• 한국고분자학회:학술대회논문집
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• 한국고분자학회 2006년도 IUPAC International Symposium on Advanced Polymers for Emerging Technologies
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• pp.348-348
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• 2006

In the present study, porcine pepsin in various pH conditions was investigated by small-angle X-ray scattering (SAXS) in order to detailed information on the structure and its variations with pH conditions. These analyses identified the structure of pepsin, and compared with that obtained by single crystallography. Moreover, this study found the structure' variations with changing pH conditions. All the results will be discussed with considering the conformational characteristics of pepsin in solution and further correlate to the biological and spectroscopic characteristics reported previously.

• Animal cells and systems
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• 제3권3호
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• pp.311-317
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• 1999

Prolactin (PRL) was reported to be locally synthesized in many brain areas including the hypothalamus, thalamus (TH) and hippocampus (HIP). In the pituitary lactotrophs, PRL synthesis is dependent upon a pituitary-specific transcription factor, Pit-1. In the present study, we attempted to identify Pit-1 or Pit-1-like protein in brain areas known as the synthetic sites of PRL. Reverse transcription-polymerase chain reaction (RT-PCR) and Northern blot analysis showed the same Pit-1 transcripts in brain areas such as the medial basal hypothalamus (MBH), preoptic area (POA), TH, and HIP with the Pit-1 transcripts in the anterior pituitary (AP). Electrophoretic mobility shift assay (EMSA) was run with nuclear protein extracts from brain tissues using a double strand oligomer probe containing a putative Pit-1 binding domain. Shifted bands were found in EMSA results with nuclear proteins from MBH, POA, TH and HIP. Specific binding of the Pit-1-like protein was further confirmed by competition with an unlabeled cold probe. Antisense Pit-1 oligodeoxynucleotide (Pit-1 ODN), which was designed to bind to the Pit-1 translation initiation site and block Pit-1 biosynthesis, was used to test Pit-1 dependent brain PRL transcription. Two nmol of Pit-1 ODN was introduced into the lateral ventricle of a 60-day old male rat brain. RNA blot hybridization and in situ hybridization indicated a decrease of PRL mRNA signals by the treatment of Pit-1 ODN. Taken together, the present study suggests that Pit-1 may play an important role in the transcriptional regulation of local PRL synthesis in the brain.

• Journal of Microbiology and Biotechnology
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• 제9권2호
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• pp.140-146
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• 1999

When methanol was the sole carbon source, Methylobacterium organophilum NCIB 11278, a facultative methylotroph, accumulated Poly-$\beta$-hydroxybutyrate (PHB) as 59% (w/w) of dry cell weight under potassium limitation, 37% under sulfate limitation, and 33% under nitrogen limitation. Based on a stoichiometric analysis of PHB synthesis from methanol, it was suspected that PHB synthesis is accompanied by the overproduction of energy, either 6-10 ATP and 1 $FADH_2$ or 6 ATP and 3 NADPH to balance the NADH requirement, per PHB monomer. This was confirmed by observation of increased intracellular ATP levels during PHB accumulation. The intracellular ATP with limited potassium, sulfate, and ammonium increased to 0.185, 0.452, and 0.390 $\mu$moles ATP/g Xr (residual cell mass) during PHB accumulation, respectively. The intracellular ATP level under potassium limitation was similar to that when there was no nutrient limitation and no PHB accumulation, 0.152- 0.186 $\mu$moles ATP/g Xr. We propose that the maximum PHB accumulation observed when potassium was limited is a result of the energy balance during PHB accumulation. Microorganisms have high energy requirements under potassium limitation. Enhanced PHB accumulation, in ammonium and sulfate limited conditions with the addition of 2,4-dinitrophenol, which dissipates surplus energy, proves this assumption. With the addition of 1 mM of 2,4-dinitrophenol, the PHB content increased from 32.4% to 58.5% of dry cell weight when nitrogen limited and from 15.1 % to 31.0% of dry cell weight when sulfate limited.

• 대한화학회지
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• 제32권1호
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• pp.60-64
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• 1988

배추좀나방의 성 유인물질인 (Z)-11-헥사데센-1-올, (Z)-11-헥사데센-1-알, (Z)-11-헥사데센-1-일 아세테이트를 합성하여 생물활성 시험을 수행하였다. 1-헥신의 리튬음이온을 10-브로모데칸-1-올 THP 에테르와 반응시켜 11-헥사데신-1-올 THP 에테르를 얻었다. 이를 수소환원시킨 후 (Z)-11-헥사데센-1-올 THP 에테르를 생성시킨 다음 보호기를 제거시켜 (Z)-11-헥사데센-1-올을 합성하였다. 아세틸화시켜 (Z)-11-헥사데센-1-일 아세테이트를 산화시켜 (Z)-11-헥사데센-1-알을 각각 합성하였다. 합성된 성 페로몬에 대한 배추좀나방 숫컷의 성 유인력을 시험해 본 결과 활성이 있음을 밝혀졌다.

• Journal of Plant Biotechnology
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• 제36권3호
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• pp.268-274
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• 2009

Porphyromonas gingivalis, the gram-negative anaerobic oral bacterium, initiates periodontal disease by binding to saliva-coated oral surface. The cholera toxin B subunit (CTB) genetically linked to FimA1 (1-200 aa) or FimA2 (201-337 aa) of the P. gingivalis fimbrial antigen were introduced into Solanum tuberosum cells by Agrobacterium tumefaciens-mediated transformation method. The integration of CTB-FimA1 or CTB-FimA2 fusion genes were confirmed in the chromosome of transformed leaves by genomic DNA PCR amplification method. Synthesis and assembly of the CTB-FimA fusion proteins into oligomeric structures with pentamer size was detected in transformed tuber extracts by immunoblot analysis. The binding activities of CTB-FimA fusion proteins to intestinal epithelial cell membrane receptors were confirmed by GM1-ganglioside enzyme-linked immunosorbent assay (GM1-ELISA). The ELISA showed that the expression levels of the CTB-FimA1 or CTB-FimA2 fusion proteins were 0.0019, 0.002% of the total soluble protein in transgenic tuber tissues, respectively The synthesis of CTB-FimA monomers and their assembly into biologically active oligomers in transformed potato tuber tissues demonstrates the feasibility of using edible plants for the production of enterocyte targeted fimbrial antigens that could elicit mucosal immune responses.

• Journal of Periodontal and Implant Science
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• 제26권1호
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• pp.317-333
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• 1996

The main goal of periodontal regeneration is to be achieved by epithelial exclusion, periodontal ligament cell activation or alveolar bone regeneration. The purpose of this study was to investigate on the physico- chemical and biological characteristics of biodegradable chitosan beads. Chitosan beads were fabricated by ionic gelation with sodium tripolyphosphate and they had the size in 300um diameter. As therapeutic agent, flurbiprofen was incorporated into the beads by 10, 20% loading contents. The release of drugs from the chitosan beads was measured in vitro. Also, biological activity tests of flurbiprofen loaded chitosan beads including cytotoxicity test, ihhibition of $IL-1{\beta}$ production, suppression to $PGE_2$ production, collagenase inhibition test, the ability of total protein synthesis, and tissue response were evaluated. The amount of flurbiprofen released from chitosan was 33-50% during 7 days. Minimal cytotoxicity was observed in chitosan beads. Flurbiprofen released from chitosan beads significantly suppressed the $IL-1{\beta}$ production of monocyte, $PGE_2$ production and markedly inhibited collagenase activity. Meanwhile, flurbiprofen released from this system showed increased ability for protein synthesis. Throughout 4 -week implantation period, no significant inflammatory cell infiltrated around chitosan bead and also fibroblast like cell types at the beads - tissue interface were revealed with gradual degradation of implanted chitosan beads. From these results, it was suggested that flurbiprofen loaded chitosan beads can be effectively useful for biocompatible local delivery system in periodontal regeneration.

• KSBB Journal
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• 제22권4호
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• pp.179-184
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• 2007

본 연구는 특정 아미노산들로 구성된 단위체가 반복되는 형태를 가지는 반복단위 단백질을 유전공학적으로 합성하는 방법들과 응용사례들을 소개하고 있다. 유전공학적 합성법은 단위체의 반복횟수를 정확하게 제어하면서 인식부위의 제한을 없애서 원하는 단백질만을 발현할 수 있도록 발전해왔으며, 최근 소개된 RDL과 CCM 방법에 의하여 가능해졌다. 반복단위 단백질의 응용사례로는 대표적으로 ELP, SLP, Prolamin 등의 단백질을 합성하여 생체재료나 약물전달시스템을 개발하는데 응용하거나, ELFSE의 drag-tag 개발에 응용되는 연구들이 진행되고 있다. 화학적으로 합성된 고분자에 비해 유전공학적으로 합성된 반복단위 고분자의 경우, 고유의 물리적 성질과 함께 환경에 미치는 유해함이 상대적으로 적다는 점 때문에 미래의 신소재로 기대되고 있다.

• 청정기술
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• 제11권4호
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• pp.171-179
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• 2005

바이오디젤은 동물성 또는 식물성 유지를 알코올과 반응시켜 생성된 물질로서 경유와 유사한 특성을 가지고 있어 기존 제품에 혼합하여 연료로 사용하고 있으며 대기오염을 감소시키는 효과와 재생 가능한 바이오매스로부터 생산된다는 장점을 가지고 있다. 기존의 알칼리 또는 산성 촉매를 사용하는 공정에 비하여 초임계 상태의 메탄올을 사용하여 바이오디젤을 제조하는 공정은 반응시간이 짧고 촉매를 사용하지 않아 분리/정제 공정이 단순하여 경제적이기 때문에 최근 많은 연구가 진행되고 있다. 특히, 국내의 경우 연간 20만톤의 폐식용유가 발생하고 있기 때문에 이의 재활용 방안으로 국내 고유의 초임계 공정이 상업화 될 경우 막대한 에너지 회수와 이산화탄소 저감 그리고 환경 개선 효과를 기대할 수 있을 것으로 사료된다.

• Animal cells and systems
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• 제2권3호
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• pp.383-388
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• 1998

A RecA-like protein (RecAps) was identified from fluorescent Pseudomonas sp. and the inducible nature of the protein was characterized in detail. It was shown by dose-response and time-course experiments using two DNA damaging agents, nalidixic acid and mitomycin-C, that the cellular level of RecAps protein was increased 3-8 fold compared to that of the control. The most effective doses of nalidixic acid and mitomycin-C for the protein induction were $30{\mu}g/ml$ and $0.3{\mu}g/ml$ at the treatment time point of 150 min, respectively. The enhanced level of RecAps protein was gradually decreased to the control level after 10 hr in normal medium. Interestingly, the cellular level of RecAps protein was increased by the same DNA damaging agents even when cell growth was completely inhibited by treatment with $170{\mu}g/ml$ of chloramphenicol, an inhibitor of protein synthesis, suggesting that new protein synthesis is not required for the induction of RecAps. All these results suggest that a typical S0S repair function driven by RecA-like protein is conserved in Pseudomonas sp. cells as in E, coli.

• Advances in nano research
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• 제15권4호
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• pp.355-366
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• 2023

Biological corrosion, a crucial aspect of metal degradation, has received limited attention despite its significance. It involves the deterioration of metals due to corrosion processes influenced by living organisms, including bacteria. Soil represents a substantial threat to pipeline corrosion as it contains chemical and microbial factors that cause severe damage to water, oil, and gas transmission projects. To combat fouling and corrosion, corrosion inhibitors are commonly used; however, their production often involves expensive and hazardous chemicals. Consequently, researchers are exploring natural and eco-friendly alternatives, specifically nano-sized products, as potent corrosion inhibitors. This study aims to environmentally synthesize silver nanoparticles using an extract from Lagoecia cuminoides L and evaluate their effectiveness in preventing biological corrosion of buried pipes in soil. The optimal experimental conditions were determined as follows: a volume of 4 ml for the extract, a volume of 4 ml for silver nitrate (AgNO3), pH 9, a duration of 60 minutes, and a temperature of 60 degrees Celsius. Analysis using transmission electron microscopy confirmed the formation of nanoparticles with an average size of approximately 28 nm, while X-ray diffraction patterns exhibited suitable peak intensities. By employing the Scherer equation, the average particle size was estimated to be around 30 nm. Furthermore, antibacterial studies revealed the potent antibacterial activity of the synthesized silver nanoparticles against both aerobic and anaerobic bacteria. This property effectively mitigates the biological corrosion caused by bacteria in steel pipes buried in soil.