• Title/Summary/Keyword: 정전기적 상호작용

Search Result 50, Processing Time 0.021 seconds

Contribution of Electrostatic Interactions to Protein Folding Reaction (정전기적 상호작용이 단백질 폴딩 반응에 끼치는 영향)

  • Kim, Dae Won;Park, Soon-Ho
    • Journal of the Korean Chemical Society
    • /
    • v.58 no.6
    • /
    • pp.560-568
    • /
    • 2014
  • The contribution of electrostatic interactions to protein folding reaction was studied by using mutant ubiquitin with lysine to alanine mutation at residue position 29. Based on the three dimensional structure of ubiquitin, lysine 29 is located close to negatively charged glutamate 16 and aspartate 21 and considered to stabilize the native state of ubiquitin by electrostatic interactions between these residues. The equilibrium unfolding experiment showed that the native stability was decreased by about ~20% upon mutation. This observation indicates lysine 29 indeed forms electrostatic interactions with nearby residues. Folding kinetics measurements using stopped-flow device and quantitative analysis of kinetics data indicate that ubiquitin folds from unfolded state to native state via intermediate state as observed previously. This intermediate state was observed to form immediately after the initiation of folding reaction. The folding intermediate was shown to be destabilized considerably upon lysine to alanine mutation. These observations indicate that electrostatic interactions can form early stage of protein folding and hence lead the folding reaction.

G 단백질 연결 수용체계(GPCR system)에서의 정전기적 포텐셜(Electrostatic Potential)에 따른 효과를 고려한 단백질과 리간드의 상호작용 예측(protein-ligand interaction prediction)

  • Choe, Gyu-Hong;Sin, Ung-Hui;Lee, Dong-Seon
    • Proceeding of EDISON Challenge
    • /
    • 2013.04a
    • /
    • pp.125-137
    • /
    • 2013
  • 2012년 G 단백질 연결 수용체(G-Protein Coupled Receptors ; GPCR) 연구가 노벨 화학상을 받았다. 상당히 많은 병과 관련되어 있어 잠재력이 크고, 많은 연구가 진행 중이다. 현재 리간드와 단백질간의 정전기적 포텐셜 연구를 통한 예측 연구가 진행되고 있지만, GPCR과 리간드 간의 연구에서 아직 리간드의 전하를 통한 단백질과 리간드간의 상호작용 예측 연구가 되어 있지 않다. 그렇기 때문에 이번 연구에서는 8가지 방법으로 전하(charge)를 띠게 하여서 단백질과 리간드의 상호작용을 계산을 통하여 예측하여 보았다.

  • PDF

A study of the formation of the liner $\lambda$-DNA bridge using the electrostatic interactions on the gold nanoelectrodes (금 나노 전극위에 정전기적 상호작용을 이용한 선형 $\lambda$-DNA 브리지 형성에 관한 연구)

  • Kim, Hyung-Jin;Yi, In-Sun;Roh, Yong-Han;Hong, Byung-You
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
    • /
    • 2004.04b
    • /
    • pp.64-67
    • /
    • 2004
  • 본 논문에서는 DNA를 이용한 나노 소자에 응용하기 위하여, photo-lithograpy를 사용하여 나노크기(<100)의 간격을 갖는 금 전극을 제작하였다. 그리고 제작되어진 되어진 나노 전극위에 2-Amino ethanthiol(AET)를 코팅하여 AET와 $\lambda$-DNA 사이의 정전기적 상호 작용을 이용, 금 나노전극 사이에 간단하고 고착율을 높이는 실험을 하였다. SEM(Scanning Electron Microscope) 분석을 통해 나노 크기의 전극 간격을 확인하였고, 두 전극사이에 연결되어진 $\lambda$-DNA는 AFM(Atomic force microscope)을 확인하였다.

  • PDF

Electrostatic Interaction between Zirconia and 11-Mercaptoundecylphosphoric-acid Layer Formed on Gold Surfaces (지르코니아와 금 표면 위의 메르캡토언데실인산층의 정전기적 상호작용)

  • Park, Jin-Won
    • Korean Chemical Engineering Research
    • /
    • v.56 no.5
    • /
    • pp.625-630
    • /
    • 2018
  • The electrostatic interactions were investigated between the zirconia and the 11-Mercaptoundecylphosphoric-acid layer formed on gold surfaces for their complex structures. For the investigation, the atomic force microscope was used to measure the surface forces between the surfaces as a function of the salt concentration and pH value. The forces were analyzed with the Derjaguin-Landau-Verwey-Overbeek theory to estimate the potential and charge density of the surfaces for each condition. The concentration dependence of the surface properties, found from the measurement at pH 4 and 8, was consistent with the prediction from the law of mass action. The pH dependence was explained with the ionizable groups on the surface. It was found that the 11-Mercaptoundecylphosphoric-acid layer had higher values for the surface charge densities and potentials than the zirconia surfaces at pH 4 and 8, which may be attributed to the ionized-functional-groups of the layer.

MO Studies of Configuration and Conformation (Ⅲ). Conformations of Some 2-Substituted Furan, Thiophene and Pyrrole Carbonyl Compounds (配置와 形態에 관한 分子軌道函數論的 硏究 (第3報). Furan, Thiophene 및 Pyrrole 카르보닐 化合物의 2-置換體의 形態)

  • Ikchoon Lee;Shi Choon Kim
    • Journal of the Korean Chemical Society
    • /
    • v.21 no.1
    • /
    • pp.32-37
    • /
    • 1977
  • Conformations of nine 2-substituted furan, thiophene and pyrrole compounds have been studied by EHT methods. The preferred conformations of furan derivatives were trans form, which were mainly stabilized by electrostatic interactions. For thiophenes, electronic conjugation between the ring S and carbonyl oxygen was dominant, while for pyrroles both the electrostatic and conjugation effects were operative in determining the preferred conformations. Results of EHT calculation agreed well with experimentally determined preferences.

  • PDF

Chitosan-electrolyte Complex (키토산-전해질 콤플렉스)

  • 손태원;이광순
    • Polymer Science and Technology
    • /
    • v.15 no.3
    • /
    • pp.334-341
    • /
    • 2004
  • 고분자 콤플렉스 (polymer complex)는 두 개 또는 그 이상의 상호 보완적인 전하를 띄는 고분자의 조합에 의해서 형성된다. 이러한 콤플렉스는 정전기적인 힘, 소수성 상호작용, 수소결합, 반데르발스힘 등 여러 힘의 조합에 의해서 일어난다. 이들 힘에 의한 콤플렉스 형성을 그림 1에 나타내었다. 고분자의 긴 사슬로 인하여, 상호보완적인 반복단위가 모여 세그먼트 콤플렉스를 형성하고, 이렇게 모인 많은 반복단위가 자유도의 손실 없이 쉽게 회합한다. (중략)

  • PDF

Electrostatic Interaction between Mercaptoundecanoic-acid Layers on Gold and ZrO2 Surfaces (금 표면 위의 메르캡토언데카노익산층 표면과 이산화지르코늄 표면 사이의 정전기적 상호작용)

  • Park, Jin-Won
    • Applied Chemistry for Engineering
    • /
    • v.25 no.6
    • /
    • pp.607-612
    • /
    • 2014
  • The physical properties of mercaptoundecanoic-acid layer formed on gold surfaces, which may affect the distribution of either gold particles adsorbed to the zirconium dioxide surface or vice versa, were investigated. To conduct this investigation, the surface forces were measured between the surfaces with respect to the salt concentration and pH value using atomic force microscope (AFM). The forces were quantitatively converted by the Derjaguin-Landau-Verwey-Overbeek (DLVO) theory to the surface potential and charge density of surfaces. The converted-value dependence on the salt concentration and pH was described with the law of mass action, and the dependence was consistent with the theoretical prediction. It was found that the mercaptoundecanoic-acid layer had higher values for the surface charge densities and potentials than the $ZrO_2$ surfaces, which may be attributed to the ionized-functional-groups of the mercaptoundecanoic-acid layer.

The Studies on Formation of Aggregates of Dyes-Surfactant System in Aqueous Solution (수용액에서 색소-계면활성제 계의 회합 생성에 관한 연구)

  • Choi, Ho Soeb;Kim, Heung-Tu
    • Journal of the Korean Chemical Society
    • /
    • v.39 no.3
    • /
    • pp.143-149
    • /
    • 1995
  • At low concentration a simplified model of organic dye-surfactant system has been used to evaluate. By applying the resultant three parameter equation to the experimental data, values for the equilibrium constants for the ion-pair formation $(K_O)$, surfactant molecule addition to aggregates $(K_S)$ and dye aggregation reactions $(K_D)$ could be calculated and changes of free energy have obtained from its values. $K_O$ and K_S$ values were larger than those expected electrostatic interaction indicatihng a hydrophobic contribution and the $K_D$ values were about 10~20 times higher than those found for association in pure aqueous solutions which can be ascribed to the screening effect of the electrostatic repulsion.

  • PDF

Surface Properties of Glutathione Layer Formed on Gold Surfaces (금 표면 위에 형성된 글루타싸이온 층의 표면 물성)

  • Park, Jin-Won
    • Korean Chemical Engineering Research
    • /
    • v.50 no.2
    • /
    • pp.379-384
    • /
    • 2012
  • It is investigated that that the physical properties of Glutathione layer formed on gold surfaces may make an effect on the distribution of either gold particle adsorbed to the $TiO_2$ surface or vice versa with the adjustment of the electrostatic interactions. For the investigation, the atomic force microscope (AFM) was used to measure the surface forces between the surfaces as a function of the salt concentration and pH value. With the Derjaguin-Landau-Verwey-Overbeek (DLVO) theory, the forces were quantitatively analyzed to acquire the surface potential and charge density of the surfaces for each salt concentration and each pH value. The surface potential and charge density dependence on the salt concentration was described with the law of mass action, and the pH dependence was explained with the ionizable groups on the surface. The salt concentration dependence of the surface properties, found from the measurement at pH 8 and 11, was consistent with the prediction from the law. It was found that the Glutathione layer had higher values for the surface charge densities and potentials than the titanium dioxide surfaces at pH 8 and 11, which may be attributed to the ionized-functional-groups of the Glutathione layer.