• 제목/요약/키워드: Protein-protein interactions

검색결과 781건 처리시간 0.034초

Ig G fusion 단백질을 사용한 리간드-수용체의 상호작용

  • 천혜경
    • 한국응용약물학회:학술대회논문집
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    • 한국응용약물학회 1994년도 제2회 추계심포지움
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    • pp.143-145
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    • 1994
  • Chimeric fusion proteins involving IgG have proven valuable in studying protein-protein interactions and may possess therapeutic applications as well. For example, three receptor subtypes for the natriuretic peptides, when fused to the Fc portion of human IgG ${\gamma}$ chain, were quantitatively and qualitatively indistinguishable from the native receptor, thus allowing detailed structure-function studies of the receptor. In an attempt to block human immunodeficiency virus infectivity with soluble derivatives of CD4, a CD4/IgG Fc chimeric molecule was shown to increase the plasma half life of soluble CD4 and possessed the added advantage of IgG Fc-mediated placental transfer. In the case of the KGFR, this approach provided a framework for dissection of its ligand binding domains and made it possible to demonstrate that high affinity binding sites for two ligands, aFGF and KGF, reside within different receptor Ig-like domains. Chimeric molecules fused to immunoglobulins would have the advantages of secretion from transfected cells as well as detection and purification from medium utilizing Staphylococcus aureus Protein A. In addition, where highly related receptors make their discrimination very hard due to the difficulties in generating specific immunochemical probes, IgG fusion protein with tailor-made specificities confers particular advantages to elucidate patterns of receptor distribution and expression. The approach described here may have general applications in defining ligand-receptor interactions as well as searching for specific agonists and antagonists of receptor function.

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P22-Based Challenge Phage Constructs to Study Protein-Protein Interactions between the $\sigma$$^{54}$-Dependent Promoter, dctA, and Its Transcriptional Regulators

  • Song, Jeong-Min;Kim, Eungbin;Lee, Joon H.
    • Journal of Microbiology
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    • 제40권3호
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    • pp.205-210
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    • 2002
  • To study interactions between $C_{4}$-dicarboxylic acid transport protein D and E$\sigma$$^{54}$ in the dctA promoter regulatory region, we used the challenge phage system. An ant'-`lac fusion was recombined onto the challenge phage, and this ant'-`lac fusion along with Pant and the R. meliloti dctA promoter regulatory region were cloned onto a plasmid. The plasmid bearing the ant'-`lac fusion was used as a reporter plasmid in a coupled transcription-translation system. Addition of purified $\sigma$$^{54}$ to the coupled system specifically repressed transcription of the plasmid-borne ant'-`lac fusion. When DCTD was added along with $\sigma$$^{54}$ to the coupled system, transcription of the ant'-`lac fusion was even further repressed, suggesting that DCTD may stabilize closed complexes between E$\sigma$$^{54}$ and the dctA promoter.

A Cell-based Method to Monitor the Interaction between Hepatitis B Virus Capsid and Surface Proteins

  • Kim, Yun-Kyoung;Oh, Soo-Jin;Jin, Bong-Suk;Park, Chan-Hoo;Jeon, Hye Sung;Boo, Doo-Wan;Yu, Yeon-Gyu
    • Bulletin of the Korean Chemical Society
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    • 제30권3호
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    • pp.577-581
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    • 2009
  • Interactions between the surface and capsid proteins of the hepatitis B virus (HBV) are critical for the assembly of virus particles. In this study, we developed a cell-based method to visualize the interactions between the capsid and surface proteins of HBV. Capsid-GFP, a capsid protein fused to a green fluorescence protein (GFP), forms nucleocapsid-like structures in the cytoplasm of mammalian cells. It relocates to the plasma membranes in cells expressing PH-PreS, a fusion protein consisting of the PreS region of the HBV surface protein and the PH domain of PLC-$\gamma$. Membrane localization of the capsid-GFP in these cells is prevented by an inhibitory peptide that blocks the interaction between the capsid and surface proteins. This dynamic localization of capsid-GFP is applicable for screening compounds that may potentially inhibit or prevent the assembly process of HBV particles.

Effects of Morphine and Panax ginseng on the Opioid Receptor-G protein Interactions

  • Kim, Young-Ran;Kim, Ae-young;Kim, Kyeong-Man
    • Biomolecules & Therapeutics
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    • 제7권1호
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    • pp.1-6
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    • 1999
  • Effects of Panax ginseng on the morphine toxicity were studied in relation to its effects on the opioid receptor-G protein interactions. Morphine treatments (3 days) reduced the body weight increment rate and the weight of the thymus and spleen. These changes were usually recovered by the concomitant administration of ginseng total saponin (GTS) but occasionally further deteriorated. This discrepancy was studied in relation to the opioid receptor coupling to G protein, that is, the effects of morphine and GTS on the opioid receptors were studied using the antagonist-agonist competitive binding studies. When GTS recovered the morphine toxicity, morphine shifted the striatal $\delta$ receptors to slightly higher affinity state, and this was partly recovered by the GTS treatment. However, morphine did not have any effect on the affinity state of $\delta$ receptor from NG108-15 cells, suggesting that additional factors were needed for the modulation of the affinity states of $\delta$ receptor. Effects of morphine and GTS on $\mu$ receptor were complicate and variable, and we could not reach a clear conclusion. The morphine toxicity might accompany complicate biological involvements, and the modulation of the affinity states of the opioid receptors might explain a part of the effects of GTS on the morphine toxicity.

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Tempeh 제조시 Phytic Acid 함량변화 및 그에 따른 단백질, 무기질과의 상호작용에 관한 연구 (The Changes of Phytic Acid Content and its Interactions with Protein and Minerals in the Preparation of Tempeh)

  • 박은순;윤선
    • Journal of Nutrition and Health
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    • 제16권4호
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    • pp.281-286
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    • 1983
  • 본 연구에서는 tempeh제조 과정중의 phytic acid함량 변화를 측정하였고 그에 따른 단백질, 무기질과의 상호작용을 조사하였다. 또한 한국인의 기호에 맞는 대두 발효식품의 소개를 목적으로 tenpeh의 수응도도 아울러 조사하였다. 이상의 실험결과를 요약하면 다음과 같다. 1 ) Tempeh제조시 회수율은 75.28 %였다. 2) 날콩, 삶은 콩, teulpeh의 총 인 함량은 $718.60{\sim}744.2mg%$로 각 시료간에는 유의적인 차이가 없었다. 그러나 phytic acid p 함량은 날콩에 539.38 mg%, 삶은 콩에 462.28 mg%, tempeh에 348.64 mg%로 열처리나 발효에 의해 phytic acid p 함량이 유의적으로 낮아짐을 보였고 열처리보다는 발효에 의해 phytic acid p가 유의적으로 감소됨을 나타냈다. 3 ) 총 단백질 함량은 날콩과 tenlpeh간에 유의적인 차이가 없었고 Ultrafiltration한 후 보유된 단백질 함량에는 약간의 차이가 있었으나 통계적 유의성은 없었다. 단백질 g당 phytic acid mg양을 산출한 결과 Ultrafiltration한 후 retentate내의 phytic acid/protein ratio는 날콩에서 14.66 , tempeh에서 7.80으로 유의적인 차이를 보였다. 4 ) Ca의 함량은 날콩과 tempeh에서는 유의적인 차이가 없으나 Ultrafiltration한 후 retentate의 Ca보유율은 tenlpeh에서 유의적으로 낮았다. Zn의 함량도 날콩과 tempeh에서 유의적인 차이가 없었고 Ultrafiltradon한 후 retentate 내 Zn보유율은 tempeh에서 유의적으로 낮았다. 5) 관능검사 결과는 마늘을 첨가한 것이 냄새, general desirability 및 전체적 점수에서 유의적으로 높게 평가되었다. 그러나 두 시료 모두 색깔, 외관, 풍미, 질감, 냄새 및 general desirability에서 3.31이상의 좋은 평가를 받았으므로 tempeh가 새로운 식품으로 소개될때 별 저항없이 받아들여질 것으로 사료된다.

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Surface Interactions of Model Peptides for Mussel Adhesive Protein

  • Cho, Eun-Kyung;Lee, Yoon-Hee;Cho, Nam-Jun;Cha, Hyung-Joon
    • 한국생물공학회:학술대회논문집
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    • 한국생물공학회 2003년도 생물공학의 동향(XIII)
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    • pp.630-633
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    • 2003
  • The mussel adhesive protein Mefp-1 is a natural, strong and durable adhesive that is stable under corrosive, saline conditions. Mefp-1 is found in the marine mussel Mytilus edulis and it has a molecular weight of ca. 130,000. The primary structure is mainly composed of repeating decapetides: Ala-Lys-Pro -Ser-Tyr Hyp-Hyp-Thr-DOPA-Lys. To elucidate the mechanism by which Mefp-1 bonds to metal surfaces, we have used surface-enhanced Raman spectroscopy to study the interactions of peptides related to the Mefp-1 decapeptide repeat with gold surfaces. We have concluded that the tyrosine residue and the carboxyl terminus interact strongly with the gold surface, and that proline and hydroxyproline constrain the conformations of the peptides, thereby limiting the types of possible interactions of the functional groups with the gold surface.

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Involvement of Electrostatic Interactions between the Components of Toluene Dioxygenase from Pseudomonas putida Fl

  • Lee, Kyoung
    • Journal of Microbiology and Biotechnology
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    • 제8권4호
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    • pp.416-421
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    • 1998
  • A carboxyl group modifier, l-ethyl-3-(3-dimethylaminopropyl)carbodiimide (EDC) was used to study the interactions between three components of toluene dioxygenase (TDO) from Pseudomonas putida FI. $Ferredoxin_{TOL}$ activity was increased by the treatment with EDC; however, the activity was rapidly declined in the prolonged incubation. In covalent cross-linking experiments with EDC, $Ferredoxin_{TOL}$ made a one-to-one complex with $Reductase_{TOL}$ or the large subunit of $ISP_{TOL}$. These results provide evidence for the involvement of electrostatic interactions in the TDO electron transfer system.

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Convolutional Neural Network (CNN) 기반의 단백질 간 상호 작용 추출 (Extraction of Protein-Protein Interactions based on Convolutional Neural Network (CNN))

  • 최성필
    • 정보과학회 컴퓨팅의 실제 논문지
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    • 제23권3호
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    • pp.194-198
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    • 2017
  • 본 논문에서는 학술 문헌에서 표현된 단백질 간 상호 작용(Protein-Protein Interaction) 정보를 자동으로 추출하기 위한 확장된 형태의 Convolutional Neural Network (CNN) 모델을 제안한다. 이 모델은 기존에 관계 추출(Relation Extraction)을 위해 고안된 단순 자질 기반의 CNN 모델을 확장하여 다양한 전역 자질들을 추가적으로 적용함으로써 성능을 개선할 수 있는 장점이 있다. PPI 추출 성능 평가를 위해서 많이 활용되고 있는 준거 평가 컬렉션인 AIMed를 이용한 실험에서 F-스코어 기준으로 78.0%를 나타내어 현재까지 도출된 세계 최고 성능에 비해 8.3% 높은 성능을 나타내었다. 추가적으로 CNN 모델이 복잡한 언어 처리를 통한 자질 추출 작업을 하지 않고도 단백질간 상호 작용 추출에 높은 성능을 나타냄을 보였다.

단백질 함량 및 철분 농도의 변화에 따라 홍차 추출물이 철분의 용해도에 미치는 영향 (Effects of Protein and Iron Concentrations on Iron Solubility in Black Tea Infusion)

  • 김희선
    • Journal of Nutrition and Health
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    • 제29권8호
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    • pp.861-866
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    • 1996
  • Tannins in plant foods and beverages may produce antinutritional or toxic effects although some proteins with high affinity for tannins seem to function as defense mechanism to tannin toxicity. Our objectives were to investigate of tea tannins, iron and protein and to evaluate the role of proteins in tannin effects on iron solubility. Iron solubility in vitro was measured using tea with and without proteins. Mixtures of tea, protein in varying concentrations(either gelatin or bovine serum albumin), and iron(eithe 10 or 50ug/mL) were prepared. Controls contained water in place of tea. Iron bioavailability was assessed by measuring iron solubility in the simulated gastric condition with pepsin digestion. Bound iron was removed by centrifugation and soluble in tea alone. When iron concentratin was 10ug/mL, addition of small amounts of protein to tea dramatically reduced iron solubility, but solubility of iron increased in the tea mixturea as the concentration of protein was increased. The percnetage of iron that precipitated was much greater at 10ug Fe/mL than the values at 50ug Fe/mL suggesting that the iron binding sites on the tea-protein complex was saturated. These results suggest that interactions of iron with tea tannins are influenced by the concentratins of protein and iron.

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Construction and Characterization of an Enhanced GFP-Tagged TIM-1 Fusion Protein

  • Qing, Jilin;Xiao, Haibing;Zhao, Lin;Qin, Guifang;Hu, Lihua;Chen, Zhizhong
    • Journal of Microbiology and Biotechnology
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    • 제24권4호
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    • pp.568-576
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    • 2014
  • TIM-1 (also known as KIM-1 and HAVcr-1) is a type I transmembrane glycoprotein member of the TIM family that may play important roles in innate and adaptive immune responses. The overexpression of proteins associated with membrane proteins is a major obstacle to overcome in studies of membrane protein structures and functions. In this study, we successfully coupled the overexpression of the TIM-1 protein with a C-terminal enhanced green fluorescent protein (GFP) tag in Escherichia coli. To the best of our knowledge, this report is the first to describe the overexpression of human TIM-1 in E. coli. The purified TIM-1-EGFP fusion protein recognized and bound directly to apoptotic cells and did not to bind to viable cells. Furthermore, we confirmed that the interactions of TIM-1-EGFP with apoptotic cells were blocked by TIM-1-Fc fusion proteins. This fusion protein represents a readily obtainable source of biologically active TIM-1 that may prove useful in future studies of human TIM-1.