• 제목/요약/키워드: Binding study

검색결과 3,893건 처리시간 0.029초

전해질 첨가에 따른 키토산/Sodium Dodecyl Sulfate 상호작용의 변화 (The Change of Interactions of Chitosan/Sodium Dodecyl Sulfate in the Presence of Electrolytes)

  • 배현숙;강인숙
    • 한국의류학회지
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    • 제27권5호
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    • pp.524-532
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    • 2003
  • The change of interactions of anionic surfactants, sodium dodecyl sulfate(SDS) and sodium tetradecyl sulfate(575) in the presence of electrolytes, to the chitosan-based polyelectrolyte(sol'n and gel phase) were studied. The chitosan gel used in this study were crosslinked with epichlorohydrin(ECH). Binding isotherms were determined by potentiometric technique using a surfactant ion selective solid-state electrode and the results were represented by using the sequence generating function(SGF) method. The results of binding isotherm were shown comparatively high cooperativity. The addition of electrolytes in the chitosan/SDS system resulted in a shift of the binding to higher free surfactant concentration because of screen effect by the electrolytes. Degree of binding of chitosan gel was higher than that of chitosan sol'n. And also a conformational phase transition of the chitosan gel in the presence of electrolytes has been investigated.

Salt Effects on the Critical Micelle Concentration and Counterion Binding of Cetylpyridinium Bromide Micelles

  • Jong Jae Chung;Sang Wook Lee;Joon Ho Choi
    • Bulletin of the Korean Chemical Society
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    • 제12권4호
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    • pp.411-413
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    • 1991
  • The effects of electrolyte on the critical micelle concentration (cmc) and bromide counterion binding in the micelles of cetylpyridinium bromide (CPB) have been investigated by UV spectroscopy and conductance measurements. Salts used in this study decreased cmc in the order $Cl^-\;<\;Br^-\;<\;NO3^-$ (which parallels the lyotropic series for the inorganic anions) and the effects on cmc followed the equation proposed by Shinoda: log cmc = A - B log (cmc + [NaX]). In the equation, constant B represents the counterion binding to the micelles at cmc and for the micelle of CPB at $25^{\circ}C$, B=80.76%. The association constant for the binding of counterions to long chain cations within micelles was also derived from the cmc values and counterion binding constant to the micelles.

Studies on the interaction of edible dyes with protein I

  • Jang, Seong-Ki;Kim, Bak-Kwang;Lee, Wang-Kyu
    • Archives of Pharmacal Research
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    • 제8권3호
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    • pp.169-175
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    • 1985
  • The binding of bovine serum albumin (BSA)-edible dyes was studied by spectrophotometric method. The edible dyes used in this study were amaranth, erythrosine, tartrazine and sunset yellow. The binding free energies and binding sites were determined at pH 7.4. The ranges of edible dye concentration were from 0.3 to $7{\times}10^{-5}$M, and those of BSA were from 0.15 to $3{\times}10^{-5}$M. The binding free energies of BSA-edible dyes were from -6, 300 to -8, 100 cal/mole.

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Role of Cel5H protein surface amino acids in binding with clay minerals and measurements of its forces

  • Renukaradhya K. Math;Nagakumar Bharatham;Palaksha K. Javaregowda;Han Dae Yun
    • Applied Microscopy
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    • 제51권
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    • pp.17.1-17.10
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    • 2021
  • Our previous study on the binding activity between Cel5H and clay minerals showed highest binding efficiency among other cellulase enzymes cloned. Here, based on previous studies, we hypothesized that the positive amino acids on the surface of Cel5H protein may play an important role in binding to clay surfaces. To examine this, protein sequences of Bacillus licheniformis Cel5H (BlCel5H) and Paenibacillus polymyxa Cel5A (PpCel5A) were analyzed and then selected amino acids were mutated. These mutated proteins were investigated for binding activity and force measurement via atomic force microscopy (AFM). A total of seven amino acids which are only present in BlCel5H but not in PpCel5A were selected for mutational studies and the positive residues which are present in both were omitted. Of the seven selected surface lysine residues, only three mutants K196A(M2), K54A(M3) and K157T(M4) showed 12%, 7% and 8% less clay mineral binding ability, respectively compared with wild-type. The probable reason why other mutants did not show altered binding efficiency might be due to relative location of amino acids on the protein surface. Meanwhile, measurement of adhesion forces on mica sheets showed a well-defined maximum at 69±19 pN for wild-type, 58±19 pN for M2, 53±19 pN for M3, and 49±19 pN for M4 proteins. Hence, our results demonstrated that relative location of surface amino acids of Cel5H protein especially positive charged amino acids are important in the process of clay mineral-protein binding interaction through electrostatic exchange of charges.

Ligand Binding energy of CdS/ZnS various interfaces: ab-initio study intimately related with anisotropic CdS/ZnS quantum rod growth

  • Jeong, Incheol
    • EDISON SW 활용 경진대회 논문집
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    • 제4회(2015년)
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    • pp.292-295
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    • 2015
  • The effect of Ligand Binding energy in quantum rod (CdS/ZnS) plays a critical role in anisotropic growth. As mimicking large chain of ligands and using the head of the chain, I plan to bind the quantum rod and ligands so that it can grow well consequently. So the ultimate goal of this study is on how ligand binding can affect the growth of this quantum rod. There are preferred surfaces between the quantum rod and ligands, and we empirically know that ligands which bind the quantum rod; Phosphoric oxide (PO), Phosphoric acid(PA), Carboxylic acid(CA), Trimethylamine(TMA), have strong tendency to be attached on the surfaces of CdS/ZnS; ($11{\bar{2}}0$), ($10{\bar{1}}0$), ($000{\bar{1}}$), (0001). I virtually bond the surface and the ligands, and calculated the ligand binding energy after optimizing their structure, utilizing EDISON simulator. After all, I figured out how they are linked each other and how the quantum rod grows.

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QFPR Analysis for Selectivity of between Na+ and Li+ Ions to 12-Crown-4: by a Monte Carlo Simulation Study

  • Kim, Hag-Sung
    • Bulletin of the Korean Chemical Society
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    • 제31권10호
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    • pp.2823-2829
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    • 2010
  • We investigated the solvent effects on the relative free energies of binding of $Na^+$ and $Li^+$ ions to 12-crown-4 and ${\Delta}log\;K_s$ (the difference of stability constant of binding) by a Monte Carlo simulation of statistical perturbation theory (SPT) in several solvents. Comparing the relative free energies of binding of $Na^+$ and $Li^+$ ions to 12-crown-4, in $CH_3OH$ of this study with experimental works, there is a good agreement among the studies. We have reported the quantitative free energy polarity (of solvent) relationships (QFPR) of the relationship between the relative free energies and solvent polarity studied on the solvent effects on the relative free energies of binding of $Na^+$ and $Li^+$ ions to 12-crown-4.

Repeated Morphine Administration Increases TRPV1 mRNA Expression and Autoradiographic Binding at Supraspinal Sites in the Pain Pathway

  • Nguyen, Thi-Lien;Nam, Yun-Son;Lee, Seok-Yong;Jang, Choon-Gon
    • Biomolecules & Therapeutics
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    • 제30권4호
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    • pp.328-333
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    • 2022
  • Repeated morphine administration induces tolerance to its analgesic effects. A previous study reported that repeated morphine treatment activates transient receptor potential vanilloid type 1 (TRPV1) expression in the sciatic nerve, dorsal root ganglion, and spinal cord, contributing to morphine tolerance. In the present study, we analyzed TRPV1 expression and binding sites in supraspinal pain pathways in morphine-tolerant mice. The TRPV1 mRNA levels and binding sites were remarkably increased in the cortex and thalamus of these animals. Our data provide additional insights into the effects of morphine on TRPV1 in the brain and suggest that changes in the expression of, and binding to TRPV1 in the brain are involved in morphine tolerance.

콘크리트 내 Friedel염의 XRD를 이용한 반정량적 측정기법에 관한 연구 (A study of semi-quantification of the Friedel's salt using the X-ray diffraction method in concrete)

  • 이호재;이장화;김도겸
    • 분석과학
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    • 제25권1호
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    • pp.33-38
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    • 2012
  • 염화물 고정화능력의 중요성에도 불구하고 고정화능력을 측정하는 것은 어려우며 특히, 이미 건설되어 공용중인 구조물에서는 더욱 어렵다. 실제로 고정염화물을 측정하는 과정은 온도, 시료의 분말도, 공극수 추출기법 등과 같은 환경적 요인에 의해 큰 영향을 받는다. 본 연구에서는 X-선 회절분석법(XRD; X-ray diffraction)을 이용하여 콘크리트 내 염화물 이온의 고정화능력을 정량화하는 방법에 대해 중점을 두고 연구를 진행하였다. 염화물의 고정능력 isotherm은 물/시멘트비, 양생기간, 결합재 종류에 영향을 받으며 Langmuir isotherm 을 통하여 일단 결정된 고정염화물(Friedel 염)은 XRD를 이용하여 동시에 분석을 진행한다. XRD 그래프에서 나타난 고정염화물량의 피크 강도와 측정된 고정염화물의 총량의 관계를 결정한다. 결과적으로 양생기간이 증가될수록, 물/시멘트비가 감소될수록 고정화 능력은 증가하였다.

QSPR Analysis of Solvent Effect on Selectivity of 18-Crown-6 between $Nd^{3+}$ and $Eu^{3+}$ Ions: a Monte Carlo Simulation Study

  • Kim, Hag-Sung
    • Bulletin of the Korean Chemical Society
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    • 제27권12호
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    • pp.2011-2018
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    • 2006
  • We have investigated the solvent effects on $\Delta log\;K_s $(the difference of stability constant of binding) and the different free energies of binding of $Nd^{3+}$ and $Eu^{3+}$ ions to 18-crown-6, i.e., the selectivity of $Nd^{3+}$ and $Eu^{3+}$ ions to 18-crown-6 using a Monte Carlo simulation of statistical perturbation theory (SPT) in diverse solvents. The stability constant ($\Delta log\;K_s $) of binding of $Nd^{3+}$ and $Eu^{3+}$ ions to 18-crown-6, in $CH_3OH$ was calculated in this study as -1.06 agrees well with the different experimental results of -0.44~-0.6, respectively. We have reported here the quantitative solvent-polarity relationships (QSPR) studied on the solvent effects the relative free energies of binding of $Nd^{3+}$ and $Eu^{3+}$ ions to 18-crown-6. From the calculated coefficients of QSPR, we have noted that solvent polarity (ET) and Kamlet -Tafts solvatochromic parameters (b ) dominate the differences in relative solvation Gibbs free energies of $Nd^{3+}$ and $Eu^{3+}$ ions but basicity (Bj) dominates the negative values in differences in the stability constant ($\Delta log\;K_s $) as well as the relative free energies of binding of $Nd^{3+}$ and $Eu^{3+}$ ions to 18-crown-6 and acidity (Aj) dominates the positive values in differences in the stability constant ($\Delta log\;K_s $) as well as the relative free energies of binding of $Nd^{3+}$ and $Eu^{3+}$ ions to 18-crown-6.