• 제목/요약/키워드: ligand screening

검색결과 64건 처리시간 0.023초

C형 간염바이러스(HCV)의 NS5B RNA Replicase에 의해 그 활성이 조절되는 HCV지놈 표적 Hammerhead 리보자임 개발 (Development of Hepatitis C Virus (HCV) Genome-Targeting Hammerhead Ribozyme Which Activity Can Be Allosterically Regulated by HCV NS5B RNA Replicase)

  • 이창호;이성욱
    • 미생물학회지
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    • 제43권3호
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    • pp.159-165
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    • 2007
  • C형 간염바이러스(hepatitis C virus; HCV)증식을 효과적이며 특이적으로 제어할 수 있는 유전산물을 개발하기 위하여 HCV 중식조절이자인 NS5B RNA replicase 존재에 의해 allosteric하게 그 활성 이 조절될 수 있는 HCV internal ribosome entry site (IRES) 표적 hammerhead 리보자임을 개발하였다. 우선 HCV IRES 염기서열 중+382 nucleotide(nt) 부위가 리보자임에 의해 가장 잘 인식되었음을 관찰하였다. 이러한 allosteric 리보자임은 NS5B RNA replicase와 특이적으로 결합하는 RNA aptamer 부위, aptamer와 NS5B와의 결합에 의해 리보자임 활성을 유도할 수 있도록 구조적 변이를 전달할 수 있는 communication module부위 및 HCV IRES의 +382 nt를 인지하는 hammerhead 리보자임 등으로 구성되도록 설계하였다. 특히 in vitro selection기법을 활용하여 NS5B 의존적으로 리보자임 활성을 증가시킬 수 있는 communication module 염기서열을 밝혀내었다. 이러한 리보자임은 단백질이 없거나 대조 단백질인 bovine serum albumin이 존재할 때에는 절단반응을 유도하지 못하였으나 HCV NS5B 단백질이 존재할 매에만 효과적으로 NS5B 농도 의존적으로 절단 반응을 유도할 수 있음을 관찰하였다. 이러한 allosteric 리보자임은 HCV중식의 효과적인 증식 억제 선도물질 뿐만 아니라 HCV 치료선도물질의 스크리닝용 도구 및 HCV 조절 인자를 탐색할 수 있는 HCV 진단용 리간드로서도 활용될 수 있을 것이다.

Effects of gintonin on the proliferation, migration, and tube formation of human umbilical-vein endothelial cells: involvement of lysophosphatidic-acid receptors and vascular-endothelial-growth-factor signaling

  • Hwang, Sung-Hee;Lee, Byung-Hwan;Choi, Sun-Hye;Kim, Hyeon-Joong;Won, Kyung Jong;Lee, Hwan Myung;Rhim, Hyewon;Kim, Hyoung-Chun;Nah, Seung-Yeol
    • Journal of Ginseng Research
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    • 제40권4호
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    • pp.325-333
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    • 2016
  • Background: Ginseng extracts are known to have angiogenic effects. However, to date, only limited information is available on the molecular mechanism underlying the angiogenic effects and the main components of ginseng that exert these effects. Human umbilical-vein endothelial cells (HUVECs) are used as an in vitro model for screening therapeutic agents that promote angiogenesis and wound healing. We recently isolated gintonin, a novel ginseng-derived lysophosphatidic acid (LPA) receptor ligand, from ginseng. LPA plays a key role in angiogenesis and wound healing. Methods: In the present study, we investigated the in vitro effects of gintonin on proliferation, migration, and tube formation of HUVECs, which express endogenous LPA1/3 receptors. Results: Gintonin stimulated proliferation and migration of HUVECs. The LPA1/3 receptor antagonist, Ki16425, short interfering RNA against LPA1 or LPA3 receptor, and the Rho kinase inhibitor, Y-27632, significantly decreased the gintonin-induced proliferation, migration, and tube formation of HUVECs, which indicates the involvement of LPA receptors and Rho kinase activation. Further, gintonin increased the release of vascular endothelial growth factors from HUVECs. The cyclooxygenase-2 inhibitor NS-398, nuclear factor kappa B inhibitor BAY11-7085, and c-Jun N-terminal kinase inhibitor SP600125 blocked the gintonin-induced migration, which shows the involvement of cyclooxygenase-2, nuclear factor kappa B, and c-Jun N-terminal kinase signaling. Conclusion: The gintonin-mediated proliferation, migration, and vascular-endothelial-growth-factor release in HUVECs via LPA-receptor activation may be one of in vitro mechanisms underlying ginsenginduced angiogenic and wound-healing effects.

Integration of virtual screening and proteomics reveals potential targets and pathways for ginsenoside Rg1 against myocardial ischemia

  • Rongfang Xie;Chenlu Li;Chenhui Zhong;Zuan Lin;Shaoguang Li;Bing Chen;Youjia Wu;Fen Hu;Peiying Shi;Hong Yao
    • Journal of Ginseng Research
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    • 제48권4호
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    • pp.395-404
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    • 2024
  • Background: Ginsenoside Rg1 (Rg1) is one of the main active components in Chinese medicines, Panax ginseng and Panax notoginseng. Research has shown that Rg1 has a protective effect on the cardiovascular system, including anti-myocardial ischemia-reperfusion injury, anti-apoptosis, and promotion of myocardial angiogenesis, suggesting it a potential cardiovascular agent. However, the protective mechanism involved is still not fully understood. Methods: Based on network pharmacology, ligand-based protein docking, proteomics, Western blot, protein recombination and spectroscopic analysis (UV-Vis and fluorescence spectra) techniques, potential targets and pathways for Rg1 against myocardial ischemia (MI) were screened and explored. Results: An important target set containing 19 proteins was constructed. Two target proteins with more favorable binding activity for Rg1 against MI were further identified by molecular docking, including mitogen-activated protein kinase 1 (MAPK1) and adenosine kinase (ADK). Meanwhile, Rg1 intervention on H9c2 cells injured by H2O2 showed an inhibitory oxidative phosphorylation (OXPHOS) pathway. The inhibition of Rg1 on MAPK1 and OXPHOS pathway was confirmed by Western blot assay. By protein recombination and spectroscopic analysis, the binding reaction between ADK and Rg1 was also evaluated. Conclusion: Rg1 can effectively alleviate cardiomyocytes oxidative stress injury via targeting MAPK1 and ADK, and inhibiting oxidative phosphorylation (OXPHOS) pathway. The present study provides scientific basis for the clinical application of the natural active ingredient, Rg1, and also gives rise to a methodological reference to the searching of action targets and pathways of other natural active ingredients.

Streptomyces longwoodensis로부터 Autoregulator Receptor Protein 유전자의 클로닝 및 특성 (Characterization and Cloning of the Gene Encoding Autoregulator Receptor Protein from Streptomyces longwoodensis)

  • 여수환;이성봉;김현수
    • 한국미생물·생명공학회지
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    • 제33권2호
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    • pp.96-105
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    • 2005
  • 공시균인 S. longwoodensis IFO 14251의 autoregulators 및 receptor gene 탐색의 일환으로 기존의 Streptomyces속 receptor gene의 공통배열을 primer로 이용하여 PCR을 수행하였다. 예상되는 100 bp 크기의 단편을 pUC19 vector에 ligation하여 E. coli $DH5{\alpha}$에 transformation한 후, plasmid를 분리하여 BamHI을 처리하여 $2\%$ agarose gel에 전기영동한 결과, pUC19 외에 receptor gene PCR product가 100 bp 위치에 존재하는 것을 확인하였다. 형질전환된 plasmid로 PCR을 수행한 후, 염기배열을 결정하여 분석한 결과, Streptomyces sp. 유래의 receptor gene의 일부분임이 확인되었다. 따라서 S. longwoodensis IFO 14251에는 lysocellin 생산에 관여한다고 추정되는 autoregulator receptor protein을 코드하는 유전자가 존재할 것으로 예상되어 100 bp의 PCR product를 probe로 이용하여 Southern 및 colony hybridization을 통하여 4.4 kb의 SphI 단편을 가지는 plasmid(pSLT)를 제작하였고 이를 sequencing한 결과, Streptomyces 속 유래의 autoregulator receptor 단백질을 코드하는 유전자와 3개의 open reading frame(651 bp)을 확인하여 sltR이라 명명하였다. 유전자 해석 결과, 기존의 autoregulator receptor proteins과 비교시 $35{\sim}46\%$의 homology를 나타내었다. 재조합 단백질의 발현을 위해, sltR/pET-l7b plasmid를 제작하고 E. coli BL21(DE3)/pLysS을 host cell로 이용하여 재조합 단백질을 발현시켰다. SltR 재조합 단백질의 정제는 DEAE-Sephacel column chromatography와 DEAE-5PW chromatography(HPLC)를 통해 수행하였다. Gel filtration chromatography(HPLC, 55 kDa)와 SDS-PAGE(28 kDa)를 통해 분자량을 확인한 결과, 재조합 단백질은 dimer형태로 존재하는 것으로 확인되었다. 또한, 결합활성에 있어 A-factor type의 autoregulator에 대해 가장 강한 결합활성을 나타내었다.