• 한국미생물·생명공학회지
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• 제41권4호
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• pp.456-461
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• 2013

단일가닥 DNA와 이중가닥 DNA의 흡착 율의 차이를 이용하여, 본 연구는 산화 그래핀에 흡착된 단일 가닥 DNA을 사용하여 Klenow fragment의 효소 활성을 검출하기 위하여 실시간 형광에세이 방법을 사용했다. 실험 결과에 의하면, 산화그래핀에 흡착된 형광표지 ssDNA는 형광이 ��칭(quenching) 되지만, cDNA 첨가에 의해서 흡착된 단일가닥 DNA가 유리되었다. Klenow fragment의 활성을 측정하기 위해서 형광표지 틀(template) DNA, 산화그래핀과 시발체(primer)가 존재할 때, 고분자 반응이 진행됨에 따라 ��칭된 형광세기가 증가하였다. 그리고 겔 전기영동 실험은 산화 그래핀에서 DNA 합성과 hybridization 반응을 확인하였다.

• BMB Reports
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• 제38권1호
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• pp.24-27
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• 2005

The role of 3' exonuclease excision in DNA polymerization was evaluated for primer extension using inert allele specific primers with exonuclease-digestible ddNMP at their 3' termini. Efficient primer extension was observed in amplicons where the inert allele specific primers and their corresponding templates were mismatched. However, no primer-extended products were yielded by matched amplicons with inert primers. As a control, polymerase without proofreading activity failed to yield primer extended products from inert primers regardless of whether the primers and templates were matched or mismatched. These data indicated that activation was undertaken for the inert allele specific primers through mismatch proofreading. Complementary to our previously developed SNP-operated on/off switch, in which DNA polymerization only occurs in matched amplicon, this new mutation detection assay mediated by $exo^+$ DNA polymerases has immediate applications in SNP analysis independently or in combination of the two assays.

• 한국미생물·생명공학회지
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• 제40권3호
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• pp.274-277
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• 2012

본 연구에서는 다제내성을 보이는 인체 병원균의 하나인 S. aureus에서 유래된 FtsZ 단백질의 유전자를 클로닝하고 대장균에 형질전환하여 재조합 단백질을 만들고, in vitro 상에서 폴리머 형성 활성을 측정하였다. Bradford 방법을 이용하여 SA FtsZ단백질의 농도를 측정한 후, SA FtsZ단백질의 폴리머 형성 활성을 확인하기 위해 형광계를 이용하여 excitation 방향과 $90^{\circ}$의 방향에서 산란되는 빛의 양을 측정하는 방법을 사용하였을 때에 대조군에서는 빛이 산란되지 않았고, SA FtsZ 단백질에 GTP와 $Mg^{2+}$를 처리한 실험군에서만 빛이 산란되는 현상을 관찰하였다. 1분여의 시간이 지난 이후에는 다시 산란되는 빛이 줄어드는 것을 볼 수 있는데, 이것은 SA FtsZ 단백질의 아미노말단 도메인의 GTPase 활성에 의해서 GTP가 분해되어서 SA FtsZ 단백질의 폴리머가 단량체로 분해되었기 때문이라고 예측된다. 본 연구를 통하여 확립된 SA FtsZ 활성 측정 방법은 향후 SA FtsZ 단백질의 폴리머 형성을 저해하는 방식으로 S. aureus를 표적으로 하는 항생제 후보물질 도출을 위한 스크리닝 방법으로 사용될 수 있을 것이다.

• Journal of Microbiology and Biotechnology
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• 제28권10호
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• pp.1723-1729
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• 2018

The aim of this work is to investigate the protective efficacy of emodin, an active, naturally-occurring anthraquinone derivative of several traditional Chinese herbs, against Brucella abortus infection in macrophages. Brucella were incubated with different concentrations of emodin and showed that bacterial survival rates were markedly reduced in a dose-dependent manner at increasing incubation time points. Through bacterial infection assay, the highest non-cytotoxic concentration of emodin demonstrated attenuated invasion of Brucella into macrophages, however it did not inhibit the growth of these pathogens within the host cells. On the other hand, emodin effectively decreased the number of bacteria that adhered to host cells, which indicated its potential as an anti-adhesin agent. Furthermore, using immunoblotting and FACS assay for detecting MAPK signaling proteins and F-actin polymerization, respectively, the results showed that the emodin-incubated cells displayed modest reduction in the phosphorylation levels of ERK1/2 and inhibition of F-actin polymerization as compared to control cells. These findings indicate the potential use of emodin as a naturally-occurring alternative method for the prevention of animal brucellosis although this requires confirmation of safe clinical doses.

• Fisheries and Aquatic Sciences
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• 제1권2호
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• pp.187-191
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• 1998

Chemotherapy can not be applied for the control of fish viral diseases because viruses depend on host machinery for their replication. Although new control strategies including vaccination are under development, avoidance of virus introduction by rapid and correct diagnosis is the best way of fish viral disease control. Although observation of virus particles with an electron microscope is an easy method for virus detection, it take a few days for the sample preparation. In order to shorten the sample preparation time, microwave radiation was applied in the procedure. With this method, 15 seconds was enough for fixation of virus infected fish samples or cultured cells inoculated with infectious hematopoietic necrosis virus, which takes 2-4 hours with routine methods. Also four minutes was enough for polymerization of embedding resin which takes 24-48 hours with routine methods. Samples prepared with microwave were good enough for direct electron microscopic observation and immunogold labeling assay.

• 생명과학회지
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• 제28권7호
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• pp.802-810
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• 2018

노화란 나이가 들면서 생기는 몸의 변화로 검은 머리가 흰 머리로 변하는 백발화, 과산화 지질과 단백질로 구성되어 생성되는 검버섯, 주름 등으로 나타난다. 멜라닌은 tyrosine에서 DOPA를 거쳐 산화 중합반응에 의해 생성되는 고분자 물질로 인체 내에 존재하는 머리카락 및 피부 색을 결정한다. 이러한 멜라닌은 melanocyte에서 합성되며, 활성산소에 의해 과도하게 생성되면 노화를 일으킨다는 연구가 보고되고 있다. 본 연구의 목적은 항산화 효과 및 멜라닌 합성에 대한 바나나 껍질 추출물(MPEE)의 직접적인 효과를 밝히는 것이다. MPEE는 DPPH radical scavenging assay와 reducing power assay를 수행한 결과, 두 실험 모두 양성대조군인 vitamin C와 비슷한 항산화 활성을 나타내었다. 세포 실험에 앞서 세포 독성을 알아보기 위해 B16F1 세포에서 MTT assay를 수행하였다. MPEE는 $32{\mu}g/ml$ 이하의 농도에서 세포독성이 없는 것으로 나타났다. 또한, MPEE는 invitro에서 tyrosinase 활성과 DOPA-oxidation 뿐만 아니라 살아있는 세포에서 멜라닌 합성을 증가시켰다. 더욱이, $H_2O_2$로 세포를 노화시켜 L-DOPA 실험을 수행한 결과, MPEE는 멜라닌 합성을 증가시켰다. 단백질 수준의 발현을 위한 Western blot 분석을 수행한 결과, TRP-1, TPR-2와 SOD-2의 발현 수준은 MPEE의 존재 하에서 증가되었다. 이상의 결과는 MPEE가 항산화 소재로 멜라닌 합성을 촉진시킨다는 것을 암시하고 있다.

• 치위생과학회지
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• 제19권1호
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• pp.39-47
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• 2019

Background: Light-emitting diodes curing unit (LCU), which emit blue light, is used for polymerization of composite resins in many dentistry. Although the use of LCU for light-cured composite resin polymerization is considered safe, it is still controversial whether it can directly or indirectly have harmful biological influences on oral tissues. The aim of this study was to elucidate the biological effects of LCU in wavelengths ranging from 440 to 490 nm, on the cell viability and secretion of inflammatory cytokines in MDPC-23 odontoblastic cells and inflammatory-induced MDPC-23 cells by lipopolysaccharide (LPS). Methods: The MTT assay and observation using microscope were performed on MDPC-23 cells to investigate the cell viability and cytotoxic effects on LCU irradiation. Results: MDPC-23 cells and LPS stimulated MDPC-23 cells were found to have no effects on cell viability and cell morphology in the LCU irradiation. Nitric oxide (NO) and prostaglandin $E_2$ which are the pro-inflammatory mediators, and interleukin-$1{\beta}$ and tumor necrosis factor-${\alpha}$ (TNF-${\alpha}$) which are the proinflammatory cytokines were significantly increased in MCPD-23 cells after LCU irradiation as time increased in comparison with the control. LCU irradiation has the potential to induce inflammation or biological damages in normal dental tissues, including MDPC-23 cells. Conclusion: Therefore, it is necessary to limit the use of LCU except for the appropriate dose and irradiation time. In addition, LCU irradiation of inflammatory-induced MDPC-23 cells by LPS was reduced the secretion of NO compared to the LPS alone treatment group and was significantly reduced the secretion of TNF-${\alpha}$ in all the time groups. Therefore, LCU application in LPS stimulated MDPC-23 odontoblastic cells has a photodynamic therapy like effect as well as inflammation relief.

• 한국안광학회지
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• 제20권1호
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• pp.75-81
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• 2015

목적: 본 연구는 안구에 존재하는 항산화효소인 superoxide dismutase(SOD)와 catalase(CAT)가 UV-A에 반복적으로 노출되었을 때 이들의 구조 및 활성의 변화가 유발되는지 알아보고 이들의 상관관계를 밝히고자 수행되었다. 방법: SOD와 CAT의 표준품으로 각각의 효소용액을 제조하고 하루 30분, 1시간 및 2시간씩 365 nm의 UV-A에 노출시키는 조건으로 1, 2, 3, 4 및 5일 동안 UV-A에 반복적으로 노출시켰다. UV-A 반복노출에 따른 SOD와 CAT의 구조변성은 전기영동분석으로 확인하였으며, 이들 효소의 활성은 분석키트를 이용하여 비색분석법으로 측정하였다. 결과: UV-A에 반복노출된 SOD는 일일 1시간 이상 조건으로 반복노출되었을 때 전기영동분석에서 효소의 다중화(polymerization)가 관찰되었으나 활성의 변화는 12% 이내로 나타났다. 반면 UV-A에 반복노출된 CAT는 전기영동 시 효소의 밴드크기가 감소하여 구조변성이 나타났음을 알 수 있었으며, 효소활성 또한 유의하게 감소됨을 확인하였다. 반복노출시간이 긴 경우 CAT은 전기영동분석에서는 효소밴드를 보임에도 불구하고 그 활성은 완전히 소실됨을 알 수 있었다. 결론: 이상의 결과로 UV-A 반복노출에 따른 항산화효소의 구조변성은 효소의 종류에 따라 그 정도와 양상이 다르게 나타나며, 구조변성이 효소활성의 감소정도와 반드시 일치하는 것은 아님을 알 수 있었다.

• Journal of Ginseng Research
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• 제42권4호
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• pp.496-503
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• 2018

Background: Korean ginseng (Panax ginseng) plays an anti-inflammatory role in a variety of inflammatory diseases such as gastritis, hepatitis, and colitis. However, inflammation-regulatory activity of the calyx of the P. ginseng berry has not been thoroughly evaluated. To understand whether the calyx portion of the P. ginseng berry is able to ameliorate inflammatory processes, an ethanolic extract of P. ginseng berry calyx (Pg-C-EE) was prepared, and lipopolysaccharide-activated macrophages and HEK293 cells transfected with inflammation-regulatory proteins were used to test the anti-inflammatory action of Pg-C-EE. Methods: The ginsenoside contents of Pg-C-EE were analyzed by HPLC. Suppressive activity of Pg-C-EE on NO production, inflammatory gene expression, transcriptional activation, and inflammation signaling events were examined using the Griess assay, reverse transcription-polymerization chain reaction, luciferase activity reporter gene assay, and immunoblotting analysis. Results: Pg-C-EE reduced NO production and diminished mRNA expression of inflammatory genes such as cyclooxygenase-2, inducible NO synthase, and tumor necrosis factor-${\alpha}$ in a dose-dependent manner. This extract suppressed luciferase activity induced only by nuclear factor-${\kappa}B$. Interestingly, immunoblotting analysis results demonstrated that Pg-C-EE reduced the activities of protein kinase B (AKT)1 and AKT2. Conclusion: These results suggest that Pg-C-EE may have nuclear-factor-${\kappa}B$-targeted anti-inflammatory properties through suppression of AKT. The calyx of the P. ginseng berry is an underused part of the ginseng plant, and development of calyx-derived extracts may be useful for treatment of inflammatory diseases.

• 한국임상수의학회지
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• 제34권2호
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• pp.70-75
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• 2017

Fucoidan increases the chemotactic activity of peripheral blood polymorphonuclear cells (PMNs) through interleukin (IL)-8 produced by peripheral blood mononuclear cells (PBMCs). It has been demonstrated that fucoidan can regulate the chemotaxis of PMNs by activating F-actin polymerization. The objectives of this study are to investigate the direct effect of fucoidan on the chemotaxis of porcine PMNs and to examine whether this effect is associated with changes in phosphoinositide 3-kinase (PI3K) activity. The chemotactic activity of porcine PMNs was evaluated by modified Boyden chamber assay. Akt phosphorylation activity, a main downstream of PI3K, was measured by Western blotting assay. Fucoidan itself has no chemoattractant effect for PMNs. However, direct treatment of PMNs with fucoidan showed higher chemotactic activity to porcine recombinant (pr) IL-8 than that of PMNs without fucoidan. The increased chemotactic activity of fucoidan-treated PMNs to pr IL-8 was suppressed by treatment of wortmannin, an inhibitor of PI3K. Treatment of PMNs with fucoidan also increased Akt phosphorylation level. This increase was also suppressed by wortmannin. These results suggested that fucoidan can upregulate chemotactic activity of porcine PMNs to IL-8, which is associated with PI3K activation.