• 한국자원식물학회:학술대회논문집
• /
• 한국자원식물학회 2020년도 추계국제학술대회
• /
• pp.3-13
• /
• 2020

Pseudomonas aeruginosa is a ubiquitous gram-negative bacterium causing serious infections. The P. aeruginosa T3SS is a syringe-like apparatus on the bacterial surface, with 4 effector toxins: ExoS, ExoT, ExoY, and ExoU. Here, we investigated the effect of ExoS and ExoT of the T3SS of P. aeruginosa K strain (PAK). The type three secretion system (T3SS) is a major virulence system of Pseudomonas aeruginosa (P. aeruginosa). The effector protein Exotoxin S (ExoS) produced by P. aeruginosa is secreted into the host cells via the T3SS. For the purpose of screening the inhibitors with regard to ExoS secretion, we developed the sandwich-type enzyme-linked immunosorbent assay (ELISA) system. PAK clinical strains induce proinflammatory cytokine production through the T3SS, and this involves NF-κB activation in pneumonia mouse models. We tried to confirm the role of the NF-κB transcription factor in ExoS- and ExoT-induced pneumonia mouse models. pro-inflammatory cytokines induction in response to ExoS and ExoT infection relied on NF-κB activation. Our findings highlight the roles of natural poduct in inhibiting proinflammatory cytokine expression during ExoS and ExoT exposure in PAK infections, paving the way for a novel therapeutic approach for the treatment of pulmonary infections.

• 한국구조물진단유지관리공학회 논문집
• /
• 제19권5호
• /
• pp.38-44
• /
• 2015

본 논문에서는 효과적인 제진설계를 구현하기 위한 설계기술 개발의 일환으로 최근 제안된 Exo-type 감쇠시스템을 활용하여 15층과 20층의 연구 대상 건물을 대상으로 감쇠시스템의 최적 강성비와 적용된 감쇠장치의 최적 항복비에 따른 철근콘크리트 라멘조 건물의 제진 효과를 검토해 보았다. 해석결과, Exo-type 감쇠시스템을 3개층 적용 시에는 대상 건물 15층과 20층 모두 밑면전단력과 최상층 최대응답변위 감소라는 관점에서 유효한 제진효과를 얻기 위해서는 Exo-type 감쇠시스템과 대상 건물의 강성비는 7.0 이상 확보를 하여야 하며, 감쇠시스템에 적용된 감쇠장치의 항복비는 대상 건물의 층전단력의 약 8.0% 이상 확보할 필요가 있는 것으로 나타났다. 또한, Exo-type 감쇠시스템을 5개 층 적용 시에는 대상 건물 15층과 20층 모두 Exo-type 감쇠시스템과 대상 건물의 강성비는 2.5 이상 확보 하여야 하며, 감쇠시스템에 적용된 감쇠장치의 대상 건물의 층전단력의 약 3.5%이상 확보할 필요가 있는 것으로 나타났다.

• 한국식품영양학회지
• /
• 제30권6호
• /
• pp.1359-1363
• /
• 2017

The purpose of this study was that the optimal hydrolysis conditions of endo- and exo-type enzymes were selected to utilize organic cheese byproducts. Optimal substrate concentration and optimum enzyme ratio were measured by using 4 kinds of endo-type enzymes (alcalase, neutrase, protamex, and foodpro alkaline protease) and two exo-type enzymes (flavourzyme and prozyme 2000P) for whey protein hydrolysis were analyzed using liquid chromatography. As a result, the optimal endo-type enzyme through the first enzyme reaction was selected as alcalse, and as a result of the secondary enzyme reaction, flavourzme was selected as the Exo type enzyme. The concentration of whey protein substrate for optimal primary and secondary enzyme reactions was 10%. In addition, the optimum ratio of enzyme was 0.5% of alcalase and 0.2% of flavourzyme, which showed low molecular weight chromatography pattern compared to 2% of alcalase and 1% of flavourzyme hydrolyzate. Therefore, hydrolyzing the endo-type enzyme alcalase at a concentration of 0.5% for 10 hours and then hydrolyzing the exo-type enzyme flavouryme at a concentration of 0.2% for 4 hours was considered to be the optimum condition.

• 한국추진공학회:학술대회논문집
• /
• 한국추진공학회 2010년도 제35회 추계학술대회논문집
• /
• pp.294-299
• /
• 2010

본 연구의 목적은 열안정성을 향상시키는 첨가제 (열안정제)를 이용하여 exo-tetrahydrodicyclopentadiene (exo-THDCP, $C_{10}H_{16}$)의 열안정성을 향상시키는 것이다. 실험은 반응 진행 중 미량의 시료 추출이 가능한 회분식 반응기에서 수행되었다. 추출한 시료를 gas chromatography-mass spectrometry (GC-MS)를 이용해 성분 분석하여 첨가제 성능-exo-THDCP의 열분해성-을 확인하고, 반응시간에 따른 exo-THDCP의 분해생성물의 성분 및 조성 변화를 통해 첨가제의 작용 메커니즘을 규명하였다. 열안정제로써 수소공여체를 사용하여 실험한 결과 1,2,3,4-tetrahydroquinoline (THQ), benzyl alcohol (BnOH) 등을 첨가하였을 때 exo-THDCP의 열안정성이 향상되었다. 이러한 수소공여체 물질들은 개시반응이 진행된 exo-THDCP 라디칼에 수소원자 (hydrogen radical)를 제공함으로 라디칼의 반응성을 완화시켜 1차 생성물의 활성을 감소시키어 2차생성물질인 $C_{11}$ 이상 생성물의 발생을 감소시키는 것으로 밝혀졌다.

• 한국균학회지
• /
• 제21권2호
• /
• pp.106-111
• /
• 1993

사과 겹무늬썩음병균 Botryosphaeria dothidea에 의해 부패된 사과과실에서 pectin질 분해효소를 추출하여 그들의 활성과 pectin 성분의 변화를 조사하였다. 본 병원균은 exo-polygalacturonase(exo-PG), exo-polymethylgalacturonase(exo-PMG), polygalacturonate-trans -e1iminase(PGTE)와 pectinmethyl-trans-eliminase(PMTE)를 생산하였다. 부패된 사과 과육에서 exo-PG와 exo-PMG는 접종 후 7일째 specific activity가 각각 21.15 및 24.65 units/mg protein으로 높게 나타났다. PGTE와 PMTE의 활성은 7일째 각각 5.60과 7.90 uints/mg protein으로 나타났으나 exo-type의 효소보다는 그 활성이 낮았다. 수용성 pectin은 부패가 진행됨에 따라 14일째에 11.50 mg/100 mg-AIS이었고, versene-soluble pectin 역시 7.31 mg/100 mg-AIS로 나타나 건전과와 비교하여 각각 4.23 및 2.16 mg/100 mg-AIS 증가하였다. 부패과의 총 가용성 펙틴 함량은 총 pectin의 72.4%로서 건전과와 비교하여 24.8% 더 높았다. 불용성 pectin 함량은 부패가 진행됨에 따라 15.32 mg/100 mg-AIS에서 7.16 mg/100 mg-AIS로 현저하게 감소하였으며, 총 pectin 함량은 큰 변화가 없었다.

• Journal of Microbiology and Biotechnology
• /
• 제33권4호
• /
• pp.430-440
• /
• 2023

The type three secretion system (T3SS) is a major virulence system of Pseudomonas aeruginosa (P. aeruginosa). The effector protein Exotoxin S (ExoS) produced by P. aeruginosa is secreted into the host cells via the T3SS. For the purpose of an experiment on inhibitors with regard to ExoS secretion, we developed a sandwich-type enzyme-linked immunosorbent assay (ELISA) system. Quercetin was selected because it has a prominent ExoS inhibition effect and also is known to have anti-inflammatory and antioxidant effects on mammalian cells. In this study, we investigated the effects of quercetin on the expression and secretion of ExoS using ELISA and Western blot analysis methods. The results showed that the secretion of ExoS was significantly decreased by 10 and 20 µM of quercetin. Also, popB, popD, pscF, and pcrV which are composed of the T3SS needle, are reduced by quercetin at the mRNA level. We also confirmed the inhibitory effect of quercetin on cytokines (IL-6, IL-1β, and IL-18) in P. aeruginosa-infected H292 cells by real-time polymerase chain reaction (PCR) and ELISA. Collectively, quercetin inhibits the secretion of ExoS by reducing both ExoS production and the expression of the needle protein of T3SS. Furthermore, these results suggest that quercetin has the potential to be used as an anti-toxic treatment for the inflammatory disease caused by P. aeruginosa infection.

• Asian Pacific Journal of Cancer Prevention
• /
• 제15권6호
• /
• pp.2571-2576
• /
• 2014

Background: Published studies on the association between the exonuclease 1 (EXO1) Glu589Lys polymorphism and cancer susceptibility have yielded conflicting results. Thus, a meta-analysis of published studies was performed to assess the possible association. Materials and Methods: All eligible case-control studies published up to January 2013 on the association between the EXO1 Glu589Lys polymorphism and cancer susceptibility were identified by searching PubMed, Web of Science, Science Direct and hand search. Either fixed-effect or random-effect models were used to calculate pooled odds ratios (ORs) with 95% confidence intervals (CIs) using the Comprehensive Meta-Analysis software version 2.2. Results: A total of 4,391 cancer cases and 4,339 controls from 10 studies were included. Overall, no significant association between the EXO1 Glu589Lys polymorphism and cancer susceptibility was observed in either genetic model. However; in subgroup analyses by cancer type, a significant association between EXO1 Glu589Lys and lung cancer risk was found (Lys vs Glu: OR=1.23, 95%CI=1.07-1.41, $p_{heterogeneity}$=0.05). Further, subgroup analysis by ethnicity indicated that there was a statistically increased cancer risk in Asians (Lys vs Glu: OR=1.42, 95%CI=1.30-1.55, $p_{heterogeneity}$=0.07; Lys/Lys vs Glu/Glu: OR=1.93, 95%CI=1.20-3.12, $p_{heterogeneity}$=0.01; Lys/Lys+Glu/Lys vs Glu/Glu: OR=1.52, 95%CI=1.37-1.68, $p_{heterogeneity}$=0.42; Lys/Lys vs Glu/Lys+Glu/Glu: OR=1.68, 95%CI=1.07-2.65, $p_{heterogeneity}$=0.02). However, significant association was absent in Caucasians. Conclusions: This meta-analysis suggests, for the first time, that the EXO1 Glu589Lys polymorphism is not associated with overall cancer susceptibility, although marginal associations were found for lung cancer and Asian subgroups. Additional well-designed studies with larger sample size focusing on different ethnicities and cancer types are needed to confirm these findings.

• 한국식품영양과학회지
• /
• 제22권3호
• /
• pp.340-348
• /
• 1993

Penicillium funiculosum과 Trichoderma viride cellulase의 정제효소들을 사용하여 cross-synergism을 조사하였다. Exo-exo형 상승작용이 Avicel을 분해하는데 가장 효과적이었으며 exo-endo형은 다소 효과가 떨어졌다. 정제효소성분과 이종의 조효소를 혼합하여 70시간 이상 Avicel을 가수분해하며 생성된 total sugar를 측정한 결과, P. funiculosum cellulase에서 분리정제한 $\beta$-glucosidase 성분효소는 T. viride cellulase와 상승작용을 크게 나타내며 Avicel을 가수분해하였다. 또한, T. viride cellulase에서 분리정제한 exoglucanase 성분효소도 P. funiculosum cellulase의 가수분해능을 크게 향상시켰다. 이와같은 결과로 미루어 볼 때, 이종의 cellulase로 부터 부족한 성분효소를 보충시켜 효소성분비율을 변화시킴으로써 Avicel의 가수분해도를 향상시킬 수 있을 것으로 사료된다. 이 때 최대한 높은 가수분해를 얻기 위하여 여러 형식의 상승작용이 같이 이루어져야할 것이다.

• 한국미생물·생명공학회지
• /
• 제20권1호
• /
• pp.14-19
• /
• 1992

부패한 나무, 퇴비, 제지공장의 폐지 및 폐수 등으로부터 분리한 300여 종류의 섬유소 분해균 중 xylanase 활성이 다른 균주에 비해 비교적 높았던 33번 균주를 균의 형태학적, 생화학적 특성과, 균체 지방산 조성에 의하여 Pseudomonas sp.로 동정하였다. Xylanase 활성의 최적 온도외 최적 pH는 각각 $50^{\circ}C$와 5.5이었고, 효소의 안정성은 $45^{\circ}C$ 이하의 온도와 pH 5.0에서 7.0 사이에서 유지되었다. 이 균주가 생산하는 xylanase는 효소반응분해물의 paper chromatography에 의하여 주로 exo-type의 xylanase임이 밝혀졌다.

• Applied Microscopy
• /
• 제51권
• /
• pp.2.1-2.7
• /
• 2021

Synaptic vesicles, which are endogenous to neurotransmitters, are involved in exocytosis by active potentials and release neurotransmitters. Synaptic vesicles used in neurotransmitter release are reused via endocytosis to maintain a pool of synaptic vesicles. Synaptic vesicles show different types of exo- and endocytosis depending on animal species, type of nerve cell, and electrical activity. To accurately understand the dynamics of synaptic vesicles, direct observation of synaptic vesicles is required; however, it was difficult to observe synaptic vesicles of size 40-50 nm in living neurons. The exo-and endocytosis of synaptic vesicles was confirmed by labeling the vesicles with a fluorescent agent and measuring the changes in fluorescence intensity. To date, various methods of labeling synaptic vesicles have been proposed, and each method has its own characteristics, strength, and drawbacks. In this study, we introduce methods that can measure presynaptic activity and describe the characteristics of each technique.