• Reproductive and Developmental Biology
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• v.33 no.3
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• pp.119-123
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• 2009

The two dimensional quantitative structure-activity relationships (2D-QSARs) models concerning the binding affinity constants ($p[Od.]_{50}$) between 2-cyclohexyltetrahydropyrane and 2-cyclohexyltetrahydrofurane analogues as substrates, and bovine odorant binding protein (bOBP) as receptor were derived by multiple regression analyses method and discussed. The statistical quality of the optimized 2D-QSAR model (5) was good (r=0.907). From the model, the binding affinity constants ($p[Od.]_{50}$) were dependent upon the optimal value ($(TL)_{opt.}$=2.737) of total lipole (TL) of substrate molecules. Based on these findings, the high active compounds predicted by optimized 2D-QSAR model (5) were 2-(dimethylcyclohexyl)tetrahydropyrane molecule and their isomer molecules. The binding affinity constants regarding bOBP of the tetrahydrofuryl-2-yl family compounds were dependent upon the hydrophobicity (logP) of whole substrate molecules. In any case of porcine odorant-binding proteins (pOBP), the constants were dependent upon the hydrophobicity (${\pi}x={\log}P_X-{\log}P_H$) of substituents (R) in substrate molecules. Also, from the optimal values of hydrophobic constant, the hydrophobicity for bOBP influenced ca. twice time bigger (bOBP>pOBP) than that for pOBP.

• Reproductive and Developmental Biology
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• v.31 no.1
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• pp.15-20
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• 2007

To search of a new porcine pheromonal odorant for biostimulation control system technologies to offer a potentially useful and practical way to improve reproductive efficiency in livestock species, the two dimensional quantitative structure-activity relationship (QSAR) models between physicochemical parameters as descriptors of 2-cyclohexyloxytetrahydrofurane (A), 2-phenoxytetrahydrofurane (B) analogues and binding affinity constant ($p[Od.]_{50}$) for porcine odorant-binding protein (pOBP) as receptor of pig pheromones were derived and disscused. The statistical quality of the optimized 2D-QSAR model is good ($r^{2}=0.964$) and accounts for 96.4% of the variance in the binding affinity constants. It was found that the binding affinity constants were dependent upon the optimal value, $(SL)_{opt.}=1.418$ of substituent lipole (SL) in molecules. Therefore, the SL constant was very important factor for binding affinity.

• Archives of Pharmacal Research
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• v.10 no.1
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• pp.18-24
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• 1987

Mouse monocolonal antibodies to Hepatitis B surface antien (HBsAg) were prepared and their functional capabilities tested by the method of solid phase enzyme linked immuno sorbent assay (ELISA). HBsAg binding studies inicated that one monoclonal antibody 6E-1-1 bound more HBsAg at a faster rate than the other monoclonal antibodies. Also, for the binding inhibition studies with the selected monoclonal antibody 6E-1-1, one monoclonal antibody 8D-3-6 didn't exhibit binding inhibition for HBsAg. Then, a simultaneous ELISA method was developed for the immunodiagnosis of HBsAg. Different combinations of two monoclonal antibodies as solid phase and horseradish peroxidase (HRPO) labeled phase were studied. The combination of monoclonal antibody of higher affinity constant (6E-1-1) immobilized in a solid phase and monoclonal antibody of lower affinity constant (8D-3-6) as a HRPO laeled phase was more sensitive when two monoclonal antibodies of different affinity constants for HBsAg were prepared.

• BMB Reports
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• v.29 no.3
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• pp.205-209
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• 1996

To investigate the role of heparin in keratinocyte growth factor (KGF) and acidic fibroblast growth factor (aFGF) high affinity binding to the KGF receptor (KGFR), a cell free system was established which utilized a secreted chimeric molecule between the KGFR extracellular domain and the immunoglobulin heavy chain Fc domain (KGFR-HFc). KGFR-HFc was purified from NIH 3T3 cells and demonstrated the binding of $[^3H]-heparin$ as well as heparin Sepharose. Scatchard analysis showed that the dissociation constant for heparin binding to KGFR-HFc was 140 nM. High affinity KGF and aFGF binding to KGFR-HFc remained unchanged after treatment with 0.6 M NaCl, which is the concentration sufficient to release any bound heparin to the KGFR-HFc. These results strongly suggest that although the KGFR interacts with heparin, the presence of heparin is not absolutely required for high affinity binding of either KGF or aFGF to the KGFR.

• Journal of Pharmaceutical Investigation
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• v.19 no.3
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• pp.163-171
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• 1989

To investigate the protein binding characteristics of cephalothin, the effects of ionic strength, pH and temperature on the binding of cephalothin to bovine serum albumin (BSA) were studied by UV difference spectrophotometric method. With increasing ionic strength at constant PH and temperature, association constant decreased, but the number of binding sites sites was about 2 constantly. It may be deduced that the binding process is not only due to electrostatic forces. And the increased association constant at high ionic strength is explained by conformational changes of BSA from complex to subunits. The pH effect on the affinity of interaction indicated that the binding affinity of drug is higher in the neutral region than in the alkaline region. And, at high pH value, the number of binding sites decreased from 2 to 1 because of the conformational changes of BSA in alkaline region. The decrease in binding affinity of BSA to drug with increasing temperature was characteristic of an exothermic reaction. And the negative sign of ${\Delta}G^{\circ}$ meant that the binding process occurs spontaneously under the experimental conditions. In cephalothin-BSA complex formation, since the net enthalpy change value and entropy change value are positive, it is assumed that hydrophobic bindings are predominant in this binding process.

• Archives of Pharmacal Research
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• v.12 no.3
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• pp.160-165
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• 1989

Binding of sulfaethidole to bovine serum albumin was studied by equilibrium dialysis, fluorescence probe technique, uv difference spectrophotometry and circular dichroism. Equilibrium dialysis method enabled us to estimate the total number of drug binding sites of albumin molecule. For sulfaethidole, albumin had 6 primary and 40 secondary binding sites. The primary and secondary binding constants were 0.9 * 10/sup 5/ M/sup -1/ and 0.2 * 10/sup 6/ M/sup -1/, respectivitely. 1-Anilino-8-naphthalenesulfonate (ANS) and 2-(4-hydroxylbenzeneazo)- benzoic acid (HBAB) were used as the fluorescence probe and the uv spectrophotometric probe, respectively. In fluorescence probe technique, results indicated that the number of higher affinity drug binding site of albumin was 1 and the number of lower affinity drug binding sites of albumin was 3, and the primary and secondary drug binding constants for bovine serum albumin were 2.15 * 10/sup 5/M/sup -1/ and 1.04 * 10/sup 5/ M/sup -1/, respectively. In uv difference spectrophotometry, binding sites were 3 and binding constant was 1.88 * 10/sup 5/M/sup -1/. The above spectrophotometry, binding sites were 3 and binding constant was 1.88 * 10/sup 5/M/sup -1/. The above results suggest that several different methods should be used in ompensation for insufficient information about drug binding to albumin molecule given by only one method.

• 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.

• YAKHAK HOEJI
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• v.28 no.3
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• pp.129-138
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• 1984

Specific [$^{3}H$] ouabain binding and $Ca^{2+}$ -uptake were measured to elucidate the role of high affinity [$^{3}H$] ouabain binding site in rat cardiac myocytes which contain 65% of rod cells. High affinity [$^{3}$H] ouabain binding site, which is about 3% of total pump sites, with apparent dissociation constant ($K_{D}$) of $1.1{\times}10^{-7}M$ and maximum binding site concentration (Bmax) of 1.2 pmol/mg protein ($1.754{\times}10^{5}cells$) were identified. At the concentration of $10^{-7}M$ to $10^{-4}M$, ouabain produced concentration dependent increase in $Ca^{2+}$-uptake of myocytes. The effect of ouabain on $Ca^{2+}$-uptake was not effected by membrane depolarization (elevated K+ in incubation medium) or verapamil. These results suggest that in rat ventricular myocytes the ouabain receptor complex to high affinity site may increase Na+ - $Ca^{2+}$ exchange across the sarcolemmal membrane by inhibition of Na+, K+ - ATPase.

• Archives of Pharmacal Research
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• v.7 no.2
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• pp.87-93
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• 1984

The effects of ionic strength and pH on the binding of cefazolin to bovine serum albumin (BSA) were studied by UV difference spectrophotometry. As ionic strength at constant pH and temperature increases, the apparent bining constant decreased but the number of binding sites remained almost constant at 2. The constancy of the number of binding sites with increasing the ionic strength suggests that purely electrostatic forces between BSA and drug do not have great importance in the drug binding, even though there is a decrease in the apparent binding constant. Thus, the effect of ionic strength on the interaction between drug and BSA may be explained by the changes in ionic atmosphere of the aggregated BSA molecules and competitive inhibition by phosphate ions. In addition, the higher apparent binding constant at high ionic strength is explained by conformational changes of BSA from its aggregate forms into subunits. The pH effects on the afinity of interactions indicated that the binding affinity of cefazoline is higher in the neutral region than in the alkaline region. An d at high pH value, the number of binding sites decreased from 2 to 1 because of the conformational change of BSA in the alkaline region.

• Journal of Microbiology and Biotechnology
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• v.17 no.11
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• pp.1848-1855
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• 2007

Antibacterial activity of essential oils (Tea tree, Chamomile, Eucalyptus) on Staphylococcus aureus growth was evaluated as well as the essential oil-loaded alginate beads. The binding interactions between the cell and the essential oils were measured using an optical biosensor. The antibacterial activity of the essential oils to the cell was evaluated with their binding interaction and affinity. The antibacterial activity appeared in the order of Tea Tree>Chamomile>Eucalyptus, in comparison of the inhibition effects of the cell growth to the essential oils. The association rate constant and affinity of the cell binding on Tea Tree essential oil were $5.0{\times}10^{-13}\;ml/(CFU{\cdot}s)$ and $5.0{\times}10^5\;ml/CFU$, respectively. The affinity of the cell binding on Tea Tree was about twice higher than those on the other essential oils. It might be possible that an effective antibacterial activity of Tea Tree essential oil was derived from its strong adhesive ability to the cell, more so than those of the other essential oils.