• Journal of Plant Biology
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• v.37 no.2
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• pp.151-158
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• 1994

Aleurone layers of normal and vp1 mutant maize kernels were extracted and centrifuged at 100,000g to yield a cytosol fraction. Binding of [3H]ABA cis, trans (＋)ABA to a soluble macromolecular components present in the cytosol was demonstrated by Sephadex chromatography and non-denaturing PAGE. The binding component was of high molecular weight and seems to be an aggregate of proteins. A rapid DEAE-cellulose filter method for assaying bound [3H]ABA to a soluble protein was adapted. Binding assays were performed with cytosol that had been preheated or incubated with several enzymes, indicating that heat and protease treatments disrupted the binding. This suggested that binding occurred to proteins. Some properties of the ABA binding proteins were described. The [3H]ABA binding were reduced dramatically when unlabeled ABA was added as a competitor, suggesting a specific binding of [3H]ABA. Gel filtration profiles and autoradiogram of [3H]ABA binding showed no difference in the binding components of Vp1 and vp1/vp1 mutant cytosol, indicating that Vp1 protein is not a sole ABA binding protein.

• 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.

• 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.

• Journal of Pharmaceutical Investigation
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• v.23 no.3
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• pp.119-125
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• 1993

The protein binding of salicylate analogs has been investigated by equilibrium dialysis. A series of binding experiments were performed in order to elucidate the effects of physicochemical properties of salicylate analogs on the binding with bovine serum albumin. Attempts to correlate affinity constants with capacity factor, steric factor and Hammett ${\sigma}$ values suggested hydrophobic forces to be involved in the binding of salicylate analogs. Steric factor contributes to binding process partly, whereas electronic interaction appears to be insignificant.

• Journal of Life Science
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• v.13 no.5
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• pp.746-750
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• 2003

Lactose operon contains two CRP binding sites at promoter(CRP1 site) and operator(CRP2 site) regions at lac operon. CRP protein can bind to both sites with the different binding affinity. CRP1 site, major CRP binding site, acts the transcription activation with the fully unknown mechanism by binding of CRP. In this study, the binding affinities of CRP1 site and CRP2 site were measured with the fluorescein-labeled oligomers, which contain CRP1 site and the three different spacing sequences between GTGA and TCAC at CRP2 site. Results showed that CRP:cAMP complex bound to CRP1 site 3 times more strongly than CRP2 site and the base spacing between GTGA and TCAC was not the only factor to affect the binding affinity of CRP to CRP2 site.

• The Korean Journal of Zoology
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• v.34 no.2
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• pp.196-202
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• 1991

Juvenile honnone binding protein (JHBP) was identified in the last instar larval hemolymph of Lymantria dispar using dextran coated charcoal (DCC) binding assay and gel filtration. The p1 value of JHBP was estimated to be 5.3. JHBP was partially pudfied by polyethylene glycol(PEG) precipitation, DEAE-cellulose ion-exchange chromatography and gel filtration, and was confirmed by DCC binding assay.

• BMB Reports
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• v.29 no.1
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• pp.1-10
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• 1996

The binding interaction of ethidium to a series of synthetic deoxyoligonucleotides containing a B-Z junction between left-handed Z-DNA and right-handed B-DNA, was studied. The series of deoxyoligonucleotides was designed so as to vary a dinucleotide step immediately adjacent to a B-Z junction region. Ethidium binds to the right-handed DNA forms and hybrid B-Z forms which contain a B-Z junction, in a highly cooperative manner. In a series of deoxyoligonucleotides, the binding affinity of ethidium with DNA forms which were initially hybrid B-Z forms shows over an order of magnitude higher than that with any other DNA forms, which were entirely in B-form DNA The cooperativity of binding isotherms were described by an allosteric binding model and by a neighbor exclusion model. The binding data were statistically compared for two models. The conformation of allosterically converted DNA forms under binding with ethidium is found to be different from that of the initial B-form DNA as examined by CD spectra. The ratio of the binding constant was interestingly correlated to the free energy of base unstacking and the conformational conversion of the dinucleotide. The more the base stacking of the dinucleotide is unstable, or the harder the conversion of B to A conformation, the higher the ratio of the binding constant of ethidium with the allosterically converted DNA forms and with the initial B-Z hybrid forms. DNA sequence around a B-Z junction region affects the binding affinity of ethidium. The results in this study demonstrate that ethidium could preferentially interact with unusual DNA structures.

• KSBB Journal
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• v.14 no.3
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• pp.273-278
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• 1999

The molecularly imprinted polymers(MIPs) synthesized at various polymerization conditions were examined as ibuprofen receptors in terms of binding characteristics. The 4-vinylpyridine polymers had 1.2 times higher adsorption capability for (S)-(+)-ibuprofen than the methacrylic acid polymers. The methacrylic acid polymers synthesized by UV radiation had 1.9 times higher selectivity for (S)-(+)-ibuprofen compared to those by thermal initiation. Effects of various solvents for binding were also examined in this research. According to the Scatchard analysis, the (S)-(+)-ibuprofen artificial receptors had two different kinds of binding sites for (S)-(+)-ibuprofen while having only single kind of binding site for ketoprofen. The binding sites of (S)-(+)-ibuprofen, n were calculated as 4.3~4.9 $\mu$mol/g and the dissociation constants, $K_D$ were 0.68 mM for the specific binding.

• The Korean Journal of Physiology and Pharmacology
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• v.6 no.2
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• pp.109-112
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• 2002

The signal pathways involved in the regulation of AP-1 DNA binding activity in long-term nicotine stimulated bovine adrenal medullary chromaffin (BAMC) cells have not been well characterized. To understand the involvement of second messengers in the regulation of AP-1 DNA binding activity, the present study was designed to define the time-course for inhibition of nicotine-induced responses by cholinergic antagonists, $Ca^{2+}$ and calmodulin (CaM) antagonists, and calcium/calmodulin-dependent protein kinase (CaMK) II inhibitor using electrophoretic mobility shift assay. Nicotine $(10{\mu}M)$ stimulation increased AP-1 DNA binding activity at 24 hr after treatment. Posttreatment with hexamethonium (1 mM) plus atropine $(1{\mu}M)$ (HA), nimodipine $(1{\mu}M),$ or calmidazolium $(1{\mu}M)$ at 0.5, 3, and 6 hr after the nicotine treatment significantly inhibited the AP-1 DNA binding activity increased by long-term nicotine stimulation. However, posttreatment with HA, nimodipine, or calmidazolium at 9 or 12 hr after the nicotine treatment did not affect the nicotine-induced increase of AP-1 DNA binding activity. The pretreatment of BAMC cells with various concentrations of KN-62 inhibited the increase of AP-1 DNA binding activity induced by nicotine in a concentration-dependent manner. KN-62 $(10{\mu}M)$ posttreatment beginning at 0.5, 3, or 6 hr after the nicotine treatment significantly inhibited the increase of AP-1 DNA binding activity. However, KN-62 posttreatment beginning at 9 or 12 hr after the nicotine treatment did not affect the increase of AP-1 DNA binding activity. This study suggested that stimulation (for at least 6 hr) of nicotinic receptors on BAMC cells was necessary for increase of AP-1 DNA binding activity, and activation of $Ca^{2+},$ CaM, and CaMK II up to 6 hr at least seemed to be required for the increase of nicotine-induced AP-1 DNA binding activity.

• Bulletin of the Korean Chemical Society
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• v.35 no.8
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• pp.2317-2325
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• 2014

P-glycoprotein (P-gp) is a member of the ATP-Binding Cassette transporter superfamily and mediates transmembrane efflux of many drugs. Since it is involved in multi-drug resistance activity in various cancer cells, the development of P-gp inhibitor is one of the major concerns in anticancer therapy. Human P-gp protein has at least two "functional" drug binding sites that are called "H" site and "R" site, hence it has multi-binding-specificities. Though the amino acid residues that constitute in drug binding pockets have been proposed by previous experimental evidences, the shapes and the binding poses are not revealed clearly yet. In this study, human P-gp structure was built by homology modeling with available crystal structure of mouse P-gp as a template and docking simulations were performed with inhibitors such as verapamil, hoechst33342, and rhodamine123 to construct the interaction between human P-gp and its inhibitors. The docking simulations were performed 500 times for each inhibitor, and then the interaction frequency of the amino acids at the binding poses was analyzed. With the analysis results, we proposed highly contributing residues that constitute binding pockets of the human P-gp for the inhibitors. Using the highly contributing residues, we proposed the locations and the shapes of verapamil binding site and "R" site, and suggested the possible position of "H" site.