• Title/Summary/Keyword: chemical binding

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Binding affinity of some herbal extracts on the glycine binding site of NMDA (N-Methyl-D-Aspartate) receptor (수종 생약추출물의 NMDA(N-Methyl-D-Aspartate) 수용체 glycine binding site에 대한 친화력 검색)

  • Kim, Young-Sup;Kim, Jeoung-Seob;Kim, Seong-Kie;Heor, Jung-Hee;Lee, Byung-Eui;Ryu, Shi-Yong
    • Korean Journal of Pharmacognosy
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    • v.32 no.3 s.126
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    • pp.212-218
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    • 2001
  • The water extracts of 82 Korean medicinal herbs were prepared and were examined for the binding affinity on the glycine binding site of NMDA (N-methyl-D-aspartate) receptor prepared by the synaptic membranes from the forebrains of male Sprague-Dawley rats. Among the tested, the extracts of Dioscoreae Rhizoma, Hoveniae Semen cum Fructus, Astragali Radix, Armeniacae Semen, Huttuynia cordata Herba, Acanthopanacis Cortex, Aurantii nobilis Pericarpium, Phellinus linteus, Amomi Fructus, Artemisiae capillaris Herba, Polyporus, Agastachis Herba and of Galli Stomachichum Corium were found to exhibit significant competitions with $[^3H]-MDL$ 105,519 for the glycine specific binding site of NMDA receptor in a dose dependent manner, respectively.

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Thermodynamic Elucidation of Binding Isotherms for Hemoglobin & Globin of Human and Bovine upon Interaction with Dodecyl Trimethyl Ammonium Bromide

  • Bordbar, A.K.;Nasehzadeh, A.;Ajloo, D.;Omidiyan, K.;Naghibi, H.;Mehrabi, M.;Khajehpour, H.;Rezaei-Tavirani, M.;Moosavi-Movahedi, A.A.
    • Bulletin of the Korean Chemical Society
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    • v.23 no.8
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    • pp.1073-1077
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    • 2002
  • Binding of dodecyl trimethylammonium bromide (DTAB) to human and bovine hemoglobin and globin samples has been investigated in 50 mM glycine buffer pH = 10, I = 0.0318 and 300 K by equilibrium dialysis and temperature scanning spectrophotometry techniques and method for calculation of average hydrophobicity. The binding data has been analyzed, in terms of binding capacity concept $({\theta})$, Hill coefficient (nH) and intrinsic Gibbs free energy of binding $({\Delta}Gbv).$ The results of binding data, melting point (Tm) and average hydrophobicity show that human hemoglobin has more structural stability than bovine hemoglobin sample. Moreover the results of binding data analysis represent the systems with two and one sets of binding sites for hemoglobin and globin, respectively. It seems that the destabilization of hemoglobin structure due to removal of heme group, is responsible of such behavior. The results indicating the removal of heme group from hemoglobin caused the depletion of first binding set as an electrostatic site upon interaction with DTAB and exposing the hydrophobic patches for protein.

Binding Set Analysis for Interaction of Human Serum Albumin with Cethyl Trimethylammonium Bromide

  • Bordbar, Abdol-Khalegh;Sohrabi, Nasrin;Gharibi, Hossain
    • Bulletin of the Korean Chemical Society
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    • v.25 no.6
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    • pp.791-795
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    • 2004
  • The binding of cethyl trimethylammonium bromide, (CTAB) with human serum albumin (HSA) has been investigated at 5 mM phosphate buffer pH 7.0, 27 $^{\circ}C$ and various ionic strength using ion selective membrane electrodes. This method is faster and much more accurate than equilibrium dialysis technique, so provides sufficient and accurate data for binding data analysis. A novel and simple method was introduced for resolution and characterization of binding sets on basis of binding capacity concept. The values of Hill binding parameters were estimated for each set and used for calculation of intrinsic binding affinity. The results interpreted on basis of nature of forces which interfered in the interaction and represent the existence of three and two binding sets for binding of CTAB at $10^{-4}$ and $10^{-3}$ M of NaBr, respectively.

Leucine Zipper as a Fine Tuner for the DNA Binding; Revisited with Molecular Dynamics Simulation of the Fos-Jun bZIP Complex

  • 최용훈;양철학;김현원;정선호
    • Bulletin of the Korean Chemical Society
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    • v.20 no.11
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    • pp.1319-1322
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    • 1999
  • Leucine zipper dynamically tunes the degree of bifurcation of the DNA binding segments in the basic region of the Fos-Jun bZIP complex. Molecular dynamics simulation indicated that site-specific mutagenesis of conserved leucine residues inside the leucine zipper domain caused the change of dynamic behavior of the basic region, and efficient DNA binding occurs only within a certain range of distance between the two DNA binding segments in the basic region. Distribution of α-helices in the hinge region is also suggested to influence the bifurcation of the DNA binding segments.

Synthesis of a Novel Anthraquinone Diamino-Bridged Bis(β-cyclodextrin) and Its Cooperative Binding toward Guest Molecules

  • Zhao, Yan;Yang, Zi Ming;Chi, Shao Ming;Gu, Juan;Yang, Yong Cun;Huang, Rong;Wang, Bang Jin;Zhu, Hong You
    • Bulletin of the Korean Chemical Society
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    • v.29 no.5
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    • pp.953-958
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    • 2008
  • A novel anthraquinone diamino-bridged bis($\beta$ -cyclodextrin) 2 was synthesized. The inclusion complexation behaviors of the native $\beta$ -cyclodextrin 1 and the novel bis($\beta$ -cyclodextrin) 2 with guests, such as acridine red (AR), neutral red (NR), ammonium 8-anilino-1-naphthalenesulfonate (ANS), sodium 2-(p-toluidinyl) naphthalenesulfonate (TNS) and rhodamine B (RhB) were investigation by fluorescence, circular dichroism and 2D NMR spectroscopy. The spectral titrations were performed in phosphate buffer (pH 7.20) at 25 ${^{\circ}C}$ to give the complex stability constants (Ks) and Gibbs free energy changes (−${\Delta}G^0$) for the stoichiometric 1:1 inclusion complexation of host 1 and 2 with guests. The results indicated that the novel bis($\beta$ -cyclodextrin) 2 greatly enhanced the original binding affinity of the native $\beta$ -cyclodextrin 1. Typically, bis($\beta$ -cyclodextrin) 2 showed the highest binding constant towards ANS up to 34.8 times higher than that of 1. The 2D NMR spectra of bis($\beta$ -cyclodextrin) 2 with RhB and TNS were performed to confirm the binding mode. The increased binding affinity and molecular selectivity of guests by bis($\beta$ -cyclodextrin) 2 were discussed from the viewpoint of the size/shape-fit concept and multipoint recognition mechanism.