• 생명과학회지
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• 제26권1호
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• pp.17-22
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• 2016

에탄올은 산업적으로 매우 가치 있는 물질이지만, 효모세포에 있어서 에탄올의 축적은 세포 독성과 목적산물의 생산성을 감소시키는 스트레스원이다. 따라서 효모세포에 있어서 에탄올 내성의 증가는 에탄올 생산성 증대와 밀접한 관계가 있는 중요한 요소라고 할 수 있다. 본 연구에서는 에탄올 내성을 증가시키기 위해 YDJ1과 PEP5 유전자를 목적 유전자로 선정하여 이들 유전자의 과발현과 과발현에 따른 상호발현조절을 분석하여 에탄올 내성 메커니즘의 일부를 해명하고자 한다. YDJ1과 PEP5 유전자를 ADH1 promoter 하류에 연결시켜 pA-YDJ1과 pA-PEP5 plasmid를 구축하고 각각 BY4742, BY4742△ydj1와 BY4742△pep5 균주에 도입하였다. YDJ1과 PEP5 유전자의 과발현에 의해서 BY4742△ydj1/pA-YDJ1과 BY4742△pep5/pA-PEP5 균주의 에탄올내성이 숙주세포의 수준까지 회복되었음을 확인 할 수 있었다. 이 두 유전자의 상호발현조절을 조사하기 위해, BY4742△ydj1△pep5 균주에서 YDJ1과 PEP5 유전자의 과발현을 시도해본 결과, BY4742△ydj1△pep5/pA-YDJ1, pA-PEP5 균주의 경우, 8% 에탄올 배지에서 BY4742 균주의 약 90%정도 까지 에탄올 내성이 회복됨을 확인하였다. BY4742△ydj1△ pep5/pA-YDJ1, pA-PEP5 균주에서 YDJ1 유전자는 PEP5 유전자의 과발현을 더욱더 유도하여 에탄올 내성을 증가시켰으며, 이는 YDJ1 유전자가 PEP5 유전자의 상위에서 발현을 부분적으로 조절한다고 생각 할 수 있다.

• BMB Reports
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• 제44권4호
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• pp.256-261
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• 2011

PEP-1 peptide has been used for transduction of native protein into mammalian cells. This work describes the findings that the fusion of PEP-1 to target proteins led to protein truncation likely in a non-protein-specific manner. Approximately 75% of PEP-1-MsrA fusion protein was truncated in the N-terminal region of MsrA between Lys-27 and Val-28 during expression in Escherichia coli and purification. This large protein truncation was also observed in another PEP-1 fused protein, PEP-1-MsrB2, in the N-terminal region of MsrB2. The full-length PEP-1-MsrA protein was rapidly transduced into keratinocyte cells within 15 min. The transduced PEP-1-MsrA was functionally active and could protect skin cells against oxidative stress- and ultraviolet radiation-induced cell death. Collectively, our data demonstrated the protective roles of MsrA in skin cells and, moreover, may raise a concern of protein truncation caused by fusion of PEP-1 about the general use of this peptide for protein transduction.

• Journal of Microbiology and Biotechnology
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• 제33권3호
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• pp.371-377
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• 2023

In this study, a pepA gene encoding glutamyl (aspartyl)-specific aminopeptidase (PepA; E.C. 3.4.11.7) was cloned from Tetragenococcus halophilus CY54. The translated PepA from T. halophilus CY54 showed very low similarities with PepAs from Lactobacillus and Lactococcus genera. The pepA from T. halophilus CY54 was overexpressed in E. coli BL21(DE3) using pET26b(+). The recombinant PepA was purified by using an Ni- NTA column. The size of the recombinant PepA was 39.13 kDa as determined by SDS-PAGE, while its optimum pH and temperature were pH 5.0 and 60℃, respectively. In addition, the PepA was completely inactivated by 1 mM EDTA, indicating its metallopeptidase nature. The Km and Vmax of the PepA were 0.98 ± 0.006 mM and 0.1 ± 0.002 mM/min, respectively, when Glu-pNA was used as the substrate. This is the first report on PepA from Tetragenococcus species.

• Journal of Periodontal and Implant Science
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• 제50권3호
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• pp.159-170
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• 2020

Purpose: Immunization with Porphyromonas gingivalis heat shock protein 60 (PgHSP60) may have an immunoregulatory effect on atherogenesis. The aim of this study was to determine whether nasal immunization with a PgHSP60 peptide could reduce atherosclerotic plaque formation in apolipoprotein E knockout (ApoE KO) mice. Methods: Seven-week-old male ApoE KO mice were assigned to receive a normal diet, a Western diet, a Western diet and challenge with PgHSP60-derived peptide 14 (Pep14) or peptide 19 (Pep19), or a Western diet and immunization with Pep14 or Pep19 before challenge with Pep14 or Pep19. Results: Atherosclerotic plaques were significantly smaller in mice that received a Western diet with Pep14 nasal immunization than in mice that received a Western diet and no Pep14 immunization with or without Pep14 challenge. An immunoblot profile failed to detect serum reactivity to Pep14 in any of the study groups. Stimulation by either Pep14 or Pep19 strongly promoted the induction of CD4⁺CD25⁺ forkhead box P3 (FoxP3)⁺ human regulatory T cells (Tregs) in vitro. However, the expression of mouse splenic CD4⁺CD25⁺FoxP3⁺ Tregs was lower in the Pep14-immunized mice than in the Pep14-challenged or Pep19-immunized mice. Levels of serum interferon gamma (IFN-γ) and transforming growth factor beta were higher and levels of interleukin (IL) 10 were lower in the Pep14-immunized mice than in the other groups. Induction of CD25^- IL-17⁺ T helper 17 (Th17) cells was attenuated in the Pep14-immunized mice. Conclusions: Nasal immunization with Pep14 may be a mechanism for attenuating atherogenesis by promoting the secretion of IFN-γ and/or suppressing Th17-mediated immunity.

• Journal of Microbiology and Biotechnology
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• 제25권10호
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• pp.1629-1633
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• 2015

Peptide assimilation in Helicobacter pylori necessitates a coordinated working of the peptide transport systems (PepTs) and aminopeptidase (PepA). We found that H. pylori hydrolyzes two detector peptides, _L-phenylalanyl- _L-3-thiaphenylalanine (PSP) and _L-phenylalanyl- _L-2-sulfanilylglycine (PSG), primarily before intake and excludes their antibacterial effects, whereas Escherichia coli readily transports them with resultant growth inhibition. PSP assimilation by H. pylori was inhibited by aminopeptidase inhibitor bestatin, but not by dialanine or cyanide-m-chlorophenylhydrazone, contrary to that of E. coli. RT- and qRT-PCR analyses showed that H. pylori may express first the PepTs (e.g., DppA and DppB) and then PepA. In addition, western blot analysis of PepA suggested that the bacterium secretes PepA in response to specific inducers.

• Journal of Applied Biological Chemistry
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• 제49권3호
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• pp.110-113
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• 2006

Prolyl endopeptidase (PEP, EC 3.4.21.26, also referred to as prolyl oligopeptidase) degrades proline containing, biologically active neuropeptides such as vasopressin, substance P and thyrotropin-releasing hormone by cleaving peptide bonds on carboxyl side of prolyl residue within neuropeptides of less than 30 amino acids. Evaluation of PEP levels in postmortem brains of Alzheimer's disease patients revealed significant increases in PEP activity. Therefore, a specific PEP inhibitor can be a good candidate of drug against memory loss. Upon our examination for PEP inhibitory activity from micronutrients, ascorbic acid (vitamin C) showed small but significant PEP inhibition (13% PEP inhibition at $8{\mu}g{\cdot}ml^{-1}$). Palmitic acid showed almost no PEP inhibition. However, 6-O-palmitoyl ascorbic acid ($\underline{1}$) showed 70% PEP inhibition at $8{\mu}g{\cdot}ml^{-1}$ indicating that hydrophobic portion of the compound $\underline{1}$ may facilitate the inhibitory effect. $IC_{50}$ value of compound $\underline{1}$ was $12.6{\pm}0.2{\mu}M$. The primary and secondary Lineweaver Burk and Dixon plots for compound $\underline{1}$ indicated that it is a non-competitive inhibitor with inhibition constant (Ki) value of $23.7{\mu}M$.

• Journal of Microbiology and Biotechnology
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• 제22권4호
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• pp.494-500
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• 2012

Silk fibroin (SF) peptide has been traditionally used as a treatment for flatulence, spasms, and phlegm. In this study, we examined whether SF peptide enhanced the anti-inflammatory effect of PEP-1-FK506 binding protein (PEP-1-FK506BP) through comparing the anti-inflammatory activities of SF peptide and/or PEP-1-FK506BP. In the presence or absence of SF peptide, transduction levels of PEP-1-FK506BP into HaCaT cells and mice skin and anti-inflammatory activities of PEP-1-FK506BP were identified by Western blot and histological analyses. SF peptide alone effectively reduced both mice ear edema and the elevated levels of cyclooxygenase-2, interleukin-6 and $-1{\beta}$, and tumor necrosis factor-${\alpha}$, showing similar anti-inflammatory effect to that of PEP-1-FK506BP. Furthermore, co-treatment with SF peptide and PEP-1-FK506BP exhibited more enhanced anti-inflammatory effects than the samples treated with SF peptides or PEP-1-FK506BP alone, suggesting the possibility that SF peptide and PEP-1-FK506BP might interact with each other. Moreover, the transduction data demonstrated that SF peptide did not affect the transduction of PEP-1-FK506BP into HaCaT cells and mice skin, indicating that the improvement of anti-inflammatory effect of PEP-1-FK506BP was not caused by enhanced transduction of PEP-1-FK506BP. Thus, these results suggest the possibility that co-treatment with SF peptide and PEP-1-FK506BP may be exploited as a useful therapy for various inflammation-related diseases.

• Molecules and Cells
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• 제44권11호
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• pp.830-842
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• 2021

When perceiving microbe-associated molecular patterns (MAMPs) or plant-derived damage-associated molecular patterns (DAMPs), plants alter their root growth and development by displaying a reduction in the root length and the formation of root hairs and lateral roots. The exogenous application of a MAMP peptide, flg22, was shown to affect root growth by suppressing meristem activity. In addition to MAMPs, the DAMP peptide PEP1 suppresses root growth while also promoting root hair formation. However, the question of whether and how these elicitor peptides affect the development of the vascular system in the root has not been explored. The cellular receptors of PEP1, PEPR1 and PEPR2 are highly expressed in the root vascular system, while the receptors of flg22 (FLS2) and elf18 (EFR) are not. Consistent with the expression patterns of PEP1 receptors, we found that exogenously applied PEP1 has a strong impact on the division of stele cells, leading to a reduction of these cells. We also observed the alteration in the number and organization of cells that differentiate into xylem vessels. These PEP1-mediated developmental changes appear to be linked to the blockage of symplastic connections triggered by PEP1. PEP1 dramatically disrupts the symplastic movement of free green fluorescence protein (GFP) from phloem sieve elements to neighboring cells in the root meristem, leading to the deposition of a high level of callose between cells. Taken together, our first survey of PEP1-mediated vascular tissue development provides new insights into the PEP1 function as a regulator of cellular reprogramming in the Arabidopsis root vascular system.

• 전자통신동향분석
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• 제30권3호
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• pp.64-73
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• 2015

최근 위성통신은 물리계층의 고속 모뎀, 링크 계층에서의 고효율 패킷처리 기술 등의 발달로 양방향 광대역 멀티미디어 통신 서비스를 제공할 수 있는 기반을 마련하였다. 그러나 긴 전송 지연시간과 유선망에 비해 여전히 높은 패킷 손실률을 갖는 위성링크 고유의 특징은 현재 통신을 위해 가장 많이 사용하는 전송계층 프로토콜인 TCP(Transmission Control Protocol)를 여전히 위성망에서 제대로 동작시키기 어렵게 만들고 있다. 이에 본고에서는 위성망에서 TCP가 갖는 문제점을 해결하기 위해 도입된 PEP(Performance Enhancing Proxy) 기술에 대해서 관련 표준문서에서부터, 다양한 PEP 구성형태, 그리고 응용계층, 전송계층, 네트워크 계층에 따라 각각 적용된 PEP 주요 기술들을 살펴보고, 더불어 해외의 주요 PEP 제품들의 특징들을 분석함으로써 PEP 관련 전반적인 기술동향을 살펴보고자 한다.

• 정보와 통신
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• 제32권10호
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• pp.11-17
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• 2015

네트워크 중심전에서 위성통신체계에 대한 중요성은 증가하고 있고, 차기 위성 통신 체계의 요구사항들을 만족하기 위해서는 PEP (Performance Enhancing Proxy) 기술의 적용이 필수적이다. 본 고에서는 차기 군 위성 통신 체계에서 적용 가능한 PEP 주요기술들과 상용 제품들의 특성을 알아보고, cross-layer 기반 PEP기술과 SOTM (Satellite communication On-The-Move) 단말을 위한 PEP 기술 동향에 대해서 살펴본다.