• Archives of Pharmacal Research
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• v.27 no.9
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• pp.978-983
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• 2004

The effects of glycyrrhizic acid (GLZ) on protein binding of diltiazem, verapamil, and nifedipine were investigated. Protein binding studies (human serum, human serum albumin (HSA) and (X1-acid glycoprotein (AAG)) were conducted using the equilibrium dialysis method with and without addition of GLZ. The binding parameters, such as the number of moles of bound drug per mole of protein, the number of binding sites per protein molecule, and the association con-stant, were estimated using the Scatchard plot. The serum binding of nifedipine, verapamil, and diltiazem was displaced with addition of GLZ, and the decreases of Ks for serum were observed. GLZ decreased the association constants of three drugs for HSA and AAG, while the binding capacity remained similar with addition of GLZ. Although the characteristics of interaction were not clear, GLZ seemed to mainly affect HSA binding of nifedipine rather than AAG binding, while GLZ seemed to affect both AAG- and HSA-bindings of verapamil and dilt-iazem resulting in a serum binding displacement.

• Journal of the Korean Society of Food Science and Nutrition
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• v.23 no.3
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• pp.414-419
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• 1994

This study was trying to find what physical changes occurred to albumin when it reacted with estrogen and other ligands. Each concentration of human serum albumin with 100$\mu$l estradiol reacted at the highest binding capacity of 280nm. In addition, 1 hr of reaction time showed the highest binding rate. Conformational changes in human serum albumin with dietylstillbesterol and N-ethyl-maleimide produced strong binding capacities. The changes were immediate and they did not increase or decrease over time. Effects of human serum albumin with estriol induced no interaction each other. The binding capacity of human serum albumin with vitamin D$_2$was lower than estradiol. and the highest binding rate showed 1 hr of reaction time. Vitamin D$_2$ was very similar to the binding capacity of estradiol.

• YAKHAK HOEJI
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• v.32 no.3
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• pp.182-186
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• 1988

Binding of four cephalosporins(cefaclor, cefpiramide, ceftazidime, ceforanide) to bovine serum albumin was studied. Difference spectrophotometry was employed to evaluate the nature and the degree of association of cephalosporin-albumin complex. 2-(4'-hydroxybenzen azo) benzoic acid was used as the uv spectrophotometric probe for measuring the binding of cephalosporins to bovine serum albumin. Competitive bindings between cephalosporins and probe were observed. For the binding of cephalosporins to bovine serum albumin, three binding sites were identified. The binding constants of cefaclor, ceforanide, ceftazidime and cefpiramide were $12.57\;{\times}\;10^{-2}M^{-1}$, $6.49\;{\times}\;10^{-2}M^{-1}$, $4.70\;{\times}\;10^{-2}M^{-1}$ and $6.20\;{\times}\;10^{-2}M^{-1}$ respectively.

• YAKHAK HOEJI
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• v.26 no.4
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• pp.223-229
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• 1982

Uremia is associated with defective protein binding of weakly acidic drugs, whereas the protein binding of basic drugs tends to be normal. The exact chemical nature of compound(s) and mechanism for these changes as yet is unknown, and has not been defined. Organic solvent extraction of pooled normal human urine following hydrolysis by hydrochloric acid produced an extract, which when added to normal human serum, was capable of inducing binding defects similar to those in uremia. Binding defects were observed with the weakly acidic drugs such as nafcillin, salicylate, sulfamethoxazole and phenytoin while the binding of the basic drugs such as trimethoprim and quinidine were unaffected. The binding defects induced by the hydrolyzed urine extract could readily be corrected by same organic solvent extraction of acidified serum and the defects could be transferred to the normal human serum using the organic solvent layer at the physiologic pH (7.4). Followed by reacidification ind extraction of the binding defects induced serum with the same solvent, separated several fractions were obtained on thin-layer chromatography. One of these fractions could reinduce the binding defects and this factor(s) is apparently weakly acidic compounds and tightly bound to serum at physiologic pH, but extractable at acidic pH, and its molecular weight range is approximately 500 or less similar to those seen in uremia. These findings strongly support the hypothesis that the drug binding defect in uremia is due to the accumulation of endogenous metabolic products which arc normally excreted by the kidneys but accumulate in renal failure.

• 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.

• Archives of Pharmacal Research
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• v.4 no.1
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• pp.19-24
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• 1981

The possibility of using a fluorescence probe technique for the study of ibuprofenlysine binding to human and bovine serum albumin was investigated. 1-anilino-8-naphalenesulfonate was used as the probe. The number of binding sites of human and bovine serum albumins for ibuprofenlysine appears to be 4 and 2, respectively. By using this technique, the association constants were found to be $1.533{\times}10^{4}M^{-1}$ and $2.238{\times}10^{4}M^{-1}$, respectively.

• 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.

• Applied Biological Chemistry
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• v.1
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• pp.48-54
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• 1960

Studing the binding of the 5-Iodopyrimdines by human serum albumin we obtained the following conclusions; 1. The more strong electron donating groups in the molecule of 5-Iodopyrimidines, the larger the binding force with human serum albumin. This trend seems to be attributed by increase of polarization of the electron donating groups in 5-Iodopyrimidines molecule. 2. The binding force of 5-Iodopyrimidines by human serum albumin is increased with the pH increasing could be occurred the configurational changes of human albumin molecule, and this new binding sites of human serum albumin molecule would form the intermolecular complex with 5-Iodopyrimidines molecule more strongly.

• YAKHAK HOEJI
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• v.25 no.4
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• pp.161-165
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• 1981

The binding of two cephalosporins, cephalothin and cefazoline to human serum albumin(HSA) was studied by difference spectrophotometry using a spectrophotometric probe, 2-(4'-hydroxybenzeneazo) benzoic acid. The probe is strong visible absorbing material which interacts with serum albumin to give characteristic spectrophotometric peaks and provides the basis for a convenient assay to measure free and bound amounts in the presence of serum albumin and competitive drugs. The results obtained showed that the probe and cephalosporin compete for the same binding site on human serum albumin; thus the probe can be used to gauge the displacement of cephalosporins from human serum albumin. The data were interpreted on the basis of theory of multiple equilibria. The number of binding sites of human serum albumin for 2-(4'-hydroxybenzeneazo) benzoic acid(HBAB), cephalothin and cefazoline appears to be 4. By using this technique the binding constants were found as follows: HSA-HBAB, $7.89{\times}10^{4}M^{-1}$; HSA-cephalothin, $1.09{\times}10^{3}M^{-1}$ ; HSA-cefazoline, $1.21{\times}10^{3}M^{-1}$.

• Bulletin of the Korean Chemical Society
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• v.35 no.7
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• pp.2114-2122
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• 2014

The association of silybin with ${\beta}$-cyclodextrin and its influence on silybin's binding with bovine serum albumin are reported. The stoichiometry, binding constant, and the structure of silybin-${\beta}$-cyclodextrin inclusion complex are reported. The titrations of silybin with bovine serum albumin in the absence and presence of ${\beta}$-cyclodextrin are carried out and the differences in binding strengths are discussed. Molecular modeling is used to optimize the sites and mode of binding of silybin with bovine serum albumin. F$\ddot{o}$rster resonance energy transfer is calculated and the proximity of interacting molecules is reported in the presence and absence of ${\beta}$-cyclodextrin.