위에서 클라미디아 균이 고정되었음을 확인 하였다. 그리고, 항체를 투여한 후에 SPR 파장의 증가를 확인하였다. 파장 변화는 항원의 농도와 관련이 있었다. 결론 : 전하를 이용하여 클라미디아 폐렴균의 EB를 단백질 칩에 고정하였고, 단백질 칩 위에서의 항원 항체 반응을 확인하였다. 비정형 폐렴의 진단에 SPR 센서가 기여할 수 있을 것으로 사료되나, 실제 임상 시료에의 적용을 위해서는 좀더 연구가 필요할 것으로 사료된다.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2002년도 생물공학의 동향 (X)
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• pp.232-234
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• 2002

공업적으로 중요성이 날로 더해가는 phospholipase C (PLC) 를 Bacillus cereus를 이용하여 생산하였다. 또한, plc::gfp fusion protein 을 생산하는 재조합 E. coli 를 제조하고 배양하였으며 특히 형광센서를 이용하여 PLC 의 생산 특성을 모니터링하였다.

• 분석과학
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• 제8권3호
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• pp.221-227
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• 1995

$Ca^{2+}$에 대하여 특이한 선택성을 보이는 광섬유형광센서에 대하여 연구하였다. 이 센서는 $Ca^{2+}$과 형광성 킬레이트를 형성하는 단백질 Calmodulin(CaM)을 사용하였으며, 두 갈래로 된 광섬유 다발의 끝면에 플루오르세인 이소티오시아네이트로써 형광 표지된 Calmodulin(FCaM)으로 만든 용액을 투석막 안에 넣어서 제작하였다. 이 센서의 감응 메카니즘은 FCaM이 $Ca^{2+}$과 결합하여 킬레이트를 형성할 때에 나타나는 형광 스펙트럼의 이동 현상을 바탕으로 한다. CaM은 $Ca^{2+}$과 결합할 때에 형태변화를 일으키며, 이로 인해 유발되는 FCaM의 형광세기 변화로써 농도를 결정하였다. 광전자증배관으로 형광의 세기를 측정하여 $Ca^{2+}$에 대한 검정곡선을 작성하였으며, 센서의 $Ca^{2+}$에 대한 검출한계와 $Mg^{2+}$, $Eu^{3+}$, $La^{3+}$들에 의한 방해효과, 감응 시간 및 수명을 조사하였다.

• 한국광학회:학술대회논문집
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• 한국광학회 2009년도 창립 20주년기념 특별학술발표회
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• pp.163-164
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• 2009

• Journal of Yeungnam Medical Science
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• 제29권2호
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• pp.77-82
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• 2012

AMP-activated protein kinase (AMPK) is an important cellular fuel sensor. Its activation requires phosphorylation at Thr-172, which resides in the activation loop of the ${\alpha}1$ and ${\alpha}2$ subunits. Several AMPK upstream kinases are capable of phosphorylating AMPK at Thr-172, including LKB1 and CaMKK${\beta}$ ($Ca^{2+}$/calmodulin-dependent protein kinase kinase${\beta}$). AMPK has been implicated in the regulation of physiological signals, such as in the inhibition of cholesterol fatty acid, and protein synthesis, and enhancement of glucose uptake and blood flow. AMPK activation also exhibits several salutary effects on the vascular function and improves vascular abnormalities. AMPK is modulated by numerous hormones and cytokines that regulate the energy balance in the whole body. These hormone and cytokines include leptin, adiponectin, ghrelin, and even thyroid hormones. Moreover, AMPK is activated by several drugs and xenobiotics. Some of these are in being clinically used to treat type 2 diabetes (e.g., metformin and thiazolidinediones), hypertension (e.g., nifedipine and losartan), and impaired blood flow (e.g., aspirin, statins, and cilostazol). I reviewed the precise mechanisms of the AMPK activation pathway and AMPK-modulating drugs.

• 센서학회지
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• 제9권3호
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• pp.208-212
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• 2000

A protein based vision biomembrane was fabricated by adsorbing bacteriorhodopsin into electrochemically polymerized polypyrrole film substrate mainly through strong electrostatic interaction. The immobilized bacteriorhodopsin on the polypyrrole film was demonstrated by SEM and SRET. The light signal transducing function from the bacteriorhodopsin which was adsorbed into Polypyrrole film was evaluated by electroretinogram(ERG). A wave form analysis of the electroretinogram indicated that the adsorbed bacteriorhodopsin retained its activity and light signal was obtained from the protein for at least one month.

• Genomics & Informatics
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• 제13권2호
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• pp.26-30
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• 2015

nc886 (=vtRNA2-1, pre-miR-886, or CBL3) is a newly identified non-coding RNA (ncRNA) that represses the activity of protein kinase R (PKR). nc886 is transcribed by RNA polymerase III (Pol III) and is intriguingly the first case of a Pol III gene whose expression is silenced by CpG DNA hypermethylation in several types of cancer. PKR is a sensor protein that recognizes evading viruses and induces apoptosis to eliminate infected cells. Like viral infection, nc886 silencing activates PKR and induces apoptosis. Thus, the significance of the nc886:PKR pathway in cancer is to sense and eliminate pre-malignant cells, which is analogous to PKR's role in cellular innate immunity. Beyond this tumor sensing role, nc886 plays a putative tumor suppressor role as supported by experimental evidence. Collectively, nc886 provides a novel example how epigenetic silencing of a ncRNA contributes to tumorigenesis by controlling the activity of its protein ligand.

• Nutrition Research and Practice
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• 제3권1호
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• pp.64-71
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• 2009

Amino acids are fundamental nutrients for protein synthesis and cell growth (increase in cell size). Recently, many compelling evidences have shown that the level of amino acids is sensed by extra- or intra-cellular amino acids sensor(s) and regulates protein synthesis/degradation. Mammalian target of rapamycin complex 1 (mTORC1) is placed in a central position in cell growth regulation and dysregulation of mTOR signaling pathway has been implicated in many serious human diseases including cancer, diabetes, and tissue hypertrophy. Although amino acids are the most potent activator of mTORC1, how amino acids activate mTOR signaling pathway is still largely unknown. This is partly because of the diversity of amino acids themselves including structure and metabolism. In this review, current proposed amino acid sensing mechanisms to regulate mTORC1 and the evidences pro/against the proposed models are discussed.