• BMB Reports
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• 제50권7호
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• pp.345-354
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• 2017

Autophagy, a catabolic process necessary for the maintenance of intracellular homeostasis, has recently been the focus of numerous human diseases and conditions, such as aging, cancer, development, immunity, longevity, and neurodegeneration. However, the continued presence of autophagy is essential for cell survival and dysfunctional autophagy is thought to speed up the progression of neurodegeneration. The actual molecular mechanism behind the progression of dysfunctional autophagy is not yet fully understood. Emerging evidence suggests that basal autophagy is necessary for the removal of misfolded, aggregated proteins and damaged cellular organelles through lysosomal mediated degradation. Physiologically, neurodegenerative disorders are related to the accumulation of amyloid ${\beta}$ peptide and ${\alpha}-synuclein$ protein aggregation, as seen in patients with Alzheimer's disease and Parkinson's disease, respectively. Even though autophagy could impact several facets of human biology and disease, it generally functions as a clearance for toxic proteins in the brain, which contributes novel insight into the pathophysiological understanding of neurodegenerative disorders. In particular, several studies demonstrate that natural compounds or small molecule autophagy enhancer stimuli are essential in the clearance of amyloid ${\beta}$ and ${\alpha}-synuclein$ deposits. Therefore, this review briefly deliberates on the recent implications of autophagy in neurodegenerative disorder control, and emphasizes the opportunities and potential therapeutic application of applied autophagy.

• Molecules and Cells
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• 제24권1호
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• pp.69-75
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• 2007

Alzheimer's disease is a neurodegenerative disorder associated with progressive loss of cognitive function and memory. Amyloid beta peptide ($A{\beta}$) is the major component of senile plaques and is known to exert its cytotoxic effect mainly by producing $H_2O_2$. Vascular endothelial growth factor (VEGF) is elevated in the cerebrospinal fluid (CSF) and brain of AD patients, and $H_2O_2$ is one of the factors that induce VEGF. Therefore, we tested whether $A{\beta}$ might be responsible for the increased VEGF synthesis. We found that $A{\beta}$ induced the production of $H_2O_2$ in vitro. Comparison of the amount of $H_2O_2$ required to induce VEGF synthesis in HN33 cells and the amount of $H_2O_2$ produced by $10{\mu}M\;A{\beta}_{1-42}$ in vitro suggested that a toxic concentration of $A{\beta}$ might induce VEGF synthesis in these cells. However, toxic concentrations of $A{\beta}$ failed to induce VEGF synthesis in several cell systems. They also had no effect on antioxidant enzymes such as glutathione peroxidase, catalase, and peroxiredoxin in HN33 cells. $Cu^{2+}$, $Zn^{2+}$ and $Fe^{3+}$ are known to accumulate in the brains of AD patients and promote aggregation of $A{\beta}$, and $Cu^{2+}$ by itself induces synthesis of VEGF. However, there was no synergistic effect between $Cu^{2+}$ and $A{\beta}_{1-42}$ in the induction of VEGF synthesis and $Zn^{2+}$ and $Fe^{3+}$ also had no effect on the synthesis of VEGF, alone or in combination with $A{\beta}$.

• Journal of Microbiology and Biotechnology
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• 제29권11호
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• pp.1707-1716
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• 2019

The development of new antimicrobial agents is essential for the effective treatment of diseases such as sepsis. We previously developed a new short peptide, Pap12-6, using the 12 N-terminal residues of papiliocin, which showed potent and effective antimicrobial activity against multidrug-resistant Gram-negative bacteria. Here, we investigated the antimicrobial mechanism of Pap12-6 and a newly designed peptide, Pap12-7, in which the 12^th Trp residue of Pap12-6 was replaced with Val to develop a potent peptide with high bacterial selectivity and a different antibacterial mechanism. Both peptides showed high antimicrobial activity against Gram-negative bacteria, including multidrug-resistant Gram-negative bacteria. In addition, the two peptides showed similar anti-inflammatory activity against lipopolysaccharide-stimulated RAW 264.7 cells, but Pap12-7 showed very low toxicities against sheep red blood cells and mammalian cells compared to that showed by Pap12-6. A calcein dye leakage assay, membrane depolarization, and confocal microscopy observations revealed that the two peptides with one single amino acid change have different mechanisms of antibacterial action: Pap12-6 directly targets the bacterial cell membrane, whereas Pap12-7 appears to penetrate the bacterial cell membrane and exert its activities in the cell. The therapeutic efficacy of Pap12-7 was further examined in a mouse model of sepsis, which increased the survival rate of septic mice. For the first time, we showed that both peptides showed anti-septic activity by reducing the infiltration of neutrophils and the production of inflammatory factors. Overall, these results indicate Pap12-7 as a novel non-toxic peptide with potent antibacterial and anti-septic activities via penetrating the cell membrane.

• Bulletin of the Korean Chemical Society
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• 제34권12호
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• pp.3665-3670
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• 2013

The R3V6 peptide includes a hydrophilic arginine stretch and a hydrophobic valine stretch. In previous studies, the R3V6 peptide was evaluated as a gene carrier and was found to have low cytotoxicity. However, the transfection efficiency of R3V6 was lower than that of poly-L-lysine (PLL) in N2A neuroblastoma cells. In this study, the transfection efficiency of R3V6 was improved in combination with high mobility group box 1A domain (HMGA). HMGA is originated from the nuclear protein and has many positively-charged amino acids. Therefore, HMGA binds to DNA via charge interaction. In addition, HMGA has a nuclear localization signal peptide and may increase the delivery efficiency of DNA into the nucleus. The ternary complex with HMGA, R3V6, and DNA was prepared and evaluated as a gene carrier. First, the HMGA/DNA complex was prepared with a negative surface charge. Then, R3V6 was added to the complex to coat the negative charges of the HMGA/DNA complex, forming the ternary complex of HMGA, R3V6, and DNA. A physical characterization study showed that the ternary complex was more stable than the PLL/DNA complex. The HMGA/R3V6/DNA complex had a higher transfection efficiency than the PLL/DNA, HMGA/DNA, or R3V6/DNA complexes in N2A cells. Furthermore, the HMGA/R3V6/DNA complex was not toxic to cells. Therefore, the HMGA/R3V6/DNA complex may be a useful gene delivery carrier.

• 환경생물
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• 제36권4호
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• pp.601-609
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• 2018

본 연구에서는 CyanoHABs를 제어하기 위해 주요 우점종인 Microcystis aeruginosa에 대한 항균 펩타이드의 살조 활성을 조사하고, 구조적 특이성을 바탕으로 새로운 M. aeruginosa 제어 펩타이드를 제작하였다. 본 실험에서 CA-MA 유래 펩타이드 CMA1, CMA2와 Helicobacter pylori 유래 펩타이드 HPA3P, HPA3NT3는 처리 48시간 후 각각 67.3, 73.1, 76.7, 69.8%의 최대 살조 효율을 보였다. 또한, 신규 펩타이드 K160242~5는 처리 48시간 후 각각 64.0, 64.1, 66.4, 70.1%의 최대 살조 효율을 보였다. CA-MA 유래 펩타이드는 처리 24시간 이후 세포의 재성장이 관찰되었으므로 세포 표면과의 정전기 인력을 통해 세포를 응집하고 간접적으로 제어하는 것으로 조사되었다. 반면에, 양친매성 펩타이드는 세포의 재성장이 관찰되지 않았으므로 세포 응집과 더불어 세포 내 침투를 통해 직 간접적으로 세포를 제어하는 것으로 추정되었다. 또한, 펩타이드의 살조 기작 및 효율에는 구성 아미노산의 종류, 수, 구조 및 펩타이드의 분자량, 처리 농도 등이 복합적으로 영향을 미치는 것으로 나타났다. 그러나 펩타이드를 이용한 CyanoHABs의 제어 가능성을 제고하기 위해서는 정확한 기작과 관련 인자들의 확인 및 증명이 요구된다.

• 한국미생물·생명공학회지
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• 제40권4호
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• pp.409-413
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• 2012

인돌리시딘(indolicidin)은 소의 호중구(bovine neutrophils)로 부터 분리된 13개의 아미노산 잔기로 이루어 지고, 트립토판(tryptophan)을 많이 함유한 항균 펩타이드(antimicrobial peptide)이다. 인돌리시딘은 강력한 항균활성과 더불어 mammalian cells에 대해 독성을 나타낸다. 본 연구에서는 인돌리시딘 보다 서열이 짧으며, 보다 증가된 원핵세포 선택성(박테리아세포에 대해 독성을 나타내지만 mammalian cells에 대해서는 독성을 나타내지 않음을 의미함)을 지닌 새로운 짧은 항균 펩타아드를 개발하기 위해, 몇 종의 인돌리시딘 유사체 펩타이드를 설계하고 합성하였다. 결과적으로, 인돌리시딘 보다 서열이 짧으며(10개의 아미노산 잔기로 이루어짐), 증가된 원핵세포선택성을 지닌 4종의 새로운 펩타이드(SI, SI-PA, SI-WF 및 SI-WL)를 개발하였다. 본 연구를 통하여 가장 높은 원핵세포선택성을 나타내는 인돌리시딘 유사체 펩타이드 SI의 항균활성에는 중앙부위에 위치하는 소수성 및 방향족 아미노산이 중요하며, 2군데의 프로린(proline) 잔기는 중요하지 않다는 것을 알았다. 인돌리시딘과 유사체 펩타이드에 대한 원핵세포 선택성은 SI>SI-PA>SI-WF>SI-WL>ID>SI-WA의 순서 이였다. 따라서, 본 연구에서 설계되고 합성한 4종의 인돌리시딘 유사체 펩타이드(SI, SI-PA, SI-WF 및 SI-WL)는 박테리아 감염의 치료제로서 개발될 수 있을 것이다.

• 생물정신의학
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• 제18권2호
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• pp.90-94
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• 2011

Objectives It is well-known that tobacco smoking is related to various disease entities including chronic obstructive pulmonary disease, inflammation, cardiovascular disease, and neoplasms. The prohibition of smoking is important for the protection of these health problems. Regarding leptin, ghrelin, glucagon-like peptide 1 (GLP-1), and nerve growth factor (NGF) levels, correlations with the smoking are suggested but the reports on the effects after smoking cessation are not sufficient. Method The changes of plasma levels of leptin, ghrelin, GLP-1, and NGF levels were analyzed after quitting smoking in Korean adults. Eleven participants succeeding in quitting smoking among 37 male smokers were included in the final analysis. The plasma levels of NGF, leptin, ghrelin, and GLP-1 were measured before and after 8-weeks period of smoking cessation. Results The plasma level of leptin increased after 4 weeks of smoking cessation. In addition, the plasma level of NGF increased after 8 weeks of smoking cessation (p < 0.05). Conclusion Our results suggested that smoking cessation induces increases in leptin and the NGF level after smoking cessation. Many toxic materials including nicotine in the cigarette may be related to these changes of plasma level of leptin and NGF, playing a key role in neurogenesis and synaptic plasticity.

• 한국동물생명공학회지
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• 제37권4호
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• pp.239-245
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• 2022

Protein and peptide candidates are screened to apply therapeutic application as a drug. Ensuring that these candidates are delivered and maximized effectiveness is still challenging and a variety of studies are ongoing. As drug delivery system vehicles, cell-penetrating peptide (CPP) can deliver various kinds of cargo into the cell cytosol. In a previous study, we developed Ara27 CPP, which are a zinc knuckle family protein of Arabidopsis, and confirmed internalization in human dermal fibroblasts and human dental pulp stem cells at low concentration with short time treatment condition without any toxicity. Ara27, an amphipathic CPP, could be modified and utilized in the biomedical field excluding the risk of toxicity. Therefore, we would like to confirm the non-toxic induced penetrating ability of Ara27 in various cell lines. The purpose of this study was to screen the cell internalization ability of Ara27 in various cell lines and to confirm Ara27 as a promising core CPP structure. First, Ara27 was screened to confirm non-toxicity concentration. Then, fluorescence-labeled Ara27 was treated on human normal cell lines, cancer cell lines and animal cell lines to identify the cellular internalization of Ara27. Ara27 was well intracellular localized in all cell lines and the intensity of fluorescence was remarkably increased in time pass manner. These results indicate that Ara27 has the potential as a core structure for applications in various drug delivery systems.

• Journal of Nutrition and Health
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• 제25권6호
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• pp.492-500
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• 1992

본 연구에서는 비타민 A 과량 섭취가 비타민 K 기능에 미치는 영향을 알아보기 위하여 carboxylase의 기질인 쥐의 간내 microsome 단백질과 첨가된 펩티드의 vitamin K-dependent carboxylation rate를 측정하였다. In vitro 실험에서는 정상 vit.A 섭취군의 간 microsome을 vit.A 로 incubation했을때 간 내 prothrombin 선구 물질이나 첨가된 peptide기질의 carboxylation rate는 영향을 받지 않았다. 이와 비슷한 양상으로서 무비타민 K 식이와 함께 비타민 A를 정상수준 혹은 과잉 수준으로 섭취한 쥐를 비교한 경우에는 동일군 간에는 carboxylation rate에 유의한 차이를 나타내지 않았다. 그러나 비타민 A 과잉군의 간내 단백질의 carboxylation rate는 대조군에 비하여 증가하는 경향이었다, 비타민 A 과잉군은 비타민 A로 incubate한 경우나 하지 않은 경우 모두 대조군에 비하여 약 2~3 배 의 carboxylase 활성을 보였다. In vivo study 에서는 첨가된 peptide에 대한 carboxylase활성은 비타민 A 광일 섭취에 의하여 영향을 받지 않았다. 그러나 간 내 단백질의 carboxylation rate는 비타민 A과잉군이 대조군에 비하여 2~3 배나 더 높았다. Carboxylase 활성은 대조군이나 비타민 A과잉군 모두 연구기간이 진행될수록 더 증가하였다. 그리고 간 내 단백질의 carboxylation에 대한 비타민 A 과잉 효과는 실험 식이를 시작한 후 일주일 정도에서 나타나기 시작하였다. 그러므로 이 연구 결과는 비타민 A 과잉 시에는 과잉증이 빠른 시일내에 일어나며, 비타민 A 과잉은 비타민 K 결핍의 지표인 prothrombin 의 선구물질을 증가시킨다는 것을 시사한다.

• Journal of Applied Biological Chemistry
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• 제63권4호
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• pp.387-392
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• 2020

Pseudomonas tolaasii는 인공재배 버섯에 갈반병을 일으키는 병원 세균이다. 이전 연구에서, 갈반병이 발생한 버섯 조직에서 다양한 P. tolaasii 균주를 분리하였으며, 그들은 16S rRNA 유전자 분석을 통하여 Ptα와 Ptβ, Ptγ 소그룹으로 세분류되었다. Tolaasin 및 이의 유사 펩티드 분비를 조사하기 위하여, Pt 그룹 균주들의 배양추출액을 gel permeation chromatography로 분석하였다. Ptα 소그룹 균주들의 배양추출액은 두 개의 chromatographic band인 band A와 B로 이루어졌다. 반면, Ptβ와 Ptγ 소그룹 균주들의 배양추출액은 주로 band A 성분만을 가졌으며, band B는 약하게 나타났다. 배양액 중 독성 펩티드들을 MALDI-TOF 질량분석기를 이용하여 분석하였다. Ptα 소그룹 균주들에서 band A와 B의 펩티드 조성은 tolaasin I (1987 Da)과 tolaasin II (1943 Da), 1,973 Da과 2,005 Da인 두 개의 유사 펩티드를 포함하여 동일하였다. Ptβ와 Ptγ 소그룹 균주들은 분자량 1,100-1,200 Da의 많은 성분들을 분비하였으나, 이들은 tolaasin 유사 펩티드를 포함하지 않았다. 이러한 결과는 Ptα 소그룹 균주들만이 tolaasin 및 유사 펩티드 독소를 분비하며, Ptβ와 Ptγ 소그룹 균주들은 갈반병을 일으키는 다른 병원 특성을 가짐을 보여준다.