• Journal of Microbiology and Biotechnology
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• 제23권12호
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• pp.1791-1801
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• 2013

Diketopiperazine is produced by various organisms, including bacteria, fungi, and animals, and has been suggested as a novel signal molecule involved in the modulation of genes with various biological functions. Vibrio vulnificus, which causes septicemia in humans, produces cyclo($\small{L}$-phenylalanine-$\small{L}$-proline) (cFP). To understand the biological roles of cFP, the effect of the compound on the expression of the total mRNA in V. vulnificus was assessed by next-generation sequencing. Based on the transcriptomic analysis, we classified the cFP-regulated genes into functional categories and clustered them according to the expression patterns resulted from treatment with cFP. From a total of 4,673 genes, excepting the genes encoding tRNA in V. vulnificus, 356 genes were up-regulated and 602 genes were down-regulated with an RPKM (reads per kilobase per million) value above 3. The genes most highly induced by cFP comprised those associated with the transport and metabolism of inorganic molecules, particularly iron. The genes negatively regulated by cFP included those associated with energy production and conversion, as well as carbohydrate metabolism. Noticeably, numerous genes related with biofilm formation were modulated by cFP. We demonstrated that cFP interferes significantly with the biofilm formation of V. vulnificus.

• 센서학회지
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• 제21권1호
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• pp.59-67
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• 2012

It was reported that the latest sensor technology allow an 65536 conductive polymer sensor array to be made with broad but overlapping selectivity to different families of chemicals emulating the characteristics found in biological olfaction. However, the supernumerary redundancy always accompanies great error and risk as well as an inordinate amount of computation time and local minima in signal processing, e.g. neural networks. In this paper, we propose a new method to reduce the number of sensor for analysis by reducing redundancy between sensors and by removing unstable sensors using the cosine similarity method and to decide on representative sensor using FCM(Fuzzy C-Means) algorithm. The representative sensors can be just used in analyzing. And, we introduce DWT(Discrete Wavelet Transform) for data compression in the time domain as preprocessing. Throughout experimental trials, we have done a comparative analysis between gas sensor data with and without reduced redundancy. The possibility and superiority of the proposed methods are confirmed through experiments.

• Journal of Applied Biological Chemistry
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• 제63권2호
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• pp.137-145
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• 2020

Oxidative stress is one of the pathogenic mechanisms of various neurodegenerative diseases, such as Alzheimer's disease. Neuroglia, the most abundant cells in the brain, is thought to play an important role in the antioxidant defense system and neuronal metabolic support against neurotoxicity and oxidative stress. We investigated the protective effect of paeoniflorin (PF) against oxidative stress in C6 glial cells. Exposure of C6 glial cells to hydrogen peroxide (H₂O₂, 500 μM) significantly decreased cell viability and increased amounts of lactate dehydrogenase (LDH) release, indicating H₂O₂-induced cellular damage. However, treatment with PF significantly attenuated H₂O₂-induced cell death as shown by increased cell survival and decreased LDH release. The H₂O₂-stimulated reactive oxygen species production was also suppressed, and it may be associated with improvement of superoxide dismutase activity by treatment with PF. In addition, an increase in ratio of Bcl-2/Bax protein expression was observed after treatment with PF. In particular, the down-stream of the apoptotic signaling pathway was inhibited in the presence of PF, mostly by reduction of cleaved-poly ADP ribose polymerase, cleaved caspase-3, and -9 protein expression. Furthermore, H₂O₂-induced phosphorylation of c-Jun N-terminal kinase and extracellular signal-regulated kinase 1/2 was attenuated by treatment with PF. Taken together, neuroprotective effect of PF against oxidative stress probably result from the regulation of apoptotic pathway in C6 glial cells. In conclusion, our findings suggest that PF may be a potent therapeutic agent for neurodegenerative disorders.

• Biomolecules & Therapeutics
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• 제22권3호
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• pp.193-199
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• 2014

The aim of this study was to determine whether britanin, isolated from the flowers of Inula japonica (Inulae Flos), modulates the generation of allergic inflammatory mediators in activated mast cells. To understand the biological activity of britanin, the authors investigated its effects on the generation of prostaglandin $D_2$ ($PGD_2$), leukotriene $C_4$ ($LTC_4$), and degranulation in IgE/Ag-induced bone marrow-derived mast cells (BMMCs). Britanin dose dependently inhibited degranulation and the generations of $PGD_2$ and $LTC_4$ in BMMCs. Biochemical analyses of IgE/Ag-mediated signaling pathways demonstrated that britanin suppressed the phosphorylation of Syk kinase and multiple downstream signaling processes, including phospholipase $C{\gamma}1$ ($PLC{\gamma}1$)-mediated calcium influx, the activation of mitogen-activated protein kinases (MAPKs; extracellular signal-regulated kinase 1/2, c-Jun $NH_2$-terminal kinase and p38), and the nuclear factor-${\kappa}B$ ($NF-{\kappa}B$) pathway. Taken together, the findings of this study suggest britanin suppresses degranulation and eicosanoid generation by inhibiting the Syk-dependent pathway and britanin might be useful for the treatment of allergic inflammatory diseases.

• 대한의용생체공학회:의공학회지
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• 제23권1호
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• pp.33-38
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• 2002

심실보조장치(ventricular assist device, VAD)는 그 특성상 손상된 자연심장의 기능을 보조하기 위해서 사용된다. 따라서, 심실보조장치의 제어 알고리즘을 고려할 때에는 가능한 한 자연심장에 걸리는 부하를 최소한으로 줄여주는 것이 중요하다. 이처럼 자연심장에 걸리는 부하를 줄여주기 위해 가장 일반적으로 사용되는 제어 방식이 바로 자연심장과 심실보조장치 상호간의 동시 박출을 방지하는 counterpulsation 제어 방식이다. 실제로 Nanas[1][2] 등은 동물실험을 통해 좌심실이 손상된 상황에서 counterpulsation 장cl가 혈류역학적으로 어떠한 영향을 미치는가를 연구하였다 본 연구에서는, 현재 서울대학교 인공심장연구실과 (주)바이오메드랩에서 공동으로 개발 중인 이동작동기형 심실보조장치 (AnyHeart/ sup TM/)에 사용할 수 있는 counterpulsation 제어 알고리즘을 개발하고. 개발된 알고리즘을 실제 동물 실험에 적용하기에 앞서 모의순환장치를 이용하여 개발된 알고리즘의 효용성을 검증하여 보았다. 자연심장의 박출 상태를 실시간으로 파악하기 위해 심전도(electrocardiogram, ECG) 신호를 입력으로 받아들여 제어를 수행하는 방식을 채택하였으며, 모의순환장치에서의 실험 결과 심실보조장치와 자연심장 간의 동시 박출 방지 효과가 정상적으로 일어남을 확인할 수 있었다.

• Journal of Life Science
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• 제11권2호
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• pp.103-107
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• 2001

The equine chorionic gonadotropin (eCG) subunits $\alpha$ and ${\beta}$ are transcribed from different genes and associate noncovalently to form the bioactive eCG heterodimer. Dimerization is rate limiting for eCG secretion, and dissociation leads to hormone inactivation. The correct conformation of the heterodimer is alto important for efficient secretion, hormone-specific post-translational modifications, receptor binding and signal transduction. To determine whether ${\alpha}$ and ${\beta}$ subunits can be synthesized as a single polypeptide chain (tethered-eCG) and also display biological activity, the tethered-eCG molecule by fusing the carboxyl terminus of the eCG ${\beta}$-subunit to the amino terminus of the af-subunit was construe-ted and transfected into chinese hamster ovary (CHO-Kl) cells. LH- and FSH-like activities were assayed in terms of testosterone production and aromatase activity in primary cultured rat Leydig cells and granulosa cells, respectively. The tethered-eCG was efficiently secreted and showed similar LH-like activity to the dimeric eCG ${\alpha}$/${\beta}$ and native eCG. FSH-like activity of the tethered-eCG was also shown similarly in comparison with the native and wild type eCG ${\alpha}$/${\beta}$. Our data for the first time suggest that the tethered-eCG can be expressed efficiently and the produced product by the CHO-K1 cells is fully LH- and FSH-like activities in rat in vitro bioassay system. Our results also suggest that this molecular can imply particular models of FSH-like activity not LH-like activity in the eCG. Taken together, these data indicate that the constructs of tethered molecule will be useful in the study of mutants that affect subunit association and/or secretion.

• KSBB Journal
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• 제20권2호
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• pp.88-92
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• 2005

인산화 과정은 serine, threonine, tyrosine에서 발생하는 생화학적 반응으로, 본 연구에서는 다양한 응용의 잠재능력이 있는 phosphoserine, phosphothreonine, phosphotyrosine에 대한 엡타머를 개발하였다. 우선 in vitro selection 방법에 의해 combinatorial chemistry로부터 얻어진 RNA library로부터 이들 phosphoamino acids와 친화도를 가지고 있는 엡타머를 찾아낼 수 있었다. 총 10번의 일련 과정을 통해 phosphoserine에 대해서 2.6 nM의 친화도를 가지고 있는 엡타머를 (SeA-06), phosphothreonine에 대해서는 2.7nM의 친화도를 가지고 있는 엡타머 (TrA-18)를 찾아낼 수 있었고, 이들의 RNA 2차 구조를 각각 예측하여 보았다. 그러나 phosphotyrosine의 경우 짧은 길이의 엡타머가 selection됨으로 내부적으로 구조를 가지는 엡타머는 얻을 수 없었다. o-phosphoserine에 대한 항체가 기존에 보고가 되었으나 유사한 구조를 지닌 o-phosphothreonine에도 비슷한 활성을 보여 이들을 구분할 수 있는 리간드를 찾기 힘들었으나, 본 연구에서는 엡타머를 사용한 특이성 조사에서도 서로를 극명하게 구별할 수 있음을 확인할 수 있었다. 이와 같이 발굴된 엡타머를 사용하여 biochip이나 Proteomics 분석 도구의 응용에 큰 기대효과를 제공할 수 있을 것이라 사료된다.

• Journal of Microbiology and Biotechnology
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• 제20권12호
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• pp.1653-1663
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• 2010

The first gene (${\alpha}$-gal1) encoding an extracellular ${\alpha}$-Dgalactosidase from the thermophilic fungus Talaromyces emersonii was cloned and characterized. The ${\alpha}$-gal1 gene consisted of an open reading frame of 1,792 base pairs interrupted by six introns that encoded a mature protein of 452 amino acids, including a 24 amino acid secretory signal sequence. The translated protein had highest identity with other fungal ${\alpha}$-galactosidases belonging to glycosyl hydrolase family 27. The ${\alpha}$-gal1 gene was overexpressed as a secretory protein with an N-terminal histidine tag in the methylotrophic yeast Pichia pastoris. Recombinant ${\alpha}$-Gal1 was secreted into the culture medium as a monomeric glycoprotein with a maximal yield of 10.75 mg/l and purified to homogeneity using Hisbinding nickel-agarose affinity chromatography. The purified enzyme was maximally active at $70^{\circ}C$, pH 4.5, and lost no activity over 10 days at $50^{\circ}C$. ${\alpha}$-Gal1 followed Michaelis-Menten kinetics ($V_{max}\;of\;240.3{\mu}M/min/mg,\;K_m\;of\;0.294 mM$) and was inhibited competitively by galactose ($K_m{^{obs}}$ of 0.57 mM, $K_i$ of 2.77 mM). The recombinant T. emersonii ${\alpha}$-galactosidase displayed broad substrate preference, being active on both oligo- and polymeric substrates, yet had strict specificity for the ${\alpha}$-galactosidic linkage. Owing to its substrate preference and noteworthy stability, ${\alpha}$-Gal1 is of particular interest for possible biotechnological applications involving the processing of plant materials.

• 한국응용곤충학회지
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• 제44권4호
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• pp.341-344
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• 2005

실험실 조건에서 고구마 뒷날개흰밤나방의 교미 전 행동습성을 관찰하였다. 짝이 있고 어두운 상태에서 안테나를 치켜세우고 날개를 진동하는 습성을 보였으며, 암컷과 수컷 모두 날개를 진동하고 안테나를 치켜세우는 행동을 보이다가 수컷이 암컷에게로 날아가는 습성을 보였다. 불이 꺼진상태로 20여분이 지나면 안테나를 치켜세우는 반응을 보이기 시작하였으며 40분이 지났을 때부터 마치 짝을 유인하는 음향을 생성하듯이 날개를 빠르게 진동하는 반응을 보였다. 짝짓기는 우화 후 이튿날부터 관찰되었으며 대부분 4일에서 6일 사이에 짝짓기를 하였다. 짝짓기는 평균 207분 동안 지속되었고, 대부분 3회까지 반복적으로 교미를 하였다. 관찰결과를 종합적으로 분석해보면 암컷이 신호를 보내고 수컷이 이에 반응하는 것으로 보이며, 암컷이 내는 음향이 뒷날개흰밤나방의 교미전 행동습성에 관련되어 있을 가능성이 높은 것으로 판단되었다.

• Journal of Ginseng Research
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• 제44권1호
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• pp.123-134
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• 2020

Background: The lepidopteran Asiatic corn borer (ACB), Ostrinia furnacalis (Guenee), has caused huge economic losses throughout the Asian-Western Pacific region. Usually, chemical pesticides are used for the control, but excessive use of pesticides has caused great harm. Therefore, the inartificial ecotypic pesticides to ACB are extremely essential. In our previous study, we found that panaxadiol saponins (PDS) can effectively reduce the harm of ACB by causing antifeedant activity. Therefore, it is necessary to reveal the biological molecular changes in ACB and the functionary mechanism of PDS. Methods: We analyzed the global transcription of ACB with different PDS concentration treatment (5 mg/mL, 10 mg/mL, and 25 mg/mL) by high-throughput sequencing and de novo transcriptome assembly method. Results: PDS treatment could cause the changes of many gene expressions which regulate its signal pathways. The genes in peroxisome proliferator-activated receptor (PPAR) signaling pathway were significantly downregulated, and then, the downstream fatty acid degradation pathway had also been greatly affected. Conclusion: Through this experiment, we hypothesized that the occurrence of antifeedant action of ACB is because the PDS brought about the downregulation of FATP and FABP, the key regulators in the PPAR, and the downregulation of FATP and FABP exerts further effects on the expression of SCD-1, ACBP, LPL, SCP-X, and ACO, which leads to the disorder of PPAR signaling pathway and the fatty acid degradation pathway. Not only that, PDS treatment leads to enzyme activity decrease by inhibiting the expression of genes associated with catalytic activity, such as cytochrome P450 and other similar genes.